Overrunning Clutches and Backstops
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Overrunning Clutches and Backstops

MANY CUSTOMERS PUT THEIR TRUST IN STIEBER. ALTRA INDUSTRIAL MOTION Stieber was founded in Munich in 1937 and is now a medium-sized company employing 140 people at its locations in Heidelberg and Garching near Munich. Altra is a leading multinational designer, producer and marketer of a wide range of mechanical power transmission products. We sell our products in over 70 countries throughout the world. Our products are frequently used in critical applications, such as fail-safe brakes for elevators, wheelchairs and forklifts, and in high-volume manufacturing processes, where the reliability...

Contents Overrunning Clutches and Backstops Stieber – Competence is our strength 2 The principle 3 Design 5 Selection 6 Mounting instructions 12 Lubrication and maintenance 13 Products 14 Special designs 92 Selection procedure Selection table Alphabetical list SMZ FSO 300-700 FSO-GR 300-700 HPI 300-700 FS 750-1027 FSO 750-1027 HPI 750-1027 AL..G CEUS BC MA RDBR-E Centrifugally Lift-Off Sprags Freewheels Built-In Freewheels 74 Built-in freewheels RSCI 20-130 RSCI 180-300 RSXM RSRV RSRT RDBK IMPRINT Published by: © Stieber GmbH Hatschekstraße 36 69126 Heidelberg Germany This document must not...

STIEBER: COMPETENCE IS OUR STRENGTH. INNOVATIVE: DEVELOPMENT Throughout it’s long history Stieber has been familiar with all types of freewheel designs such as roller and sprag variants and consistently led the way in developing new designs and technologies. We have an unmatched ability in the field of over unning clutches, built on the long r experience of our team of qualified engineers and always seeking the best nswers in design and manufacture. a Alongside a continuous program of product develop ment unique solutions have been found over the years including: • Encased overrunning...

THE PRINCIPLE: THE RIGHT ANSWER – EVERYTIME. 1 1 OVERRUNNING CLUTCH The freewheel disengages automatically when the driven member rotates faster than the driving member. 2 INDEXING CLUTCH The freewheel allows the conversion of reciprocating motion into a discontinuous rotational movement. 3 BACKSTOP The freewheel allows rotation in one direction only. It overruns continuously during operation. The freewheel prevents reverse rotation if the drive is disconnected. Overrunning clutches are directional couplings, which means they are engaged and disengaged automatically, depending on the...

BASIC FORMS: ALWAYS A PERFECT SOLUTION. To achieve the functions described overleaf, so-called locking elements are positioned between an outer and an inner race which effect engaging and disengaging. These locking elements are of two basic designs: ROLLER CLUTCH Mainly used as overrunning and indexing clutches. SPRAG CLUTCH Most suitable as backstops, and mostly the contact-free versions. Outer Race Outer Race Inner Race Inner Race Locking Roller Spring-Loaded Plunger • High overrunning speed • High torque capacity • High indexing accuracy • High eccentricity tolerances • High performance...

DESIGN: MANY VERSIONS – ONE QUALITY. ROLLER FREEWHEELS These 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. Note: the highest overrunning speed is possible if the outer race is overrunning. For this reason it is particularly adapted to high speed overrunning clutch application for dual drivers. 1 Outer race 2...

STIEBER SOLUTIONS: ALWAYS THE RIGHT CHOICE. Unit selection is initially determined by the type of application: OC Overrunning clutch, IC Indexing clutch, BS Backstop. Different technical information is required for each one of them. Mounting details and lubrication requirements finally determine the unit selected. The information required for each type of application is as follows: OVERRUNNING CLUTCH INDEXING CLUTCH • Static reverse torque • Nm start/Nm nominal of E-motors • Index angle • Internal combustion engines, please consult Stieber • Nominal torque • Nominal driving torque •...

Model Selection THE SELECTION PROCEDURE: WE ADVISE, YOU DECIDE. If we have the data described on the previous page, Stieber can make the most accurate selection. If all of the information is not available, or if you want to make a selection yourself, the following service factor procedure may be used. Note: The following method and the service factors used are only a guide based on experience and cannot cover all situations. We cannot accept responsibility for incorrect selection resulting from the use of these tables. TORQUE SELECTION The first step is to calculate the catalogue torque...

Model Selection SERVICE FACTORS. INDEXING Type of freewheel Roller type Sprag type 3.0 4.0 Indexing speed Over 150 strokes/min Angle > 90° | Over 100 strokes/min Angle > 90° | Less than 100 strokes/min BACKSTOP Driven machine Driving machine Other machines No overloads Dynamic overloads Elastic conveyor belts with risk of jam Pump drives with more than 5 metres shaft Motors with hydraulic couplings Asynchronous motors with direct start1 Internal combustion engine 1) These values do not cover a motor start in the wrong direction. OVERRUNNING Working conditions Driving machine Starting torque...

Model Selection MODEL SELECTION When the catalogue torque is known, the model will be selected from the following criteria: • Built-in or self-contained design • Driving and overrunning speed limits • Dimensions • Lubrication and maintenance Please refer to the selection table page 10 for a guide to selection. The product range is presented in this order: SELF-CONTAINED BALL BEARING UNITS (CSK RANGE) General purpose, economical units for light applications. Grease lubricated, maintenance free. With or without key(s) mounting to shaft and housing. BUILT-IN UNITS Made of inner- and outer race...