BOCK FK40 Seroes User manual

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Page Contents
5 Introduction
5 Safety instructions
6 Product description
6 Short description, nameplate, type code
7 Main and functional parts
8 Dimension drawing, connections
9 Technical data
10 Maintenance
1 Function checks, oil level check, oil change
11 Operation of the shut-off valves
12 Fault diagnosis / Remedying t e malfunction
12 General, function faults - symptoms
12 Compressor stand still
13 Compressor cutoff
14 Cooling performance too low
14 Compressor temperature too high
15 Oil problems
15 Abnormal running noise from compressor
16 Malfunction of the electromagnetic clutch
17 Installation of service kits
17 Safety
18 Leak oil collection ring, Part no. 8 19
19 Shaft seal, Part no. 8 23
2 Capacity regulating valve, Part no. 7541
21 Valve plate
23 Electromagnetic clutc
25 Compressor defects
26 Disassembly of compressor
26 Removal of the compressor from the cooling system
26 Disassembly of compressor
27 1 Removal of all shut-off valves and blind flanges
28 2 Removal of oil filter
29 3 Removal of the cylinder cover and of the valve plates
3 4 Removal of the shaft seal
31 5 Removal of the oil pump
32 6 Removal of the baseplate
33 7 Disassembly of the connecting rods from the crankshaft
34 8 Removal of the front bearing flange
35 9 Removal of the crankshaft
36 1 Removal of the pistons and connecting rods
37 11 Removal of the remaining parts
38 12 Removal of the roller bearings
96 8- 9. 3-DGbFEI
- 3 -

Page Contents
39 C ecking t e components of t e compressor for damage / wear
39 Limiting values for wear
39 Cylinder liners
39 Crankshaft
4 Pistons
4 Connecting rods
4 Valve plates
4 Oil pump
41 Oil filter / suction filter
41 Internal safety valve
42 Assembly of t e compressor
42 1 Fitting the roller bearings
43 2 Fitting the sight glass, the plugs and the internal safety valve
44 3 Assembly of the pistons / connecting rods
45 4 Fitting the piston / connecting rod sets
46 5 Fitting the crankshaft
47 6 Installation of the front bearing flange
48 7 Assembly of the inserted connecting rods / pistons
49 8 Installation of the oil pump
5 9 Fitting the shaft seal
51 1 Installation of the baseplate
52 11 Installation of the oil filter
53 12 Installation of the cylinder cover and valve plates
54 13 Installation of the shut-off valves and blind flanges
55 Checking the compressor
55 Tig tening torques for screws
56 Spare parts list
58 Repair kits parts list
59 Parts list for optional accessories
60 Exploded drawing
- 4 -
96 8- 9. 3-DGbFEI

Introduction
Vehicle compressors Series FK 4 of Bock are among the most wide-spread machines
used for bus A/C applications. The criteria that speak for choosing a FK 4 compressor are
its compact dimensions, its low weight, the wide capacity spectrum together with the high
operating safety and service-friendliness.
This maintenance manual is intended to make the repair and maintenance of the FK 4
easier for the servicing personnel. The maintenance manual contains a complete
description of each work step for the disassembly and assembly of the compressor
components. Each step must be carefully adhered to in order to ensure a reliable repair.
Reminder:
For replacing components Bock provides suitable spare part kits. Yet assembly jobs
which go beyond the replacement of the shaft seal, the valve plates and - if there
is one - the capacity regulator (accessory) should be checked carefully for their
economic efficiency beforehand.
The maintenance manual describes the standard type of the FK 4 compressor
which we deliver. Because of different system conceptions, some passages in this
service manual may differ from the unit which you have come across. In these
Safety
Safety instructions
Attention! Refrigeration compressors are mac ines under pressure and as suc
require special care in andling.
Only qualified personnel are allowed to perform any work on refigeration compressors
T e national safety regulations, accident prevention regulations, tec nical rules
and specific regulations (EN 378 and ot ers) must be taken into account
absolutely.
Do not exceed t e maximum operating pressure - not even for purposes of c ecking!
Never put t e safety switc out of action!
Prior to commissioning, c eck w et er all t e components installed by t e user
ave been fastened expertly and connected pressure-tig t wit t e compressor
(e.g. piping, plugs, union nuts, replaced components etc.)
Before commissioning, evacuate t e cooling system carefully including
t e compressor and afterwards c arge refrigerant.
Prior to starting t e compressor open disc arge s ut-off valve and suction s ut-off
valve.
Do not start t e compressor in vacuum. Operate t e compressor only w en t e
system is c arged.
According to t e conditions of use surface temperatures in excess of 100°C may
occur on t e disc arge side and temperatures below 0°C on t e suction side.
Never grab rotating parts during operation! Danger of injury!
96 8- 9. 3-DGbFEI
- 5 -

