Drive system for a load

Abstract

Drive system for a load, wherein the drive system comprises a shaft part (4), an electric motor and a braking device that can be intermediately arranged between the electric motor and the load, wherein the electric motor has a rotor shaft and a cage part (23), wherein the brake device has a brake drum (3) which has a recess, wherein the braking device is designed as a rotation-direction-independent backstop, so that the braking device is activated, that is, the rotor shaft is slowed down when a torque generated by the electric motor is less than a torque transmitted from the load to the electric motor. and the torque generated by the electric motor is passed through the braking device to the load without loss, if the torque generated by the electric motor is greater than the torque transmitted from the load to the electric motor, wherein the distance between a first and second inclined surface (28) of the respective recess, determined on a given radial distance, decreases with increasing radial distance, characterized by the fact that the cage part (23) has a bushing section (24) in which the rotor shaft of the electric motor is received and connected to the bushing section (24) by means of a keyway connection, wherein the bushing section (24) of the cage part (23) is radially spaced from a ring section of the cage part (23), wherein the bushing section (24) and the ring section are connected via a connecting section of the cage part (23), wherein the recesses (29) are arranged in the ring section of the cage part (23), wherein a bearing (22) can be arranged in the radial spacing area between radial section and bushing section (24) for supporting the shaft part (4), wherein an outer ring of another bearing (26) of the brake drum (3) is received and the inner ring of this further bearing (26) of the shaft part (4) is received.

Description

[0001] The invention relates to a drive system for a load.

[0002] It is generally known that electromagnetically actuated brakes can be controlled by applying or de-energizing them.

[0003] From DE 10 2004 022 368 A1, a blocking coupling and a gear unit protected against backlash is known as the closest prior art.

[0004] An irreversible wheel coupling is known from US 4 706 791 A.

[0005] The invention is therefore based on the objective of further developing a drive system for a load, whereby safety is to be increased by preventing unwanted torque flows.

[0006] According to the invention, the problem is solved in the drive system according to the features specified in claim 1 or 2.

[0007] Important features of the invention in the drive system according to claim 1 are that the drive system is designed for a load, wherein the drive system comprises an electric motor and a braking device that can be intermediately ordered between the electric motor and the load, wherein the braking device is designed as a rotation-direction-independent backstop, in particular such that the braking device is activated, In particular, the rotor shaft is slowed down when the torque generated by the motor is less than the torque transmitted from the load to the motor. and the torque generated by the motor is passed through the braking device to the load without loss, if the torque generated by the motor is greater than the torque passed from the load to the motor.

[0008] An advantage of this design is that no torque can be transmitted from the load to the motor. However, torque can be transmitted from the motor to the load. The operation is automatic; therefore, no control current needs to be generated to actuate the braking device. Instead, the activation of the braking device, i.e., the transfer of torque via the brake drum, occurs automatically depending on the direction of torque flow—that is, when the torque current flows from the load to the motor. In reverse operation, i.e., when the torque current flows from the motor to the load, the braking device releases automatically.

[0009] Important features of the invention in the drive system according to claim 2 are that the drive system is designed for a load, wherein the drive system comprises an electric motor and a braking device that can be intermediately ordered between the electric motor and the load, wherein a cage part, which is non-rotatably connected to the rotor shaft of the electric motor, has recesses, wherein a roller is arranged in each of the recesses, wherein a shaft section supported by at least one bearing in the cage part has a non-circular section, wherein a brake drum is rigidly connected to the engine housing, in particular rotationally fixed and / or screwed together, where the non-circular section limits the respective roller radially inwards and the brake drum limits the respective roller radially outwards, wherein the roller is limited in the circumferential direction by means of a first inclined surface of the cage part to define the edge of the recess and against the circumferential direction by means of a second inclined surface of the cage part to define the edge of the recess.

