Differential device

Abstract

To provide a differential device, in particular, a drive axle of an automobile, in which a clutch portion can be further easily formed.SOLUTION: A differential device comprises a drive gear, a differential gear mechanism having an input member, and a changeover clutch effectively arranged between the drive gear and the differential gear mechanism. In a state that the changeover clutch is connected, torque is transmitted to the differential gear mechanism from the drive gear, and in a state that the changeover clutch is disconnected, the transmission of the torque is blocked. A first portion of the changeover clutch is firmly connected to one of the input member and a differential housing of the differential gear mechanism, and a second clutch portion of the changeover clutch is firmly connected to the other of the input member and the differential housing.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention particularly relates to a differential device for a drive shaft of an automobile. This differential device includes a drive gear, a differential gear mechanism having an input member, and a switching clutch effectively disposed between the drive gear and the differential gear mechanism. In the connected state of this switching clutch, torque is transmitted from the drive gear to the differential gear mechanism, and in the disconnected state of the switching clutch, torque transmission is interrupted. The first clutch portion of the switching clutch is firmly coupled to the input member or the differential housing of the differential gear mechanism, and the second clutch portion of the switching clutch is firmly coupled to the other of the input member and the differential housing respectively.

[0002] Based on German Patent Application Publication No. 102009056088, a differential device is known. This known differential device includes a drive gear and a differential gear mechanism having one input member and two output members. The output members are drivingly coupled to the input member and have a compensating effect on each other. A switching clutch is effectively disposed between the drive gear and the differential gear mechanism. In the connected state of this switching clutch, torque is transmitted from the drive gear to the differential gear mechanism, and in the disconnected state of the switching clutch, torque transmission is interrupted. A controllable actuator is provided to operate the switching clutch, and a sensor is provided to detect at least three switching positions of the switching clutch.

[0003] A drive device for use in an automobile powertrain is known, in accordance with German Patent Application Publication No. 102013111891. This known drive device comprises a rotatable housing, a driven member, and a clutch positioned between the rotatable housing and the driven member. The clutch has a first clutch portion that is held axially movable and not rotatable relative to the housing, and a second clutch portion that is rigidly coupled to the driven member and positioned within the rotatable housing. A controllable actuator is provided for operating the clutch. When the clutch is operated, a transmitting element is axially movable, and a sensor detects the clutch's switching position. The first clutch portion has an annular section positioned on the outside of the housing and a plurality of projections extending axially from this annular section into the interior of the housing through an opening provided in the housing.

[0004] An axially movable clutch portion, which is located inside the differential housing and operated via an element extending axially from the inside of the differential housing through an opening, or an axially movable clutch portion, which is located at least partially outside the differential housing and coupled to transmit torque to another clutch portion via an element extending axially into the inside of the differential housing through an opening, is subjected to high mechanical loads, making it complex to construct and expensive to produce.

[0005] The objective is to provide a differential that allows for easier formation of the clutch portion.

[0006] The solution is a differential, particularly for the drive axle of an automobile, comprising a drive gear, a differential gear mechanism having an input member, and a switching clutch effectively positioned between the drive gear and the differential gear mechanism, wherein when the switching clutch is engaged, torque is transmitted from the drive gear to the differential gear mechanism, and when the switching clutch is disengaged, torque transmission is interrupted, the first clutch portion of the switching clutch is firmly coupled to the differential housing of the differential gear mechanism, and the second clutch portion of the switching clutch is firmly coupled to the input member, in the differential. The switching clutch comprises a coupling element that is movable relative to a first clutch portion and a second clutch portion, and at least one switching element acting on the coupling element, the switching element moving the coupling element between a first position that results in an engaged state of the switching clutch, where the coupling element is positioned between the first clutch portion and the second clutch portion so as to transmit torque, and a second position that results in a disengaged state of the switching clutch, where the first clutch portion is disengaged from the second clutch portion, and at least six coupling elements are provided.

[0007] The input member of a differential gear mechanism is, for example, a differential carrier, also called a differential case. The output member of the differential may be a side shaft gear when using a bevel gear type differential or a crown gear type differential, or a ring gear or sun gear when using a planetary gear type differential. The switching clutch is particularly formed as a shape-connected clutch.

