Actuating device for a differential gear device and differential gear device with an actuating device

Abstract

An actuating device (1) for a differential gear device is shown and described, wherein the actuating device (1) comprises a housing (3) and an electrically driven pumping device (5) attached to the housing (3), wherein the housing (3) defines a channel (13) extending from a first channel access (15) to a second channel access (17), wherein the housing (3) defines a first cavity (19) connected to the second channel access (17), wherein a fluid may be arranged in the channel (13) and a section (7) of a locking device may be arranged in the first cavity (19), the locking device being configured to be moved in the first cavity (19) along a direction of movement (37) into a coupled position and into a decoupled position, and wherein the pumping device (5) is configured to then,If a fluid is arranged in the channel (13) and the section (7) of the locking device is arranged in the first cavity (19), the fluid is pressurized at the first channel access (15) such that the pressurized fluid moves the section (7) of the locking device into the coupled position along the direction of movement (37). A differential gear device with an actuating device (1) is also described.

Description

[0001] The present invention relates to an actuating device for a differential gear device and a differential gear device with an actuating device.

[0002] Actuating devices for differential gear units are known from the prior art. These devices often include a locking mechanism that can be moved into a coupled position and a decoupled position. When the locking mechanism is in the coupled position, two wheel shafts of the differential gear unit are rotationally fixed to one another. When the locking mechanism is in the decoupled position, the two wheel shafts are rotatable relative to each other. In this way, the actuating devices for differential gear units known from the prior art can provide the actuation of a differential lock or even the function of a differential lock itself.

[0003] In general, for actuating devices for differential gear systems, it is desirable to provide an actuation of a differential lock or even the function of the differential lock in a particularly simple and space-saving manner.

[0004] It is therefore the object of the present invention to provide, in a particularly simple and space-saving manner, an actuation of a differential lock or even the function of the differential lock.

[0005] According to a first aspect of the invention, the aforementioned problem is solved by an actuating device with the features of claim 1. The actuating device is designed for a differential gear device. The actuating device comprises a housing and an electrically driven pump attached to the housing. The housing defines a channel extending from a first channel access to a second channel access. The housing defines a first cavity connected to the second channel access. A fluid may be arranged in the channel. A section of a locking device may be arranged in the first cavity. The section of the locking device is configured to move within the first cavity along a direction of movement into a coupled position and into a decoupled position.The pumping device is designed, when a fluid is arranged in the channel and the section of the locking device is arranged in the first cavity, to pressurize the fluid at the first channel access in such a way that the pressurized fluid moves the section of the locking device into the coupled position along the direction of movement.

[0006] As previously described, the actuating device comprises the housing and the electrically driven pump assembly attached to the housing. The electrical drive of the pump assembly ensures particularly quiet operation. Preferably, some components of the pump assembly are mounted on the housing. Preferably, the pump assembly, together with one or more sections of the housing, ensures that a fluid can be pressurized. Specifically, the pump assembly is designed to pressurize the fluid at the first channel inlet when a fluid is present in the channel.

[0007] As previously described, the housing defines the channel that extends from the first channel inlet to the second channel inlet. A fluid can enter the channel through the first channel inlet and exit through the same inlet. Similarly, a fluid can enter the channel through the second channel inlet and exit through the same inlet.

[0008] As previously described, the housing defines the first cavity connected to the second channel inlet. By defining this first cavity, the housing ensures that fluid located in the channel can exit the channel via the second channel inlet into the first cavity. When the fluid is pressurized, this pressure is then also present in the portion of the fluid located in the first cavity.

[0009] As previously described, a fluid can be arranged in the channel. Preferably, a fluid is arranged in the channel during operation of the actuating device. Preferably, the fluid is an oil. As previously described, the section of the locking device can be arranged in the first cavity. Preferably, the section of the locking device is arranged in the first cavity during operation of the actuating device. The section of the locking device is designed to move into the coupled position and into the uncoupled position in the first cavity along the direction of movement.The fact that a fluid can be arranged in the channel and that the section of the locking device can be arranged in the first cavity, which is designed to be moved in the first cavity along the direction of movement into the coupled position and into the decoupled position, ensures that a coupled position can be brought about by means of the section of the locking device, in which the section of the locking device or a further section of the locking device is engaged with both a first section of the first wheel shaft of the differential gear device and with a second section of the second wheel shaft of the differential gear device, so that the first wheel shaft and the second wheel shaft are rotationally fixed to each other.