Product description
Series FK 4 vehicle compressors are designed for mobile applications.
FK 40 -
N
FK 40 -
K
FK 40 -
TK
A/C compressor
for R134a
nmax= 3 rpm
Peak value = 35 rpm
A/C compressor
for R134a
nmax= 35 rpm
Deep-freeze compressor
for R4 4A (R22)
nmax= 26 rpm
S ort description
Compact 4-cylinder compressor in V design
Four sizes as regards capacity
Aluminum light-weight construction
Crankshaft supported in roller bearings on both sides
Bidirectional lubricating oil pump with relief valve
Variable arrangement of shut-off valves
Ideally equipped with valve plates for each application
Integrated pulsation damper for especially quiet running
Nameplate (Example)
1. Type of compressor 4. Serial number
2. Theoretic volume flow rate at 145 rpm 5. Oil type filled in compressor by the manufacturer
3. LP: max. tol. stand still pressure intake side note limits of
HP: max. tol. Derating pressure high pressure side aplication diagrams!
}
FK X 40 / 655 N
Type code (Example)
Explanation of the type designation
Code letter for area of application
Code number for displacement
Code number for size
Code letter for ester-oil filling
Code letter for series
- 6 -
96 8- 9. 3-DGbFEI
Product description

Main and functional parts
Figure 1
Figure 2
1. Discharge shut-off
2. Valve plate
3. Cylinder cover
4. Compressor casing
5. Locating hole for fitting magnetic clutch
6. Integrated leak oil collector
7. Shaft seal
8. Shaft end
9. Nameplate
1 . Connection for heat protection thermostat
11. Oil filling plug
12. Sight glasses for oil (2x)
13. Oil drain plug
14. Suction shut-off valve
15. Oil pump
16. Oil drain plug / oil filter
17. Baseplate
96 8- 9. 3-DGbFEI
- 7 -

FK 4 /39 FK 4 /47 FK 4 /56 FK 4 /655
Dimension drawing
Connections
SV Suction shut-off valve, pipe dia.(L)*
DV Discharge shut-off valve,
pipe dia. (L)*
[mm]
[Inches]
[mm]
[Inches]
28 35 35 35
1 1/8 1 3/8 1 3/8 1 3/8
22 28 28 28
7 / 8 1 1/8 1 1/8 1 3/8
ASuction side port, not lockable [Inches] 1/8" NPTF
A1 Suction side port, lockable [Inches] 7/16"UNF
BPressure side port, not lockable [Inches] 1/8" NPTF
B1 Pressure side port, lockable [Inches] 7/16"UNF
COil pressure safety switch connection OIL [Inches] 1/8" NPTF
DOil pressure safety switch connection LP [Inches] 1/8" NPTF
EPort for oil pressure gage [Inches] 1/8" NPTF
FOil drain plug [mm] M 22x1.5
HOil filling plug [mm] M 22x1.5
LHeat protection thermostat connection [Inches] 1/8" NPTF
MOilfilter [mm] M 22x1.5
*L = Soldering connection
- 8 -
96 8- 9. 3-DGbFEI