[0008] The advantage of a differential is that, by a coupling element that is relatively movable relative to the first and second clutch portions, a connection for transmitting torque can be formed or disengaged without moving one of the clutch portions. This makes it easier to form at least one of the clutch portions. In particular, it is not necessary for the clutch portions to be operated by an actuator. The fact that the switching clutch has at least six coupling elements has the advantage that the torque transmission is divided among the coupling elements, and each individual coupling element can be manufactured with less effort in terms of its strength. The coupling elements may be evenly distributed, for example, around the entire circumference of the switching clutch. In this case, the torque load is advantageously distributed evenly among all coupling elements. By using a larger number of small coupling elements, it is possible to save the configuration space required for the switching clutch. Higher torque can be transmitted, advantageously, through a larger number of coupling elements. This makes the switching clutch advantageously expandable and contractible. In particular, at least eight coupling elements may be provided. Up to 20 coupling elements are possible, and in the case of a correspondingly larger differential, more than 20 coupling elements are possible.

[0009] Torque is transmitted directly from the first clutch portion to the coupling element or from the coupling element to the first clutch portion. Similarly, torque is transmitted directly from the second clutch portion to the coupling element or from the coupling element to the second clutch portion. According to one embodiment, the coupling element is guided within an opening in the first clutch portion or the second clutch portion, and when the switching clutch is engaged, the switching element extends the coupling element out of the opening in a first position, thereby specifying that the coupling element is engaged within a notch in the other clutch portion of the first clutch portion and the second clutch portion. When the switching clutch is disengaged, the switching element returns the coupling element from the notch back into the opening in a second position. The coupling element extends out of the opening by protruding beyond the outer contour of each clutch portion in at least one direction. Note that in this case, the coupling element is not positioned completely outside the clutch portion. The coupling element can be said to be returned into the opening when it does not protrude beyond the contour of the clutch portion in at least the same direction.

[0010] The switching element is held coaxially with respect to, for example, the first clutch portion and is axially movable between a first position and a second position. A particularly controllable actuator may be provided to operate the switching clutch. This actuator advantageously acts on the switching element, moving it from the second position to the first position. The actuator can also optionally move the switching element from the first position to the second position. Alternatively, the switching element may be preloaded in the direction of the second position by a spring. Advantageously, the actuator acts on the switching element that is not involved in torque transmission between the clutch portions. Therefore, the switching element can be easily formed as a movable member because it is subjected to relatively little mechanical load. In all embodiments, axial, coaxial, and radial directions refer to the spatial directions or orientations of the components with respect to the pivot axis of the differential gear mechanism, which serves as the reference axis when the drive gear, input member, and side shaft gear rotate, unless another axis is strictly specified as the reference axis.

[0011] According to one embodiment, the connecting element is specified to be formed as a ball or a cylindrical pin. The diameter of this ball or cylindrical pin may be 5 mm to 15 mm, particularly 8 mm to 12 mm. Torque is transmitted directly from the first clutch portion to the spherical or cylindrical surface of the connecting element, or from the spherical or cylindrical surface of the connecting element to the first clutch portion. Similarly, torque is transmitted directly from the second clutch portion to the spherical or cylindrical surface of the connecting element, or from the spherical or cylindrical surface of the connecting element to the second clutch portion. A cylindrical pin means a substantially cylindrical pin which may optionally have a plurality of grooves or similar notches in the longitudinal or circumferential direction.

[0012] In another embodiment, the coupling element is specified to be guided to be axially movable within an axial opening of the first clutch portion. The axial opening of the first clutch portion is formed, for example, as an axial through-hole in the differential housing. Thus, the switching element may have an annular section that acts on the coupling element from outside the differential housing.

[0013] In another embodiment, the coupling element is identified as being formed as a cylindrical pin and guided to be axially movable within an axial opening of the first clutch portion. The cylindrical pin as the coupling element may be rigidly coupled to the switching element. For example, the coupling element is geometrically coupled to the switching element in the axial direction. Advantageously, the switching element may act as a transmitting element for a sensor to detect the switching position of the switching clutch.

