|
|
For
rack & pinion applications requiring ultra-precise positioning and
repeatability, the system backlash can be eliminated by using two
pinions - one to drive the axis and one to "preload" the axis to remove
the backlash. We have two different solutions to achieve a
zero-backlash drive system:
SPLIT-PINIONS:
The
simplest zero-backlash drive system utilizes a
split-pinion, which consists of two pinion halves and an
axial spring pack. The pinions halves mesh with opposite tooth flanks on
the same rack, eliminating the backlash.
The
split-pinion shafts mount directly into our
High-Torque (HT) &
High-Performance (HP)
Servo-Worm Reducers.
DUAL-PINION
ELECTRICAL PRELOAD:
 Another
method to remove the backlash at the rack & pinion is to use two
motor/reducer assemblies with dual pinions - one to drive the axis and
one to "preload" to remove the backlash. The preload is created
electronically with a special motor controller; these systems can also
be set up to drive together when backlash is not critical.
Our
Automatic Lubrication
Systems are highly recommended for use with these drives,
providing continuous grease lubrication to the rack & pinion tooth
flanks to preserve the quality and lifetime of the gearing.
These drives
are perfect for
precise positioning
applications, such as traveling
gantries and columns, milling machines, CNC routers and material feel axis drives.
Two reducers/motors can also be used to eliminate the axis backlash by
electrical preload.
Split-Pinions |
Electrical Preload |
Systems Overview |
Lubrication |
Application Sheet
The system
precision, including the pitch error and backlash, can be found below:
|
System Precision Level: |
Rack Type: |
Rack Quality Level: |
Rack Pitch Error: |
Rack & Pinion Minimum Backlash:
* |
|
Ultra-High |
Hardened & Ground |
DIN 4 to 6
(~AGMA 12+) |
< 0.012 to 0.048 mm
per meter |
Zero |
* The rack and pinion
backlash depends on the alignment of the rack to the linear guides.
There are
three levels of precision for the hardened & ground racks, with rack
pitch error ranging from 0.012 mm to 0.048 mm per meter length depending
on which rack is used. Follow this link for more information on
our
Precision Racks.
|
Split-Pinion Rack & Pinion Drive Systems: |
The
simplest zero-backlash drive system utilizes a
split-pinion, which consists of two pinion halves and an
axial spring pack. The pinions halves mesh with opposite tooth flanks on
the same rack, eliminating the backlash. The axial spring pack is
used to preload the rack & pinions to insure that no backlash develops
during the operating cycle.
The
split-pinion shafts mount directly into our
Servo
Reducers and are fixed in place by means of a compression coupling. This provides
rigid support and tight integration of the split-pinion shaft into the
reducer. The end result is a compact and ultra-precise positioning
axis drive. These reducers have backlash levels down to one
arc-minute and ratios from 4.75:1 to 52:1 (higher ratios available with
planetary-worm reducers).
The maximum drive force that each system
can handle (with safety factor 1.0) is listed below; this should be
compared to the application peak force, which can be
calculated here,
or by filling out our
Application Sheet.