[0010] As already described, the pumping device is designed, when a fluid is arranged in the channel and the section of the locking device is arranged in the first cavity, to pressurize the fluid at the first channel access in such a way that the pressurized fluid moves the section of the locking device into the coupled position along the direction of movement.By designing the pumping device to pressurize the fluid at the first channel access when a fluid is arranged in the channel and the section of the locking device is arranged in the first cavity, such that the pressurized fluid moves the section of the locking device into the coupled position along the direction of movement, it is ensured that the coupled position can be selectively brought about in a particularly simple and space-saving manner using the pumping device, wherein in the coupled position the section of the locking device or a further section of the locking device is engaged with both the first section of the first wheel shaft of the differential gear device and with the second section of the second wheel shaft of the differential gear device, so that the first wheel shaft and the second wheel shaft are rotationally fixed to each other.In particular, the actuating device can be used to provide the function of a differential lock.

[0011] In summary, it can be stated that the present invention makes it possible to provide the actuation of a differential lock or even the function of the differential lock in a particularly simple and space-saving manner.

[0012] In one embodiment, the housing is a section of the differential gear housing. Because the housing is a section of the differential gear housing, the actuating device is positioned particularly close to the other components of the differential gear, which in turn allows the pump and channel to be located very close to these components. This also enables the channel to be shorter compared to prior art designs. The fact that the housing is a section of the differential gear housing is particularly advantageous compared to prior art hydraulic locking devices for differentials, where the central pressure generation unit mounted in the vehicle, such as a pump, is used for actuation.In these hydraulic locking devices known from the prior art, lines and valves are required to distribute the hydraulic energy from the vehicle to the differential lock, and the pressure generation unit typically has a pressure accumulator that is kept permanently pressurized. The size of the pressure accumulator often depends on the number and size of the hydraulic consumers. Because the housing is a section of the differential gear housing, the actuating mechanism ensures a particularly simple, component-free, and weight-saving design for the differential gear.

[0013] In one embodiment, the pumping device comprises an electric motor mounted on the housing, a first gear rotatably mounted relative to the housing and driven by the electric motor, and a second gear rotatably mounted relative to the housing and driven by the first gear. This arrangement of the pumping device—the electric motor mounted on the housing, the first gear rotatably mounted relative to the housing and driven by the electric motor, and the second gear rotatably mounted relative to the housing and driven by the first gear—ensures that the fluid can be pressurized using an electrically driven gear pump. Preferably, the first gear is non-rotatably connected to a drive shaft of the electric motor. This non-rotatable connection of the first gear to the drive shaft of the electric motor ensures that the electric motor can drive the first gear into rotation.Preferably, the first gear is rotatably mounted relative to the housing by means of a bearing bushing. This rotatable mounting ensures particularly simple installation of the first gear relative to the housing. Preferably, the first gear has a first tooth that engages with a second tooth of the second gear. This first tooth engagement ensures that the first gear can drive the second gear into rotation. Preferably, the second gear is non-rotatably connected to an axle, which is itself rotatably mounted relative to the housing. This non-rotatable connection ensures particularly simple installation of the second gear relative to the housing.

[0014] In one embodiment, the pumping device has a housing cover which, in an attached state, is affixed to the housing, wherein the housing cover, in the attached state, together with the housing, defines a second cavity connected to the first channel access. By having the housing cover in the attached state, and by defining the second cavity connected to the first channel access, it is ensured that fluid can pass from the second cavity into the channel via the first channel access. Then, when the fluid in the second cavity is pressurized, this pressure is also present in the portion of the fluid located in the channel, and also, via the second channel access, in the portion of the fluid located in the first cavity.

[0015] In one embodiment, the first gear and the second gear are arranged in the second cavity. By arranging the first gear and the second gear in the second cavity, it is ensured that a fluid is conveyed from the second cavity into the channel via the first channel access by means of the first gear and the second gear, and that the fluid in the second cavity can be pressurized by means of the first gear and the second gear so that this pressure is also present in the portion of the fluid located in the channel, and, if a portion of the fluid is also located in the first cavity, this pressure is also present in the portion of the fluid located in the first cavity.

[0016] In one embodiment, the actuating device has the section of the locking device which is arranged in the first cavity and is designed to be moved in the first cavity along the direction of movement into the coupled position and into the decoupled position.By having the actuating device comprising the section of the locking device which is arranged in the first cavity and is designed to be moved in the first cavity along the direction of movement into the coupled position and into the decoupled position, it is ensured that a force can be exerted on the section of the locking device by means of a fluid arranged in the first cavity and pressurized, in order to bring the section of the locking device into the coupled position, wherein in the coupled position the section of the locking device or a further section of the locking device is engaged with both a first section of a first wheel shaft of the differential gear device and a second section of a second wheel shaft of the differential gear device, so that the first wheel shaft and the second wheel shaft are rotationally fixed to each other.

