Parker Denison GOLD CUP series User manual

aerospace
climate control
electromechanical
filtration
fluid & gas handling
hydraulics
pneumatics
process control
sealing & shielding
Denison GOLD CUP®Application Handbook
Piston Pumps & Motors
For Open & Closed Circuits
HY28-2668-01/GC/NA,EU
Effective: June 01, 2013
www.comoso.com

ii
WARNING - USER RESPONSIBILITY
FAILURE OR IMPROPER SELECTION OR IMPROPER USE OF THE PRODUCTS DESCRIBED HEREIN OR RELATED ITEMS CAN CAUSE DEATH,
PERSONAL INJURY AND PROPERTY DAMAGE.
This document and other information from Parker-Hannifin Corporation, its subsidiaries and authorized distributors provide product or system options for further investigation
by users having technical expertise.
The user, through its own analysis and testing, is solely responsible for making the final selection of the system and components and assuring that all performance, endurance,
maintenance, safety and warning requirements of the application are met. The user must analyze all aspects of the application, follow applicable industry standards, and follow
the information concerning the product in the current product catalog and in any other materials provided from Parker or its subsidiaries or authorized distributors.
To the extent that Parker or its subsidiaries or authorized distributors provide component or system options based upon data or specifications provided by the user, the user is
responsible for determining that such data and specifications are suitable and sufficient for all applications and reasonably foreseeable uses of the components or systems.
OFFER OF SALE
The items described in this document are hereby offered for sale by Parker-Hannifin Corporation, its subsidiaries or its authorized distributor. This offer and its acceptance
are governed by the provisions stated in the detailed "Offer of Sale" elsewhere in this document.
The product information, specifications, and descriptions contained in this publication have been compiled for the
use and convenience of our customers from information furnished by the manufacturer; and we can not, and do not,
accept any responsibility for the accuracy or correctness of any description, calculation, specification, or information
contained herein. No such description, calculation, specification, or information regarding the products being sold
has been made part of the basis of the bargain, nor has same created or amounted to an express warranty that the
products would conform thereto. We are selling the goods and merchandise illustrated and described on this publi-
cation on an “as is” basis, and disclaim any implied warranty, including any warranty of merchantability or warranty
of fitness for any particular purpose whatsoever, with respect to the goods and merchandise sold. All manufacturer
warranties shall be passed on to our customers, but we shall not be responsible for special, indirect, incidental, or
consequential damages resulting from the use of any of the products or information contained or described on this
publication. Further, we reserve the right to revise or otherwise make product improvements at any time without
notification.
Hydraulic Pump Division and Denison Hydraulics
The Hydraulic Pump Division of Parker Hannifin was formed in 2004 when our significant piston pump business was
expanded through the acquisition of Denison Hydraulics. The addition of Denison allowed us to marry the wealth
of knowledge that both companies have in the design, manufacture, and application of piston products in both open
circuit and closed circuit system applications. Since before WWII, Denison products have been chosen for Military
test stand applications and for shipboard hydraulic applications being recognized as technology leaders.
The heavy duty GOLD CUP®series of pumps and motors in this catalog represent a broadening of our product
offering with hydrostatic transmission applications in marine, drilling, and shredding applications, among others.The
tried and true design of the GOLD CUP®product line incorporates features such as integral servo and replenishing
pump, hot oil shuttle, and a unique servo control system; all of which combine to provide a rugged self contained
package which can withstand the harshest of conditions and continue to perform with trouble free long life.
The division is a leading worldwide manufacturer of hydraulic components and systems for earthmoving and
construction vehicles; for mining equipment; for pulp and paper, chemical and other processing equipment; for
ships and ordnance equipment; and for such in-plant machines as machine tools, plastic molding, die casters, and
stamping presses.
© Copyright 2013, Parker Hannifin Corporation. All Rights Reserved.
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
ii
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Introduction
A reference text on the design & application
of the GOLD CUP®line of Hydrostatic transmissions pumps & motors
The GOLD CUP®pump has four key features which set it apart and ahead of other hydro-
static pumps.
The first of these key features is the rocker cam and cradle assembly which provides for the
variable displacement. The piston rotating group rides on the rocker cam. The cam and cradle
assembly uses hydrostatic balance which provide a smooth displacement change, instead of
relying on roller bearings or trunnions, which tend to transmit noise. The combination of the
rigidity of the cam and cradle in addition to the hydraulic balance and lack of roller bearings
provide lowest noise levels and hysteresis currently available. Position of the cam is accom-
plished by two stroking vanes which are mounted on either side of the cam and cradle as-
sembly. The pressure loaded assemblies are part of the cam and provide a very direct precise
means of controlling pump displacement. The lack of any mechanical linkages to a stroking
piston eliminates mechanical wear and stress which can cause slow response, control degra-
dation, or failure.
The second key feature is the unique servo control system. From the output of the servo
pump thru the rotary servo control to the vane chamber, the control system provides a reliable
control that compensates for change in system pressure and responds to changes in the input
command almost instantly. When the displacement of the pump matches the command of
the rotary servo, the control fluid is trapped in the vane chambers. Because of the compact
size, the volume of the trapped fluid is very small and is very stable. As the command signal
is changed, the pressure balanced rotary servo opens one set of vane chambers to the pump
case, while directing servo oil to the other set of vane chambers. As the cradle moves to the
position commanded by the rotary servo, the vane ports which are connected to the cradle
assembly provide the feedback to once again block the servo passages in and out of the vane
chamber. The pressure balance of the rotary servo stem insures that only minimal torque is
required for the input signal. The close tolerance between the vane chamber ports and the
servo stem insures that any error signal is instantly corrected. The servo stem is controlled by
an external signal to the servo shaft providing an input command through an arc of +19° to
-19°. Additional controls are readily available and are discussed in further detail later.