[0014] The cylindrical pin as a connecting element has a conical head region at the end facing the second clutch portion, which may be tapered axially from the second clutch portion toward the first clutch portion. Furthermore, the notch in the second clutch portion may be widened axially from the surface facing the first clutch portion toward the second clutch portion. The conical head region and / or widened notch are advantageously suited to holding the connecting element within the notch by sufficient friction between the conical head region and the walls of the notch, thereby avoiding unintended disengagement of the switching clutch, particularly when little or no torque is transmitted through the connecting element between the first and second clutch portions.

[0015] In another embodiment, the notches in the second clutch portion are specified to be formed as elongated holes having the longest circumferential extension length, thereby facilitating the displacement of the cylindrical connecting element to the first position. The number of notches in the second clutch portion may be greater than the number of connecting elements, for example, by an integer multiple of two or more of the number of connecting elements.

[0016] According to another embodiment, at least one switching element has a pin engaged within an axial opening, and the coupling element is identified as being formed as a ball. The coupling element is held by the pin within a notch in the second clutch portion when the switching clutch is engaged. A guide sleeve for guiding the coupling element may be provided within the axial opening.

[0017] In another embodiment, the coupling element is identified as being guided to be radially movable within a radial opening of a second clutch portion. At least one switching element has a switching contour that acts on the coupling element to move the coupling element. The switching contour can return the coupling element to the radial opening of the second clutch portion in a second position and partially push the coupling element out of the radial opening in a first position.

[0018] The radial opening of the second clutch portion may be formed as a radial through-hole in the input member. When the switching clutch is engaged, the coupling element is radially locked by at least one switching element. This is particularly advantageous when the switching element is positioned radially between the second clutch portion and the differential housing. At least one switching element may have a sleeve-shaped section with a switching contour. Alternatively, the switching element may have a plurality of pins arranged in an annular manner, in which case each pin acts on one coupling element.

[0019] At least one switching element has, for example, at least one projection extending axially through a through-hole in the differential housing, and the switching element may be operated by an actuator via at least one projection. Furthermore, at least one projection may be coupled, for example, to a transmitting element for a sensor for detecting the switching position of the switching clutch.

[0020] Several embodiments are described below with reference to the drawings. [Brief explanation of the drawing]

[0021] [Figure 1] This is a longitudinal cross-sectional view of the differential in the disengaged switching position of the switching clutch in one embodiment. [Figure 2] This figure shows the differential gear shown in Figure 1 at the switching position with the switching clutch engaged. [Figure 3] Figure 2 is a perspective view of the differential gear shown. [Figure 4] Figure 2 is a cross-sectional view of the differential gear shown. [Figure 5] This is a longitudinal cross-sectional view of the differential in the disengaged switching position of the switching clutch in another embodiment. [Figure 6] Figure 5 is a perspective view of the differential gear shown. [Figure 7] Figure 5 is a longitudinal cross-sectional view of the details of the differential. [Figure 8] This is a diagram showing the differential device shown in Fig. 5 at the switched position where the switching clutch is connected. [Figure 9] This is a diagram showing the details shown in Fig. 7 at the switched position where the switching clutch is connected. [Figure 10] This is a longitudinal sectional view of the differential device at the disconnected switching position of the switching clutch in yet another embodiment. [Figure 11] This is a perspective view of the differential device shown in Fig. 10. [Figure 12] This is a longitudinal sectional view of the details of the differential device shown in Fig. 10. [Figure 13] This is a diagram showing the differential device shown in Fig. 10 at the switched position where the switching clutch is connected. [Figure 14] This is a perspective view of the differential device shown in Fig. 13. [Figure 15] This is an enlarged view of the details shown in Fig. 12. [Figure 16] This is a cross-sectional view of the differential device shown in Fig. 10. [Figure 17] This is a diagram showing the details shown in Fig. 15 according to an alternative embodiment. [Figure 18] This is a perspective view of the details of the differential device shown in Fig. 10. [Figure 19] This is another perspective view of the details shown in Fig. 18. [Figure 20] This is yet another perspective view of the details shown in Fig. 18. [Figure 21] This is a schematic diagram of a drive device equipped with a differential device.

