Patent Application
20250180074
The present invention relates to an apparatus for transmitting torque, a differential transmission with an apparatus for transmitting torque, and a vehicle with a differential transmission.
Take-up toothings for transmitting torque are known. In a take-up toothing, non-uniform wear and local failure of a take-up toothing profile may occur.
It is an object of the present invention to provide an improved apparatus for transmitting torque, with which a long service life and a high load-bearing capacity are achieved.
The present invention achieves the object with an apparatus that comprises the features of claim 1. Advantageous developments are the subject matter of the dependent claims.
An apparatus for transmitting torque comprises a hub element and a shaft element. The hub element comprises a hub engagement section with a hub take-up profile which may be brought into engagement with a shaft engagement section with a shaft take-up profile for transmitting torque. The hub engagement section may comprise the hub take-up profile at an inner circumference. The shaft engagement section may comprise the shaft take-up profile at an outer circumference. The hub element comprises a hub connection section which is arranged offset in an axial direction towards a connection side relative to the hub engagement section. The hub engagement section of the hub element may be arranged offset in a radial direction, for example inwardly, relative to the hub connection section.
The shaft element comprises a shaft connection section which is arranged offset in the axial direction towards the connection side relative to the shaft engagement section.
The shaft element may be torque-proofly connectable to the hub element via the engagement of the shaft engagement section with the hub engagement section.
A torque-proof connection of two elements is understood to mean a connection in which the two elements are rigidly coupled to one another for all intended states of the transmission, so that they have substantially the same rotational speed. The elements may be present here as individual components connected in a torque-proof manner to one another or else in one piece. A torque-proof connection may comprise a spline profile. The spline profile may be configured, for example, as a splined shaft, toothed shaft or notched profile. An axial securing means, for example a securing ring, snap ring or spiral ring, may be provided for limiting a relative movement in the axial direction. The torque-proof connection may be configured as a press connection or by means of screw connections of flanges of the elements.
The hub element and the shaft element may be rotatable about a common axis of rotation. The shaft take-up profile and the hub take-up profile may be configured for transmitting torque. The torque may be transmitted by means of a circumferential force in a circumferential direction and a distance from the axis of rotation. The distance of the circumferential force from the axis of rotation may be formed by a diameter of the shaft take-up profile or of the hub take-up profile. The shaft take-up profile and the hub take-up profile may each be configured as a spline or as a polygon profile. The shaft take-up profile and the hub take-up profile may each extend in the axial direction. The shaft take-up profile and the hub take-up profile may each extend in a spiral shape.
The connection sides of the shaft element and of the hub element may be configured for receiving or outputting torque. The hub connection section may be configured for receiving torque. For example, the hub connection section may comprise receptacles for bolts. The hub element may be driven from outside the apparatus. The shaft connection section may be configured for outputting torque. The shaft connection section may be configured for connection to a wheel hub of a drive wheel of a vehicle.
The hub element may be hollow. The shaft element may be cylindrical. The shaft element may extend through the hub element. The shaft engagement section may be arranged within the hub engagement section in the radial direction. The shaft element may comprise the shaft engagement section at one end in the axial direction on the engagement side. The hub connection section may be torque-proofly connected to the hub engagement section. The torque-proof connection may be configured for an advantageous introduction of force. The torque-proof connection may be configured such that an advantageous force distribution profile is established in the axial direction between the shaft take-up profile and the hub take-up profile.
In an embodiment, the hub element may be displaceable in the axial direction relative to the shaft element.
In an embodiment, the hub engagement section and the shaft engagement section may be configured for a uniform force distribution in the axial direction between the hub take-up profile and the shaft take-up profile. A uniform force distribution may comprise a circumferential force between the hub take-up profile and the shaft take-up profile that is substantially constant section-wise in the axial direction. A uniform force distribution may comprise a circumferential force between the hub take-up profile and the shaft take-up profile that is adapted in the axial direction to load-bearing capacities of the hub take-up profile and of the shaft take-up profile that are different in certain areas.
In an embodiment, the hub element may comprise an offset section which extends in the axial direction from the hub connection section towards an engagement side opposite the connection side. The offset section may be torque-proofly connected to an area of the hub engagement section.
The offset section may be configured in one piece with the connection section of the hub element. The offset section may be connected to an outer circumference of the hub engagement section. The offset section may extend in the axial direction. The offset section may extend from the connection section in the axial direction towards the engagement side. The offset section may be hollow. The offset section may be tubular. The offset section may be cylindrical. The offset section may comprise a radial section at an end section on the engagement side, which extends inwardly in a radial direction. The radial section may be toque-proofly connected to the hub engagement section.
