SKF SRSA User manual

Installation, operation and maintenance manual
Electric cylinders
SRSA, SVSA and SLSA



 Introduction – general safety instructions . . . . . . . . . . . . . . . 
. Structure of safety instructions . . . . . . . . . . . . . . . . . . . . . . . 
. Manual use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. General safety instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Exclusion of liability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Future changes to user manual . . . . . . . . . . . . . . . . . . . . . . . 
 General notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. General description of system components. . . . . . . . . . . . . . 
. Operating principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Detailed description of supplied product . . . . . . . . . . . . . . . . 
. Designation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Nameplate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Performances, operation limits and operation environment 
. Storage conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 Installation – general recommendations . . . . . . . . . . . . . . . . 
. Important notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Mechanical installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
.. Cylinder dimensions – Cylinder drawing . . . . . . . . . . . . . 
.. Visual cylinder position – Lt and Ltdefinition . . . . . . . . . 
.. Handling – Transportation . . . . . . . . . . . . . . . . . . . . . . . 
.. General recommendations for installation . . . . . . . . . . . 
. Electrical installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
.. Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
.. Cables for motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
.. Limit switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
... Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
... Mounting instructions of limit switch for “retracted pos.” 
... Mounting instructions of limit switch for “extended pos.” 
.. Home switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
... Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
... Mounting instructions of home switch. . . . . . . . . . . . . 
.. Temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
.. Cables for sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
.. Additional brake mounted on screw . . . . . . . . . . . . . . . . 
.. Automatic lubrication pump . . . . . . . . . . . . . . . . . . . . . . 
.. Servoamplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Contents


 Commissioning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. General procedure for commissioning . . . . . . . . . . . . . . . . . . 
. General recommendations for use. . . . . . . . . . . . . . . . . . . . . 
. How to define zero reference . . . . . . . . . . . . . . . . . . . . . . . . . 
. How to check position control behaviour – first approach . . . 
. Position control parameters – to be known . . . . . . . . . . . . . . 
 Maintenance, upkeep and routine checks. . . . . . . . . . . . . . . 
. SKF maintenance service . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Lubrication – detailed description . . . . . . . . . . . . . . . . . . . . . 
.. Roller screw (or ball screw) . . . . . . . . . . . . . . . . . . . . . . . 
.. Bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
.. Profile rail guides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
.. Spherical plain bearing . . . . . . . . . . . . . . . . . . . . . . . . . . 
.. Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Routine checks – detailed description . . . . . . . . . . . . . . . . . . 
.. Additional brake mounted on screw . . . . . . . . . . . . . . . . 
.. Belt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
 Malfunctions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Mechanical malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Electrical malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
. Before requiring SKF assistance . . . . . . . . . . . . . . . . . . . . . . 


 Introduction –
general safety instructions
. Structure of safety instructions
To best warn the user, depending on the nature of the danger, safety
instructions will be written as follows.
. Introduction – general safety instructions
Note
Points to note, tips, advice or
information for efficient operation with-
out any problem.
!
CAUTION
Indicates a potentially hazardous situation.
If precautionary measures aren’t taken,
it could result in minor or moderate injury.
WARNING
Indicates a potentially hazardous situation.
If precautionary measures aren’t taken,
it could result in death, serious injury or
property damage.
DANGER
Indicates an imminently hazardous situation.
If precautionary measures aren’t taken,
it could result in death, serious injury or
property damage.
. Manual use
This manual gives information and advice for the commissioning and
maintenance of SKF modular cylinders from the SRSA, SLSA, SVSA
range of products that will minimize the risk of injury and property
damage.
This document is intended for all persons who are involved with
the installation, commissioning or maintenance of these products.
Note
In the electronic document,
hypertext links have been created to
allow faster browsing inside the manual.
To use these, please press CTRL key and
while CTRL key is pressed, click on the
hypertext link. To come back, please
press ALT key and while ALT key is
pressed, press on “left arrow” key.
Generally, all titles from table of
contents are hypertext links. All other
hypertext links are pointed out in blue.
!


. General safety instructions
. Introduction – general safety instructions
DANGER
In operation, SKF cylinders could make parts move and could have hot
surfaces or parts fed by electrical current,depending on the situation.
Serious or fatal injuries or property damage will occur if the information
or precautionary measures given in this manual aren’t followed.
Generally, all works related to transportation, setup/mounting
(mechanical and electrical), startup, maintenance or storage have to be
carried out by qualified personnel in full compliance with relevant
regulations.
. Exclusion of liability
SKF does not assume liability for injury to persons or damage to
equipment or property resulting from non-observance of these
operating instructions. In such cases, any liability is excluded.
. Future changes to user manual
To constantly improve the quality of its products, SKF reserves the
right to modify this manual without informing its customers. It is the
responsibility of the customer to have the current release of the
manual so that the user will benefit from the latest information and
advice. For more details, please contact your SKF sales representative.
In any event, SKF won’t be liable for any adverse consequences to
the SKF product user or any property because of user manual
modification.