[0022] Figures 1 to 4 show a first embodiment of the differential 2 according to the present invention for the drive axle in the drive system of an automobile shown in Figure 20. First, Figures 1 to 4 will be described together below. Figure 1 shows a differential 2 equipped with a switching clutch 4 in a longitudinal cross-sectional view at the switching position with the switching clutch 4 disengaged. Figure 2 shows a longitudinal cross-sectional view of the differential in the switching position with the switching clutch 4 engaged. Figure 3 shows a perspective view of the differential. Figure 4 shows a cross-sectional view along the BB line shown in Figure 2. The differential 2 has a differential gear mechanism 3, a switching clutch 4, and an actuator 5 for operating the switching clutch 4. A drive gear 6 is provided to introduce torque from a prime mover (not shown). This drive gear 6 is rigidly coupled to a differential housing 7. This differential housing 7 is formed from two members and includes a pot-shaped first housing member 8 and a pot-shaped second housing member 9. This second housing member 9 is formed integrally with the drive gear 6. The first housing member 8 is firmly bonded to the second housing member 9, particularly by welding. Naturally, the connection between the drive gear 6 and the differential housing 7, or between the first housing member 8 and the second housing member 9, may be made by other means, such as screw fastening or other conventional coupling means. A differential gear mechanism 3, which is rotatable around the pivot axis A, is located within the differential housing 7.

[0023] The differential gear mechanism 3 includes a differential carrier 13. This differential carrier 13 has a substantially cylindrical outer surface 14. On this outer surface 14, the differential carrier 13 is rotatably supported on the corresponding inner cylindrical surface section 15 of the first housing member 8 about the pivot axis A. The differential carrier 13 is provided with two holes. A pin 17 is inserted into both of these holes. Two differential pinion gears 19 are rotatably supported on this pin 17 about the pin axis B. Both of these differential pinion gears 19 mesh with first and second side shaft gears 20, 22 which are arranged coaxially with respect to the pivot axis A. Both of these side shaft gears 20, 22 each have a longitudinal tooth row 23. Within this longitudinal gear row 23, a corresponding gear row of a side shaft (Figure 20) may be inserted for torque transmission. The first side shaft gear 20 is supported axially by the first housing member 8. Preferably, a sliding disc is positioned between the first side shaft gear 20 and the support surface of the first housing member 8. Correspondingly, a sliding disc for supporting axial force is also positioned between the second side shaft gear 22 and the second housing member 9.

[0024] In the illustrated configuration, the switching clutch 4 is formed in the form of a shape-connected clutch. The shape-connected switching clutch 4 comprises a first clutch portion 25 firmly coupled to the differential housing 7, a second clutch portion 26 firmly coupled to the input member 13, 10 connecting elements 10 that are movable relative to the first clutch portion 25 and the second clutch portion 26, and a switching element 12 that acts on these 10 connecting elements 10. When the switching clutch 4 is engaged, torque is transmitted between the first clutch portion 25 and the second clutch portion 26 via the connecting elements 10, whereas when the switching clutch 4 is disengaged, the connecting elements 10 do not transmit torque. Figure 2 shows the switching clutch 4 in the engaged state. The switching element 12 is in a first position, and in this first position, the switching element 12 holds the connecting elements 10 between the first clutch portion 25 and the second clutch portion 26 so as to transmit torque. Figure 1 shows the switching clutch 4 in a disengaged state. The switching element 12 is in a second position, in which the switching element 12 releases the connecting element 10, thereby disengaging the first clutch portion 25 from the second clutch portion 26 and interrupting torque transmission. The connecting element 10 is guided within the opening 11 of either the first clutch portion 25 or the second clutch portion 26. When the switching clutch 4 is engaged, the switching element 12 extends the connecting element 10 out of the opening 11 in its first position, thereby engaging the connecting element 10 within the notch 21 of the other clutch portion of either the first clutch portion 25 or the second clutch portion 26. When the switching clutch 4 is disengaged, the switching element 12 returns the connecting element from the notch 21 back into the opening 11 in its second position. The switching element 12 is held coaxially with respect to the first clutch portion 25 and is axially movable between a first position and a second position. A controllable actuator 5 is provided to move the switching element 12 from the second position to the first position in order to operate the switching clutch 4.