[0017] In one embodiment, the locking device section comprises a piston unit and a locking slide unit rotatably mounted relative to the piston unit. The inclusion of the piston unit and the locking slide unit rotatably mounted relative to the piston unit in the locking device section ensures that the piston unit is designed for movement along the direction of movement and can be mounted to move along the direction of movement relative to the housing, and that the locking slide unit can be mounted to rotate about an axis of rotation extending along the direction of movement relative to the piston unit.so that the locking slide unit can either engage with a first section of a first wheel shaft and rotate with the first section of the first wheel shaft about the axis of rotation relative to the piston unit, or engage with both the first section of the first wheel shaft and a second section of a second wheel shaft and rotate with both the first section of the first wheel shaft and the second section of the second wheel shaft about the axis of rotation relative to the piston unit. Preferably, the piston unit is a piston. Preferably, the locking slide unit is a locking slide. Preferably, the piston unit is mounted so as to be movable relative to the housing along the direction of movement. Preferably, the locking slide unit is mounted so as to be rotatable relative to the piston unit about an axis of rotation that extends along the direction of movement.so that the locking slide unit either engages with a first section of a first wheel shaft and can rotate with the first section of the first wheel shaft about the axis of rotation opposite the piston unit, or engages with both the first section of the first wheel shaft and a second section of a second wheel shaft and can rotate with the first section of the first wheel shaft and with the second section of the second wheel shaft about the axis of rotation opposite the piston unit.

[0018] In one embodiment, the actuating device includes a return element configured to move the section of the locking device into the decoupled position along the direction of movement. By including this return element, the actuating device ensures that moving the section of the locking device into the decoupled position is particularly simple and requires fewer components, as no additional components are needed for actively actuating the section of the locking device into the decoupled position, such as a separate fluid circuit with a separate pump. Preferably, the return element is a spring, in particular a conical helical spring.The use of the spring, in particular the conical coil spring, ensures a particularly simple design of the actuating device.

[0019] In one embodiment, the actuating device has a control device, wherein the control device and the pump device are connected to each other in such a way that a control signal sent by the control device can be received by the pump device, wherein the pump device can be brought into an activated state depending on the control signal, in which the pump device pressurizes the fluid, and can be brought into a deactivated state in which the pump device does not pressurize the fluid.By having the actuating device include the control device, wherein the control device and the pump device are connected to each other in such a way that a control signal sent by the control device can be received by the pump device, wherein the pump device can be brought into an activated state depending on the control signal, in which the pump device pressurizes the fluid, and into a deactivated state in which the pump device does not pressurize the fluid, it is ensured that the pressurization of the fluid can be activated and deactivated in a particularly simple way.

[0020] According to a second aspect of the invention, the aforementioned problem is solved by a differential gear device with the features of claim 10. The differential gear device comprises an actuating device according to the first aspect of the invention and two wheel shafts. When the section of the locking device is in the engaged position, the two wheel shafts are rotationally fixed to one another, and when the section of the locking device is in the disengaged position, the two wheel shafts are rotatable relative to one another. The features, technical effects, and / or advantages described in connection with the actuating device according to the first aspect of the invention also apply, at least analogously, to the differential gear device according to the second aspect of the invention, so a corresponding repetition is omitted here.

[0021] Further features, advantages, and applications of the present invention will become apparent from the following description of the exemplary embodiments and the figures. All features described and / or illustrated, individually and in any combination, constitute the subject matter of the invention, irrespective of their composition in the individual claims or their cross-references. In the figures, the same reference numerals denote identical or similar objects. Fig. Figure 1 shows a schematic representation of a section of an embodiment of an actuating device according to the invention for a differential gear device, Fig. Figure 2 shows a schematic representation of a section of the in Fig. 1 schematically illustrated embodiment of the actuating device according to the invention, and Fig. Figure 3 shows a schematic representation of a section of the [unclear text] in the Fig. 1 and Fig. 2 schematically illustrated embodiments of the actuating device according to the invention.

[0022] Fig. Figure 1 shows a schematic representation of a section of an embodiment of an actuating device 1 according to the invention for a differential gear device, Fig. Figure 2 shows a schematic representation of a section of the in Fig. 1 schematically illustrated embodiment of the actuating device 1 according to the invention, and Fig. Figure 3 shows a schematic representation of a section of the [unclear text] in the Fig. 1 and Fig. 2 schematically illustrated embodiments of the actuating device according to the invention 1.

[0023] The actuating device 1 has a housing 3, a pumping device 5, a section 7 of a locking device, a reset element 9 and a control device 11.