The third key feature is the servo pressure control. The servo pressure is determined by the
servo relief valve. Since replenishing oil is first directed to the servo system, total control is
always insured. A pressure modulating pin causes the servo pressure to increase as the
system pressure increases at a rate of 40 psi, 2,8 bar servo pressure per 1000 psi, 69 bar
system pressure. This increase in servo pressure adds to the rigidity of the servo system as
the pump experiences increasing load.
The fourth key feature is the large barrel bearing. This bearing absorbs the mechanical imbal-
ance caused by the forces of the pistons against the angled cam assembly. Thus the barrel is
held squarely against the port plate eliminating the possibility of barrel “tipping” or separating
from the port plate. This design eliminates the need for a large shaft bearing and consequent-
ly reduces the size of the bore circle.
The resulting component designs proved to be a unique approach in the areas of displace-
ment control mechanisms and control circuits. This manual is an attempt to convey an under-
standing of these concepts and mechanisms to the design engineering personnel who will be
using this equipment in the design of new machinery. This manual, therefore, assumes a level
of understanding of hydrostatic transmissions and hydraulic circuitry and does not attempt to
explain basic concepts.
The information contained in this manual is intended to be supplemented by specific detailed
information contained in sales brochures and service brochures.
INTRODUCTION
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
iii
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Contents
The GOLD CUP®package pump and motor internal configuration........................................1.1
Package pump internal configuration .....................................................................................1.1
Figure 1.1 Pump internal configuration-rotating group .......................................................1.1
Figure 1.2 Stroking vane assembly ....................................................................................1.2
Figure 1.3 Stroking vane installation ..................................................................................1.2
Figure 1.4 Pump internal configuration vane chambers and servo stem ...........................1.3
Figure 1.5 Pump internal configuration vane chamber cover and servo plates..................1.3
Figure 1.6 Vane chamber covers........................................................................................1.3
Figure 1.7 Pump internal config. rotary servo input and displacement indicator................1.4
Figure 1.8 Control cover - rotary servo input......................................................................1.4
Figure 1.9 Ring check assembly ........................................................................................1.5
Package motor configuration..................................................................................................1.5
Figure 1.10 Fixed displacement motor ...............................................................................1.5
Figure 1.11 Variable displacement motor ...........................................................................1.6
GOLD CUP®circuitry..............................................................................................................2.1
Package pump circuitry ..........................................................................................................2.1
Figure 2.1 Poppets .............................................................................................................2.1
Servo & replenishing circuits ..................................................................................................2.1
Pressure compensator override .............................................................................................2.2
Figure 2.2 6.0, 7.25 and 8.0 in3/rev. pump circuit................................................................2.4
Figure 2.2.1 6.0, 7.25 and 8.0 in3/rev. pump circuit (ISO standard)....................................2.5
Nomenclature for ISO circuit figure 2.2.1 ...............................................................................2.6
Figure 2.3 11,14 pump circuit.............................................................................................2.7
Figure 2.3.1 11, 14 pump circuit (ISO standard) ................................................................2.8
Nomenclature for ISO circuit figure 2.3.1 ...............................................................................2.9
Figure 2.4 24, 30 pump circuit..........................................................................................2.10
Figure 2.4.1 24, 30 pump circuit (ISO standard) ..............................................................2.11
Nomenclature for ISO circuit figure 2.4.1 .............................................................................2.12
Package motor circuitry ........................................................................................................2.13
Figure 2.5 GOLD CUP®package motor circuit.................................................................2.13
GOLD CUP®controls..............................................................................................................3.1
Rotary servo input ..................................................................................................................3.2
Figure 3.1 Control cover-rotary servo input........................................................................3.2
Spring centering rotary servo .................................................................................................3.3
Figure 3.2 Spring centered rotary servo (zero stroke)........................................................3.3
Figure 3.3 Spring centered rotary servo (on stroke)...........................................................3.3
Adjustable stops .....................................................................................................................3.4
Manual screw adjustment.......................................................................................................3.4
Figure 3.4 Manual screw adjustment..................................................................................3.4
Motor cylinder control .............................................................................................................3.4
Figure 3.5 Motor cylinder control (max. stroke) ..................................................................3.5
Figure 3.6 Motor cylinder control (min. stroke) ...................................................................3.5
Pump two position cylinder control.........................................................................................3.6
Figure 3.7 Pump two position cylinder control....................................................................3.6
Pump three position cylinder control ......................................................................................3.6
Figure 3.8 Pump three position cylinder control .................................................................3.7
Motor electrohydraulic cylinder control (2M* motor control) ...................................................3.7
Figure 3.9 Motor electrohydraulic cylinder control (full stroke) ...........................................3.7
Pump two position electrohydraulic cylinder control (2M* pump control) ...............................3.7
Figure 3.10 Pump two position electrohydraulic cylinder control........................................3.8
Pump three position electrohydraulic cylinder control (2N* control) .......................................3.8
Figure 3.11 Three position electrohydraulic cylinder control ..............................................3.8
Automatic brake and neutral bypass control...........................................................................3.9
Figure 3.12 Automatic brake and neutral bypass (400 and 500 series)
(input & output at zero stroke) ............................................................................................3.9
Figure 3.13 Automatic brake and neutral bypass (400 and 500 series)
(input and output on stroke)..............................................................................................3.10
Figure 3.14 Automatic brake and neutral bypass (400 and 500 series)
(input zero, output on stroke)............................................................................................3.11
Figure 3.15 Automatic brake and neutral bypass (800 and 900 “C” series)