[0025] In the embodiments shown in Figures 1 to 4, ten connecting elements 10 are formed as balls that are guided to move radially within a radial opening 11 of the second clutch portion 26. The switching element 12 has a switching contour 45 that acts on the connecting elements 10. In the illustrated configuration, this switching contour 45 is provided with a housing into which the ball-shaped connecting elements 10 can be retracted. When the switching element 12 is displaced axially from a second position to a first position, the switching contour 45 pushes the connecting elements 10 out of the opening 11, which is formed as a radial through-hole in the input member 13, over the outer contour of the second clutch portion 26, like a retraction wedge. When the switching clutch 4 is engaged, the connecting elements 10 are radially locked by at least one switching element 12 radially positioned between the second clutch portion 26 and the differential housing 7.

[0026] The switching element 12 has at least one projection 27 extending axially through a through-hole 28 of the differential housing 7, thereby enabling the switching element 12 to be operated by the actuator 5 via at least one projection 27. Furthermore, at least one projection 27 is coupled to a transmitting element 38 for a sensor (44, Figure 20) for detecting the switching position of the switching clutch 4. A return spring 43 is positioned between the differential housing 7 and the transmitting element 38. In the illustrated configuration, this return spring 43 is formed in the form of a disc spring. Of course, other forms of springs, such as a coil spring, may be used. The switching element 12 may have a sleeve-like section with a switching contour 45. One or more projections 27 extend axially from this sleeve-like section. Alternatively, the switching contour 45 may be arranged on axial pins arranged in annular shape in the same axis direction. In this case, each pin is assigned to one connecting element 10.

[0027] Sensor 44 (Figure 20) is positioned axially within the region of actuator 5 and cooperates with transmitting element 38. Sensor 44 may be formed in the form of a Hall sensor capable of non-contact detection of its distance from transmitting element 38. However, another non-contact sensor, such as an inductive sensor, may be used. In the disengaged position of the switching clutch 4, the transmitting element 38 is brought axially close to sensor 44. This position, where the switching clutch 4 is disengaged, is shown in Figure 1. In contrast, Figure 2 shows the switched state, where the switching clutch 4 is engaged for torque transmission from the drive gear 6 to the differential carrier 13. It can be seen that the transmitting element 38 is moved toward sensor 44 together with the switching element 12 toward the first clutch portion 25 or the differential gear mechanism 3.

[0028] Figures 5 to 9 show another embodiment of the differential gear 2. This embodiment is substantially equivalent to the embodiment shown in Figures 1 to 4, so please refer to the above description for common features. In this case, the same or modified components are denoted by the same reference numerals as in Figures 1 to 4. Figure 5 shows the differential gear 2 with the switching clutch 4 in the disengaged switching position. Figure 6 shows the differential gear in a perspective view. Figure 7 shows the differential gear in detail in a longitudinal section along the CC line shown in Figure 5. Figure 8 shows the differential gear 2 in the engaged switching position with the switching clutch 4 connected. Figure 9 shows the differential gear in detail in a longitudinal section along the CC line shown in Figure 5. The differences will be explained below with reference to Figures 5 to 9.

[0029] A feature of the illustrated embodiment is that a ball-shaped connecting element 10 is guided to move axially within an axial opening 11 of the first clutch portion 25. At least one switching element 12 has a pin 29 that engages within the axial opening 11. This pin 29 acts on the connecting element 10. Figures 6, 8, and 9 show the switching clutch 4 in the engaged state. The switching element 12 is in a first position, in which the switching element 12 holds the connecting element 10 between the first clutch portion 25 and the second clutch portion 26 to transmit torque. Figures 5 and 7 show the switching clutch 4 in the disengaged state. The switching element 12 is in a second position, in which the switching element 12 releases the connecting element 10, thereby disengaging the first clutch portion 25 from the second clutch portion 26 and interrupting torque transmission. When the switching clutch 4 is engaged, the switching element 12 extends the connecting element 10 from the axial opening 11 in its first position, thereby engaging the connecting element 10 within the notch 21 of the second clutch portion 26. When the switching clutch 4 is disengaged, the switching element 12 retracts the connecting element 10 from the notch 21 into the opening 11 in its second position. The switching element 12 is held coaxially with respect to the second clutch portion 26 and is axially movable between the first and second positions.