Tec nical data
No. of cylinders 4
Mass moment of inertia of the driving unit [kgm2] , 43
Lubrication Forced lubrication
Oil pump Bidirectional
Type of oil for R134a, R4 4A FUCHS Reniso Triton SE 55
Type of oil for R22 FUCHS Reniso SP 46
Oil filling [liters] 2,
Rotational speed see limits of application
Max. allowable operating pressure [bar], high-pressure side HD 25
low-pressure side ND 19
FK 4 /39 FK 4 /47 FK 4 /56 FK 4 /655
Displacement [cm3] 385 465 555 65
Theoretical volume flow rate [m3/h] 33,5 4 ,5 48,2 56,6
Weight incl. oil filling [kg] 33 32 32 31
96 8- 9. 3-DGbFEI
- 9 -

Maintenance
Maintenance
Service intervals
Practically no maintenance is required. However, for an optimal operating safety and service
life of the compressor we recommend to carry out the necessary maintenance work regulary
according to the specifications of the manufacturer of the refrigerating plant.
Function c ecks to be carried out once a year:
Leak test of the plant
Checking the running noise of compressor
Checking pressures and temperatures of the plant
Checking the tensioner for orderly seating
Checking the V belts for tension and condition
Checking the oil level in the cranckcase
Checking the fixing screws for tightening
Checking the function of the ancillary units
Checking the electrical connections for clean, firmly fixed contacts and the leads for chafing points
Oil level c eck
C anging oil:
After starting the compressor, the oil level has to be checked. For this:
The driving engine should be in the "High idle" operating condition (elevated idling speed).
Compressor running time at least 1 min.
The plant should have reached the operating point.
T e oil level must be visible in t e sig t glass.
In case of orderly manufactured and operated plants an oil change is in principle not absolutely
necessary.
Yet, based on decades-long experience we recommend to carry out the following oil change and
servicing.
- First oil change at the first maintenance of the vehicle.
- After that, changing the oil every 5 operating hours, but at the latest after 3 years. At the
same time the oil filter and the suction filter should be cleaned and the oil collecting ring from
the shaft seal replaced.
Lubricants
Standard oil type used by Bock Recommended alternatives
For H-FCKWs (e.g.R22)
FUCHS Reniso SP 46
For H-FKWs (e.g.R 134a, R4 4A, R4 7C)
FUCHS Reniso Triton SE 55
MOBIL SHC 425
SHELL Clavus SD 22-12
SUNOIL Suniso 3GS
SUNOILSuniso 4GS
TEXACO Capella WF 46
FUCHS SEZ 32 / 68 / 8
ICI Emkarate RL 46 S
MOBIL Arctic EAL 46
SHELL Clavus R 46
Information about other suitable oils should be taken from Bock lubricant tables.
Information may also be retrieved from www.bock.de.
- 1 -
96 8- 9. 3-DGbFEI

Operation of t e s ut-off valves
Opening t e s ut-off valve
a) Spindle 1: Turn to the left (ccw) until the
end stop
Shut off valve fully open / Service port
2 closed (Position A), Fig.
Opening t e service port (2)
b) b) Spindle 1: Turn 1/2-1 turn to the right
Service port 2 open / Shut-off valve open
(Position B), Fig
Port 3 is intended for safety devices and cannot
be shut off.
Position A
Position B
Note: Before opening or closing t e s ut-off valve, loosen t e valve spindle seal
(Fig. left) by 1/4 turn. After operating t e s ut-off valve, tig ten t e valve spindle
seal carefully again (Fig. rig t).
®
®
96 8- 9- 3-DGbFEI
- 11 -