[0010] An advantage of this design is that no torque can be transmitted from the load to the motor. However, torque can be transmitted from the motor to the load. A further advantage is that only one coupling part, the cage part, needs to be connected to the motor's rotor shaft, and a second coupling part, the shaft part, needs to be connected to the driven shaft of the load. Thus, the intermediate rollers can be used to transmit torque by being pressed against the shaft part by the inclined surfaces of the cage part, creating a clamping connection when the motor's torque is directed to the load. However, when torque wants to flow from the load to the motor, the rollers are pressed radially outwards onto the brake drum by means of the non-circular sections, such as polygonal surface pieces, thereby initiating braking. This provides a particularly simple way to prevent backflow.

[0011] In an advantageous embodiment, the distance between the first and second inclined surfaces of the respective recess, determined at a given radial distance, decreases with increasing radial distance. In particular, the recess is designed to taper radially outwards. The advantage of this is that the rollers are pressed towards the non-circular section and thus clamp the shaft part when the effective torque from the motor flows via the rotor shaft and the cage part to the load.

[0012] In an advantageous embodiment, the cage part has a bushing section in which the rotor shaft of the motor is received, and in particular is connected to the bushing section by means of a keyway connection. wherein the bushing section of the cage part is radially spaced from a ring section of the cage part, wherein the bushing section and the ring section are connected via a connecting section of the cage part, the recesses are arranged in the ring section of the cage part. An advantage of this is that the bushing section receives the rotor shaft on its radial inner side and On its outer circumference is a bearing of the shaft part. In addition, the hollow, non-circular outer section of the shaft part can be arranged such that it radially surrounds the bushing section and is itself surrounded by the ring section of the cage part.

[0013] In an advantageous embodiment, the recesses extend radially through the ring section and / or are regularly spaced apart from one another in the circumferential direction. It is advantageous that the ring section limits the clearance, and in particular the play, of each roller in the circumferential direction, especially by means of the inclined surfaces associated with the respective recess. In the radial direction, the rollers are each limited by the bushing section radially inwards and by the brake drum radially outwards.

[0014] In an advantageous embodiment, a bearing can be arranged in the radial spacing area between the radial section and the bushing section for supporting the shaft part. In particular, an outer ring of the bearing is received by the cage part and an inner ring of the bearing by the shaft part. An advantage of this is that a compact brake device can be manufactured; in particular, the second coupling part can be mounted within the first coupling part.

[0015] In a preferred embodiment, the outer ring of a further bearing is received by the brake drum, and the inner ring of this further bearing is received by the shaft section. The advantage here is that the shaft section is supported in the brake drum by only one bearing.

[0016] In an advantageous embodiment, the shaft section has a section for connection to the driven load, in particular a section for a keyway connection to the driven load. It is advantageous that the braking device also acts as a coupling between the motor and the load.

[0017] In an advantageous embodiment, the non-circular section is a polygonal segment, in particular an external polygonal facet, such as an external hexagon, wherein the respective roller rests on the respective external polygonal facet, in particular the external hexagonal facet. An advantage of this is that simple manufacturing is enabled by allowing the polygonal faces to be designed as tangent surfaces.

[0018] Further advantages arise from the dependent claims. The invention is not limited to the combination of features of the claims. For those skilled in the art, further meaningful combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent, in particular from the problem statement and / or the problem arising from a comparison with the prior art.

[0019] The invention will now be explained in more detail with the help of illustrations: In the Fig. Figure 1 shows a drive system according to the invention in an oblique view, comprising an electric motor with motor housing 1 and a direction-independent braking device, in particular a backstop, arranged between the load to be driven and the electric motor, wherein the braking device comprises a housing-forming brake drum 3. In the Fig. Figure 2 shows the brake device exploded in an oblique view. In the Fig. Figure 3 shows the brake device without brake drum 3 in oblique view.

[0020] As shown in the figures, the brake device has a brake drum 3 which can be screwed to the electric motor, in particular to its motor housing 1.

[0021] For this purpose, the brake drum has recesses 29 on its axial end faces, so that connecting means for creating a screw connection on the one hand with the motor and on the other hand with the load to be driven by the drive system can be provided, in particular inserted into the recesses 29.

[0022] The brake drum 3 and the motor housing 1 can thus be connected in a rotationally fixed manner. Likewise, a flange part of the load to be driven can also be connected to the brake drum 3 in a rotationally fixed manner.

