DE102013021084B3 - Electromagnetically actuated brake with armature disc and electric motor - Google Patents

Abstract

Electromagnetically actuated brake with armature disc and electric motor, wherein the armature disc has a receiving part and a further part, wherein the further part is made of a material of higher electrical conductivity than the receiving part.

Description

The invention relates to an electromagnetically actuated brake with armature disc and electric motor.

It is well known that in electromagnetically actuated brakes an armature disc is attracted by an electromagnet when energized against the force of spring elements.

From the US 5642797 A For example, a plastic injection molded rotor is known for an electromagnetic friction brake.

From the GB 2339861 A is a noise-damping arrangement for an electromagnetic clutch known.

From the US 5036964 A An electromagnetic coupling is known, wherein a receiving part made of electrically conductive or non-conductive plastic and another part made of steel is provided for noise damping.

From the US 2012/0000742 A1 For example, a laminated armature disk for torque modulation of an electromagnetically actuable spring-applied brake is known.

From the DE 41 26 672 A1 is known an electromagnetically actuated brake, wherein between the magnetic body of an electromagnet and armature disc, a metallic damping disc is arranged.

The invention is therefore based on the object to reduce the noise emission of a brake.

According to the invention the object is achieved in the brake according to claim 1 and in the engine according to the features indicated in claim 13.

Important features of the invention in the electromagnetically actuated brake with armature disc and coil winding are that the armature disc has a receiving part in which a laminated core is accommodated on its side facing the coil winding, wherein one of the individual sheets of the laminated core is made as a further part of copper and on the coil winding side facing the laminated core is arranged and the other individual sheets of the laminated core are made of steel,
so that the further part is made of a material of higher electrical conductivity than the receiving part,
wherein the further part is made as a perforated disc.

The advantage here is that caused by the induction of an eddy current in the other part, the cause counteracting force, the movement of the armature disk is damped and thus the impact noise is reduced. Because the noise resulting from the impact of the armature disk on the electromagnet, in particular the coil core of the electromagnet, is reduced by the impact speed is reduced.

In an advantageous embodiment, the further part is arranged on the electromagnet side facing the receiving part. The advantage here is that a strong eddy current can be generated because there the magnetic field generated by the coil winding has a large field strength.

In an advantageous embodiment, the further part is made as a perforated disc. The advantage here is that an annular current can be formed, the ring axis of the central axis of the armature disc, ie the disc axis is equal.

In an advantageous embodiment, the further part is made as a stamped and bent part. The advantage here is that a simple production is possible. Thus, a sheet, such as a copper sheet, machinable in a simple manner.

In an advantageous embodiment, the further part is made of copper or a copper-containing material and the receiving part of a steel or aluminum. The advantage here is that the other part is executable as a very good electrical conductor. However, the remaining receiving part of the armature disk is executable from a less expensive, electrically poorly conductive material.

In an advantageous embodiment, a laminated core is arranged between further part and receiving part, in particular wherein the laminated core is made of a stack of sheet metal parts, in particular perforated discs, whose stacking direction is aligned parallel to the shaft axis. The advantage here is that reduced losses are effected.

In an advantageous embodiment, the further part covers in the axial direction an area which exceeds the wall thickness of the further part,
in particular, wherein the wall thickness of the further part is substantially constant everywhere. The advantage here is that despite thin wall thickness by means of kinking or beading a much larger axial area is covered.

In an advantageous embodiment of the overlaps of the other part radially overlapped Area covered by the coil winding radial area or overlaps at least with him. The advantage here is that the field lines for eddy current generation are used as effectively as possible, especially with low material costs.

In an advantageous embodiment, the further part has an annular elevation, in particular on the further part an annular elevation, in particular an annular, axially pronounced and / or protruding elevation, is formed,
in particular, wherein the annular protrusion is a bead,
in particular, wherein the annular elevation is aligned concentrically to the armature disk and / or perforated disk, in particular the ring axis is the disk axis. The advantage here is that eddy current can be effectively generated with a simple production method and low material costs, the eddy current counteracts the cause, that is, the changing magnetic field and thus slows down the movement of the armature disk.

