TORQUE LIMITERS

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single-position multi-position load holding full disengagement ADDITIONAL INFORMATION BACKLASH-FREE TORQUE LIMITERS FROM R+W Behaviour and characteristic Disengagement behavior Spring characteristic Degressive spring characteristic Torque in (Nm) Without torque limiter Spring force T KN max Adjustment range Actuation path Present disengagement torque with conventional disc springs T KN min Malfunction With R+W disc springs 0 10 40 Actuation time (msec) Spring path Spring package: R + W torque limiters function by means of a disc spring with a digressive characteristic developed exclusively for this application. Upon the couplings actuation, this characteristic (13) brings about an immediate drop in the torque (14) and an interruption of the force flux. The spring force of the disc spring drops to a lower value after the disengagement process. This advantage guarantees extremely short actuation times (1-3 ms), low wear and very low residual friction (between 2-5 %). Speed: The service life of the coupling is essentially determined by the number of rotations after disengagement. Wear: No wear occurs during engaged operating condition. In the event of an overload the drive should be stopped through a mechanical limit switch or proximity switch immediately. Maintenance: When properly engaged, the torque limiters are wear free, and therefore require no maintenance. The ball detent mechanism within each coupling is permanently lubricated. Seal: Sealing of the torque limiters is available. Torque Limiter in sealed version (Option) Advantages of the sealing: ■ Protection from dirt and liquid contamination ■ Appropriate for food service and light washdown environments ■ No escape of grease possible Seal for actuation ring Actuation path engaged disengaged Prior technical approval is suggested for applications using our products other than specified. 26 R+W www.rwcouplings.com
single-position multi-position load holding full disengagement SELECTION BACKLASH FREE TORQUE LIMITERS FROM R+W According to disengagement torque As a rule torque limiters are rated according to the required disengagement torque, which must be greater than the torque that is necessary for regular machine operation. T KN 1.5 · T AS (Nm) T KN = rated torque of coupling T AS = peak torque of motor (Nm) (Nm) The disengagement torque of the torque limiters is determined as a rule in accordance with the drive specifications. The following calcucation has proven itself as a good rule of thumb: or T KN P 9550 · –— AN n · 1.5 (Nm) T KN = rated torque of coupling (Nm) P AN = drive power (kw) n = speed of drive (rpm)) According to acceleration torque (start-up at no load) S A = shock or load factor S A = 1 (uniform load) S A = 2 (non-uniform load) S A = 3 (high dynamic load) Values for S A = 2-3 are usual for servo drives on machine-tools J T KN · J L ––––– L · T AS · S A (Nm) J A + J L T KN = rated torque of coupling α = angular acceleration = –– t = ––––– · n t · 30 (Nm) ––– 1 s 2 t = acceleration time (s) ω = angular speed in (s- 1 ) n = speed of drive (rpm) J L = moment of inertia on load side (kgm 2 ) J A = moment of inertia on driving side (kgm 2 ) T AS = peak torque of motor (Nm) According to acceleration and load torque (start with load) J T KN · J L + T AN ––––– L · (T AS - T AN ) + T AN · S A (Nm) J A + J L S A = shock or load factor S A = 1 (uniform load) S A = 2 (non-uniform load) S A = 3 (high dynamic load) Values for S A = 2-3 are usual for servo drives on machine-tools T KN = rated torque of coupling α = angular acceleration = –– t = ––––– · n t · 30 (Nm) ––– 1 s 2 t = acceleration time (s) ω = angular speed in (s- 1 ) n = speed of drive (rpm) J L = moment of inertia on load side (kgm 2 ) T AN = load torque (Nm) J A = moment of inertia on driving side (kgm 2 ) T AS = peak torque of motor (Nm) www.rwcouplings.com R+W 27
Page 1 and 2: COMPACT AND BACKLASH FREE. single-p
Page 3 and 4: single-position multi-position load
Page 13 and 14: MODEL SK3 BACKLASH FREE TORQUE LIMI
Page 19 and 20: MODEL ATEX FOR USE IN HAZARDOUS ARE
Page 25: single-position multi-position load
Page 29 and 30: FACTORS AND SIZING CALCULATIONS BAC
Page 33 and 34: ROBUST AND COMPACT Full disengageme
Page 35 and 36: Full disengagement MODELS FEATURES
Page 37 and 38: Full disengagement MODEL STN TORQUE
Page 39 and 40: Designs for Direct Drives with inte
Page 41 and 42: MODEL ST 2 The elastomer segments T
Page 43 and 44: MODEL ST 4 Function of the gear cou
Page 45 and 46: MODEL ATEX FOR USE IN EXPLOSIVE ATM
Page 47 and 48: MODEL ST Ordering example Model Ser
Page 49 and 50: SELECTION According to linear feed
Page 51 and 52: SELECTION Specifications of gear co

TORQUE LIMITERS

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