The offset section may be arranged outside the hub engagement section in the radial direction. The offset section may overlap the hub engagement section in the axial direction. The offset section may extend in the axial direction in an area of the hub engagement section. A relief groove may be provided between the hub engagement section and the offset section. The relief groove may be formed as a gap. The gap may be formed by an inner circumference of the offset section. The gap may be formed by an outer circumference of the hub engagement section. The gap may be annular. The gap may extend from the radial section towards the connection side in the axial direction. The gap may be formed by cutting. The gap may be manufactured by means of eroding. The gap may be forged. A force transmission from the offset section to the hub engagement section in the area of the gap may be prevented via the gap. A force flow may thus be diverted.
An introduction of force into the hub engagement section may be advantageously formed via the position of the connection of the offset section to the hub engagement section in the axial direction. The connection may be positioned at an end area of the hub engagement section on the engagement side. The connection may be positioned in the axial direction in a central area of the hub engagement section. The connection may be positioned in the axial direction in an area between the central area and the end area on the engagement side of the hub engagement section.
In an embodiment, the offset section may be connected to an area of the hub engagement section which is central in the axial direction. The central area may include the geometric center of the hub engagement section in the axial direction. The central area may extend from a first third of the extension of the hub engagement section in the axial direction to a second third of the extension of the hub engagement section in the axial direction. As a result, the torque may be introduced close to the center or through the geometric center in the axial direction of the hub engagement element and the shaft engagement element. This is advantageous for the force flow through the shaft take-up profile and the hub take-up profile. As a result, the shaft take-up profile and the hub take-up profile may be loaded to a larger extent. A diameter in the radial direction of the shaft take-up profile and the hub take-up profile may be reduced. As a result, a diameter of the shaft element as a whole may be reduced.
In an embodiment, the offset section may be connected to an end area of the hub engagement section, which is arranged on the engagement side in the axial direction. The end area may extend from the central area to the end of the hub engagement section on the engagement side. The end area may extend within the last third of the extension of the hub engagement section in the axial direction on the engagement side. As a result, the torque may be introduced close to the center into an area on the engagement side of the hub engagement section in the axial direction of the hub engagement element and the shaft engagement element. This is advantageous for the force flow through the shaft take-up profile and the hub take-up profile.
In an embodiment, the offset section and the hub engagement section may be configured in two parts. The offset section may be torque-proofly connected to the hub engagement section by means of welding. The gap may then be configured to be thin in the radial direction, for example thinner than in the case of a gap produced by forging. The hub engagement section may comprise a positioning section, which extends in the axial direction, on which the offset section may be positioned in the radial direction. The positioning section may be cylindrical. The hub engagement section may comprise a contact section, which extends in the radial direction and at which the offset section may be positioned in the axial direction.
In an embodiment, the offset section may be configured in one piece with the hub engagement section and the connection section. The hub element may be produced by forging.
In an embodiment, the apparatus may comprise an axial securing means which is arranged on the engagement side in the axial direction relative to the offset section and positions the shaft element in the axial direction relative to the hub element. The axial securing means may be configured as a bearing, as an axial stop, as a securing ring or as a snap ring. With the axial securing means, a movement of the shaft element and of the hub element relative to one another may be restrictable. The axial securing means may be fitted into a groove extending in the circumferential direction in the shaft element. The axial securing means may be fitted into a groove extending in the circumferential direction in the hub element. A groove may be arranged in an area of the shaft take-up profile. A groove may be arranged in an area of the hub take-up profile. A groove may be arranged on the engagement side in the axial direction between the connection of the offset section to the hub engagement section and an end area of the hub engagement section in the axial direction. The axial securing means may be arranged at an end area of the hub engagement section on the engagement side. The axial securing means may be positioned on the engagement side in the axial direction directly before the connection of the offset section to the hub engagement section.
In an embodiment, the hub element may be formed by a first planet carrier for a first planet gear set. The apparatus for transmitting torque may be usable for a differential transmission with the first planet gear set. The hub connection section may be configured for receiving first planet bolts of the first planet gear set. The hub connection section may comprise cylindrical bores. The hub connection section may comprise a plurality of receptacles distributed in the circumferential direction. The receptacles may be uniformly distributed in the circumferential direction.
In one aspect, a differential transmission comprises an input element, a first gear set, a second gear set, a first output shaft, a second output shaft and an apparatus for transmitting torque according to one of the preceding embodiments. The input element is mechanically operatively connected to the first gear set for the transmission of a torque. The first gear set is mechanically operatively connected to the second gear set for the transmission of a torque. The first gear set is mechanically operatively connected to the first output shaft for the output of a torque. The second gear set is mechanically operatively connected to the second output shaft for the output of a torque. The first output shaft forms the shaft element of the apparatus for transmitting torque.