In an advantageous embodiment, the axial area covered by the further part exceeds the wall thickness of the further part,
in particular wherein the further part, in particular the further part formed as a sheet metal part and / or perforated disc, has the same wall thickness everywhere. The advantage here is that with little material expenditure, a strong decelerating effect can be achieved.

In an advantageous embodiment, the area covered radially by the annular elevation is arranged within the area radially overlapped by the coil winding. The advantage here is that the magnetic field lines of the coil winding are effectively used for generating eddy current.

In an advantageous embodiment, the axial area covered by the further part overlaps with the axial area covered by the coil core,
in particular wherein between the further part and the coil winding, an air gap is arranged, that is, the further part is axially spaced from the coil winding. The advantage here is that the further part of the coil winding immersed in the region of the recess of the coil core and thus comes very close to the coil winding. As a result, a particularly effective design can be achieved.

In an advantageous embodiment, the armature disk on a laminated core, wherein one of the individual sheets of the laminated core, the other part is executed. The advantage here is that losses are reducible.

Important features of the electric motor are that it is executable with the aforementioned brake.

The advantage here is that the engine is designed as a brake motor.

Further advantages emerge from the subclaims. The invention is not limited to the combination of features of the claims. For the skilled person, further meaningful combination options of claims and / or individual claim features and / or features of the description and / or figures, in particular from the task and / or the task posing by comparison with the prior art arise.

The invention will now be explained in more detail with reference to figures:

In the 1 is an armature disk of an electromagnetically actuated brake, in particular holding brake, shown.

N the 2 In addition, the brake coil is shown with the armature disc is far off.

In the 3 is shown a magnetically attracted armature disk.

In the 4 An anchor plate is shown in an oblique view.

As shown in the figures, the electromagnetically operable brake comprises a brake coil having a coil winding, 21 that is in a bobbin 20 is included.

Here is the coil winding 21 preferably designed as a ring winding and in the coil core 20 arranged with potting compound. The coil core 20 is preferably made of a cast steel. The coil core 20 indicates the reception of the coil winding 21 an annular recess into which the coil winding 21 is arranged inlaid.

The coil core 20 is connected by means of fastening elements with a braking surface having a part, for example, a flange of an electric motor.

A shaft is rotatably mounted in the part having a braking surface or a part fixedly connected thereto.

With the shaft is non-rotatably, but axially, so in shaft axis, slidably connected to a brake pad carrier.

An armature disk is non-rotatable but axially displaceable with the spool core 20 connected by the fasteners are guided by recesses of the armature disk.

Axially between the armature disk and the braking surface of the brake pad carrier is arranged, which has on both sides, ie toward the armature disk and the braking surface, a respective brake pad.

Now if the coil winding 21 is energized, the armature disk against the spring force generated by spring elements to the coil winding 21 Pulled out and thus released the brake.

In Nichtbestromung the spring force generated by the spring elements pushes the armature disc axially to the brake pad carrier and this on the braking surface, wherein a first brake pad in frictional contact with the armature disc and a second brake pad in frictional contact with the braking surface thus enters the brake and brakes the rotational movement of the shaft from.

The spring elements are preferably on the spool core 20 supported.

According to the invention, the armature disk at its the coil winding 20 side facing a perforated disc 3 , In particular, therefore, an annular member made of metal, which has a higher electrical conductivity, as a portion of the remaining armature disc. Preferably, the perforated disc made of copper and / or aluminum, and the remaining armature disc made of steel, such as steel casting and / or steel sheet.

As in 1 shown, the armature disk in the embodiment of the invention a receiving disk 1 which is preferably manufacturable as a machined steel part. On the side facing the coil winding, a sheet steel package is received, on which of the receiving part 1 opposite side of the perforated disc 3 is arranged.