[0030] When the switching clutch 4 is engaged, the connecting element 10 is held by the pin 29 within the notch 21 of the second clutch portion 26. The axial opening 11 of the first clutch portion 25 is formed in this configuration as an axial through hole in the differential housing 7. The switching element 12 has an annular section 30 that acts on the pin 29 from the outside of the differential housing 7. The actuator 5 acts directly on this annular section 30 to operate the switching element 12. The transmitting element 38 may be located in the annular section 30, or the annular section itself may function as the transmitting element 38.

[0031] Figures 10 to 20 show yet another embodiment of the differential gear 2. This embodiment is substantially equivalent to the embodiment shown in Figures 5 to 9, so refer to the above description for common features. In this case, the same or modified components are denoted by the same reference numerals as in Figures 1 to 9. The differences are described below. Figure 10 shows the differential gear 2 with the switching clutch 4 in a longitudinal section view at the switching position with the switching clutch 4 disengaged. Figure 11 shows the differential gear in a perspective view. Figure 12 shows the details of the differential gear 2 in a longitudinal section view along the CC line shown in Figure 10. Figure 13 shows the differential gear 2 in the switching position with the switching clutch 4 connected. Figure 14 shows the differential gear 2 in a perspective view. Figure 15 shows the details shown in Figure 12 in an enlarged view, whereas Figure 17 shows the details in an alternative embodiment. Figure 16 shows the differential gear 2 in a cross-sectional view along the DD line shown in Figure 10. Figures 18 to 20 show the details of the differential gear 2 in different diagrams. The differences will be explained below with reference to Figures 10 to 20.

[0032] In this embodiment, ten connecting elements 10 are provided. These ten connecting elements 10 are guided to move axially within the axial opening 11 of the first clutch portion 25. A feature of the illustrated embodiment is that the connecting elements 10 are formed as cylindrical pins. The connecting elements 10 are tightly coupled to the switching element 12. A cylindrical pin means a substantially cylindrical pin which may optionally have a plurality of grooves or similar notches in the longitudinal or circumferential direction.

[0033] Figures 13 and 14 show the switching clutch 4 in the engaged state. In the engaged state of the switching clutch 4, the switching element 12 extends the cylindrical connecting element 10 from the axial opening 11 in its first position, thereby engaging the connecting element 10 with the notch 21 of the second clutch portion 26. Figures 10 to 12 show the switching clutch 4 in the disengaged state. In the disengaged state of the switching clutch 4, the switching element 12 returns the pin-shaped connecting element 10 from the notch 21 back into the opening 11 in its second position. The switching element 12 is held coaxially with respect to the second clutch portion 26 and is axially movable between the first and second positions.

[0034] Figure 12 shows a cross-sectional view along the CC line shown in Figure 10. This cross-sectional view shows the switching element 12 in the second position of the switching clutch 4, i.e., in the disengaged state. It can be seen that one connecting element 10 is returned to one opening 11 from one notch 21. Figure 15 shows the details again in magnification. Figure 16 shows a cross-sectional view along the DD line shown in Figure 10. The diameter of the cylindrical connecting element 10 fits into the notch 21 defined by the wall 34. This notch 21 is formed as an elongated hole in the circumferential direction, which facilitates the displacement of the connecting element 10 to the second position. The connecting element 10 is clearance-fitted into the notch 21 provided in the second clutch portion 26. The clearance is, for example, 0.02 mm to 0.06 mm in the radial direction. In the circumferential direction, the gap is 0.6 mm to 0.8 mm larger than in the radial direction due to the elongated hole of the notch 21. In the illustrated embodiment, the notch 21 is not formed as a complete hole in the solid material of the second clutch portion 26, but rather in an annular tubular piece of the differential carrier 13 having a radial extension length smaller than the hole diameter. The gap between the connecting element 10 and the first clutch portion 25 compensates for positional errors in the clutch geometry of the differential carrier 13 and deformation of the differential carrier 13 and the connecting element 10 under load. The gap may be, for example, 0.08 mm to 0.3 mm.

