SHAFT-HUB CONNECTION AND BRAKE ASSEMBLY WITH A SHAFT-HUB CONNECTION

Description

[0001] The invention relates to a shaft-hub connection and brake arrangement with a shaft-hub connection.

[0002] It is generally known that in a shaft-hub connection the shaft is connected to the hub in a rotationally fixed manner.

[0003] From the DE 10 2011 121 790 A1 A toothed clutch with a suspension, brake and system is known.

[0004] From the US 4 136 982 A A centered connection arrangement is known.

[0005] From the US 2 800 800 A An anti-chatter arrangement is known.

[0006] From the DE 10 2006 010 656 B3 A spring-loaded brake with a brake disc having friction surfaces on opposite sides is known.

[0007] From the WO 96 / 05101 A1 A mounting arrangement for propellers is known.

[0008] From the WO 2011 / 058000 A1 The closest prior art is a device for coupling a drive shaft of an auxiliary unit of a commercial vehicle to a wheel drive.

[0009] From the DE 10 2018 131836 A1 A gear arrangement is known.

[0010] From the WO 2018 / 174844 A1 A hydraulic clamping arrangement is known.

[0011] From the WO 2009 / 116615 A1 a wire ring is known.

[0012] From the US 2012 / 076576 A1 A spring-loaded brake with a brake disc having friction surfaces on opposite sides is known.

[0013] From the US 5 361 740 A A mechanical arrangement with hardened bearing surfaces is known.

[0014] The invention is therefore based on the object of developing a shaft-hub connection that can be operated with low noise.

[0015] According to the invention, the object is achieved by the features specified in claim 1.

[0016] Important features of the invention in the shaft-hub connection are that the rotatably mounted shaft has an external toothing and the hub has an internal toothing, wherein the hub with its internal toothing is placed onto the shaft with external toothing in such a way that the external toothing is in engagement with the internal toothing, wherein the shaft has an annular groove, in particular an annular groove which runs completely and / or continuously in the circumferential direction, in particular wherein the shaft is connected to the hub in a rotationally fixed manner and is arranged so as to be displaceable in the axial direction relative to the hub, wherein an annular spring, in particular a spring ring, is arranged in the annular groove, wherein the annular groove is introduced in particular centrally in the external toothing and / or the area covered by the annular groove in the axial direction is encompassed by the area covered by the external toothing in the axial direction.

[0017] The advantage here is that the annular spring creates a backlash-free shaft-hub connection, thus suppressing the noise caused by speed fluctuations. Furthermore, the annular spring is positively secured in the annular groove and thus securely positioned. Furthermore, the annular spring can be clamped within the groove and is thus itself positioned in the annular groove without backlash. Thus, the annular spring also does not produce any rattling noises, especially during speed fluctuations.

[0018] The annular spring can also be referred to as a spring washer. However, the pitch in the axial direction is a monotonically increasing function, specifically a linear function, of the circumferential angle. Only the radial distance of the annular spring is a periodic function of the circumferential angle.

[0019] According to the inventionthe annular spring has a maximum radial distance relative to the axis of rotation of the shaft, which is a variable function, in particular a periodic function, of the circumferential angle, In particular, the annular spring rests against the bottom of the annular groove at the local minima of the function, and in particular, the local maxima of the function are arranged in the circumferential direction between two teeth of the internal gearing of the hub. The advantage here is that the annular spring is elastically tensioned in the radial direction when the hub is pushed onto the shaft, thus preventing any play between the shaft and hub in the radial direction.

[0020] In an advantageous embodiment, the annular spring is made of a metal wire, in particular as a bent part, In particular, the wire diameter of the metal wire is constant, in particular, it does not depend on the circumferential angle, but is a constant function of the circumferential angle. This is advantageous in that it allows for cost-effective production and a long service life for the annular spring. Furthermore, operation is also possible at high temperatures. Compared to rubber or plastic, metal is elastically deformable at much higher temperatures, in particular, it is reversibly elastically deformable.

[0021] In an advantageous embodiment, the annular spring has a pitch and / or a helix angle. This is advantageous because the annular spring is held elastically between the groove walls and is thus axially securely positioned. This allows the annular spring to be clamped within the annular groove and thus also sits within the annular groove without play. This also prevents the annular spring from producing rattling noises, especially during speed fluctuations.

