Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/06—Electromagnets; Actuators including electromagnets
  • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05B—SEWING
  • D05B69/00—Driving-gear; Control devices
  • D05B69/10—Electrical or electromagnetic drives
  • D05B69/12—Electrical or electromagnetic drives using rotary electric motors
  • D05B69/125—Arrangement of clutch-brake construction
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D55/00—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D2121/00—Type of actuator operation force
  • F16D2121/18—Electric or magnetic
  • F16D2121/20—Electric or magnetic using electromagnets

Definitions

• the invention relates to an electromagnetic single-disc brake according to the preamble of claim 1.
• Such single-disc brakes are generally known and are used as brakes in electrical devices in which rotating parts are to be braked optionally. If both parts that can be coupled due to electromagnetic effects can be rotated, the brake must be referred to as a clutch.
• the brake disc forming the anchor is one of those
• Brakes are usually provided with return springs, so that when the brake is inactive, i. H. in the de-energized state of the electromagnet to generate a distance between the brake disc and the opposite parts of the electromagnet, which ensures an absolute free running of the two parts and thus reduces wear.
• the invention is therefore based on the object to provide a brake according to the preamble of claim 1, the switching noise in operation as far as possible. is avoided and secured against premature abrasion.
• the brake disc is axially movable on the part carrying it, for example a shaft or armature hub without restoring force, so that the electromagnet does not have to overcome a restoring force when excited.
• the disc can face the adjacent electromagnet without a noticeable air gap, whereby the gap in the yoke of the electromagnet ensures that the magnetic force caused by residual magnetism is reduced in the unexcited state of the electromagnet to such an extent that the brake disc is not pulled against the electromagnet by it.
• this gap is sufficiently narrow that it does not noticeably reduce the magnetic force developed by it when the electromagnet is excited.
• the brake disc In the de-energized state, the brake disc therefore rotates with a minimal air gap in relation to the electromagnet, so that it is protected against wear in this state.
• the gap in the magnetic yoke has a width of approximately 0.1 to 0.2 mm.
• This gap could be filled with air, but for practical implementation it is more favorable if it is filled with a film made of a material of high magnetic resistance because this simplifies assembly. This film can also reduce the penetration of dirt into the electromagnet.
• the electromagnet is designed in the form of a ring, consisting of a ring coil which is surrounded on its inner and outer circumference by pole legs, which are covered on its side facing away from the brake disc by a yoke plate, between which and at least one of the pole legs said film is located, which is designed as a disc.
• the two pole legs form a gap between them, which the brake disc faces.
• a brake pad material may be contained in this gap. This magnetic construction is thus completely closed to the outside.
• a shaft runs through the electromagnet, which carries the brake disc in a rotationally fixed but axially movable manner.
• Fig. 1 is an exploded perspective view of an electromagnetic single disc brake for a toothed belt pinion
• Fig. 2 is an axial section through the arrangement of FIG. 1 in the assembled state in an enlarged Presentation.
• FIG. 1 an exploded view of a single-surface brake, consisting of an annular electromagnet (1), which in the present example is intended for mounting on a fixed part, and a rotatable brake disc (2), which is axially opposite the electromagnet (1) and which has a bore with internal toothing (3) into which the external toothing (4) of an anchor hub (5) engages, which is positively coupled to a belt sprocket (6), which in turn is mounted on a shaft (7) in a rotationally fixed manner by means of a keyway connection, which penetrates the electromagnet (1), the brake disc (2), the armature hub (5) and the pinion (6).
• the armature hub (5) and the pinion (6) are clamped in the axial direction on the shaft (7) between a shaft collar (8) and a clamping nut (9) screwed onto the shaft.
• the clamping nut (9) is secured by a lock nut (10).
• the electromagnet (1) comprises a magnetic yoke with two concentric pole legs (11 and 12), between which there is an annular magnetic coil (13), and on the side facing away from the brake disc (2) a yoke plate (14), which in the present case also provides fastening means for the electromagnet (1).
• the two pole legs (11 and 12) form an annular gap between them, in which a brake pad (15) is arranged.
• the pole legs (11 and 12) are axially opposed by the brake disc (2), which is movable in the axial direction on the toothing of the armature hub (5).
• Fig. 2 is between the brake disc (2) and the opposing pole legs (11 and 12) and the Brake pad (15) shown a gap that should be as small as possible to avoid hard switching noises when the brake is applied.
• Fig. 2 shows that there is a gap between the outer pole leg (11) and the yoke plate (14), which in the present case is filled by a film disc (16) made of a material of high magnetic resistance.
• This film disc (16) can have a thickness of, for example, 0.1 to 0.2 mm and in the present case also extends over the adjacent end face of the magnet coil (13). It has a central bore which is centered on the inner pole leg (12) on the electromagnet (1).
• the film disc (16) thus defines a certain distance between the end face of the outer pole leg (11) and the yoke plate (14) which increases the magnetic resistance in the magnetic circuit to such an extent that in the de-energized state of the electromagnet (1) that of the residual magnetism on the brake disc (2) the force exerted cannot cause the brake disc (2) to "stick" to the pole legs (11 and 12) and the brake disc (2) is therefore free in front of the pole legs (11 and 12).
• the increase in the magnetic resistance caused by the film disc (16) is so small that, when the electromagnet (1) is excited, its function is not impaired and its active braking force is only insignificantly reduced.
• the film disc (16) has the further advantage that it connects the yoke plate (14) at least with the outer pole leg (11) in the manner of a seal, as a result of which a dust-tight seal of the electromagnet is achieved on its rear side, so that there no ferritic brake abrasion and can influence the magnetic resistance.
• the diameter of the film disc (16) is preferably somewhat larger than the outer diameter of the outer pole leg (11).

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Power Engineering (AREA)
• Braking Arrangements (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6348021

Family Applications (1)

Country Status (2)

Cited By (1)

Families Citing this family (3)

Citations (5)

Family Cites Families (3)

• 1988
  • 1988-02-24 DE DE19883805705 patent/DE3805705C1/de not_active Expired
  • 1988-12-22 WO PCT/EP1988/001196 patent/WO1989008209A1/de not_active Ceased

Patent Citations (5)

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