PM-ERV-B/USA
Maintenance Instructions & Generic Parts List
ERV Series Actuator
5
Parker Hannifin Corporation
Actuator Division
Wadsworth, OH 44281
9. Only after marking the cam locations should you remove a roller assembly. If a roller needs to be
replaced or the preload needs to be adjusted, remove the wheel retainer screw in combination with
the appropriate sized hex wrench.
*** Note: Using a socket is the best way to get a firm grip on the roller cams (5). ***
10. If you are adjusting the preload skip to step 14, otherwise continue.
11. If you are replacing a roller you will need to remove the bearing retainer (2) from the inside of the
roller wheel (3). The fit between the two pieces is tightly controlled. They will probably fall apart
but they can be disassembled with finger pressure. Do not use a hammer etc.
12. Insert the bearing retainer into the roller wheel assembly.
13. Reinstall the wheel washer (4).
14. Apply a drop of removable anaerobic adhesive (thread locking agent – ex. Loctite®) to the internal
threads of the bearing retainer (2).
15. Pass the wheel retainer screw (6) through the appropriate style of roller cam (i.e. on-center or off-
center). At this time take special note that there are interlocking steps milled on both the cam and
the bearing retainer. The interlocking steps allow you to preload the carriage while the carriage is
on the body extrusion.
16. Assemble the cam through the carriage body itself and engage the thread of the wheel retainer
screw into the bearing retainer.
17. Finger tighten the wheel retainer screw while taking caution to make sure the two steps interlock.
18. If this particular cam is one with the screw in the center (i.e. for the load bearing wheels), tighten
the screw to the proper torque per the specification in the rear of this instruction. Otherwise wait to
tighten the screw if the following carriage preloading discussion.
19. Roll the carriage back onto the extruded cylinder body.
Adjusting the Carriage Preload
– Since this step is “Pre-loading” of a carriage assembly, we
will only be discussing the off center roller cams. The other cams should be properly torqued at this point.
20. Use the socket to rotate the hex/cam until the roller underneath the carriage comes into contact
with the body extrusion. This is identified by a slight increase to the amount of torque required to
turn the cam/socket. It is very beneficial at this point to turn the cam past the maximum preload
point so that you can feel the maximum and more importantly the minimum/contact point. This also
verifies that the wheel retainer screw is not tightening and you are preloading the carriage.
Note: Anymore than a minimal amount of preload puts unnecessary stress/load on the main carriage
bearings and roller tire material.
21. Turn the cam back to the point at which the wheel comes into contact with the body extrusion.
22. While holding the cam in a fixed position with the socket, tighten the wheel retainer screw (6) and
torque it to the specification in the rear of this instruction.
23. Be sure to adjust the wheels evenly on all three sides so that the carriage runs parallel with the
body.
Note: If several of the wheels have lost their preload it may be difficult to immediately find the contact point.
You may need to tighten a few of the questionable wheels and then adjust them one at a time.
Belt Tension
Tension the actuator drive belt (23) using either an inductive or laser based frequency meter. See the
manual for the specific meter you have chosen for specific setup and use instructions.
1. After installation of the belt into the actuator body and the belt clamps (11), tighten the belt by hand
using the belt clamp bolts (12).
2. Space the carriage assembly, that is attached to the belt by way of the shuttle, away from one of
the endcaps by a distance “L” (see below chart). “L” should be measured from the centerline of the
drive endcap to the attachment point of the belt to the shuttle (belt clamp bolts). Use the largest
measurement possible from the chart below for tensioning (i.e. an actuator with an 850mm stroke
would use the 500mm measurement).