 General notes
. General description of system
components
Generally, the scope of supply of SKF cylinders includes:
• Cylinder
• Motor power cable
• Motor sensor cable
• Motion controller
• Electronic interface to make connection between PC and motion
controller.
To know the exact definition of SKF supply, please read paragraph
. Detailed description of supplied product
. General notes


The general drawing below illustrates the SKF electromechanical
cylinder’s relationship with the user’s environment:
. General notes
Customer PC
Customer main controller /PLC
Customer electrical cabinet
SKF
motion
controller
Sensors (limit switches, home switch)
Motor power cable.
Motor sensor cable.
Possible communications with external environment
– if necessary – : analog/digital inputs/outputs, fieldbus.
Connection with PC (temporarily necessary for setting up)
F3
F2
F5
F4
F1
7
STU
4
JKL
ESC
+/-
«
1
ABC
8
VWX
5
MNO
←
0
π
2
DEF
9
YZ
6
PQR
RET
–

3
GHI
MEMFIX
ESC RET
F3
z
F2
z
F1
z
F4
z
F5
z
3 x 400 V AC
1 x 24 V DC
3
4
2
1


. Operating principle
. General notes
The operating principle of SKF electromechanical cylinders
Comments
Motor rotor
ωaRotating speed of motor shaft
ωbRotating speed of roller screw or ball screw
Gear system between motor shaft and roller screw
(or ball screw) shaft. ris gear ratio.
ωa
r = –––
ωb
Roller screw or ball screw = screw gear changing
rotation of screw (green color) into translation of
nut and pushing tube of cylinder (red color).
Pushing tube of cylinder
Sc Translation speed of pushing tube
xTranslation move of pushing tube
Anti-rotation of pushing tube. Depending on cylin-
der definition, this system is integrated into the
cylinder or located on the customer’s machine.
Description of kinematic joints
JRevolute joint
JScrew joint
JPrismatic joint
J
J
J
The operating principle of SKF electromechanical cylinders is described
by the cinematic drawing below (established in accordance with
NF EN ISO - standard).
J1
J1J2
J3
wa
wb
Sc
x
1
2
3
4
5
Anti-rotation system


Relationships to be known
For each motor revolution cylinder moves x millimetres, x defined as
follows:
ph
x= –––
r
xCylinder move
phRoller or ball screw lead
Depending on case, rdefinition can change:
• Cylinder with motor in line without gear
r= 
• Cylinder with motor in line and gear
r= rgwith rggear ratio
• Cylinder with motor in parallel without gear
r= rbwith rbbelt system ratio
• Cylinder with motor in parallel and gear
r= rb · rg
. Detailed description of supplied product
Generally, a detailed description of the supplied product is given by
the two following documents (called “documents for approval”):
• Technical description
• Cylinder drawing
IMPORTANT: Before starting cylinder commissioning, these two
documents must be read. If there is a problem, please make contact
with your local SKF representative.
. General notes


. General notes
. Designation
Two designations:
• Designation for linear unit (=actuator without motor).
Example: SRSA-U---TRAF-N
• Designation for complete actuator (=actuator with motor and servoamplifier).
Example: SRSA-U---TRAF-LLABYA
The meaning of linear unit designation is:
SRS A - U -     -     - T R A F - N
Type
RPlanetary roller screw
VRecirculating roller screw
LLong lead ball screw
Linear unit only
Screw diameter
Screw lead
Stroke
Rear attachment
T Trunnions
Z Special
NNo attachment
Front attachment
RRod end
FRod end with fork
ZNon standard
NNo attachment (female thread)
Anti-rotation
A Anti-rotation
NNo anti-rotation
Limit switches
F limit switches and  home switch
S limit switches only
M limit switch and  home switch
L limit switch only
H home switch only
NNo switch
Motor interface
NNo interface
LInline interface (on request)
PParallel interface (on request)
The meaning of complete actuator designation on the next page.