Fault diagnosis
In case of malfunctions during compressor operation we recommend to prepare a
measurement record for aiding the fault search:
Pressure measurement: Discharge side, suction side, oil pressure
Temperature measurement: Compressor casing, discharge end temperature, suction gas
overheating
According to the expected cause of the fault it may be necessary to check the electrical
system for faults in the control.
In order to localize the causes of operating malfunctions as easy as possible we have
compiled the following table with suggestions for remedying compressor malfunctions.
Fault diagnosis
Function faults-Symptoms
Function faults arising most frequently and their symptoms are:
Compressor stoppage, compressor cutoff
- Compressor does not start
- Compressor starts and then stops again
Cooling performance too low
Too high compressor temperature
Oil problems
Abnormal compressor running noise
Malfunction of the electromagnetic clutch
Compressor stand still
Compressor does not start
Symptom
Open circuit
Possible cause
- Fuse blown
Cutoff through:
- Low pressure switch
- High pressure switch
- Heat protection thermostat
- Control thermostat
- Other safety elements
Remedy
- Replace fuse
Determine and remove the cause
- Localize the interruption in the circuit and
remove the cause of the interruption
- Checking
- see also p.16 Malfunction of
electromagnetic clutch
Malfunction of
electromagnetic clutch
96 8- 9- 3-DGbFEI
- 12 -


Compressor cutoff
Cutoff though low-
pressure switch
Compressor starts and stops again
Symptom
Suction pressure too low:
- Check the setting of the low pressure
switch
- Suction valve of the compressor closed
- Capacity of compressor too large
- Refrigerant deficiency
- Filter / dryer in the liquid line blocked
- Expansion valve not functioning properly
- Solenoid valve on the liquid line not
opening
Possible cause
- Adjust the switching points or replace
switch
- Open shut-off valve
- Check operating conditions
- Leak test / Add refrigerant
- Replace filter / dryer
- Check the setting of the valve
- Check the control / function
Remedy
Cutoff through high-
pressure switch
Condensing pressure too high
- Check the setting of the high-pressure
switch
- Pressure valve of the compressor closed
- Condenser fan not functioning
- Condenser dirty
- Excessive refrigerant filling
- Non-condensible gases in refrigerant
- Adjust the switching points or replace
switch
- Open shut-off valve
- Check the control / replace motor
- Cleaning of condenser
- Extract refrigerant to normal filling
- Extract refrigerant and evacuate the
refrigeration plant / refill refrigerant
Cutoff through heat-
protection thermostat
(accessory)
Discharge end temperatures is too high
- Operating limits of compressor
exceeded
- Suction gas overheating
- Cooling of the condenser insufficient
- Valve plate damage
- Internal safety valve has opened
- Adapt the operating conditions to the
operating range
- Check expansion valve / Check
insulation on the suction side
- Check fan motors / Clean the condenser
- Replace valve plate
- Replace safety valve
Check compressor and refrigeration
plant Determine and remove the
cause for the inadmissible high
pressure in the high-pressure side
®
Cutoff through control
thermostat
- Temperature over / below the desired
range
- Check operating points
- 13 -
96 8- 9- 3-DGbFEI




Cooling performance too low
Suction pressure too
high
Symptom
- Evaporator iced up
- Expansion valve not functioning properly
- Lack of compressor capacity
Possible cause
- Remove the cause
- Check valve setting; replace valve, if
necesaary
- Check the functioning of the compressor
by evacuating to vacuum.
Check function of capacity regulator
(accessory)
Remedy
Suction pressure too low
High-pressure too high
High-pressure too low
- See "Cutoff through low-pressure switch"
- See "Cutoff through high-pressure switch"
- Condenser being cooled to much
- Lack of compressor capacity
- Pressure laminations of valve plate leaking
By-pass between suction and discharge
side
- Checking
- Checking
- Adjust the control of condenser
cooling
- Check compressor / Check the functioning
of capacity regulator
- Replace valve plate
Localize leak between the discharge and
suction side and repair it
Cooling temperature too ig
Suction gas
temperature too high
Symptom
- Suction gas overheating
- Too little refrigerant filling
- Liquid filter blocked
Possible cause Remedy
- Adjust expansion valve
Insulate the gas suction line
- Establish the operating filling (see
Operating Instruction for the refrigeration
plant) Localize leak
- Clean / replace filter / dryer
Discharge pipe
temperature too high - Suction gas temperature too high
Condensing pressure too high
- Operating limits of compressor
exceeded
- Cooling insufficient
- Short circuit between the discharge and
the suction side of compressor
- Valve plate damage
- Internal safety valve has opened
see point above
see Cutoff through high-pressure
switch
see Cutoff through heat-protection
thermostat
- Replace defective valve plate
- Replace safety valve
(see the section on Dismantling /
Assembly of Compressor)
®
®
®
96 8- 9- 3-DGbFEI
- 14 -