(zero stroke) .....................................................................................................................3.12
Figure 3.16 Automatic brake and neutral bypass (800 and 900 “C” series)
(full stroke)........................................................................................................................3.12
Torque limit override control .................................................................................................3.12
Figure 3.17 Torque limit override circuit............................................................................3.13
Figure 3.18 Torque limit override shoe .............................................................................3.13
Figure 3.19 Torque (horsepower) limit override ................................................................3.14
SECTION 1
GOLD CUP®package pump and motor
internal configuration
SECTION 2
GOLD CUP®circuitry
SECTION 3
GOLD CUP®controls
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
iv
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Contents
Electrohydraulic stroker (500 series) ....................................................................................3.14
Figure 3.20 Electrohydrauic stroker (zero stroke).............................................................3.14
Figure 3.21 Electrohydraulic stroker (on stroke)...............................................................3.15
Figure 3.22 Stroke vs. current ..........................................................................................3.15
Hydraulic stroker (800 series)...............................................................................................3.15
Figure 3.23 Hydraulic stroker (centered)..........................................................................3.16
Figure 3.24 Hydraulic stroker (on stroke) .........................................................................3.16
Electrohydraulic servo (HI IQ ) (700 series) .........................................................................3.17
Figure 3.25 Electrohydraulic servovalve (HI-IQ)...............................................................3.17
Electrohydraulic stroker (900 series) ....................................................................................3.17
Figure 3.26 900 series hydraulic circuit............................................................................3.18
Introduction.............................................................................................................................4.1
Remote control of pressure compensator override ................................................................4.1
Figure 4.1 Circuit to control speed of venting compensator ...............................................4.1
Figure 4.2 Remote control of multiple PCOR .....................................................................4.1
Figure 4.3 Remote control of PCOR by pressure sources .................................................4.2
Load sensing ..........................................................................................................................4.2
Figure 4.4 Load sensing.....................................................................................................4.2
Constant speed drives............................................................................................................4.3
Figure 4.5 Constant speed drive ........................................................................................4.3
Dead man control ...................................................................................................................4.3
Overhauling load-dynamic braking .........................................................................................4.3
Replenishment requirements..................................................................................................4.4
Figure 4.6 Case pressure replenishment circuit.................................................................4.4
Figure 4.7 Additional replenishment flow............................................................................4.5
Engine startup ........................................................................................................................4.5
Cold startup ............................................................................................................................4.5
New system or new component startup .................................................................................4.6
System filtration ......................................................................................................................4.6
Cleaning procedures ..............................................................................................................4.7
Shaft type selection ................................................................................................................4.7
Applying splined shafts...........................................................................................................4.8
Applying keyed shafts.............................................................................................................4.8
Series6 Variable volume pump with 1.07 in3/rev., 17,5 cc/rev. aux. pump...............................5.1
Series6 Variable volume motor...............................................................................................5.2
Series7 Variable volume pump with 1.07 in3/rev., 17,5 cc/rev. aux. pump...............................5.3
Series7 Variable volume motor...............................................................................................5.4
Series8 Variable volume pump with 1.07 in3/rev., 17,5 cc/rev. aux. pump...............................5.5
Series11 Variable volume pump with 2x1.07 in3/rev., 2x17,5 cc/rev. aux. pump.....................5.6
Series11 Variable volume motor.............................................................................................5.7
Series14 Variable volume pump with 2x1.07 in3/rev., 2x17,5 cc/rev. aux. pump.....................5.8
Series14 Variable volume motor.............................................................................................5.9
Series24 Variable volume pump with 2.81 in3/rev., 46 cc/rev. aux. pump..............................5.10
Series24 Variable volume motor...........................................................................................5.11
Series30 Variable volume pump with 2.81 in3/rev., 46 cc/rev. aux. pump..............................5.12
Fluid power formulas ..............................................................................................................6.1
Pg1 Pump ordering code........................................................................................................6.2
Pg2 Pump ordering code........................................................................................................6.3
Pg1 Motor ordering code........................................................................................................6.4
Pg2 Motor ordering code........................................................................................................6.5
Pump control combinations ....................................................................................................6.6
Motor control combinations ....................................................................................................6.7
Notes ......................................................................................................................................7.1
Offer of Sale ...........................................................................................................................7.2
SECTION 3
GOLD CUP®controls (continued)
SECTION 4
GOLD CUP®application suggestions
SECTION 5
GOLD CUP®performance curves
SECTION 6
Reference information
SECTION 7
Offer of Sale
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
1.1
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 1
GOLD CUP®series package pumps and motors are equipped with all the components
required by most hydrostatic transmission circuits. In the pump are the main system rotating
group, the servo and replenishing pump(s), replenishing check valves, stroking mechanisms,
and a valve block assembly containing the servo pressure relief valve, replenishing pressure
relief valve and the pressure compensator override valving. The package motor contains the
hot oil shuttle valve and the low pressure replenishing relief valve along with the main system
motor rotating unit. The circuitry and operation of these valves are detailed in the GOLD CUP®
circuitry chapter of this manual.