[0035] Figure 17 shows details of an alternative embodiment. The cylindrical coupling element 10 has a head region 33 directed toward the second clutch portion 26. This head region 33 engages within the notch 21 when the switching clutch 4 is engaged. The head region 33 has a conical shape. The head region 33 tapers axially from the second clutch portion 26 toward the first clutch portion 25. The notch 21 has a shape that substantially corresponds to the coupling element 10. The notch 21 widens axially from the first clutch portion 25 toward the second clutch portion 26. This shaping allows the coupling element 10 to be held within the notch 21 by friction between the head region 33 of the coupling element 10 and the wall 34 of the notch 21, even when the acting torque is very small.

[0036] Figure 19 shows the switching element 12 or the transmitting element 38 without a connecting element. Figures 18 and 20 show the switching element 12 of the embodiment shown in Figure 10 in perspective as a detail. The cylindrical connecting element 10 is connected to the switching element 12 axially by shape connection, for example, by inserting a circumferential groove 31 provided in the connecting element 10 into a corresponding keyhole-shaped opening 32 provided in the annular disc-shaped switching element 12. The gap between the connecting element 10 and the switching element 12 may be, for example, 0.2 mm, because there is basically no force transmission between the connecting element 10 and the switching element 12. Alternatively, the connecting element 10 may be fixed to the annular disc-shaped switching element 12 in a suitable alternative form, for example by screw fastening, adhesive or spot welding. In this embodiment, the switching element 12 may function as a transmitting element 38 for a sensor 44 for detecting the switching position of the switching clutch. Since no force is transmitted between the connecting element 10 and the switching element 12, the switching element 12 may have a low torsional rigidity, for example, less than 20% of the torsional rigidity of the first clutch portion 25 and the second clutch portion 26, and especially less than 10%.

[0037] Figure 21 shows a schematic diagram of a drive unit 47 equipped with a differential 2. This drive unit 47 is equipped with a prime mover 48. This prime mover 48 drives the differential 2 or the drive gear 6 of the differential 2 via a gear 49. The torque introduced when the switching clutch 4 is engaged is transmitted from the differential gear mechanism 3 to both side shaft gears 20, 22. Corresponding side shafts 50, 52 are inserted into the longitudinal tooth rows 23 of both side shaft gears 20, 22 so as not to rotate relative to each other for torque transmission. Constant velocity joints 53, 54 are located at the ends of these side shafts 50, 52. These constant velocity joints 53, 54 are then coupled to the automobile's wheels 59, 60 via joint shafts 55, 56 and joints 57, 58 for torque transmission. It can be seen that the differential 2 is supported by bearings 61, 62 so as to be rotatable about the pivot axis A relative to the stationary housing 41. [Explanation of symbols]

[0038] 2 Differential device 3. Differential gear mechanism 4. Switching clutch 5 Actuators 6. Drive gear 7 Differential Housing 8. First housing member 9. Second housing member 10 Connecting elements 11 Aperture 12 Switching element 13 Differential Carriers 14 Exterior 15-sided division 17 pins 19 Differential pinion gear 20 Side shaft gear 21 Notches 22 Side shaft gear 23 Longitudinal dentition 25 First clutch section 26. Second clutch section 27. Protruding section 28 Penetration section 29 pins 30 Ring section 31 Circumferential groove 32 Keyhole-shaped opening 33 Head area 34 Wall 35 Guide Sleeves 38 Transmission elements 43 Return spring 44 sensors 45 Switching contour section 47 Drive system 48 Engine 49. Transmission 50, 52 shaft 53, 54 Joint 55, 56 Joint shaft 59,60 wheels 61,62 Bearings A rotation axis B pin axis

