What is a Sprag Clutch | GMN Bearing USA

GMN Bearing USA’s ABEC 7 high precision ball bearings are made for high speed and heavy load applications.

GMN angular contact bearings (spindle bearings) are expertly crafted for speed, precision, & accuracy.

GMN radial ball bearings are versatile, great in small spaces & when axial loads move in both directions.

We know that not every application requires super, high-precision bearings. We stock other industrial parts from quality brands.

Our one-way sprag clutches are great for applications with low to high torque capacity.

Includes built-in ball bearing support. Supports HEAVY loads & has a high torque capacity: 53 to 588 Nm. Bore (ID) sizes: 10 to 60 mm (0.393 to 2.362 in)

Includes built-in ball bearing support. Supports MEDIUM loads & low to medium torque capacity: 53 to 267 Nm. Bore (ID) sizes: 17 to 40 mm (0.669 to 1.57 in)

No built-in ball bearing support. Good for large orders & low to high torque needs: 1 to 2673 Nm. Bore (ID) sizes: 2 to 240 mm (0.078 to 9.448 in)

No built-in ball bearing support. Has no RPM limits & Supports high torque needs: 609 to 14,060 Nm. Bore (ID) sizes: 38.09 to 220 mm (1.499 to 8.66 in)

This heavy-duty clutch (aka a hold-back clutch) is good for high torque operations and ensures motion freezes in place. Bore (ID) sizes: 15 to 40 mm. (0.59 to 1.73 in)

Designed for HEAVY-DUTY applications that require tough durability.

Our non-contact labyrinth seals are the first line of protection for bearing systems.

The best protection for your bearing. Easy to install with a simple “drop-in” next to your bearing. No added space needed. CF seals offer 100% sealing efficiency against splashing liquids.

Protection against low contamination & splashing liquids.

Designed with grooves in the outer ring to offer more protection (than our L-type seal) against contamination and direct spray liquids. Liquid gets pushed out through outer grooves when in rotation.

Our GMN Gap Seals are plastic and a great choice for washdown applications, such as food conveyors and food manufacturing facilities

Backstopping, Indexing, and Overrunning

A sprag clutch rotates in one direction and prevents rotation in the opposite direction.

There are three ways a sprag clutch helps support and control an applications movement:

Backstopping
Indexing
Overrunning

Backstopping Clutch

Diagram indicating clamping direction of a GMN sprag clutch. There are arrows pointing clockwise on the outer part of the clutch, and arrows pointing counter-clockwise on the inside of the clutch

A backstop clutch is commonly used for safety precautions.

If a machine malfunctions, the backstopping clutch is designed to hold the load it’s carrying. A good example is an industrial winch. When it’s lifting and moving a heavy object, it needs to hold that object until it’s ready to be lowered. A winch clutch is an important component located inside the winch that locks the motor shaft to the brake assembly preventing the spool from unwinding when the motor stops.

Our GMN FE 8000 sprag clutch is a great choice because it has no RPM limits and a high torque capacity. For heavy-duty applications, our RA series hold-back clutch is also a good choice.

fe-8000-150x150

Backstopping Clutch Application Examples:

Conveyors & Winches: Stop Loads
High Voltage Switching: Safety Device
Textile Machine: Material Feed Protection
Industrial Fan: Motor Protection

Indexing Clutch

Diagram indicating clamping direction of a GMN sprag clutch. There are arrows pointing counter-clockwise on the outer part of the clutch, and arrows pointing clockwise on the inside of the clutch

An indexing clutch pushes motion in a circular direction and then allows it to idle or stop.

A good example is a production line that moves to one position then stops, waits, and then moves one position over. This motion is controlled, deliberate, and guided by a one-way sprag clutch.

An indexing sprag clutch can also be an added safety precaution in case of a motor or electrical failure.

Indexing Clutch Application Examples:

Printer: Industrial
Copiers: Paper Feeding
Furniture Production: Glue Roller
Food Production: Bottling Plant
Sewing Machines: Material Feeder
Automatic Winch: Controlled Raising/Lowering

Overrunning Clutch

An overrunning clutch allows the rotating component to spin faster than the actual driving component that is producing the force. An indexing clutch allows idle spinning to keep going without the engagement of force, bicycle pedals are a good example of how an indexing clutch works.

Typically, an overrunning clutch engages and disengages when the driven RPM exceeds the driving component’s RPM.

Examples of an Overrunning Clutch:

Torque Converters
Conveyors: Speed Compensation
Mixers: Motor Protection
Motorcycles: Gear Box or Automatic Transmissions
Packaging Machine: Spins Down Freely
Printing Press: Ink Roller Drive

A Critical Component

A sprag clutch supports many different applications to help control movement the momentum. It’s a vital component of many machines and without it the application would not work correctly.

Our Sprag Clutch Product Line

Quality matters when choosing a sprag clutch. GMN has been manufacturing precision components, like a one-way sprag clutch, since 1908.

If you need a one-way sprag clutch, we have three main product lines that are good for backstopping, indexing, or overrunning:

Complete Sprag Clutch Units: Designed for big loads with a high torque requirement. Manufactured with both roller bearings and ball bearings. This is our most robust product line.
Ball Bearing Sprag Clutch Units: Good for most application requirements (sizes are matched to radial bearings). This is our most popular sprag clutch product line.
Sprag Clutch Elements: Made for mounting on shafts without needing to use adapters, lock-nuts or shoulders. Elements consist of a cage, a spring, and sprags.

We offer the highest quality of manufactured precision components and would love the opportunity to quote your next project.