It is important that the electrical conductivity of the perforated disc 3 in particular in the circumferential direction or even in all directions is better than in the remaining armature disk, in particular so as in the receiving part or in the steel sheet package 2 By means of the perforated disc 3 Thus, with changing magnetic field, one of the armature disk moving magnetic attraction force generates a counterforce by means of eddy current, which is the cause, ie the tightening force directed opposite acting.

In 1 are shown for individual characteristic field lines of the magnetic field, the eddy currents resulting from a change in the magnetic field strength whose resulting current is a current flowing in the circumferential direction, ie in the ring direction.

In 2 that is from the coil winding 21 indicated magnetic field and generated by the eddy currents opposing field B _counter .

In 3 is the associated counterforce F _counter shown, the armature plate when energized the coil winding 21 is accelerated to the speed v.

Although there is also an eddy current in the receiving disk 1 the anchor plate or in the laminated core 2 , which is made of stacked sheet steel perforated discs of the armature disc is generated. However, this current is much lower because the electrical conductivity is much lower.

The thicker the perforated disc 3 Running in the axial direction is the stronger the eddy current, because more field lines, in particular more radial components of field lines, in the perforated disc 3 occur, in particular in the radial direction.

As in 4 is shown in another embodiment of the invention instead of in the 1 to 3 shown perforated disc 3 now the perforated disc 40 executed with a bead, so that through the perforated disc 40 axially covered area is greater than the axial wall thickness of the perforated disc 40 , Here is the perforated disc 40 directly on the pick-up disc 41 added. The pickup disk 41 is made of a less conductive material than the perforated disc 40 , Preferably, the perforated disc 40 made of copper or a copper-containing material and the pick-up disc 41 from steel.

Preferably, the bead is 42 in the center of the perforated disc 40 executed. The bead 42 is annular and coaxial with the perforated disc 40 self-formed.

In 4 has the bead 42 in the radial direction on a rising and a falling edge. Here is the wall thickness of the perforated disc 40 essentially constant everywhere. The perforated disc 40 is thus produced as a stamped and bent part. Characterized in that the area covered in the axial direction is greater than the wall thickness of the perforated disc 40 , Is with little material a large effective area for the radial flow portion available, so that a strong eddy current and thus a strong counteracting force component can be generated.

In this way, the armature disk is braked when releasing the brake after lifting from the brake pad carrier and the impact on the spool core 20 is muffled. Thus, the sound emission when venting or collapse of the brake is damped.

The perforated disc 40 or 3 also acts as a noise canceling.

The perforated disc ( 3 . 40 ) covers in the radial direction the area of the coil winding 21 , Thus, therefore, the radially overlapped area, so the overlapped radial distance range, greater than that of the coil winding 21 radially covered area. In this case, the radial distance refers to the distance to the axis of the receiving disk, which corresponds to the shaft axis.

The damping of the movement achieved according to the invention is preferably proportional to the speed.

This not only reduces the impact noise of the impact of the armature disk on the spool core but also the shock load of mounted on the shaft assemblies, such as an angle sensor for detecting the angular position of the shaft, in particular rotor shaft.

In addition, this is reduced by the residual ripple of the coil winding supplying DC voltage in the released state of the brake, so when energized the coil winding, caused hum noise.

In a further embodiment of the invention, the steel sheet package is eliminated 2 so that the perforated disc 3 directly on the receiving part 1 is arranged.

In a further embodiment of the invention, no beading of a piece of sheet metal is carried out with a substantially constant wall thickness but the other part, so the perforated disc ( 3 . 40 ) is designed with a non-constant, so variable wall thickness, in particular with a variable wall thickness in the radial direction. The maximum of the wall thickness in the radial direction is arranged in the same radial distance range as the bead described above. So this maximum is in the radial gap covered by the coil winding.