[0022] In an advantageous embodiment, the annular spring has an increasing axial position with increasing circumferential angle, in particular an axial position that increases proportionally to the circumferential angle, in particular with the axial direction aligned parallel to the shaft's axis of rotation. This is advantageous in that the annular spring is held elastically between the groove walls and is thus axially secured. The annular spring can thus be clamped within the annular groove and is thus arranged in the annular groove without play. Thus, the annular spring does not generate any rattling noises, especially during speed fluctuations.

[0023] In an advantageous embodiment, the annular spring is arranged elastically tensioned between the groove walls of the annular groove. Advantageously, the annular spring is arranged in a captive manner.

[0024] In an advantageous design, the two ends of the annular spring press into the bottom of the annular groove. This provides the advantage of high static friction and thus stable positioning.

[0025] In an advantageous embodiment, the hub, in particular the internal toothing of the hub, in particular only at its first axial end region, has a chamfer, in particular wherein the chamfer is designed such that the clear inner diameter, in particular the smallest clear inner diameter, of the internal toothing increases in the axial direction with increasing distance from the first axial end of the internal toothing, in particular proportional to the distance from the first axial end of the internal toothing. The advantage here is that the hub is first threaded in the sliding-on direction and then slides onto the annular spring during further axial sliding, so that the latter is then elastically deformed radially inwards, in particular is pressed onto the groove base of the annular groove. The elastic spring force of the annular spring generated in this way then suppresses any play between the shaft and the hub.

[0026] In an advantageous embodiment, the internal and external gearing are each designed as straight gears. This is advantageous because it allows the shaft to be pushed axially onto the hub.

[0027] In an advantageous embodiment, the internal and external gearing are each designed as involute gearing. This allows for cost-effective and high-precision manufacturing.

[0028] In an advantageous embodiment, the annular spring covers a circumferential angle of less than 360°, in particular a circumferential angle between 200° and 340°. This allows for quick and easy insertion of the annular spring into the annular groove.

[0029] Important features of the brake assembly with a shaft-hub connection are that the shaft is a driver of a brake assembly and the hub is a brake pad carrier of a brake assembly, with the shaft being a hollow shaft part.

[0030] The advantage here is that the brake pad carrier can be connected to the shaft with low noise, especially when speed fluctuations occur during operation.

[0031] The brake pad carrier is arranged to be axially displaceable so that when the brake is applied or released, the brake pad carrier can be positioned axially accordingly.

[0032] In an advantageous embodiment, the driver is mounted on a rotor shaft of an electric motor and connected to the rotor shaft in a rotationally fixed manner, with the rotor shaft being rotatably mounted relative to a housing part of the electric motor. The advantage here is that the driver, not the rotor shaft itself, requires external gearing. The rotationally fixed connection between the driver and the rotor shaft is preferably achieved by a cost-effective keyed connection.

[0033] In an advantageous embodiment, the brake arrangement has a magnetic body which is connected in a rotationally fixed manner to the housing part, in particular to the flange part of the electric motor or to the part which is connected in a rotationally fixed manner to a flange part of the electric motor, wherein an electrically energizable coil is accommodated in the magnetic body, wherein an armature disk is connected to the magnetic body in a rotationally fixed manner, in particular in the circumferential direction, and is arranged so as to be axially displaceable relative to the magnetic body, in particular by means of bolts which are firmly connected to the magnetic body and project through recesses in the armature disk, wherein the brake pad carrier is connected to the driver in a rotationally fixed manner, in particular in the circumferential direction, and is arranged so as to be axially displaceable relative to the driver, wherein the armature disk is arranged axially between the brake pad carrier and the magnetic body, wherein spring elements supported on the magnetic body press onto the armature disk, wherein the brake pad carrier is arranged axially between a braking surface and the armature disk. The advantage here is that the braking effect occurs automatically in the event of a power failure, thus achieving a high level of safety. The brake can be released by energizing the coil.

[0034] In an advantageous embodiment, the braking surface is formed on the housing part. This allows for efficient heat dissipation to the environment.