[0024] Housing 3 defines a channel 13. Channel 13 extends from a first channel inlet 15 to a second channel inlet 17. A fluid can enter channel 13 via the first channel inlet 15 and exit channel 13 via the same inlet 15. Similarly, a fluid can enter channel 13 via the second channel inlet 17 and exit channel 13 via the same inlet 17. Housing 3 also defines a first cavity 19 connected to the second channel inlet 17. By defining the first cavity 19, which is connected to the second channel access 17, the housing 3 ensures that a fluid located in the channel 13 can exit the channel 13 via the second channel access 17 into the first cavity 19 and that, when the fluid is pressurized, this pressure is also present in the portion of the fluid located in the first cavity 19.Housing 3 is a section of the differential gear housing, which will be discussed in detail later. Because housing 3 is a section of the differential gear housing, the actuating device 1 is positioned particularly close to the other components of the differential gear, which in turn allows the pump 5 and channel 13 to be located very close to these components. This also enables the channel 13 to be made comparatively short. The fact that housing 3 is a section of the differential gear housing is particularly advantageous compared to prior art hydraulic locking devices for differential gears, where the central pressure generation unit mounted in the vehicle, such as a pump, is used for actuation.In these hydraulic locking devices known from the prior art, lines and valves are required to distribute the hydraulic energy from the vehicle to the differential lock, and the pressure generation unit typically has a pressure accumulator that is kept permanently pressurized. The size of the pressure accumulator often depends on the number and size of the hydraulic consumers. Since housing 3 is a section of the differential gear housing, the actuating device 1 ensures a particularly simple, component-free, and weight-saving design for the differential gear.

[0025] The pumping device 5 is electrically driven. This electrical drive ensures particularly quiet operation. The pumping device 5 is mounted on the housing 3. The components of the pumping device 5 are described in detail below. Some of these components are mounted on the housing 3. The pumping device 5, together with one or more sections of the housing 3, ensures that a fluid can be pressurized. Specifically, the pumping device 5 is designed to pressurize the fluid at the first channel inlet 15 when a fluid is present in the channel 13.

[0026] The pumping device 5 comprises an electric motor 21 attached to the housing 3, a first gear 23 rotatably mounted relative to the housing 3 and driven by the electric motor 21, and a second gear 25 rotatably mounted relative to the housing 3 and driven by the first gear 23. The inclusion of the electric motor 21 attached to the housing 3, the first gear 23 rotatably mounted relative to the housing 3 and driven by the electric motor 21, and the second gear 25 rotatably mounted relative to the housing 3 and driven by the first gear 23 ensures that the fluid can be pressurized using an electrically driven gear pump. The first gear 23 is non-rotatably connected to a drive shaft 27 of the electric motor 21.The fact that the first gear 23 is non-rotatably connected to the drive shaft 27 of the electric motor 21 ensures that the electric motor 21 can drive the first gear 23 into a rotary motion. The first gear 23 is rotatably mounted relative to the housing 3 by means of a bearing bushing 29. This rotatable mounting of the first gear 23 relative to the housing 3 ensures particularly simple mounting of the first gear 23 relative to the housing 3. The first gear 23 has a first tooth that engages with a second tooth of the second gear 25. This first tooth engagement ensures that the first gear 23 can drive the second gear 25 into a rotary motion. The second gear 25 is non-rotatably connected to an axle 31, which in turn is rotatably mounted relative to the housing 3.The fact that the second gear 25 is connected to the axle 31 in a rotationally fixed manner, which is rotatably mounted relative to the housing 3, ensures a particularly simple mounting of the second gear 25 relative to the housing 3.

[0027] Furthermore, the pumping device 5 has a housing cover 33 which is attached to the housing 3 in an attached state, wherein the housing cover 33, in the attached state, together with the housing 3, defines a second cavity 35 which is connected to the first channel access 15. Because the pumping device 5 has the housing cover 33, which, in the attached state, is attached to the housing 3, and the housing cover 33, in the attached state, together with the housing 3, defines the second cavity 35 which is connected to the first channel access 15, it is ensured that a fluid can pass from the second cavity 35 into the channel 13 via the first channel access 15 and then, when the fluid in the second cavity 35 is pressurized, this pressure is also present in the portion of the fluid located in the channel 13 and also, via the second channel access 17, in the portion of the fluid located in the first cavity 19.

[0028] Furthermore, the first gear 23 and the second gear 25 are arranged in the second cavity 35. Because the first gear 23 and the second gear 25 are arranged in the second cavity 35, a fluid can be conveyed from the second cavity 35 through the first channel access 15 into the channel 13 using the first gear 23 and the second gear 25, and the fluid can be pressurized in the second cavity 35 using the first gear 23 and the second gear 25, so that this pressure is also present in the portion of the fluid located in the channel 13, and, if a portion of the fluid is also located in the first cavity 19, this pressure is also present in the portion of the fluid located in the first cavity 19.