GOLD CUP®hydrostatic transmission pumps are equipped with the following standard fea-
tures:
(1) rotary servo displacement control
(2) pressure compensator override
(3) servo and replenishing pump(s)
(4) servo pressure relief valve
(5) replenishing pressure relief valve
(6) full flow replenishing check valves
(7) displacement indicator
Figure 1.1 shows the main rotating group and the auxiliary pump(s). The main system pump
rotating group is an axial piston variable volume pump consisting of a shaft driven cylinder
barrel and pistons. The barrel is made of steel with bronze liners in the cylinder bores. It is
supported by a large diameter roller bearing located in line with the radial forces generated
by the pumping action. Because of its location, this bearing prevents the barrel from tipping at
high speeds and high pressures and gives the pump its high speed and pressure capabilities.
If the cylinder barrel is allowed to tip, the balancing areas will be altered and the barrel will be
more susceptible to blow-off. Tipping also increases internal leakage and reduces efficiency.
The 6.0, 7.25, 8.0, 11 and 14 in3/rev units all have seven pistons with bronze shoes. The 24
and 30 in3/rev units have nine. A retainer plate holds the piston shoes to the rocker cam creep
plate and is itself held to the rocker cam snout by a snap ring and thrust bearing.
A small auxiliary drive shaft is splined to the cylinder barrel and drives the auxiliary pump(s).
On the 6.0 thru 14 in3/rev , this shaft also provides cylinder barrel holddown and initial clamp-
ing of the auxiliary pump(s) pressure loaded side plate. Holddown and clamping forces are
set by a spring between the shaft and the cylinder barrel, and adjusted by the nut on the other
end of the shaft.
GOLD CUP®PACKAGE PUMP
AND MOTOR INTERNAL
CONFIGURATION
PACKAGE PUMP INTERNAL
CONFIGURATION
Figure 1.1
GOLD CUP®pump internal
configuration - rotating group
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
1.2
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 1
The input shaft passes through the rocker cam and cradle assembly and is splined to the
cylinder barrel. It is available in the following standard configurations:
SAE spline shaft
SAE key shaft
The shaft normally accepts only torsional loads and is not rated for axial and radial loads
imparted by external drive configurations. The displacement of the main system pump is
varied by the rocker cam which rotates in the rocker cradle. Both cam and cradle are loaded in
compression and are very rigid. They do not deflect as do bearing supported trunnions. This
reduction in deflection reduces transmitted noise and increases efficiency. To reduce friction
and the required higher servo pressure, the rocker cam is partially floated by system pressure
exposed to a small area of the cradle surface.
Integrally cast on either side of the rocker cam are a pair of posts to hold the stroking vanes.
The vanes are held in slots in the posts and each consists of a Teflon seal held between two
backup plates. (See figure 1.2)
The seal is held outward against the walls of the stroking chamber by an o-ring and servo
pressure which is fed into the center of the Teflon seal through slots in the backup plates and
a small shuttle valve. Figure 1.3 shows an assembled stroking vane in the vane chamber.
The stroking vanes and chambers are used on all pumps, one on either side. This duality
increases the effective vane area and balances the rocker cam from side to side. It also allows
the pump to be assembled with the control input on either side. Two arcuate shaped stroking
chambers are bolted to either side of the rocker cradle (see figure 1.4). The centerline of the
vane chamber arcuates is the same as the rocker cam center of rotation. The upper and lower
vane chambers on one side (separated by the vane) are connected to the upper and lower
vane chambers on the other side of the rocker cam by a pair of channels through the rocker
cradle.
Figure 1.2
Stroking vane assembly
Figure 1.3
Stroking vane installation
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
1.3
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 1
Flow into the upper and lower vane chambers is carried in a pair of small channels drilled into
the rocker cam (see Figure 1.1). Figure 1.4 shows the servo stems which are bolted to the
rocker cam on both sides. Channels run through the length of the servo stem and depressions
in the end of the stem connect the upper channel in the stem to the lower vane chambers and
vice versa. Orifice plugs in the servo stem limit the flow rate into and out of the vane cham-
bers and therefore the stroking rate.
A flat servo plate is bolted to the servo stem on the control side of the pump and a flat bal-
ance plate is bolted to the servo stem on the output (displacement indicator ) side of the pump
(see Figure 1.5). The servo plate has two holes which connect directly to the channels in the
servo stem while the balance plate is blank and plugs the end of its servo stem. Because
the servo stems and plates are bolted to the rocker cam, they all move with the cam during
displacement changes.
The vane chambers are sealed by covers which also form the fourth surface for the vane to
seal against. In the covers are channels to carry the flow from the pressure compensator
override tubes to the proper stroking vane chambers. The vane chamber cover on one side of
the pump will port flow into one set of vane chambers (either upper or lower) while the cover
on the opposite side ports flow into the other chambers. Figure 1.6 shows the vane cham-
ber covers and the internal porting. Vane chamber cover porting will change with rotation as
shown.
Figure 1.4
GOLD CUP®pump internal
configuration vane chambers and
servo stems
Figure 1.5
GOLD CUP®pump internal
configuration vane chamber
covers and servo plates
Figure 1.6
Vane chamber covers
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
1.4
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 1
Upward motion of the servo shoe with respect to the servo plate, opens the top hole of the
servo plate to servo pressure and the bottom hole of the servo plate to case pressure. Servo
pressure is then carried through the channels in the servo stem and rocker cam to the vane
chamber below the vane actuator, while the upper vane chamber is opened to case pressure.
