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What is a Roller Ramp Clutch?

Roller Ramp clutches are mainly used in heavy duty applications that require durability.

A Roller Ramp Clutch has four main components:

  1. The outer ring
  2. The clamping rollers
  3. The star-like clamping ramps (incorporated into the inner ring)
  4. Spring loading for each individual roller (located within the inner ring)

Roller Ramp Clutches are designed and built to be robust and handle the heavy-duty clutch work. The quick on and off action works perfectly in the harshest environments with extreme torque requirements. In the most demanding of applications, Roller Ramp Clutches gladly step up to the plate.

This is a sprag point, not a roller ramp point.

GMN Roller Ramp Series Overview

The VS, VSNU, and VF Roller Ramp Series

Our VS, VSNU, and VF series must be used inside housings because they aren’t self-supporting and require outside bearing support to ensure operational alignment of the inner and outer ring. When using these series, take extra precautions to avoid axial misalignment and thrust loads.

Contact our on-site mechanical engineers for additional information.

VS Series

VS Series

Use our VS series roller ramp clutch with our radial ball bearing 6200 series. This clutch fits shafts 8-80 mm and is rust protected.

VS Series

VSNU Series

VSNU Series

Use this series with a ball bearing 6300 series. The VSNU series roller ramp clutch fits shafts 8-80 mm and is rust protected.

VSNU Series

VF Series

VF Series

Use the VF series with ball bearing 6400 series. This roller ramp clutch fits shafts 8-60 mm and is rust protected.

VF Series

The VGF, VGV, VGL(P) and VEK Roller Ramp Series

The VGF series has integrated bearing support. Sleeve bushings are used for VGF 8 to VGF 20 products and VGF 25 to VGF 60 uses ball bearing support. This means external bearing support won’t be needed in most applications.

The VGV series has a torque arm (lever arm) which is good for indexing and backstopping applications. Sleeve bushings support this series, and these clutches are double sealed by the sleeve bushings.

The VGL & VGLP series don’t require an external housing and can be bolted straight to a wall (or other stabilizing structure) with the shaft mounted and held in place with the inner ring keyway of the roller ramp clutch.

Our VEK series is capable of multiple revolutions. When the pawl hits stop, the rollers are disengaged separating the driving parts. When the pawl is released again, driving members are connected instantly.

VGF Series

VGF Series

Our VGF series has bearing support. It fits shafts 8-60 mm and is rust protected.

VGF Series

VGV Series

VGV Series

The VGF series is supported with sleeve bushings. This roller ramp clutch fits shafts 20-80 mm and is grease packed for lifetime.

VGV Series

VGL(P) Series

VGL(P) Series

The VGL(P) series is a basic clutch, mostly used outside housings, like sprockets. This roller ramp clutch fits shafts 12-80 mm and is rust protected.

VGL(P) Series

VEK Series

VEK Series

Our VEK series roller ramp clutch fits shafts 10-50 mm and is rust protected. This series provides perfect performance with 100% repeatability.

VEK Series

Part Number Inner Diameterd [mm]Outer DiameterD [mm]Nominal TorqueT [N⋅m]Nominal TorqueT [ft⋅lb]  

Design Technology of the Roller Ramp Clutch

Indexing

Indexing can best be defined as the transformation of forward and backward movement into rotational irregular motion, like in material feeding.

When indexing roller ramp clutches, design the outer ring to be the driving component, oscillating back and forth, with intermittent rotation of the inner ring. This will boost the effectiveness of indexing.

If the roller ramp clutches are mounted side-by-side with overlapping actuation, a continuous motion is made.

For very high indexing requirements, increased spring force can be applied. Improved efficiency can be achieved by adding a second backstopping clutch and using light weight oils.

Make sure to find the best ratio of nominal torque to applied torque and account for the slight angle of engagement twist to wedge those rollers when changing from freewheel to driving directions.

A few examples of indexing clutch applications: Printing, Textile and Sewing Machines, Packaging, Agricultural Machines and more.

Overrunning

When you need an overrunning clutch, you can achieve maximum performance by designing a stationary inner ring or making it the slowest part of your clutch/application.

A few examples of overrunning clutch applications: Starter units, auxiliary drives, auxiliary power equipment, conveyors, turbines, bakery & cutlery equipment.

Backstopping

Backstopping performs the best when you hold the outer ring stationary and allow the inner ring to rotate free in one direction.

The use of low viscosity lubricants is important for backstopping. If you have high speeds that exceed catalog RPM standards, we recommend a circulating oil system for backstopping. Be sure to contact GMN Bearing USA for more details and support.

A few examples of backstopping clutch applications: winches, cranes, elevators, gearboxes, pumps, ventilators & power plant equipment.

Transmittable Torque

For our GMN roller ramp clutch series VS / VSNU / VF/ VGF / VGL / VGLP / VEK the nominal torque (M) refers to 107 cycles. It’s calculated with a safety factor of S = 2.5. Torque peaks in use may never be higher than M x 2.5 [Nm]. Please note: Series VEK torque peaks are referring to the inertia of all accelerated parts and has to be expected.

For our GMN roller ramp clutch series VGV the nominal torque (M) refers to 105 cycles and doesn’t include any safety factors. Torque peaks in use may never be higher than nominal torque.

To properly disengage, a minimum of driven mass will be required depending on the speed. Within the limits of nmax and nmin (please refer to the specific data sheets for this information) the inertia of the VEK clutch itself will be sufficient for proper disengagement (nmin) and reasonable lifetime (nmax).

Bolts – Torque Indicating Wrench

Bolts Class B Class 9 Series Series
Type Tightening Torque [NM]   VGL, VGLP VEK
M4 3, 5 4 10
M5 7 8, 5 12, 15 15, 20
M6 12, 5 14, 5 20, 25, 30, 35 30
M8 30 35 40, 45, 50 40
M10 60 70 55, 60, 70, 80 50
M12 105 120    

Thread length in outer ring: L = 1.5 x Bolt Type

 

Contact Us for Roller Ramp Clutches

Contact GMN Bearing USA for more information on how roller ramp clutches can be used to improve the performance of your application. 

Contact Us

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