[0029] Section 7 of the locking device is arranged in the first cavity 19. Furthermore, section 7 of the locking device is configured to move within the first cavity 19 along a direction of movement 37 into a coupled position and into a decoupled position. Section 7 of the locking device is configured to move within the first cavity 19 in the direction of movement 37 into the coupled position and in the opposite direction of movement 37 into the decoupled position.By arranging section 7 of the locking device in the first cavity 19 and by designing section 7 of the locking device to be moved in the first cavity 19 along a direction of movement 37 into the coupled position and into the decoupled position, it is ensured that a force can be exerted on section 7 of the locking device by means of a fluid arranged in the first cavity 19 and pressurized, in order to bring section 7 of the locking device into the coupled position, wherein in the coupled position section 7 of the locking device or a further section of the locking device is engaged with both a first section of a first wheel shaft of the differential gear device and a second section of a second wheel shaft of the differential gear device, so that the first wheel shaft and the second wheel shaft are rotationally fixed to each other.

[0030] Furthermore, section 7 of the locking device comprises a piston unit 39 and a locking slide unit 41 rotatably mounted relative to the piston unit 39. The fact that section 7 of the locking device comprises the piston unit 39 and the locking slide unit 41 rotatably mounted relative to the piston unit 39 ensures that the piston unit 39 is designed for movement along the direction of movement 37 and can be movably mounted relative to the housing 3 along the direction of movement 37, and that the locking slide unit 41 can be rotatably mounted relative to the piston unit 39 about an axis of rotation extending along the direction of movement 37.so that the locking slide unit 41 can either engage with a first section of a first wheel shaft and rotate with the first section of the first wheel shaft about the axis of rotation relative to the piston unit 39, or engage with both the first section of the first wheel shaft and a second section of a second wheel shaft and rotate with the first section of the first wheel shaft and with the second section of the second wheel shaft about the axis of rotation relative to the piston unit 39.

[0031] As already described, section 7 of the locking device is arranged in the first cavity 19 and is designed to move within the first cavity 19 along the direction of movement 37 into the coupled position and into the uncoupled position. It has also already been described that the actuating device 1 has the return element 9.

[0032] The return element 9 is configured to move section 7 of the locking device into the decoupled position along the direction of movement 37. Because the actuating device 1 includes the return element 9, and because the return element 9 is configured to move section 7 of the locking device into the decoupled position along the direction of movement 37, it is ensured that moving section 7 of the locking device into the decoupled position along the direction of movement 37 is particularly simple and requires fewer components, since, for example, no additional components are necessary for actively actuating section 7 of the locking device into the decoupled position, such as an additional fluid circuit with another pump. In the illustrated embodiment, the return element 9 is a spring, namely a conical helical spring.The use of the spring, in particular the conical helical spring, ensures a particularly simple design of the actuating device 1.

[0033] As already described, the actuating device 1 has the following features: Fig. Figure 3 shows a control device 11, at least partially and schematically. The control device 11 and the pump device 5 are connected such that a control signal sent by the control device 11 can be received by the pump device 5. Depending on the control signal, the pump device 5 can be brought into an activated state, in which the pump device 5 pressurizes the fluid. Furthermore, depending on the control signal, the pump device 5 can be brought into a deactivated state, in which the pump device 5 does not pressurize the fluid.By having the actuating device 1 include the control device 11, and by connecting the control device 11 and the pump device 5 in such a way that a control signal sent by the control device 11 can be received by the pump device 5, the pump device 5 can be brought into the activated state depending on the control signal, in which the pump device 5 pressurizes the fluid, and the pump device 5 can be brought into the deactivated state depending on the control signal, in which the pump device 5 does not pressurize the fluid, it is ensured that the pressurization of the fluid can be activated and deactivated in a particularly simple way.