. General notes
SRS A - S -     -     - T R A F - L    L A   B Y A 
Type
RPlanetary roller screw
VRecirculating roller screw
LLong lead ball screw
Servomotor
Screw diameter
Screw lead
Stroke
Rear attachment
T Trunnions
Z Special
NNo attachment
Front attachment
RRod end
FRod end with fork
ZNon standard
NNo attachment (female thread)
Anti-rotation
A Anti-rotation
NNo anti-rotation
Limit switches
F limit switches and  home switch
S limit switches only
M limit switch and  home switch
L limit switch only
H home switch only
NNo switch
Interface and gear ratio
If required, see SKF catalogue PUB  for more details
Motor
If required, see SKF catalogue PUB  for more details
Feedback
 Resolver
Absolute encoder Hiperface
Absolute encoder Endat
EM brake
BBrake  V DC
NNo brake
Motor drive
YDrive included
NNo drive
Drive fieldbus
A CanOpen
B DeviceNet
C EtherCAT
D Ethernet
EPowerlink MN/CN
FPowerlink CN
G Profibus
H Profinet
NNo fieldbus
Power and signal cables
 m
 m
 m
 m
NNo cable


. Nameplate
. General notes
Type: Cylinder reference
MM: Manufacturing month (month/year)
Serial no: Cylinder serial number
Weight: Cylinder weight
Weight including
motor and gear:
Cylinder weight when supplied with motor and possibly with gear
. Performances, operation limits
and operation environment
For more details, please read the SKF sales offer and other docu-
ments for approval. The cylinder’s performance and operational
limits and operating environment are described in the technical
requirements that define the cylinder selection.
Transrol – Ball and Roller screw
Electro-mechanical cylinder
Type: MM:
Serial no: Weight [kg]:
Weight including motor and gear [kg]:


. Storage conditions
If the cylinder has to be stored for a long time (example: cylinder as
a spare part), the following conditions must be observed:
• Cylinder has to be stored in horizontal position indoors with an
ambient temperature between  and  °C.
• Cylinder has to be packed in the retracted position inside a plastic
film with desiccant to protect the cylinder from humidity and
condensation.
A cylinder that has been stored under the conditions described above
for less than one year could be used by following the general recom-
mendations for use (see paragraph . General recommendations
for use).
If storage time exceeds one year, re-lubricate the cylinder before it is
first started (please read paragraph  Maintenance – upkeep – routine
checks, to know which parts are to be lubricated and how they are to
be lubricated).
Then, cylinder can be used by following general recommendations
for use (see paragraph . General recommendations for use).
After three years of storage, we recommend that the cylinder is
returned to SKF and a level one maintenance service be performed
(see paragraph . SKF Maintenance service).
. Disposal
Dispose of cylinders in accordance with applicable regulations and
considering the different requirements for each material:
• Iron
• Aluminium
• Copper
• Plastic
• Electronic components
• Oil and grease (not mixed with solvents)
To know the exact definition of SKF supply, please read paragraph
. Detailed description of supplied product
. Warranty
IMPORTANT: Manufacturer’s warranty is null and void if the cylinder is
disassembled by end-user.
For any other information concerning warranty, please contact
your local SKF representative.
. General notes
Note
If an automatic lubrication system
is installed, it is possible to unplug it
temporarily so that re-lubrication can
be done with a manual grease pump as
explained on this page.
!


. Installation – general recommendations
 Installation –
general recommendations
. Important notes
WARNING
During operation, the cylinder surface temperature can reach high
values. There is a risk of burns or fire. Before any work on the actuator,
let it cool down.
DANGER
Some components integrated into the SKF scope of supply are “products
bought on catalogue”. This means that the design and manufacturing of
these components haven’t been done by SKF.
For all these “products bought on catalogue”, it’s the user’s responsi-
bility to read the associated manufacturer’s user manual before starting
to install or to use the product.
WARNING
Risk of serious or fatal injuries by crushing because of vertical load fall.
Do not use the brake (of the motor or an additional brake) to hold a
vertical load while an operator is under the load. Generally, the holding
torque of the brake is created by means of friction discs and does not
provide a positive lock. In any event, lock the vertical load in position by
another means or move and stop the vertical load at the bottom position
which is safe.
WARNING
Risk of serious or fatal injuries by crushing because of unintentional
cylinder start-up.
Before starting any work on actuator, isolate the motor, brake and
fan (if installed) from the power supply and safeguard them using
lockout/tagout procedures against unintentional re-start.