Please click on values for PDF
specifications:
|
Reducer Size: |
Rack Module: |
Split-Pinion: |
Split-Pinion
# of Teeth: |
Maximum Drive Force: * |
Maximum Linear Speed : |
|
HP Size 3 |
2 |
74.92.330 |
30 |
424 lb. |
8,288 in/min |
|
3 |
74.93.320 |
20 |
424 lb. |
8,288 in/min |
|
HT Size 3 |
2 |
74.92.430 |
30 |
636 lb. |
8,288 in/min |
|
3 |
74.93.420 |
20 |
636 lb. |
8,288 in/min |
|
HP Size 4 |
2 |
74.92.430 |
30 |
636 lb. |
6,631 in/min |
|
3 |
74.93.420 |
20 |
953 lb. |
6,631 in/min |
|
HT Size 4 |
3 |
74.93.520 |
20 |
1,180 lb. |
6,631 in/min |
|
4 |
74.94.515 |
15 |
1,427 lb. |
6,631 in/min |
|
HP Size 5 |
3 |
74.93.520 |
20 |
1,180 lb. |
4,973 in/min |
|
4 |
74.94.515 |
15 |
1,815 lb. |
4,973 in/min |
|
HT Size 5 |
5 |
74.95.615 |
15 |
2,373 lb. |
6,216 in/min |
|
6 |
74.96.613 |
13 |
2,282 lb. |
6,465 in/min |
|
8 |
74.98.612 |
12 |
1,854 lb. |
7,957 in/min |
|
HP Size 6 |
5 |
74.95.615 |
15 |
2,248 lb. |
6,216 in/min |
|
6 |
74.96.613 |
13 |
2,248 lb. |
6,465 in/min |
|
8 |
74.98.612 |
12 |
2,248 lb. |
7,957 in/min |
|
HT Size 6 |
6 |
74.96.713 |
13 |
3,531 lb. |
6,465 in/min |
|
8 |
74.98.712 |
12 |
3,840 lb. |
7,957 in/min |
|
HP Size 7 |
6 |
74.96.713 |
13 |
3,531 lb. |
4,246 in/min |
|
8 |
74.98.712 |
12 |
4,635 lb. |
5,226 in/min |
* Force ratings do not
include any safety factors. Higher forces are possible depending
on gearbox ratio selected.
|
Electrical Preload Rack & Pinion Drive Systems: |
Another
method to remove the backlash at the rack & pinion is to use two
motor/reducer/pinion assemblies - one to drive the axis and one to
"preload" to remove the backlash. The preload is created
electronically with a special motor controller; these systems can also
be set up to drive together when backlash is not critical.
Our new
"Torque Supporter"
Drives, which can handle highly dynamic and heavy loads,
are perfect for these applications. These reducers have backlash
levels down to one arc-minute and ratios from 4:1 to 100:1.
The maximum drive force that each system
can handle (with safety factor 1.0) is listed below; this should be
compared to the application peak force, which can be
calculated here,
or by filling out our
Application Sheet.
Please click on the table values for PDF
specifications:
|
Reducer Size: |
Rack & Pinion Module: |
# of Pinion Teeth: |
Maximum Drive Force: * |
Maximum Linear Speed with 3,000 rpm
Motor: |
|
7 |
2 |
23 |
3,270 lb. |
4,528 in/min |
|
2 |
29 |
3,251 lb. |
5,709 in/min |
|
3 |
17 |
5,608 lb. |
5,020 in/min |
|
8 |
3 |
26 |
6,139 lb. |
7.677 in/min |
|
3 |
32 |
6,136 lb. |
9,449 in/min |
|
4 |
20 |
8,475 lb. |
7,874 in/min |
|
5 |
16 |
8,475 lb. |
7,874 in/min |
|
9 |
5 |
20 |
11,442 lb. |
3,281 in/min |
|
6 |
16 |
12,801 lb. |
3,150 in/min |
|
6 |
20 |
15,891 lb. |
3,937 in/min |
|
10 |
8 |
Please consult the
factory! |
|
10 |
|
12 |
* Force ratings do not
include any safety factors. Higher forces are possible depending
on gearbox ratio selected.
|
Other Products Available: |
High-Precision Hardened
& Ground Rack & Pinion Drive Systems,
utilizing our our precision Planetary and Servo-Worm Reducers, which have backlash
levels down to one arc-minute, to rigidly support and drive a hardened & ground
pinion. The rack used in these systems are our Hardened & Ground
Racks.
"Torque
Supporter" Precision Rack & Pinion Drive Systems
that can handle highly dynamic and heavy loads. These
systems utilize our Precision Planetary Reducers with an
integral output housing and outboard bearing to provide a rigid support to
the output pinion.
|
ATLANTA