[0035] In an advantageous embodiment, when the coil is energized, the armature disk is drawn toward the magnet body against the spring force generated by the spring elements. When the coil is de-energized, the spring elements press the armature disk toward the brake pad carrier, so that the brake pad carrier, with its side facing away from the armature disk, is pressed onto the braking surface. The advantage here is that the braking effect occurs automatically in the event of a power failure, thus achieving a high level of safety. The brake is released by energizing the coil.

[0036] In an advantageous embodiment, the brake pad carrier has a chamfer only on the axial end region of its internal toothing facing the armature disc. The advantage here is that the chamfer is only necessary on the end region intended for sliding on.

[0037] In another advantageous embodiment, the brake pad carrier has a chamfer only at the axial end of its internal toothing facing away from the armature disc. The advantage here is that the chamfer is only necessary at the end intended for sliding on.

[0038] In an advantageous embodiment, the chamfer is designed such that the internal diameter, in particular the smallest internal diameter, of the internal toothing increases in the axial direction with increasing distance from the first axial end of the internal toothing, in particular proportionally to the distance from the first axial end of the internal toothing. This allows for simple production of the chamfer and the radial force component of the spring force increases proportionally with the axial displacement.

[0039] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0040] The invention will now be explained in more detail using schematic illustrations: In the Figure 1 A hub of a shaft-hub connection, in particular of a brake assembly, designed as a brake pad carrier is shown in an oblique view. Figure 2 The hub is shown from a different angle in an oblique view. In the Figure 3 A cross-section of the hub is shown. Figure 4 An area of ​​the figure is shown enlarged. In the Figure 5 A side view of a shaft designed as a cut driver 50 is shown, in whose external toothing 51 an annular spring is accommodated in a circumferential annular groove. Figure 6 A top view of the cross-sectioned shaft is shown. Figure 7 The annular spring 52 is shown in an oblique view. In the Figure 8 a side view of the annular spring 52 is shown.

[0041] As shown in the figures, a shaft is designed with external toothing 51, onto which a hub is mounted in such a way that an internal toothing of the hub engages the external toothing 51, thus connecting the hub to the shaft in an axially movable manner but with a positive fit in the circumferential direction. Within the external toothing 51, an annular groove is arranged, preferably centrally within the external toothing in the axial direction and completely circumferentially. An annular spring 52 is received in the annular groove.

[0042] This annular spring 52 is made of a metal wire and is not completely circumferential.

[0043] The annular spring 52 covers a circumferential angle of less than 360° in the circumferential direction, in particular a circumferential angle of between 200° and 340°.

[0044] The annular spring 52 has a particular maximum radial distance which varies periodically and / or is variable depending on the circumferential angle.

[0045] The wire diameter is essentially constant along the annular spring 52.

[0046] The annular spring 52 has a non-zero pitch, so that the axial position of the annular spring increases with increasing circumferential angle. This enables elastic clamping between the groove walls formed on the annular groove in the axial direction and counteraxial direction.

[0047] In addition, the two ends of the annular spring 52 press radially inward onto the groove bottom of the annular groove, as shown in Figure 6 clearly visible. This improves the adhesion of the annular spring 52 to the shaft.

[0048] When the hub is axially fitted with its internal toothing onto the external toothing 51, a chamfer 2 formed on the hub allows the radially inwardly projecting teeth of the internal toothing to slide onto the annular spring 52. The annular spring 52 is thereby pressed radially inward, particularly toward the bottom of the annular groove. The annular spring 52 is elastically tensioned and generates a corresponding radially outward-acting spring force, which is introduced into the hub.

[0049] Thus, the hub is positively connected to the shaft in the circumferential direction, and the shaft is arranged to be displaceable relative to the hub in the axial direction. The radial play is eliminated by the elastically tensioned annular spring 52.

[0050] Due to the elastically prestressed contact of the annular spring 52 on both groove walls of the annular groove, the annular spring 52 is arranged in the annular groove without play.

[0051] In an exemplary application of this shaft-hub connection according to the invention, the hub is designed as a brake pad carrier 1 of an electromagnetically actuated brake arrangement and the shaft as a driver 50 of this brake arrangement.

[0052] The driver 50 is designed as an externally toothed hollow shaft and is placed on a rotor shaft of an electric motor and connected to the rotor shaft in a rotationally fixed manner, in particular by means of a key connection.

