Clutches for Gearboxes

Speed Reducers

Quite often, OEMs need to either increase or decrease the speed of their application. Several factors come into play when determining these needs. Examples are the speed requirements of the driven component or a change in gear ratio to achieve a desired torque. When these types of requirements arise, companies turn to gearbox manufacturers for help transmitting power from a driving source.

During the development of the gearbox, the OEM will request, or the application requires, incorporating an integrated clutching device. Because very few gearbox companies manufacture their own clutches, an outside clutch source is often sought out.  It is at this point that the gearbox manufacturer reaches out to WPT for assistance.

Gearbox Actuation Choices

WPT offers a full lineup of clutch packs to accommodate any type of application or engagement method. The mechanical style clutch pack mounts onto the gearbox shaft and uses an over-center engagement collar. The operator engages and disengages the lever-actuated clutch, very similar to operating a mechanical PTO.

Other types of engagement include pneumatic and hydraulic. While the actuation mediums differ for these two methods, the delivery systems are the same. The first is air or hydraulic fluid introduced through the end of a rifled shaft connected with a rotary coupling. As the air or fluid pressurizes the piston or air tube, it constricts the clutch plates and engages the shaft. This type of delivery system is known as “Through-the-Shaft” engagement.

The second form of delivery that can be utilized in a system is known as “Over-the-Shaft” engagement. In this system, air or hydraulic fluid is introduced through a port in the gearbox housing. The port is directly plumbed to a tube that feeds a thrust bearing engagement collar.  When pressurized, it constricts the clutch plates and in turn, engages the shaft. Both the hydraulic and pneumatic clutch packs are self-adjusting.

Experience Is Your Advantage

WPT is providing integrated clutch packs to gearbox manufacturers and has been for nearly thirty years. Our ability to meet the needs of OEMs is unmatched. That’s because our team brings a combined 100 years of experience to the clutched gearbox market.

Are you a sizable gearbox manufacturer producing quantities to fulfill OEM’s high volumes? How about a smaller shop building custom boxes with the occasional demand for a clutch? WPT can work with you to determine the best clutch and engagement type.

Give us a call today for a comprehensive application review. We can be reached at (940) 761-1971, or by email at We look forward to hearing from you soon!