Overrunning clutches are directional couplings, meaning they can engage and disengage automatically, depending on the relative direction of rotation of the driving and the driven sides.
The overrunning clutches has three different practical principles
Overrunning clutch: An overrunning clutch is used for multiple machine drives or to separate the inertia of masses of a driven machine from the driving machine after it has been switched off. The freewheel disengages automatically when the driven part rotates faster than the driving part.
Indexing clutch: Indexing clutch turns a shaft step by step, thus achieving indexed material feed or a variable speed. The freewheel allows the conversion of a reciprocating motion into a discontinuous rotary motion.
Backstop: Backstop prevents a machine shaft from turning backwards. Here, the overrunning clutch is used as a brake. The freewheel allows rotation in one direction only. It overruns continuously during operation and prevents reverse rotation if the drive is disconnected.
Locking elements
The locking elements in the clutches are in two designs: either roller clutch or sprag clutch. The roller clutches are mainly used as overrunning clutches and indexing clutches. The sprag clutches are most suitable as backstops, and primarily for the contact-free versions.
The roller freewheels feature a cylindrical outer race and an inner race consisting of ramps on which rollers are located. Springs and plungers ensure a permanent contact between the different elements for an instant torque transmission. This rugged, reliable versatile design can be used as an overrunning clutch, indexing clutch or backstop.
In the sprag freewheels the two races are cylindrical. The sprags, that are fitted in a cage, feature an active profile that ensures engagement or disengagement according to the relative motion of the races. It is possible to customise the design of sprags and cages from one model to another for significantly different characteristics
Integral bearing / freewheel
Based on series 62, 60 & 59. Type of support: Combined bearing/freewheel
To download as PDF, find the download link below the table.
| Overrun. speed inner race | Overrun. speed outer race | Overrun. Clutch | Indexing Clutch | Back-stop | Bores Ø [mm] | Torques [Nm] | Types |
| High | High | x | x | x | 8-40 | 2.5-325 | CSK |
| High | High | x | x | x | 12-40 | 2.5-325 | CSK..2RS |
| High | High | x | x | x | 12-40 | 9.3-325 | CSK..P |
| High | High | x | x | x | 12-40 | 9.3-325 | CSK..PP |
| High | High | x | x | x | 20-30 | 50-138 | CSK..P-2RS |
| High | High | x | x | x | 40-60 | 72-250 | ASK |
| High | High | x | x | x | 20-50 | 51-460 | GFK |
Download the tabel in pdf format below.
Built-in freewheels
Built in Freewheels must be integrated in a housing that provides bearing support. Low to medium torque and speeds. Type of support: Non supported
To download as PDF, find the download link below the table.
| Overrun. speed inner race | Overrun. speed outer race | Overrun. Clutch | Indexing Clutch | Back-stop | Bores Ø [mm] | Torques [Nm] | Types |
| Medium | High | x | x | x | 4-10 | 0.8-2.9 | KI |
| Medium | High | x | x | x | 6-80 | 2.1-1,063 | AS |
| Medium | High | x | x | x | 8-200 | 12-44,500 | ASNU |
| Medium | High | x | x | x | 12-70 | 17-5,813 | AE |
| Medium | High | x | x | x | 12-70 | 17-5,813 | AA |
| Medium | High | x | x | x | 8-150 | 20-44,375 | NF |
| High | Medium | x | x | x | 10-70 | 63-4,875 | DC |
| High | Medium | x | x | x | 10-70 | - - | DC RACES |
| ~ | Low | x | 12-120 | 24-14,380 | BAT | ||
| Medium | High | x | x | x | 8-130 | 20-34,750 | NFR |
~ : Not possible
Download the tabel in pdf format below.
Self contained clutches
Sealed with integral lubrication. From small to high torques, low to max speeds. Type of support: Bearing supported.
To download as PDF, find the download link below the table.
| Overrun. speed inner race | Overrun. speed outer race | Overrun. Clutch | Indexing Clutch | Back-stop | Bores Ø [mm] | Torques [Nm] | Types |
| Low | ~ | x | 25-90 | 375-4,875 | RSBW | ||
| Low | ~ | x | x | 20-120 | 265-11,000 | AV | |
| Medium | High | x | x | x | 12-250 | 55-287,500 | AL-ALP |
| Medium | High | x | x | x | 12-250 | 55-287,500 | AL..F2D2 |
| Medium | High | x | x | x | 12-250 | 55-287,500 | AL..F4D2 |
| Medium | High | x | x | x | 12-250 | 55-287,500 | ALP..F7D7 |
| Medium | High | x | x | x | 12-250 | 55-250,000 | AL..KEED2 |
| Medium | High | x | x | x | 12-120 | 50-20,000 | AL..KMSD2 |
| Medium | High | x | x | x | 12-150 | 55-70,000 | GFR-GFRN |
| Medium | High | x | x | x | 12-150 | 55-70,000 | GFR..F1F2/F2F7 |
| Medium | High | x | x | x | 12-150 | 55-70,000 | GFRN..F5F6 |
| Medium | ~ | x | 12-150 | 55-70,000 | GFR..F2F3 | ||
| Medium | ~ | x | 12-150 | 55-70,000 | GFR..F3F4 | ||
| High | Medium | x | x | x | 12-80 | 379-6,900 | FSO300-700 |
| High | Medium | x | x | x | 57-175 | 9,660-36,612 | FSO750-1027 |
| ~ | High | x | 12-150 | 288-45,000 | AL..G |
~ : Not possible
Download the tabel in pdf format below.
Centrifugally lift off sprags
Wear free above a given speed. High speeds with little lubrication demand. Specifically designed for gear reducers, motors, pumps, ventilators, turbines. Type of support: Non self-suppported (RSBI, RSCI, RSBF/CR), Bearing supported (RIZ)
To download as PDF, find the download link below the table.
| Overrun. speed inner race | Overrun. speed outer race | Overrun. Clutch | Indexing Clutch | Back-stop | Bores Ø [mm] | Torques [Nm] | Types |
| High | ~ | x* | x | 60-240 | 1,375-38,250 | RSBI | |
| High | ~ | x* | x | 20-240 | 212-100,000 | RSCI | |
| ~ | High | x | 25-90 | 85-93,750 | RSBF/CR | ||
| High | ~ | x* | x | 30-130 | 313-16,875 | RIZ/RINZ | |
| High | ~ | x* | x | 30-130 | 313-16,875 | RIZ..G1G2/G2G7 | |
| High | ~ | x | 30-130 | 313-16,875 | RIZ..G2G3 | ||
| High | ~ | x | 30-130 | 313-16,875 | RIZ..G3G4 | ||
| High | ~ | x* | 30-130 | 313-16,875 | RIZ..ELG2 | ||
| High | ~ | x* | 30-130 | 80-16,000 | RIZ..ESG2 |
* : Special working condition
~ : Not possible
Download the tabel in pdf format below.