Oil problems
Oil pressure too low
Symptom Possible cause Remedy
- Refrigerant in oil
- Too little oil in compressor
- Oil filter dirty / blocked
- see Oil foams"
- Add oil and search for the cause of
oil loss
- Clean / replace oil filter
Change oil
Oil foams during start-
up phase
- Liquid refrigerant has moved into the oil
sump
- Check the laying of pipes
- Installation of the check valve in the
discharge line
- Installation of the solenoid valve in the
liquid line
- Check the control
Oil foams during
operation
- Expansion valve not functioning - Adjust / replace expansion valve
Oil level decreases - During start-up, a portion of the oil is carried
to the refrigeration plant with the refrigerant
- Refrigerant in oil
- Piston rings worn
- Suction / discharge laminations of the valve
plate leaking
- Refrigerant and oil get mixed.
After some time the oil level should
stabilize.
Add oil, if necessary.
- see Oil foams during
operation
- Replace piston rings
- Replace valve plate
Abnormal running noise from compressor
Fixation of compressor
is loose
Symptom Possible cause Remedy
- Screwed connections hava become loose
- Securing elements for screwed
connections missing
- Vibration metals defective
- Tighten the screwed connections and
secure them anew
- Replace vibration metals
Liquid shock - Liquid refrigerant reaching the compressor
- Oil shocks because of too much oil
- Adjust / check expansion valve
Check refrigerant filling
Check evaporator fan
Icing-up of the evaporator
- Check oil level
Check the dimensioning of pipes (gas
velocity)
Replace worn piston rings
Capacity regulator
(accessory)
- switching on and off constantly / oscillating
- defective - Check the control
- Replace capacity regulator valve
Electromagnetic clutch
slipping
- see also p. 16 Malfunction of electro-
magnetic clutch - Checking
V belt drive, increased
noise generation
- Belts vibrating excessively
- Incorrect alignment of compressor and motor
- Check belt tension
Use tensioning roller / guidance roller
- Check alignment and adjust anew
- 15 -
96 8- 9- 3-DGbFEI

Malfunction of t e electromagnetic clutc
Clutch not switching
Symptom Possible cause Remedy
- No voltage applied - Apply voltage and check
Clutch slipping too
long, getting hot,
smoking and squeaking
- Voltage too low
- Driving power too high
- Rotor rubbing at the magnetic field
- Keep the voltage at 12 or 24
Volts (check vehicle network)
- Check operating conditions
- Check the seating of the magnet,
possibly to high belt tension
Clutch not separating - Voltage still being applied to the magnet
- Clutch is stuck
- Clutch overloaded,
Armature disc is deformed
- Check switch / relay
- Disconnect the armature disc
from the rotor mechanically
- Install new rotor and armature
disc
96 8- 9- 3-DGbFEI
- 16 -

Disassembly-Assembly of service kits
Safety remarks
Installation of service kits
In principle, the same safety remarks described on page 5 of this Service Manual are valid.
Furthermore the following should be taken into account:
Before starting any work on t e compressor:
Switch of the machine and guard it against switching on
Close the discharge and suction shut-off valves
Relieve the compressor from system pressure
Use only genuine Bock spare parts.
Connect the safety switch and check its function
Evacuate the compressor
Before commissioning, check whether all the components installed by the user have
been mounted expertly and connected pressure-tight to the compressor (e.g. piping,
plugs, union nuts, replaced components etc.)
Open the pressure and suction shut-off valves (see page 11)
Set off the switching-on lock
After t e work is finis ed:
For changing components in the framework of customary service works we recommend the kits
described on the following pages.
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96 8- 9- 3-DGbFEI