[0034] A fluid can therefore be arranged in the channel 13, and in the operation of the actuating device 1, a fluid is arranged in the channel 13, the fluid being oil in the illustrated example. Furthermore, section 7 of the locking device can be arranged in the first cavity 19, and in the operation of the actuating device 1, section 7 of the locking device is arranged in the first cavity 19. Section 7 of the locking device is configured to move in the first cavity 19 along the direction of movement 37 into the coupled position and into the uncoupled position.By allowing a fluid to be arranged in the channel 13 and by allowing the section 7 of the locking device to be arranged in the first cavity 19, which is designed to be moved in the first cavity 19 along the direction of movement 37 into the coupled position and into the decoupled position, it is ensured that a coupled position can be brought about by means of the section 7 of the locking device, in which the section 7 of the locking device or a further section of the locking device is engaged with both the first section of the first wheel shaft of the differential gear device and with the second section of the second wheel shaft of the differential gear device, so that the first wheel shaft and the second wheel shaft are rotationally fixed to each other.Furthermore, the pumping device 5 is designed, when a fluid is arranged in the channel 13 and the section 7 of the locking device is arranged in the first cavity 19, which is the case during operation of the actuating device 1, to pressurize the fluid at the first channel access 15 in such a way that the pressurized fluid moves the section 7 of the locking device along the direction of movement 37 into the coupled position.By designing the pumping device 5 to pressurize the fluid at the first channel access 15 when a fluid is arranged in the channel 13 and the section 7 of the locking device is arranged in the first cavity 19, such that the pressurized fluid moves the section 7 of the locking device along the direction of movement 37 into the coupled position, it is ensured that the coupled position can be selectively brought about in a particularly simple and space-saving manner using the pumping device 5, wherein in the coupled position the section 7 of the locking device or a further section of the locking device is engaged with both the first section of the first wheel shaft of the differential gear device and with the second section of the second wheel shaft of the differential gear device, so that the first wheel shaft and the second wheel shaft are rotationally fixed to each other.In particular, the actuating device 1 can be used to provide the function of a differential lock.

[0035] It has been found that the actuating device 1 is particularly advantageous compared to hydraulic locking devices for differential gears known from the prior art, which often use the central pressure generation unit or pump mounted in the vehicle for actuation. These hydraulic locking devices known from the prior art often require lines and valves for distributing the hydraulic energy, which are not required in the actuating device 1. For example, throttling losses resulting from long lines can be avoided with the actuating device 1. The pressure generation unit of the hydraulic locking devices known from the prior art often has a pressure accumulator that is kept permanently pressurized, which is not necessary in the actuating device 1.Furthermore, in hydraulic locking devices known from the prior art, the size of the pressure accumulator often depends on the number and size of the hydraulic consumers, so that in the case of a vehicle in which the actuating device 1 is used and in which a pressure accumulator is also provided for further functions, this pressure accumulator can be adapted in size to the further functions independently of the implementation of a differential lock.

[0036] As previously described, an electrically driven gear pump is provided by means of the actuating device 1. The electrically driven gear pump comprises the electric motor 21, the first gear 23, which can also be referred to as the driven gear, the second gear 25, which can also be referred to as the driven gear, the shaft 31 for the driven gear, a section of the housing 3, and the housing cover 33. The drive shaft 27 of the electric motor 21 extends through a bore 43 in the housing cover 33. The drive shaft 27 and the housing cover 33 are sealed against each other by means of a sealing element in the form of a sealing ring 45, so that the second cavity 35 is optimally sealed against the environment of the actuating device 1. The bore 43 can also be referred to as the sealed bore. The drive shaft 27 is rotationally fixed to the first gear 23 and drives the first gear 23.The second gear 25 is driven by the first gear 23. The electric motor 21 is attached to the housing 3 by two screws such that the housing cover 33 is also supported. In the assembled state, each screw 47 of the two screws extends through a corresponding bore 43 in a mounting section 49 of the housing of the electric motor 21, through a corresponding bore 43 in the housing cover 33, and into a corresponding bore 43 with a corresponding internal thread in the housing 3. Each screw 47 has an external thread with which the screw 47 engages with the corresponding internal thread.Because, in the assembled state, each screw 47 of the two screws extends through a corresponding bore 43 in a mounting section 49 of a housing of the electric motor 21, through a corresponding bore 43 in the housing cover 33, and into a corresponding bore 43 with a corresponding internal thread in the housing 3, and because each screw 47 has an external thread with which the screw 47 with the corresponding internal thread engages, a particularly component-efficient and weight-saving fastening of the electric motor 21 and the housing cover 33 to the housing 3 is ensured. A sealing element in the form of a sealing ring 45 is also provided between the housing 3 and the housing cover 33, so that the second cavity 35 is optimally sealed against the environment of the actuating device 1.

[0037] In the illustrated embodiment of the actuating device 1, the housing 3 forms a section of an axle bridge. The actuating device 1 thus forms at least a section of the axle bridge. The fact that the actuating device 1 forms at least a section of the axle bridge can also be described as the housing 3 being integrated into the axle bridge. Because the housing 3 forms a section of the axle bridge, or because the actuating device 1 forms at least a section of the axle bridge, a particularly compact design for a differential gear device with a locking function is ensured. The first gear 23 and the second gear 25 are arranged parallel to the axis and mounted in bearing bushings. The housing 3 has an oval section that surrounds the gears.The oval section of the housing 3 surrounds both gears in such a way that only a small gap remains between the housing wall and the gears. The housing 3 is closed and sealed by the housing cover 33. The space in the housing 3 occupied by the oil can be divided into a suction side and a pressure side. By reversing the direction of rotation of the gears, the suction and pressure sides are reversed. The delivery direction can thus be influenced. An oil supply channel 51, which forms a section of the second cavity 35, and an oil pressure channel 53, which corresponds to channel 13, are integrated into the housing 3 such that the meshing gears prevent a direct flow of oil from a suction side to a pressure side when they are not rotating. The rotation of the gears forces the oil from the suction side to the pressure side, generating oil pressure which exits the pumping device 5 through the oil pressure channel 53.The oil pressure channel 53 connects the pressure side of the pump to a hydraulic actuator 55 of the differential lock, the hydraulic actuator 55 comprising the piston unit 39 and the locking spool unit 41. The pressure causes the locking spool unit 41, which can also be referred to as a lock, to be actuated in the hydraulic actuator 55.