The pressure differential establishes an upward force on the stroking vane and the rocker
cam cradle rotates upward. The servo plate and stem traveling with the rocker cam also move
upward until the holes in the servo plate are covered over by the lands on the servo shoe.
With the holes covered up, there is no longer a pressure difference across the vane actuator
and the rocker cam stops its rotation.
The servo shoe is configured such that it will store the full error signal. (i.e., rotary servo input
at full displacement in one direction while the rocker cam is at full displacement in the other
direction.)
There are four servo shoes in each pump. One shoe (inside shoe on the control side) pro-
vides the 4-way valve action, the outer shoe on the control side serves to feed servo pressure
from the side plate to the inside shoe, while the other two shoes provide balancing forces
to counteract loading on the servo link assemblies and rocker cam assembly. The servo link
assembly on the control side is free to move and controls pump displacement. The servo link
assembly on the other side of the pump is restrained by the heads of the socket head cap
screws holding the servo stem and plate assembly to the rocker cam and therefore moves
with the rocker cam during displacement changes. This side forms the displacement indicator.
Figure 1.7
GOLD CUP®pump internal
configuration rotary servo input and
displacement indicator
Figure 1.8
Control cover - rotary servo input
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
1.5
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 1
Figure 1.9 shows the ring checks which are used for replenishing check valves. The ring
checks are located in the main ports (Figure 1.4). They consist of cylindrical shaped spring
steel strips wrapped inside each system port and held in place by a retainer screw and nut.
Large port areas at the ring check allow higher flow rates with small motions of the ring,
thereby reducing bending and fatigue. Upon closing, a squeeze film between the ring and
bore dampens the motion and prevents pounding. Both of these features are responsible for
the high reliability and fast response of this check valve design.
The valve block assembly bolts to the top surface of the pump port block at the rear. This as-
sembly holds the pressure compensator overrides valves, servo relief valve and replenishing
relief valves and can be removed and replaced as an assembly. Its functions and the circuitry
are described in the Circuitry Section 2.
GOLD CUP®hydrostatic transmission package motors are equipped with hot oil shuttle valves
and low pressure replenishing relief valves as standard. They are available in both variable
and fixed displacement versions.
All package motors use a rotating group of the same principle and design as the package
pump. There are slight internal porting differences to enhance the motoring capabilities.
Fixed displacement motors (Figure 1.10) have a fixed-angle cam instead of a rocker and
cradle assembly. There are no stroking mechanisms or controls.
PACKAGE MOTOR
CONFIGURATION
Figure 1.10
Fixed displacement motor
Figure 1.9
Ring check assembly
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
1.6
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 1
Variable displacement motors use the same rocker cam, cradle and stroking mechanisms as
the package pumps (see Figure 1.11).
The gerotor pump(s), valve block and ring checks are not included. Since there is no gerotor,
servo flow must be plumbed to the motor from an external source such as the pump servo
pressure.
In place of the pump valve block, the package motors have a small valve block containing the
hot oil shuttle and low pressure replenishing relief valve. Non-package motors do not have this
block.
Figure 1.11
Variable displacement motor
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
2.1
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 2
GOLD CUP®series package pumps and motors contain within them all the circuitry normally
required in a hydrostatic transmission. The pumps contain circuitry for the rotary servo actua-
tor, servo pressure relief valve, replenishing relief valve, and pressure compensator override
controls. Package motors contain the shuttle valve and low pressure replenishing relief valve.
Figures 2.2, 2.3 and 2.4 show the circuitry contained in the GOLD CUP®pumps. The circuit in
Figure 2.2 is for the 6.0, 7.25 and 8.0 in3/rev pumps. Figure 2.4 is the circuitry for the 24 and
30 in3/rev pumps. Figure 2.3 is the circuitry for the 11 and 14 in3/rev pumps, which contain a
dual section servo and replenishing pump.
All the pumps in the GOLD CUP®line use the same valve block assembly, except that the 30
in3/rev valve block’s servo pressure modulation pin is larger. It contains the pressure compen-
sator override valving for both sides of the pump, the pressure modulated servo relief valve,
replenishing relief valve and replenishing relief pilot stage. The circuitry contained in the valve
blocks and the operation of the individual valves is the same for all pumps. Figure 2.1 shows
the two types of poppets used in the valve block. The stepped poppet is a dual area poppet.
The area on top of the poppet (A1) is equal to twice the annular area (A3) and twice the area
of the underside of the poppet (A2) (the underside area equals the annular area).
The sequence poppet rests on a tapered seat and has only two important areas – the area
above (A1) and below the poppet (A2). Since the poppet has straight sides and rests on a
tapered seat, both areas are equal.
The sealing of the poppets is realized by floating seats to ensure optimal closure.
In circuits Figures 2.2, 2.3 & 2.4 the servo pressure oil flows from the servo-replenishing
pump to the rotary servovalve. The servo-replenishing pump suction is shown in heavy
blue and is drawn from a reservoir external to the pump. The rotary servovalve action was
described in the Internal Configuration Section and will not be described here. The control
flows from the servovalve are shown in dashed-blue and may be at a pressure less than servo
pressure. Servo pressure is controlled by the pressure modulated servo relief valve in the
valve block.