The second output shaft may be rotatably supported at a stationary component via a bearing. The bearing of the second output shaft may be configured as a needle bearing or grooved ball bearing. The bearing of the second output shaft and the hub engagement section may be arranged in the same plane in the axial direction. The bearing of the second output shaft may be arranged outside the hub engagement section in the radial direction.
The bearing of the second output shaft may be arranged offset in the axial direction relative to the hub engagement section. The bearing of the second output shaft may overlap the hub engagement section in the radial direction.
In an embodiment, the first gear set may be formed by a first planet gear set. The second gear set may be formed by a second planet gear set. A first planet carrier of the first planet gear set may form the hub element. The shaft engagement section and the hub engagement section may be arranged on the engagement side in the axial direction relative to the first planet gear set.
The first planet gear set may include a first sun gear, the first planet carrier, a first planet bolt, a first planet gear, and a first ring gear. The first sun gear may be in engagement with the first planet gear. The first planet gear may be in engagement with the first ring gear. The first planet gear may be rotatably mounted on the first planet bolt. The first planet bolt may be connected to the first planet carrier.
The second planet gear set may include a second sun gear, a second planet carrier, a second planet bolt, a second planet gear, and a second ring gear. The second sun gear may be in engagement with the second planet gear. The second planet gear may be in engagement with the second ring gear. The second planet gear may be rotatably mounted on the second planet bolt. The second planet bolt may be connected to the second planet carrier.
The embodiment of the forged first planet carrier may be used in a differential transmission in which the first planet gear set and the second planet gear set are arranged offset in the axial direction relative to one another.
In an embodiment, the input element may be torque-proofly connected to a first sun gear of the first planet gear set. The first planet carrier may be torque-proofly connected to the first output shaft for the output of a torque from the first planet gear set. The second ring gear of the second planet gear set may be torque-proofly connected to the second output shaft for the output of a torque from the second planet gear set.
The input element may form the first sun gear at an outer circumference. The first ring gear may be torque-proofly connected to the second sun gear. The first ring gear may be torque-proofly connected to the second sun gear via a coupling element. The second planet carrier may be torque-proofly connected to a stationary component. The stationary component may be formed by a transmission housing.
The first output shaft and the second output shaft may be arranged coaxially to the input element. The first output shaft may extend in the axial direction through the input element. The first output shaft may extend at least in sections in the axial direction within the second output shaft. The first output shaft may be rotatably supported in the second output shaft.
An outer diameter of the shaft engagement section may be smaller in the radial direction than an inner diameter of a passage through the input element.
The offset section may be arranged at least in sections within the second output shaft in the axial direction. The shaft engagement section and the hub engagement section may be arranged in sections in the second output shaft in the axial direction. The second output shaft may be hollow in sections.
With an apparatus for transmitting torque according to one of the preceding embodiments, an outer diameter of the shaft engagement section may be small. As a result, the first sun gear may be configured with a smaller outer diameter. As a result, a stationary transmission ratio of the differential transmission may be increased.
In an embodiment, the first planet gear set and the second planet gear set may be arranged in a stacked manner. A sun ring gear may form the first ring gear at an inner circumference and the second sun gear at an outer circumference. The first planet gear set and the second planet gear set may be arranged in the same plane in the axial direction. The second planet gear set may be arranged outside the first planet gear set in the radial direction.
In one aspect, a vehicle comprises a drive unit, at least two drive wheels and a differential transmission according to one of the preceding embodiments and aspects.
The drive unit is configured for driving the input element. One of the drive wheels is configured for driving the vehicle via the first output shaft. The other of the drive wheels is configured for driving the vehicle via the second output shaft.
The first planet carrier 12 is torque-proofly connected to a shaft engagement section 41 of the first output shaft 5 via a hub engagement section 42 for the output of a torque from the first planet gear set 10. The hub engagement section 42 and the shaft engagement section 41 are configured for an advantageous force distribution in the axial direction between the hub take-up profile and the shaft take-up profile.
Further details of the transmission and of the apparatus for transmitting torque are described below.
The first planet gear set 10 includes a first sun gear 11, a first planet carrier 12, a number of first planet bolts 13, a number of first planet gears 14, and a first ring gear 15. The first sun gear 11 is in engagement with one of the first planet gears 14. One of the first planet gears 14 is in engagement with the first ring gear 15 and is rotatably mounted on one of the first planet bolts 13. The first planet bolts 13 are connected to the first planet carrier 12.
The second planet gear set is not shown in
The first planet gear set 10 and the second planet gear set are arranged in the same plane in the axial direction. The second planet gear set is arranged outside the first planet gear set 10 in the radial direction.
