Torque limiter

A slipping clutch is an automatic torque type safety clutch that protects parts of installations from damage.

Definition and delimitation

• From slip clutch in the narrower sense is when the safety clutch builds up next to the preliminary definition of a friction clutch, so there is a positive connection.
• A friction clutch is also in the opposite normal case, when the clutch therefore does not separate, but closes when the presence of a defined torque.

Under the same aspect ( torque- type safety coupling) but there are still

• Blocking body couplings (positive locking ) → eg spring-loaded balls, bolts or claws that slip out corresponding grooves on reaching a limit torque or
• Shear pin couplings (positive locking ) → bolt break when reaching the limit torque
• Hydrodynamic or electrodynamic couplings

See the main article: Clutch

Function

The slipping clutch as a component ( the mechanism ) is disposed between two shafts. When a defined torque or disconnect from the clutch without external (foreign) influence. So the waves, in addition to the synchronization, even at a different speed to run down to zero speed of a wave.

In principle, all friction clutches and slip clutches. For the necessary aspect of the safety clutch doing a ( adjustable ) coupling force and as a result the initially introduced already defined torque important. Functional sense is a flat power curve ( the clutch), so that in case of wear of the clutch not too large deviation of the hedged torque results. In addition, the slip clutch to slip during normal operation (closed) should be checked and secured.

When construction joints are used depending on the purpose one-, two - or multi-plate (lamella ).

A special form is the magnetic clutch, which would be feasible, both as a disk clutch as well as a magnetic particle clutch.

Applications and Examples

In principle, slip clutches are used where to be (due to the system separation by the clutch ) to avoid overload of machine elements or injury to persons.

An example is the use as material or labor protection measure by slipping when a body part, a garment or ( generally ) come to gentle material in a machine. However, this function can only be used in areas in which the working torque is so low that the clutch in normal operation does not slip.

In industrial applications, slip clutches usually have electromechanical or electronic switches ( sensor controlled ) with a combined scheme which at standstill or when it falls below the set speed on the output side ( clutch slips ) the drive stops.

Also in the vehicle slip clutches are used:

• With power windows as a simple mechanical pinch
• The clutch is in the broadest sense designed as a slip clutch ( engine / drive train wheels )
• As an anti- hopping clutch in motorcycles
• For special designs ( eg off-road, race) redirect as variable locking differentials to provide (usually variable ) torque on a spinning shaft or on the other axis ( lamellar slip differential ).

When the tape recorder slip clutch the right band adjuster merely provides the lightweight coiling of the strip, while the actual tape drive capstan and pinch roller is via. Thus, the belt speed remains the same in spite of the variable coil diameter.

In the automatic slip clutch prevents stripping of the mainspring by the rotor.

In cordless drills, in which the slip clutch is adjustable. This prevents the screws too tight, and screw heads or bits are corrupted.

In a radio-controlled model car with electric drive slip clutch ( " slipper" ) is not only the protection of the drive, but primarily to improve the acceleration and controllability of the model on slippery surfaces. The effect of the slip clutch and thus the maximum transmissible torque is set by the bias of a compression spring. In the slip clutch built plastic disks are designed so that they expand when slipping the clutch so that the transmissible torque with increasing slip time rises sharply, ie the clutch zupackt.

Swell

• Dubbel: Taschenbuch für den Maschinenbau. ISBN 3-540-12418-7.
• Karl -Heinrich Grote, Jörg Feldhusen ( Eds.): Dubbel - Paperback for mechanical engineering. 22nd edition. Springer, Berlin, 2007. ISBN 3-540-68186-8.

• Coupling