Output flow from the servo-replenishing pump is exposed to the annular area of the servo
relief valve poppet and after the force created by pressure on the annular area exceeds the
spring force plus the force provided by the pin and replenishment pressure on the top of the
poppet, the poppet will lift and allow flow into the replenishing gallery (green lines). All other
areas of the pressure modulated servo relief valve are exposed to replenishing pressure, as
shown in green. This exposes to replenishing pressure a net area difference on top of the
poppet equal to the area exposed to servo pressure. This makes the pressure modulated
servo relief valve sensitive to replenishing pressure. The pressure setting of this relief valve
is therefore equal to the spring force plus the force generated by the pin on top of the poppet
plus replenishing pressure. Minimum servo pressure is approximately twice replenish and
increases 40 psi, 2,76 bar per 1000 psi, 69 bar as system pressure increases due to the
modulating pin.
(For the 30 series, servo pressure increases 62 psi, 4,14 bar per 1000 psi, 69 bar.) In the 6.0,
7.25 and 8 in3/rev pumps (Figure 2.2), the servo pressure gallery is threaded to receive a plug
which is supplied with each pump. If the plug is not used, servo flow is free to travel directly
from the servo-replenishing pump to the servo relief valve.
PACKAGE PUMP CIRCUITRY
Figure 2.1
Poppets
GOLD CUP®CIRCUITRY
SERVO AND REPLENISHING
CIRCUITS
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
2.2
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 2
With the plug installed as shown in Figure 2.2, servo flow must be externally plumbed
between the two filter ports. This allows filtering of the servo oil before it reaches the replen-
ishing gallery. Consult installation drawings or sales bulletins for port locations. However, not
all of the servo oil is filtered. Servo oil flowing to the rotary servo on the “B” port side is not fil-
tered. If the rotary servo control is on the “A” port side, servo flow to the rotary servo is filtered.
In the 24 and 30 in3/rev pumps (Figure 2.4), servo pump output is directed to port G, where a
customer supplied filter, filters all servo oil. Excess servo oil spills over the servo relief valve
and into the replenishing gallery.
In the 11 and 14 in3/rev pumps (Figure 2.3), the servo pressure oil is not filtered. In these
pumps, the oil is filtered at replenishing pressure.
Replenishing flow is supplied by both the servo pump and replenishing pump. Excess servo
flow from the servo pump spills over the servo relief valve and into the replenishing gallery
where it joins the flow from the replenishing pump. The combined flow from the two sources is
then fed to the replenishing checks and the replenishing relief. If the optional plug is inserted
into the replenishing gallery it blocks the flow before it reaches the replenishing checks. When
the plug is installed, the replenishing flow must be externally plumbed. See installation draw-
ings or the sales bulletins for port locations.
Replenishing pressure in all pumps is controlled by the replenishing relief valve, which is in
turn controlled by the replenishing relief pilot stage. Replenishing pressure is exposed to the
annular area of the replenishing relief valve as shown. When replenishing pressure exceeds
the pressure set into the relief pilot stage, the pilot opens, allowing a flow from the top of the
replenishing relief valve which creates a pressure drop created through the orifice leading to
the top of the valve from the replenishing gallery. The valve then opens and controls the pres-
sure in the replenishing gallery. A small filter screen between the replenishing relief poppet
and pilot section prevents the pilot from becoming stuck from contamination. Excess replen-
ishing flow is spilled into the light blue area and is carried through a passage near the port
plate in the port block before it spills into the case of the pump. This flow cools the port plate
to cylinder barrel interface during idle. Internal leakage from the rotating group and output
control flow from the manual rotary servo, join the excess replenishing flow in the case and all
are carried out the case drain.
If it becomes necessary to provide additional replenishing flow, an auxiliary replenishing port
is available at the rear of the pump for this purpose. See installation drawings or sales litera-
ture for its location. These ports are standard on all GOLD CUP®pumps.
The replenishing relief valve is a dual area valve. Replenishing pressure is exposed to the
annular area of the replenishing poppet and to the area on top of the poppet. This creates
an unbalanced area exposed to replenishing pressure on top of the poppet equal to the area
exposed to case pressure under the poppet. Replenishing pressure is therefore sensitive to
case pressure. Should the force of the case pressure exceed the force of the replenishing
pressure and spring on the replenishing relief valve, the replenishing relief valve will open
and allow backflow from the case of the pump into the replenishing gallery. This is called case
pressure replenishing. Its use is explained in the application notes Section 4.
In both circuits the area shown in red is the high pressure work port and the area shown in
green is the low pressure work port. In the high pressure port, high pressure is exposed to
the blocked side of the replenishing check valves, the blocked side of the small check valves
going to the top of the dual level relief valves in the compensator circuit, and to the underside
of the sequence valves in the pressure compensator circuit. When the pressure in the work
port exceeds the setting of the pressure compensator override pilot section, the pilot section
will open, allowing flow into the replenishing gallery. This small flow creates a pressure drop
across the orifice in the bottom of the high pressure sequence valve, and the valve opens.
This allows oil to flow into the override tube which carries it to the appropriate vane chamber.
This pressure overrides the manual rotary servo control pressure and changes the pump
displacement.
The sequence valve has equal areas above and below the poppet. Secondary port pressures
are not exposed to any unbalanced areas of the poppet and therefore the sequence valve
setting is independent of downstream pressure.
The pressure in the override tube is limited by the dual level relief valve which has servo
pressure on its top area. The annular area is half of the area on top of the dual relief valve,
therefore the pressure in the override tube is limited to twice servo pressure plus the spring
force. Excess flow which is not used to change the stroke of the pump is ported directly into
the replenishing gallery through this valve.