The first ring gear 15 and the second sun gear are torque-proofly to one another by a coupling element 1. In the present case, the coupling element 1 is formed by a sun ring gear. The sun ring gear includes the first ring gear 15 at an inner circumference. The sun ring gear includes the second sun gear at an outer circumference. As a result, the first planet gear set 10 is mechanically operatively connected to the second planet gear set.
The input element 4 forms the first sun gear 11 of the first planet gear set 10 on an outer circumference of an end section of the input element 4 on an engagement side, the right-hand side in
The first output shaft 5 and the second output shaft 6 are arranged coaxially to the input element 4. The first output shaft 5 extends in the axial direction through the input element 4. The first output shaft 5 extends in sections in the axial direction within the second output shaft 6. The second output shaft 6 is rotatably mounted to a stationary component, in the present case a transmission housing, via a bearing, in the present case a grooved ball bearing.
The first output shaft 5 comprises a shaft connection section, which is arranged, relative to the shaft engagement section 41, offset in the axial direction towards a connection side, the left side in
The first planet carrier 12 comprises the hub engagement section 42 with a hub take-up profile, in the present case a spline, at an inner circumference. In this respect, the first output shaft 5 and the first planet carrier 12 together form a take-up toothing. The hub engagement section 42 is arranged offset in the axial direction relative to the bearing of the second output shaft 6. The first planet carrier 12 comprises a hub connection section which is arranged offset in the axial direction towards the connection side relative to the hub engagement section 42. In the present case, the hub connection section is formed by receptacles of the first planet carrier 12 for the first planet bolts 13. The hub connection section serves for the introduction of a torque from the first planet gear set 10 into the first planet carrier 12.
The take-up toothing is arranged offset in the axial direction towards the engagement side relative to the hub connection section. The first planet carrier 12 comprises an offset section 30. The offset section 30 extends from the hub connection section in the axial direction towards the engagement side. The offset section 30 comprises a radial section at one end on the engagement side, which extends inwardly in a radial direction of the first output shaft 5. As a result, an annular gap is formed between the hub engagement section 42 and the offset section 30, which is arranged on the connection side relative to the radial section. The annular gap extends in the radial direction at a height, which is comparable to a height of the hub engagement section 42 in the radial direction.
The radial section is torque-proofly connected to a central area of the hub engagement section 42. At the same time, the hub engagement section 42 extends from the radial section approximately equally far towards the connection side and towards the engagement side in the axial direction. In the present case, the offset section 30 is configured in one piece with the hub engagement section 42 and the connection section. The first planet carrier 12 is produced by forging.
As a result of the configuration of the first planet carrier 12 with the offset section 30 and its connection to the hub engagement section 42, a torque to be transmitted is introduced close to the center into the take-up toothing. This is favorable for a force flow through the take-up toothing. As a result, the take-up toothing may be heavily loaded.
The first planet carrier 12 is displaceable in the axial direction relative to the first output shaft 5 via the take-up toothing. The apparatus therefore comprises an axial securing means 50 which is arranged on an engagement side in the axial direction relative to the offset section 30. The axial securing means 50 is configured as a securing ring and positions the first output shaft 5 in the axial direction relative to the first planet carrier 12. The securing ring is fitted into a groove extending in a circumferential direction of the first output shaft 5 at an outer circumference. The securing ring is fitted into a groove extending in the circumferential direction of the first planet carrier 12 at an inner circumference. The securing ring is arranged at an end area of the take-up toothing on the engagement side.
In the present case, the first planet carrier 12 is configured in two parts. The hub engagement section 42 is configured separately from the offset section 30. The offset section 30 is welded to the hub engagement section 42 at a connecting projection which extends in the radial direction. The connecting projection is provided instead of the radial section of the preceding embodiment. The hub engagement section 42 is configured within the bearing of the second output shaft 6 in the radial direction. The hub engagement section 42 and the bearing of the second output shaft 6 are arranged in the same plane in the axial direction. The bearing of the second output shaft 6 is configured as a needle bearing.
The gap between the hub engagement section 42 and the offset section 30 is configured to be significantly thinner in the radial direction than in the preceding embodiment. The axial securing means 50 is arranged at the engagement side directly from the connecting projection in the axial direction.
The offset section 30 is connected to an end area of the hub engagement section 42 which is arranged on the engagement side in the axial direction. Accordingly, the hub engagement section 42 extends from the connecting projection further towards the connection side than towards the engagement side. As a result, the torque to be transmitted is introduced further away from an end section of the take-up toothing, which is arranged on the connection side. As a result, a force flow through the take-up toothing may be distributed in a wide area in the axial direction from the connecting projection to the end area on the engagement side. This is advantageous for the force flow through the take-up toothing. As a result, the take-up toothing may be heavily loaded.
15 first ring gear
| Number | Date | Country | Kind |
|---|---|---|---|
| 102023212123.9 | Dec 2023 | DE | national |