[0038] The differential lock is engaged by pressing a button or key. For this purpose, the control unit 11 has a push button 57, which can be actuated by a user, i.e., moved into a closed position. When the push button 57 is actuated, the electric motor 21 is operated at a constant current and voltage using an energy storage device 59 in the form of a 12-volt battery, for as long as the push button 57 remains actuated, i.e., as long as the push button 57 remains in the closed position. Actuating the push button 57 thus results in an electric current that supplies energy to the electric motor 21 and thus operates it. This electric current can also be described as a control signal sent by the control unit 11, which can be received by the pump unit 5.Depending on the control signal, the pumping device 5 is brought into the activated state, in which it pressurizes the fluid. Since the control signal is represented by the supplied electrical current, this current can also be described as corresponding to a control signal representing an "on" status. The supplied electrical current is what brings the pumping device 5 into the activated state. The electric motor 21 continues to rotate even when section 7 of the locking device is in the coupled position, specifically when one of the locking device's claws is engaged. Preferably, no shutdown occurs due to overpressure or excessive temperature.To prevent thermal overload of the electric motor 21, an electric motor 21 is selected that is significantly larger than the required power output. Furthermore, in a [context missing]... Fig. 3 shown electrical circuit of the control device 11 a series resistor 61 (R V The electric motor 21 is connected in series with the electric motor 21. The series resistor 61 reduces the voltage applied to the electric motor 21. The series resistor 61 is designed such that the resulting electric current ensures that the pumping device 5 delivers the fluid at a predetermined pressure (p = p). max ) is subjected to an electric current. The electric current corresponds to a predetermined electric current (I = I). maxThe electric current can be monitored using an electric current meter 63. This delays the heating of the electric motor 21 to such an extent that the heat released to the environment provides sufficient cooling.

[0039] When the button 57 is released, the electrical current flow is interrupted and the electric motor 21 no longer provides torque to the pumping device 5. The pumping device 5 is thus deactivated in response to the control signal, in which it does not pressurize the fluid. When no electrical current is supplied, the situation can be described, in the context of the present invention, as the control signal being represented by the absence of electrical current. This can also be described as the absence of electrical current corresponding to a control signal representing an "off" state. The absence of electrical current is what deactivates the pumping device 5. The oil pressure then drops again.Section 7 of the locking device, in particular the claw, is now moved into the decoupled position along the direction of movement 37 by the force of the return element 9, here by the compressed return spring. The force of the return element 9, i.e., the return spring, acts on a surface of the piston unit 39 and generates a pressure p in the oil. Feder The oil now flows backwards through the second channel inlet 17 into the channel 13 and through the first channel inlet 15 into the second cavity 35, which forms a sump for collecting and supplying the oil in sections. During this process, the first gear 23 and the second gear 25 rotate in opposite directions.

[0040] Because there is no oil circulation in the hydraulic actuator 55 of the differential lock and the travel distance of the hydraulically moved components is very small, the generated oil pressure does not pump a significant volume of oil, allowing the sump, in particular, to be comparatively small. The pump unit 5 and especially the electric motor 21 can be very small and energy-efficient. The conversion of electrical to hydraulic energy takes place in the immediate vicinity of the differential lock and independently of the vehicle. The elimination of a hydraulic consumer has a positive effect on the dimensions of the hydraulic system in the vehicle. Furthermore, electrically powered commercial vehicles benefit from the low energy consumption for actuating the lock. This has a positive effect on their operating time.In particular, a differential gear device featuring the actuating device 1 can be used as an alternative to a conventionally hydraulically actuated differential lock. Only one cable connection is required for connection to the other vehicle components. Applications that only rarely require the traction of the locked differential especially benefit from the reduced component count.