PRESSURE COMPENSATOR
OVERRIDE
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
2.3
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 2
During compensation the flow leaving the opposite vane chamber exits through the opposite
override tube and goes across the dual level relief valve on the low pressure side of the pump.
This valve is set to a lower pressure than the opposite valve, due to the orifices on either
side of the top area. Oil, initially at servo pressure, flows through the equal size orifices which
drop the pressure on top of the poppet to half servo pressure before it exits through the small
check valve into the low pressure work port. Since the annular area is equal to half the area
on top of the dual level relief valve, and the pressure on top of the dual level relief valve is half
servo pressure, the pressure setting of the annular area of the dual level relief valve is equal
to servo pressure plus the spring force. This creates a maximum pressure difference across
the vane actuators, during pressure compensating, approximately equal to servo pressure.
Override pressure must be higher than servo pressure in order to move the rocker cam.
The pilot section of the pressure compensator override circuit consists of a spring loaded
cone and seat and two isolation check valves. The isolation check valves prevent the low pres-
sure side of the circuit from affecting the high pressure setting and also allow individual vents
or remote controls to be connected to either side of the pressure compensator override. There
is also a common vent connection which can control both sides of the override. The pressure
compensator override pilot control is externally adjustable. Please consult installation drawing
for its location on the pumps.
Pressure compensator override pilot pressure is exposed to the top of the pin which pushes
on the pressure modulated servo valve. This makes the servo pressure setting dependent
upon the pressure in the high pressure work port. Since lower control forces are required for
low system pressures, it is possible to reduce the servo pressure without loss of control. This
also reduces parasitic horsepower losses from the servo and replenishing pump. Servo pres-
sure increases approximately 40 psi for every 1000 psi, 4 bar for 100 bar of system pressure.
(For the 30 series, servo pressure increases 62 psi, 4,14 bar per 1000 psi, 69 bar.)
When system pressure drops below the pressure compensator override setting, the manual
rotary servo control, which is still displaced to the original setting, takes over control of the
pump and the pump strokes back to its original setting at a rate controlled by the orifices in
the servo stem.
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
2.4
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 2
VALVE
ASSEMBLY
PORT
BLOCK
PUMP
HOUSING
VKG
COMPENSATOR
VENT CONN.,
BOTH SIDES
PILOT FLOW
CHECK VALVE
HIGH PRESSURE
SEQUENCE VALVE
COMPENSATOR
VENT "A"SIDE
CONN.
PRESSURE
MODULATED
SERVO RELIEF VALVE
DUAL LEVEL
RELIEF VALVE
HIGH PRESSURE
PILOT CONTROL
REPLENISHING
RELIEF VALVE
REPLENISHING RELIEF
PILOT STAGE
DUAL LEVEL
RELIEF VALVE
PILOT FLOW
CHECK VALVE
HIGH PRESSURE
SEQUENCE VALVE
COMPENSATOR
VENT "B" SIDE CONN.
FILTER
SCREEN
REPLENISHING
GAGE CONN.
K
AUXILIARY
REPLENISHING
PORT
OPTIONAL
PLUG
G
FILTER
OUTLET
PORT A
SYSTEM
PORT
AG
SYSTEM
PRESSURE
GAGE
FA
CONTROL
GAGE
CONN."A" SIDE
C
AUXILIARY
PUMP INLET
REPLENISHING
CHECK VALVE
SERVO & REPLENISHING
PUMP
MANUAL ROTARY
SERVO VALVE
VANE ACTUATORS
FOR
ROCKER HANGER
CHOKES
PUMP
LEAKAGE
COOLING FLOW
PASSAGES
PORT D
CASE DRAIN
FB
CONTROL GAGE
CONN."B" SIDE
BG
SYSTEM
PRESSURE
GAGE
PORT B
SYSTEM
PORT
REPLENISHING
CHECK VALVE
HFILTER
RETURN
VA VB
COLOR CODE
OUTLET
PILOT PRESSURE
INLET
CASE DRAIN
REPLENISHING
PRESSURE
OVERRIDE
TUBE
OVERRIDE
TUBE
Figure 2.2
6.0, 7.25 and 8.0 in3/rev Pump circuit
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
2.5
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 2
Figure 2.2.1
6.0, 7.25 and 8.0 in3/rev Pump circuit
( ISO Standard )
VKKG
DG
VB
FB
G
BG
B
D2
D1
AG
A
C
H
FA
VA
8106 7 10 8
11
4
5*
11
2
3
1
9
NOTE:For the poppet valves 6, 7 & 10 the spring
side area is 2x the bottom ring area.
* CAUTION: The isolation plug included with
pump is to be installed ONLY if an external
filter circuit is provided by the user.DO
NOT operate unit with the isolation plug
installed unless an external line has been
provided between ports “G”and “H”.