[0023] The brake drum is designed to form the housing for the brake device and has a recess located in the center of it.

[0024] The motor's rotor shaft is supported in the motor housing by means of two bearings and projects axially into a bushing section 24 of a cage part 23, which is designed as a receiving. The axial area covered by the rotor shaft overlaps with the axial area covered by the cage part 23, in particular by the bushing section 24 of the cage part 23.

[0025] The cage section 23 has a ring section which has radially extending recesses spaced regularly from one another in the circumferential direction. The ring section is rigidly connected to the bushing section 23 by means of a connecting section, in particular in one piece. The bushing section 23 and the ring section are radially spaced from each other. The connecting section extends from the radial space covered by the bushing section to the radial space covered by the ring section.

[0026] A bearing 22 is inserted into this radial spacing area. It is axially limited by the connecting section, and its outer ring is received by the cage part 23. The inner ring of the bearing 22 is connected to a shaft part 4, which has a hollow section that is designed as a polygonal section on its radial outer side, in particular as a multi-sided section, such as an external hexagonal section. A projecting shaft end, which has a keyway, is axially connected to this hollow section of the shaft part 4, so that the interface part, which is rotatably mounted laterally, can be connected in a rotationally fixed manner by means of a keyway connection.

[0027] The hollow section is designed with such a radial wall thickness that it can be inserted axially between the bushing section 24 and the ring section, together with the bearing 22 mounted on the shaft part 4, the inner ring of which is mounted by the shaft part 4 and thus supports the shaft part 4 in the cage part 23.

[0028] A further receiving area 30, for receiving the inner ring of the other bearing 26, whose outer ring is received in the brake drum 3, is axially spaced from this receiving area by means of the polygonal segment. A shaft seal 25, whose sealing lip acts on a surface section of the shaft part 4 machined as a running surface, is arranged axially adjacent to this outer ring in the brake drum 3.

[0029] The radially continuous recesses, together with the bushing section 24 and the brake drum 3, each define a movement space for a respective roller 21.

[0030] When the load is driven by the motor, i.e., when the torque from the motor is transmitted to the load via the braking device, roller 21 is pressed circumferentially by an inclined surface 28 of the edge of the respective continuous recess. Since the inclined surface 28 has such a slope that its area extends increasingly circumferentially with increasing radial distance, the roller is pressed very strongly against the external hexagonal surface 20 by the inclined surface 28. Thus, the shaft section is clamped by the rollers 21 and set into rotation. In this way, the torque generated by the electric motor is transmitted through the shaft section 4 via the keyway connection to the load. No braking effect, i.e., no friction of the rollers 20 against the brake drum 3, occurs because the roller is pressed radially inwards by the inclined surface.

[0031] The same mechanism is also present in the reverse direction of rotation, so that the torque generated by the motor is transmitted to the load. This is because the two inclined surfaces 28, which act as the boundary of the respective continuous recess, are arranged symmetrically to each other in the circumferential direction. Thus, with increasing radial distance, the clear width between the inclined surfaces 28 belonging to one of the recesses decreases. The extent of the recess therefore becomes narrower with increasing radial distance. In particular, all of this applies to the spacing or clear width when measured in the circumferential direction with a constant radial distance, i.e., on an imaginary cylindrical surface with the respective radial distance.

[0032] However, if the torque coming from the load is transmitted through the braking device to the motor, especially during generator operation of the motor, then the respective roller 21 is forced by the respective external hexagonal surface 20 contacting it to a greater radial distance and then protrudes towards the brake drum 3, so that it is pressed onto it and a braking effect is achieved.

[0033] Thus, torque can be transmitted from the motor to the load in both directions of rotation, but not from the load to the motor. Preferably, the rollers 21 are made of hardened steel and the brake drum is made of cast steel or gray cast iron, or a steel, in particular a less hardened steel than the rollers.