Leak oil collection ring (Part No. 8 19)
Remove the leak oil collection ring (see Fig. 1)
The repair kit contains two felt inlays (Pos. 2 and Pos. 3,
see Fig. 2)
If the bearing flange with one oil pocket is installed
Pos. 3 must be inserted (see Fig. 3)
If the bearing flange with six oil pocket is installed
Pos. 2 must be inserted (see Fig. 4)
If the wrong felt inlay, or both felt inlays, is inserted the
functioning of the oil collection system cannot be ensured.
Procedure: Leak oil collection ring
Fig. 3 Fig. 4
Open at bottom
1
2
1
3
Type code 001 Starting from type code 007
Fig. 1
Bearing flange with
one oil pocket
Bearing flange with
six oil pockets
Open at top
96 8- 9- 3-DGbFEI
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123
Fig. 2

S aft seal (Part No. 8 23)
Dismount the drive/magnetic clutch from the compressor.
Remove the Woodruff key from seat at the shaft end
Remove the leak oil collection ring (9) and the felt inlay (8a or 8b, according to the type)
(for this, see Fig. 1 on page 18)
Unscrew the screws (7) from the shaft seal cover (6).
Remove the gasket residues and the shaft seal cover gasket (5) from the bearing flange.
Removal:
Attention: T e s aft seal cover (6) is under spring tension. T e remaining oil may
run out of t e s aft seal c amber. Keep a suitable collection container ready!
Fig. 5
TOP
Installation:
Work with utmost cleanliness.
Always replace the shaft seals complete, never individual parts thereof.
Do not use used parts.
Prior to installation, check the sliding and sealing surfaces for cleanliness and damages.
Apply a thin film of oil on the sealing surfaces of the sliding ring (4), shaft seal
cover (6), O-ring (3) and the compressor shaft (use compressor oil).
Assemble the sliding ring (4), O-ring (3) and the guide ring (2) together as a unit.
The large chamfer on the sliding ring (4) should show in the direction of the shaft seal cover (6)
During the assembly the compression spring (1) must engage audibly in the drive slot of
the crankshaft and of the guide ring (2).
Install the shaft seal cover gasket (5) dry, dont impregnate it with oil.
Install the shaft seal cover (6) with the inscription TOP upwards. Tighten the fixing screws
(7) evenly, crosswise tightening torque = 37 Nm.
After installing the shaft seal, turn the compressor shaft a few turns by hand and
then carry out the leak test.
Install the leak oil collection ring (see section on leak oil collection ring, page 18).
Insert the Woodruff key into the seat at the compressor shaft end.
Mount the drive/clutch. - 19 -
96 8- 9- 3-DGbFEI

Capacity regulation
The capacity regulation takes place through the turning off of the suction gas flows by means of a
solenoid valve on the cylinder cover. For this, the valve is activated electrically by a thermostat or
pressostat.
During normal operation the solenoid is de-energized and the suction gas channel in the valve
plate and in the cylinder cover is open.
During regulated operation the solenoid is energized and the suction gas flow is closed through
the shut-off piston of the solenoid valve. The compressor pistons of the cylinder bank which
is regulated down run idle. The capacity of the compressor is still approx. 5 %.
Further information together the description of the working principle of the solenoid valve is contained
in the publication Capacity regulation (Part no. 99 )
Capacity regulation valve (Part No. 7541)
(Only for the capacity regulation which is an accessory)
Removal:
De-energize the solenoid (4)
Screw on the fixing nut (3), pull out the solenoid
(4) with the washer (5).
Unscrew the valve body (2).
Check the valve body (2) for damages and
whether the piston moves freely. If necessary,
replace the complete valve body (2).
Screw on the valve body (2) with the enclosed
new O-ring (1) and tighten it.
Push on the washer (5) and the solenoid (4)
and fasten them with the fixing nut (3)
Put the compressor into operation and check
the functioning of the capacity regulation.
Installation
7541
Fig. 6
96 8- 9- 3-DGbFEI
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