[0053] The external toothing of the driver 50 is preferably designed as knurling or as axially directed involute toothing, i.e. having a helix angle of zero.

[0054] The radial spacing area covered by the annular spring 52 is encompassed by the radial spacing area covered by the teeth of the external toothing 51. Thus, the teeth protrude radially beyond the annular spring 52. Alternatively, the annular groove on the driver 50 is cut radially deeper than the toothing, so that the radial spacing area covered by the annular spring 52 overlaps the radial spacing area covered by the teeth of the external toothing 51.

[0055] The chamfer 2 is arranged only on one of the two axial end regions of the internal toothing of the brake pad carrier 1. In particular, the mounting direction for attaching the brake pad carrier 1 to the driver 50 is thus predetermined.

[0056] The brake pad carrier 1 has a brake pad axially on both sides.

[0057] The rotor shaft is rotatably mounted by means of bearings which are housed in flange parts which are connected to the stator housing of the electric motor.

[0058] The brake arrangement has a braking surface which is formed either on one of the flange parts itself, in particular is finely machined, or on a part connected to a first of the flange parts.

[0059] A magnetic body of the brake assembly is connected in a rotationally fixed manner to the part or flange part.

[0060] A coil, preferably designed as a toroidal winding, is housed in the magnet body. For this purpose, an annular or pot-shaped recess is preferably provided in the magnet body, into which the coil is inserted and encapsulated with potting compound.

[0061] The ring axis of the ring winding is aligned parallel to the axial direction.

[0062] An armature disk is connected to the magnetic body in a rotationally fixed manner and is arranged for axial displacement. Preferably, axially aligned bolts are connected to the magnetic body, which extend through corresponding recesses in the armature disk. In this way, the magnetic body can be connected to the part or to the flange part by means of the bolts.

[0063] The armature disk is made of ferromagnetic material.

[0064] The armature disk is arranged axially between the magnet body. The brake pad carrier 1 is arranged axially between the braking surface and the armature disk.

[0065] Elastically deformed spring elements supported on the magnet body press on the armature disk.

[0066] Thus, when the coil is energized, the armature disk is drawn toward the magnet body against the spring force generated by the spring elements. This releases the brake pad carrier 1 and releases the brake assembly.

[0067] In addition, when the coil is not energized, the spring elements press the armature disk away from the magnet body towards the brake pad carrier, which is thus pressed onto the braking surface on its side facing away from the armature disk and the braking arrangement thus engages, in particular it introduces a braking torque into the rotor shaft.

[0068] The ring spring 52 can also be referred to as a spring ring.

[0069] In further embodiments according to the invention, the minimum radial distance of the internal toothing of the brake pad carrier at chamfer 2 does not increase linearly with the axial position as in the example shown in the figures, but rather the chamfer 2 is curved. Thus, the internal toothing achieves a longer service life, especially in the area of ​​the chamfer. List of reference symbols

[0070] 1 Brake pad carrier 2 Chamfer 50 Driver 51 External toothing 52 Ring spring

Claims

1. A shaft-hub connection having a shaft and a hub, wherein the shaft has an external toothing (51) and the hub has an internal toothing, wherein the hub with its internal toothing is placed onto the shaft with external toothing (51) in such a manner that the external toothing (51) meshes with the internal toothing, wherein the shaft has an annular groove, in particular an annular groove encircling in a circumferential direction in a complete and / or uninterrupted manner, wherein an annular spring (52), in particular a spring ring, is arranged in the annular groove, characterised in that the shaft is connected to the hub in a rotationally-fixed manner and is arranged so as to be displaceable relative to the hub in an axial direction, wherein - the annular groove is made, in particular centrally, in the external toothing (51) and - the region covered in an axial direction by the annular groove is encompassed by the region covered in an axial direction by the external toothing (51), wherein the annular spring (52) has a maximum radial distance related to the rotational axis of the shaft, which distance is a variable function, in particular a periodic function, of the circumferential angle.

2. A shaft-hub connection according to claim 1, characterised in that at the local minima of the function, the annular spring (52) contacts the groove bottom of the annular groove, in particular wherein the local maxima of the function are in a circumferential direction arranged between in each case two teeth of the internal toothing of the hub.