[0041] In summary, it can be stated that the actuating device 1 provides a hydraulically actuated lock for a differential gear, which may be integrated into a vehicle axle. The differential gear is fully locked exclusively via electrical actuation. Furthermore, the actuating device 1 enables an interface between the vehicle axle and other vehicle components, where this interface can consist of only a single cable transmitting low-voltage (e.g., 12V) electrical current. Additionally, the actuating device 1 allows for the electrical supply of hydraulic pressure and flow with minimal energy consumption and in close proximity to the hydraulic consumer.Furthermore, the actuation device 1 can be operated quickly and by pressing a button by an operator or driver of the vehicle.

[0042] The described actuating device 1 is designed for a differential gear assembly. The differential gear assembly includes the actuating device 1. Furthermore, the differential gear assembly has two wheel shafts, wherein, when section 7 of the locking device is in the engaged position, the two wheel shafts are rotationally fixed to one another, and when section 7 of the locking device is in the disengaged position, the two wheel shafts are rotatable relative to each other. The features, technical effects, and / or advantages described in connection with the actuating device 1 also apply, at least analogously, to the differential gear assembly, so a corresponding repetition is omitted here.

[0043] It should be further noted that "having" does not exclude any other elements or steps, and "a" or "an" does not exclude a plurality. It should also be noted that features described with reference to one of the above embodiments may also be used in combination with other features of other embodiments described above. Reference numerals in the claims are not to be considered as a limitation. Reference sign 1 Actuating device 3 cases 5 Pumping unit 7 Section of a locking device 9 Return element 11 Control unit Channel 13 15 first channel access 17 second channel access 19 first cavity 21 Electric motor 23 first gear 25 second gear 27 Drive shaft 29 Bearing bushing 31 axle 33 Housing cover 35 second cavity 37 Direction of movement 39 piston unit 41 Locking slide unit 43 bore 45 Sealing ring 47 screw 49 Fastening section 51 Oil supply channel 53 Oil pressure channel 55 hydraulic actuator 57 buttons 59 Energy storage 61 Series resistor 63 Current meter

Claims

Actuating device (1) for a differential gear device, wherein the actuating device (1) comprises a housing (3) and an electrically driven pump device (5) attached to the housing (3), wherein the housing (3) defines a channel (13) extending from a first channel access (15) to a second channel access (17), wherein the housing (3) defines a first cavity (19) connected to the second channel access (17), wherein a fluid may be arranged in the channel (13) and a section (7) of a locking device may be arranged in the first cavity (19), the locking device being configured to move in the first cavity (19) along a direction of movement (37) into a coupled position and into a decoupled position, and wherein the pump device (5) is configured when a fluid is arranged in the channel (13) and the section (7) of the locking device is arranged in the first cavity (19),to pressurize the fluid at the first channel access (15) so that the pressurized fluid moves the section (7) of the locking device along the direction of movement (37) into the coupled position. Actuating device (1) according to the preceding claim, wherein the housing (3) is a section of a housing of the differential gear device. Actuating device (1) according to one of the preceding claims, wherein the pumping device (5) comprises an electric motor (21) attached to the housing (3), a first gear (23) rotatably mounted relative to the housing (3) and driven by the electric motor (21), and a second gear (25) rotatably mounted relative to the housing (3) and driven by the first gear (23). Actuating device (1) according to one of the preceding claims, wherein the pump device (5) has a housing cover (33) which is attached to the housing (3) in an attached state, wherein the housing cover (33) in the attached state together with the housing (3) defines a second cavity (35) which is connected to the first channel access (15). Actuating device (1) according to one of claims 3 and 4, wherein the first gear (23) and the second gear (25) are arranged in the second cavity (35). Actuating device (1) according to one of the preceding claims, wherein the actuating device (1) has the section (7) of the locking device which is arranged in the first cavity (19) and is configured to be moved in the first cavity (19) along the direction of movement (37) into the coupled position and into the uncoupled position. Actuating device (1) according to one of the preceding claims, wherein the section (7) of the locking device comprises a piston unit (39) and a locking slide unit (41) rotatably mounted relative to the piston unit (39). Actuating device (1) according to one of the preceding claims, wherein the actuating device (1) has a return element (9) which is configured to move the section (7) of the locking device along the direction of movement (37) into the decoupled position. Actuating device (1) according to one of the preceding claims, wherein the actuating device (1) comprises a control device (11), wherein the control device (11) and the pump device (5) are connected to each other in such a way that a control signal sent by the control device (11) can be received by the pump device (5), wherein the pump device (5) can be brought into an activated state depending on the control signal, in which the pump device (5) pressurizes the fluid, and can be brought into a deactivated state in which the pump device (5) does not pressurize the fluid. Differential gear device with an actuating device (1) according to one of the preceding claims and with two wheel shafts, wherein when the section (7) of the locking device is in the coupled position, the two wheel shafts are connected to each other in a rotationally fixed manner and when the section (7) of the locking device is in the decoupled position, the two wheel shafts are rotatable relative to each other.

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