Claims

1. In particular, a differential gear for the drive axle of an automobile, comprising a drive gear (6), a differential gear mechanism (3) having an input member (13), and a switching clutch (4) effectively disposed between the drive gear (6) and the differential gear mechanism (3), wherein when the switching clutch (4) is engaged, torque is transmitted from the drive gear (6) to the differential gear mechanism (3), and when the switching clutch (4) is disengaged, torque transmission is interrupted. The first clutch portion (25) of the switching clutch (4) is firmly coupled to the differential housing (7) of the differential gear mechanism (3), and the second clutch portion (26) of the switching clutch (4) is firmly coupled to the input member (13). The switching clutch (4) has a connecting element (10) that is movable relative to the first clutch portion (25) and the second clutch portion (26), and at least one switching element (12) that acts on the connecting element (10), The switching element (12) moves the connecting element (10) between a first position that results in the engaged state of the switching clutch (4), where the connecting element (10) is positioned between the first clutch portion (25) and the second clutch portion (26) so as to transmit torque, and a second position that results in the disengaged state of the switching clutch (4), where the first clutch portion (25) is disengaged from the second clutch portion (26), and at least six connecting elements (10) are provided. In a differential gear, A differential gear characterized in that the connecting element (10) is guided within an opening (11) of the first clutch portion (25) or the second clutch portion (26), and when the switching clutch (4) is engaged, the switching element (12) extends the connecting element (10) out of the opening in the first position, thereby engaging the connecting element with a notch (21) of the other clutch portion of the first clutch portion (25) and the second clutch portion (26), and when the switching clutch (4) is disengaged, the switching element (12) returns the connecting element (10) from the notch (21) back into the opening (11) in the second position.

2. The connecting element (10) is formed as a ball or a cylindrical pin, and the diameter of the ball or cylindrical pin is 5 mm to 15 mm. The differential according to claim 1, characterized in that the axial opening (11) of the first clutch portion (25) is formed as an axial through hole of the differential housing (7).

3. The connecting element (10) is guided to be axially movable within the axial opening (11) of the first clutch portion (25), The connecting element (10) is formed as a cylindrical pin, and the connecting element (10) is firmly coupled to the switching element (12). The notch (21) of the second clutch portion (26) is formed as an elongated hole in the circumferential direction. The connecting element (10) has a conical head region (33) directed toward the second clutch portion (26), and the head region (33) tapers in the axial direction from the second clutch portion (26) toward the first clutch portion (25). The differential according to claim 1 or 2, characterized in that the notch (21) of the second clutch portion (26) is widened in the axial direction from the surface facing the first clutch portion (25) into the second clutch portion (26).

4. The connecting element (10) is connected to the switching element (12) in a shape-connected manner in the axial direction. The differential device according to claim 3, characterized in that the switching element (12) functions as a transmitting element for a sensor (44) for detecting the switching position of the switching clutch (4).

5. The at least one switching element (12) has a pin (29) engaged in the axial opening (11), and the connecting element (10) is formed as a ball and is held by the pin (29) in the notch (21) of the second clutch portion (26) when the switching clutch (4) is engaged. The differential according to claim 1 or 2, characterized in that a guide sleeve (35) for guiding the connecting element (10) is arranged within the axial opening (11).

6. The differential device according to claim 1, characterized in that the connecting element (10) is guided to move radially within a radial opening (11) of the second clutch portion (26), the radial opening (11) is formed as a radial through hole of the input member (13), the at least one switching element (12) has a switching contour (45) that acts on the connecting element (10), and when the switching clutch (4) is engaged, the connecting element is radially locked by the at least one switching element (12).

7. The differential according to claim 6, wherein the at least one switching element (12) has at least one projection (27) extending axially through at least one through-hole (28) of the differential housing (7), the switching element (12) is operated by an actuator (5) via the at least one projection (27), and the at least one projection (27) is coupled to a transmitting element (38) for a sensor (44) for detecting the switching position of the switching clutch (4).

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