Basic design of spring-loaded brakes

The BP.., BR.., BY.., and BZ series brakes are spring-loaded brakes with a DC coil that open electrically and brake using spring force. The following are the essential parts of the brake system:

  • The brake lining carrier [1], which is positively connected to the motor shaft [10] by the driver [3]
  • The pressure plate [6], which is guided in the housing and can move axially
  • The brake endshield [2] on the motor side
  • The fixed electromagnet with the inserted brake springs [7]. The electromagnet consists of the magnet body housing [9] with an integrated brake coil [8].

[1]

Brake lining carrier

[2]

Brake endshield

[3]

Driver

[4]

Spring force

[5]

Working air gap

[6]

Pressure plate

[7]

Brake spring

[8]

Brake coil

[9]

Magnet body housing

[10]

Motor shaft

[11]

Electromagnetic force

Basic function of the brake

The pressure plate [6] is forced against the brake lining carrier [1] by the spring force [4] of the brake springs [7] when the brake coil [8] is de-energized. The resulting frictional torque is transferred through the driver [3] to the motor shaft [10], thereby braking the motor shaft [10].

When the appropriate DC voltage is applied to the brake coil [8], an electromagnetic field is generated in the magnet body housing [9]. The resulting electromagnetic force [11] overcomes the spring force [4]. This causes the pressure plate [6] to lift away from the brake lining carrier [1] and close the working air gap [5]. The brake lining carrier [1] is freed and the motor shaft [10] can rotate.

The working air gap [5] in spring-loaded brakes results from the production dimensions of the individual parts and does not need to be set.

Strengths of spring-loaded brakes
  • Designed according to the normally energized principle, meaning a forced brake application occurs in the absence of voltage
  • High work capacity due to their construction with multiple friction surfaces and organic friction linings
  • Robust design with closed housing
  • Responds quickly and can be adapted to many supply system environments (e.g. AC supply systems, DC supply systems, and supply by frequency inverter) due to the two-coil system from SEW‑EURODRIVE for BR.., BY.., and BZ..
  • Maintainable design in B-side motor mount (BR.., BY.., BZ..)
  • Suitable as a safety brake for applications up to PL e