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
2.6
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 2
ITEM DESCRIPTION
1 Piston pump
2 Vane chambers
3 Rotary servo
4 Servo and replenishing pump
5 Plug optional
6 Servo relief valve (modulated by operating pressure)
7 Replenishing relief valve
8 High pressure sequence valve (2)
9 High pressure pilot control
10 Dual level relief valve (2)
11 Replenishing check valve
PORT
CODE CONNECTION FUNCTION PORT SIZE OR THREAD
A,B System power 4-bolt pad for SAE-1.5” 6000 psi, 414 bar
A Open loop inlet 4-bolt pad for SAE-2” 3000 psi, 207 bar
AG,BG System pressure gage, each side SAE-6 straight thread
C Auxiliary pump inlet SAE-16 straight thread
DG Case pressure gage SAE-6 straight thread
D1,D2 Case drains SAE-12 straight thread
G Auxiliary pump outlet SAE-8 straight thread
H Auxiliary flow return SAE-8 straight thread servo pressure
K Replenishment inlet SAE-16 straight thread
KG Replenishing pressure gage SAE-6 straight thread
FA Control area, A side 1/4” NPTF Dryseal
FB Control area, B side 1/4” NPTF Dryseal
V Compensator vent, both sides SAE-4 straight thread
VA Compensator vent, A side SAE-4 straight thread
VB Compensator vent, B side SAE-4 straight thread
NOMENCLATURE
(For ISO circuit Figure 2.2.1)
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
2.7
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 2
Figure 2.3
11 and 14 in3/rev Pump circuit
COLOR CODE
OUTLET
PILOT PRESSURE
INLET
CASE DRAIN
REPLENISHING
PRESSURE
VALVE
ASSEMBLY
PORT
BLOCK
PUMP
HOUSING
VKG
COMPENSATOR
VENT CONN.,
BOTH SIDES
PILOT FLOW
CHECK VALVE
HIGH PRESSURE
SEQUENCE VALVE
COMPENSATOR
VENT "A"SIDE
CONN.
PRESSURE
MODULATED
SERVO RELIEF VALVE
DUAL LEVEL
RELIEF VALVE
HIGH PRESSURE
PILOT CONTROL
REPLENISHING
RELIEF VALVE
REPLENISHING RELIEF
PILOT STAGE
DUAL LEVEL
RELIEF VALVE
PILOT FLOW
CHECK VALVE
HIGH PRESSURE
SEQUENCE VALVE
COMPENSATOR
VENT "B" SIDE CONN.
FILTER
SCREEN
REPLENISHING
GAGE CONN.
K
AUX.REPL.PORT &
PUMP FILTER RETURN
OPTIONAL
PLUG
G
SERVO
PRESS.GAGE CONN.
PORT A
SYSTEM
PORT
AG
SYSTEM
PRESSURE
GAGE
FA
CONTROL
GAGE
CONN.
"A" SIDE
C
AUXILIARY
PUMP INLET
REPLENISHING
CHECK VALVE
SERVO & REPLENISHING
PUMP
MANUAL ROTARY
SERVO VALVE
VANE ACTUATORS
FOR
ROCKER HANGER
CHOKES
PUMP
LEAKAGE
COOLING FLOW
PASSAGES
PORT D
CASE DRAIN
FB
CONTROL
GAGE
CONN.
"B" SIDE
BG
SYSTEM
PRESSURE
GAGE
PORT B
SYSTEM
PORT
REPLENISHING
CHECK VALVE
G
VA VB
OVERRIDE
TUBE
REPLENISHING
PUMP
ALTERNATE
(CLOSED LOOP ONLY)
G2
AUX.PUMP OUTLET
(CLOSED LOOP ONLY)
J
OVERRIDE
TUBE
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
2.8
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 2
Figure 2.3.1
11 and 14 in3/rev Pump circuit
( ISO Standards )
VKKG
DG
VB
FB
G
BG
B
D2
D1
AG
A
C
G
FA
VA
9117 8 11 9
12
4
*6
12
2
3
5
J
G2
1
10
* CAUTION: The isolation plug included with
pump is to be installed ONLY if an external
filter is provided by the user.DO NOT oper-
ate unit with the isolation plug installed
unless an external line has been provided
between ports “J”and “K”.
NOTE:For the poppet valves 7, 8 & 11 the spring
side area is 2x the bottom ring area.
www.comoso.com

HY28-2668-01/GC/NA,EU GOLD CUP®Series - Application Manual
Piston Pumps & Motors
2.9
Parker Hannifin Corporation
Hydraulic Pump Division
Marysville, Ohio USA
Section 2
ITEM DESCRIPTION
1 Piston pump
2 Vane chambers
3 Rotary servo
4 Servo pump
5 Replenishing pump
6 Plug (optional)
7 Servo relief valve (modulated by operating pressure)
8 Replenishing relief valve
9 High pressure sequence valve (2)
10 High pressure pilot control
11 Dual level relief valve (2)
12 Replenishing check valve
PORT
CODE CONNECTION FUNCTION PORT SIZE OR THREAD
A,B System power 4-bolt pad for SAE-1.5” 6000 psi, 414 bar
AG,BG System pressure gage, each side SAE-6 straight thread
C Auxiliary pump inlet SAE-20 straight thread
DG Case pressure gage SAE-6 straight thread
D1,D2 Case drains SAE-16 straight thread
G Servo press. gage conn. each side SAE-4 straight thread
G2 Alternate (closed loop only) SAE-8 straignt thread
K Auxiliary Replen. pressure SAE-16 straight thread port & pump filter
return port
J Aux. pump outlet (closed loop only) SAE-10 straight thread
KG Replenishing pressure gage SAE-6 straight thread
FA Control pressure gage, A side SAE-6 straight thread
FB Control pressure gage, B side SAE-6 straight thread
V Compensator vent, both sides SAE-4 straight thread
VA Compensator vent, A side SAE-4 straight thread
VB Compensator vent, B side SAE-4 straight thread
NOMENCLATURE
(For ISO circuit Figure 2.3.1)
www.comoso.com