[0034] The rotor shaft of the electric motor is supported in the motor housing 3 by means of two bearings. Preferably, the motor housing 3 is made of multiple parts. In a further embodiment of the invention, the recesses 29 are axially continuous, thus allowing the use of tie rods for connection. Reference symbol list 1 Motor housing 2 junction boxes 3 brake drums 4 shaft section 20 External hexagonal surface 21 roll 22 warehouses 23 Cage 24 socket section 25 Shaft seal 26 warehouses 27 Keyway 28 inclined surface 29 exceptions 30 additional recording areas

Claims

[1] Drive system for a load, wherein the drive system comprises a shaft part (4), an electric motor and a braking device that can be intermediately arranged between the electric motor and the load, wherein the electric motor has a rotor shaft and a cage part (23), wherein the brake device has a brake drum (3) which has a recess, wherein the braking device is designed as a rotation-direction-independent backstop, so that the braking device is activated, that is, the rotor shaft is slowed down when a torque generated by the electric motor is less than a torque transmitted from the load to the electric motor. and the torque generated by the electric motor is passed through the braking device to the load without loss, if the torque generated by the electric motor is greater than the torque transmitted from the load to the electric motor, wherein the distance between a first and second inclined surface (28) of the respective recess, determined on a given radial distance, decreases with increasing radial distance, characterized by , that the cage part (23) has a bushing section (24) in which the rotor shaft of the electric motor is received and connected to the bushing section (24) by means of a keyway connection, wherein the bushing section (24) of the cage part (23) is radially spaced from a ring section of the cage part (23), wherein the bushing section (24) and the ring section are connected via a connecting section of the cage part (23), wherein the recesses (29) are arranged in the ring section of the cage part (23), wherein a bearing (22) can be arranged in the radial spacing area between radial section and bushing section (24) for supporting the shaft part (4), wherein an outer ring of another bearing (26) of the brake drum (3) is received and the inner ring of this further bearing (26) of the shaft part (4) is received. [2] Drive system for a load, wherein the drive system comprises an electric motor and a braking device that can be intermediately ordered between the electric motor and the load, wherein a cage part (23) which is non-rotatably connected to the rotor shaft of the electric motor has recesses (29), wherein a roller (21) is arranged in each of the recesses (29), wherein a shaft part (4) supported in the cage part (23) by means of at least one bearing (22) has a non-circular section, wherein a brake drum (3) is rigidly connected to a motor housing (1) of the electric motor, wherein the non-circular section limits the respective roller (21) radially inwards and the brake drum (3) limits the respective roller (21) radially outwards, wherein the roller (21) is bounded circumferentially by means of a first inclined surface (28) of the cage part (23) to define the recess and against the circumferential direction by means of a second inclined surface (28) of the cage part (23) to define the recess, wherein the distance between the first and second inclined surface (28) of the respective recess, which is determined at a respective radial distance, decreases with increasing radial distance, characterized by , that the cage part (23) has a bushing section (24) in which the rotor shaft of the electric motor is received and connected to the bushing section (24) by means of a keyway connection, wherein the bushing section (24) of the cage part (23) is radially spaced from a ring section of the cage part (23), wherein the bushing section (24) and the ring section are connected via a connecting section of the cage part (23), wherein the recesses (29) are arranged in the ring section of the cage part (23), wherein a bearing (22) can be arranged in the radial spacing area between radial section and bushing section (24) for supporting the shaft part (4), wherein an outer ring of another bearing (26) of the brake drum (3) is received and the inner ring of this further bearing (26) of the shaft part (4) is received. [3] Drive system according to claim 1 or 2, characterized by , that the recesses (29) extend radially through the ring section and / or are regularly spaced apart from each other in the circumferential direction. [4] Drive system according to at least one of the preceding claims, characterized by , that an outer ring of the bearing (22) is received by the cage part (23) and an inner ring of the bearing (22) by the shaft part (4). [5] Drive system according to claim 1, characterized by, that the shaft part (4) has a non-circular section for connection with the load to be driven. [6] Drive system according to at least one of the preceding claims, characterized by that the non-circular section is a polygonal section. [7] Drive system according to claim 6, characterized by , that the polygon segment is an external polygon, such as an external hexagon, wherein the respective roller (21) rests on a respective outer polygonal surface of the outer polygon.

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