Preferably, the bead or the maximum wall thickness protrudes axially, so that the perforated disc in from the coil winding 21 Covered radial distance range axially even with that of the coil core 20 overlapped axial area overlaps. Because the coil winding 21 in a recess of the spool core 20 is absorbed and something is sunk in the bobbin 20 , nevertheless an air gap remains between the perforated disc ( 3 . 40 ) available. The perforated disc ( 3 . 40 ) only dives into the depression.

In a further embodiment of the invention, the further part, so the perforated disc ( 3 . 40 ) disposed axially within the armature disk. For example, the armature disk is executable with a laminated core, wherein one of the individual sheets of the laminated core is designed as the perforated disk, in particular of copper, and the other individual sheets as sheet steel parts.

LIST OF REFERENCE NUMBERS

1

Pick-up disc of the anchor disc

2

Sheet pack of sheet steel perforated discs of the armature disc

3

Perforated disc made of metal

4

Recess for the passage of fasteners, such as bolts or screws

20

Plunger

21

Coil winding, potted with potting compound

40

Perforated disc made of metal

41

Pick-up disc of the anchor disc

42

Beading

Claims (12)

Electromagnetically actuated brake with armature disc and coil winding ( 21 ) characterized in that the armature disc a receiving part ( 1 ), in which a laminated core ( 2 ) on its coil winding ( 21 ) or the electromagnet side facing is received, wherein one of the individual sheets of the laminated core ( 2 ) is made as a further part of copper and on the coil winding ( 21 ) or the electromagnet side facing the laminated core ( 2 ) is arranged and the other individual sheets of the laminated core ( 2 ) are made of steel, so that the further part is made of a material of higher electrical conductivity than the receiving part ( 1 ), wherein the further part as perforated disc ( 3 ) is made. Brake according to claim 1, characterized in that the further part is made as a stamped and bent part. Brake according to at least one of the preceding claims, characterized in that the further part is made of copper or a copper-containing material and the receiving part ( 1 ) made of a steel. Brake according to at least one of the preceding claims, characterized in that between further part and receiving part ( 1 ) a laminated core ( 2 ), in particular wherein the laminated core ( 2 ) is made of a stack of sheet metal parts, in particular perforated discs, whose stacking direction is aligned parallel to the shaft axis. Brake according to at least one of the preceding claims, characterized in that the further part in the axial direction covers an area which exceeds the wall thickness of the further part, in particular wherein the wall thickness of the further part is substantially constant everywhere. Brake according to at least one of the preceding claims, characterized in that the area radially overlapped by the further part of the area of the coil winding ( 21 ) covered radial area covered or at least overlapped with it. Brake according to at least one of the preceding claims, characterized in that the further part has an annular elevation, in particular on the further part an annular elevation, in particular an annular, axially pronounced and / or protruding elevation, is formed, in particular wherein the annular elevation a bead ( 42 ), in particular wherein the annular elevation concentric with the armature disc and / or perforated disc ( 3 ), in particular the ring axis is the disc axis. Brake according to at least one of the preceding claims, characterized in that the axial part covered by the further part exceeds the wall thickness of the further part, in particular wherein the further part, in particular as a sheet metal part and / or perforated disc ( 3 ) formed further part, having the same wall thickness everywhere. Brake according to at least one of the preceding claims, characterized in that the area radially covered by the annular elevation within the area of the coil winding ( 21 ) is arranged radially overlapped area. Brake according to at least one of the preceding claims, characterized in that the axial area covered by the further part with that of the coil core ( 20 ) overlapped axial region, in particular wherein between further part and coil winding ( 21 ) An air gap is arranged, so the further part of the coil winding ( 21 ) is axially spaced. Brake according to at least one of the preceding claims, characterized in that the armature disc a laminated core ( 2 ), wherein one of the individual sheets of the laminated core ( 2 ) the other part is executed. Electric motor with brake according to at least one of the preceding claims.

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