. Installation – general recommendations
. Mechanical installation
.. Cylinder dimensions – Cylinder drawing
To know the cylinder dimensions and the definition of its attach-
ments, please look at cylinder drawing. The definition of drawing
cylinder is given in paragraph . Detailed description of supplied
product.
.. Visual cylinder position – Lt and Ltdefinition
During mechanical installation or cylinder operation, it is sometimes
required to know the cylinder position in relation to the “zero” posi-
tion given in the cylinder drawing.
To do this, it’s first required to know Lt (=length of pushing tube
which is visible when cylinder is in the “zero” position on the cylinder
drawing – please have a look at the cylinder drawing) – as examples,
see below some drawings illustrating Lt definition.
Lt0


. Installation – general recommendations
Then, it’s required to measure Lt: equivalent dimension of Lt when
cylinder is in any position.
Then, cylinder position in relation to the “zero” position given in the
cylinder drawing is equal to Lt-Lt.
Lt0
Lt


. Installation – general recommendations
.. Handling – Transportation
Observe relevant transport regulations during transportation.
When the shipment is received, immediately check that no dam-
age has been done during transportation. If not, immediately inform
the shipping company and SKF. If the shipment has been damaged,
do not commission it.
Use suitable load suspension devices for transport and assembly.
Weights of cylinder and any gear and motor are indicated on
corresponding nameplates. If not, please read the technical docu-
mentation of the corresponding manufacturer.
In case of a problem, please contact your local SKF representative.
.. General recommendations for installation
 When mounting the cylinder, check that all parts to which it is fixed
are correctly aligned. This should be done throughout the complete
stroke. NOTE: Poor alignment will reduce the life of the cylinder.
 Radial load or bending torque must not be applied to the cylinder
pushing tube. Otherwise cylinder lifetime might be drastically
reduced.
 Avoid shocks on the pushing tube. Do not hit it with a hammer.
 Check that cylinder can move freely and there is no obstruction
over the full stroke.
 Do not modify any part of cylinder
 Do not add any part/component on cylinder
. Electrical installation
.. Motor
Generally, please read the technical documentation from the motor
manufacturer to know how to properly install the motor. The details
concerning the motor can be found on its nameplate.
If the motor manufacturer doesn’t supply paper documentation or
documentation CD-ROM, it means that a user manual can be down-
loaded from the manufacturer’s web site.
In case of a problem and if motor has been sold by SKF, please
contact your local SKF representative. Otherwise, please contact
motor supplier.
Note
During actuator handling, please
take care not to damage the limit
switches and home switch (if these
options have been taken).
!
Note
If actuator has no anti-rotation on
the force tube, it is possible to extend or
retract by turning force tube by hand.
!
DANGER
During and after operation, some parts of the
cylinder carry dangerous voltages. Electric
shock hazard. Risk of serious or fatal injuries.
Strictly observe the safety instructions in
this manual and the safety instructions of
manuals associated with each commissioned
equipment (motor, servoamplifier, etc).
Do not unplug motor connectors before
switching off the power supply of the corre-
sponding servoamplifier. First unplug the
signal connector and then the power
connector.
Motor rotation can create voltage. Do not
touch connector pins.


. Installation – general recommendations
.. Cables for motor
If motor cables are included in SKF supply, please read the motor
technical documentation or servoamplifier technical documentation
to find the technical description and connection drawing of supplied
cables. Cable reference is written on the cable itself or on its
packaging.
In case of a problem, please contact your SKF local representative.
.. Limit switches
... Description
If this option has been taken, the following information will be
necessary for connecting the limit switches correctly:
Manufacturer: IFM Electronic (or equivalent)
Manufacturer reference: IFC (or equivalent)
Sensor type: Inductive
Technology: DC PNP
Output: Normally closed
Supply voltage (V DC): 
Consumption (mA): < (with  V DC)
Max. current output (mA): 
Connection: Mx plug
WARNING
All technical data given here have been
extracted from manufacturer’s catalogue
when this manual was edited. They are given
for information only.
If limit switch manufacturer changes this
data, SKF is not responsible for any problem
arising from such changes. Please check
with limit switch manufacturer just before
installing limit switch.
Please have a look at the servoamplifier manufacturer’s technical
documentation to know what digital input can be used for connecting
limit switches.
1
L+
L–
2
3
1
43
2


. Installation – general recommendations
... Mounting instructions of limit switch for
“retracted position”
If the limit switch for “retracted position” has been removed,
please follow these instructions to mount it again correctly:
 Move cylinder so that Lt= Lt (±, mm).
NOTE: To know the definition of Ltand Lt, please look at
paragraph .. Visual cylinder position – Lt and Ltdefinition.
 Screw in the limit switch with care by hand into the dedicated
threaded hole until it touches the roller screw nut (see cross-
section view above). Then, unscrew the limit switch to create a gap
between it and the rollerscrew nut. Stop unscrewing just before
the limit switch stops detecting.
 Fix the limit switch in this position by tightening the counter-nut
(tightening torque:  Nm).
 In this position, check that the limit switch detects the roller screw
nut.
 Move the cylinder so that Lt= Lt +  mm (±, mm). In this posi-
tion, please check that nothing is detected by the limit switch.
Limit switch for “retracted position”
Roller screw nut
(back side)
It’s this surface that’s detected by the limit switch.
In that view and in this position, Ltequals to Lt.