3. A shaft-hub connection according to any one of the preceding claims, characterised in that the annular spring (52) is manufactured from a metal wire, in particular in the form of a bent part, in particular wherein the wire diameter of the metal wire is constant, in particular is not dependent on the circumferential angle, in particular rather is a constant function of the circumferential angle.

4. A shaft-hub connection according to any one of the preceding claims, characterised in that the annular spring (52) has a slope and / or a helix angle and / or in that the annular spring (52) has an increasing axial position as the circumferential angle increases, in particular an axial position increasing proportionally to the circumferential angle, in particular wherein the axial direction is oriented parallel to the rotational axis of the shaft.

5. A shaft-hub connection according to any one of the preceding claims, characterised in that the annular spring (52) is arranged between the groove walls of the annular groove in an elastically tensioned manner.

6. A shaft-hub connection according to any one of the preceding claims, characterised in that the two ends of the annular spring (52) press into the groove bottom of the annular groove.

7. A shaft-hub connection according to any one of the preceding claims, characterised in that the hub, in particular the internal toothing of the hub, has a chamfer (2), in particular only at its first axial end-region, in particular wherein the chamfer (2) is such that the inside diameter, in particular the smallest inside diameter, of the internal toothing increases in an axial direction as the distance from the first axial end of the internal toothing increases, in particular proportionally to the distance from the first axial end of the internal toothing.

8. A shaft-hub connection according to any one of the preceding claims, characterised in that the internal toothing and the external toothing (51) are in each case in the form of spur toothing and / or in that the internal toothing and the external toothing (51) are in each case in the form of involute toothing.

9. A shaft-hub connection according to any one of the preceding claims, characterised in that the annular spring (52) covers a circumferential angular amount of less than 360° in a circumferential direction, in particular a circumferential angular amount between 200° and 340.

10. A brake arrangement having a shaft-hub connection according to any one of the preceding claims, characterised in that the shaft is a driver (50) of a brake arrangement and the hub is a brake lining carrier (1) of a brake arrangement, wherein the shaft is a hollow shaft part.

11. A brake arrangement according to any one of the preceding claims, characterised in that the driver (50) is placed onto a rotor shaft of an electric motor and is connected to the rotor shaft in a rotationally-fixed manner, wherein the rotor shaft is rotatably mounted relative to a housing part of the electric motor.

12. A brake arrangement according to any one of the preceding claims, characterised in that the brake arrangement has a magnetic body which is connected in a rotationally-fixed manner to the housing part, in particular to the flange part of the electric motor or to the part connected in a rotationally-fixed manner to a flange part of the electric motor, wherein the magnetic body receives a coil energisable electrically, wherein an armature plate is, in particular in a circumferential direction, connected to the magnetic body in a rotationally-fixed manner and is arranged in an axially displaceable manner with respect to the magnetic body, in particular by means of bolts which are securely connected to the magnetic body and which project through cutouts in the armature plate, wherein the brake lining carrier (1) is, in particular in a circumferential direction, connected to the driver (50) in a rotationally-fixed manner and is arranged in an axially displaceable manner with respect to the driver (50), wherein the armature plate is arranged axially between the brake lining carrier (1) and the magnetic body, wherein spring elements supported on the magnetic body press onto the armature plate, wherein the brake lining carrier (1) is arranged axially between a brake surface and the armature plate.

13. A brake arrangement according to any one of the preceding claims, characterised in that the brake surface is formed on the housing part, and / or in that the armature plate is upon energisation of the coil pulled towards the magnetic body counter to the spring force generated by the spring elements and the spring elements push the armature plate towards the brake lining carrier (1) upon non-energisation of the coil, so that the side of the brake lining carrier (1) remote from the armature plate is pushed onto the brake surface.

14. A brake arrangement according to any one of the preceding claims, characterised in that the brake lining carrier (1) has a chamfer (2) only at the axial end-region, facing the armature plate, of its internal toothing, or in that the brake lining carrier (1) has a chamfer (2) only at the axial end-region, remote from the armature plate, of its internal toothing.

15. A brake arrangement according to any one of the preceding claims, characterised in that the chamfer (2) is configured such that the inside diameter, in particular the smallest inside diameter, of the internal toothing increases in an axial direction as the distance from the first axial end of the internal toothing increases, in particular proportionally to the distance from the first axial end of the internal toothing.