| Quality and Autogard are
synonymous with overload protection. The companys reputation for high
quality products is derived from over 35 years of design innovation and
production. Autogard products are manufactured to meet ISO 9001 using
the latest machine tools and high quality materials.
The Series 400 has been designed to meet the emerging need for a high
and low speed, free wheeling Torque Limiter. The Series 400 differs from
previous ball detent designs by using two sets of balls on concentric
pitch circles.
In the normal drive condition, torque is transmitted through the drive
balls A. The inner strut balls B are designed to carry no
load during this time.
Disengagement on overload
When an overload condition occurs, the drive balls roll out of their
seats forcing the slide plate C and drive plate D apart. The
cage plate E, strut balls and drive balls all rotate until the
cage plate hits a stop located in the slide plate. At this point the
spring pressure has been transferred from the drive balls to the strut
balls. The strut balls prevent the drive balls from re-engaging the
drive plate. The coupling or driven media attached to adapter G is
now completely free to rotate. Although the Series 400 has been designed
to run freely after disengagement, it is recommended that a shut-down
switch is incorporated to avoid wear.
Re-engagement
Re-engagement occurs when either the driving side is reversed, or the
driven side is advanced. Pawl F engages the cage plate E and
rotates it until the drive balls are re-seated. Resetting must be done
at low speed to permit the engaging mechanism to function properly in
either direction and to prevent potential damage.
The resetting can be done manually or automatically by slowly inching
the motor in reverse.
The Series 400 comes standard as a Rapid Reset (RR) style Torque
Limiter. This gives the following maximum angles of rotation to
re-engage:
|
Size
|
Max rotation to re-set
|
|
1
|
60°
|
|
2
|
67.5°
|
|
3
|
30°
|
|
4
|
30°
|
|
5
|
30°
|
|
6
|
25.7°
|
|
Synchronous Reset (SR) designs are also available and must be
specified at the time of ordering. These reset in a constant angular
position.
|
|
| Multiple coil springs provide
improved adjustment |
|
Multiple coil springs provide
improved serviceability |
| Features and Benefits |
| |
Proven design with thousands of
units successfully in operation. |
| |
Accurate torque limitation
prevents costly down time. |
| |
Standard designs can accommodate
large torque ranges. |
| |
Instantaneous disengagement
protects equipment from damaging inertias. |
| |
Bi-direction protection. |
| |
Series 400 is designed to operate
at High or Low speeds. |
| |
Automatic or manual re-engagement
by reversing the unit. |
| |
Series 400 is offered in a large
number of styles ensuring
the right solution is available for all applications.
e.g. |
| - Timing, HTD & V-Belt drives |
| - Chain and sprocket drives |
| - Gear drives |
| - Flexible or rigid couplings |
| - Flywheel or large gear mounts etc. |
|
| |
Springs can be inspected and
changed without removing the clutch from the drive train. |
| Selection |
| Data required for torque
limiter selection. |
| |
Kilowatt or Horsepower and
rpm of the driver. |
| |
Shaft details of the driving and
driven equipment. |
| (1) Calculate the nominal torque: |
| Torque (Nm) = Kilowatt (Kw) x 9550 /
rpm or |
| Torque (lbf-ins) = Horsepower (HP) x
63025 / rpm |
| Consideration should then be given to
start torque or other special circumstances depending on
the position chosen in the drive system. Choose a set
torque with a suitable margin over nominal. Select the
torque limiter which has a higher torque rating. |
| (2) |
Check limiting conditions: |
| (a) |
Check hub bore capacity |
| (b) |
Check the torque limiter dimensions
such as the overall length and outside diameter. |
| (3) |
Select and specify the appropriate
drive medium or coupling. |
| All Autogard Series 400 units may be
supplied from the factory at a pre-set torque and with
the required drive medium assembled to the unit. |
|
__________________________________________________
| Ordering
the 400 Series Torque Limiter |
|
When
ordering please provide the following designation:
Model & Type / Size / Feature / S1 Bore / S2 Bore
Feature:
RR Rapid Reset (standard)
SR Synchronous Reset (optional)
S1 Bore & S2 Bore Please specify metric or
imperial.
Standard bore tolerance = H8 + normal Fit key
Example:
402 / 3 / SR / S1 40 mm
Refers to a type 402 size 3 torque limiter designed for
synchronous reset.
Bore S1 = 40 mm.
Also specify
Torque setting or torque range required
Pulley or sprocket details where required
|
Back To Autogard
Index
Back
To Supplier Listings
|
