Parking lock unit for a drive train of a motor vehicle and drive assembly with such a parking lock unit

Abstract

The invention relates to a parking lock unit (2) for a motor vehicle, comprising a parking lock wheel (4), a locking element (6) which can be brought into and out of selective engagement with the parking lock wheel (4), a controllable actuator (7), and an axially adjustable actuating element (8) which is guided axially in a guide sleeve (9), wherein a first cavity (12) in the guide sleeve is formed on a first side of the actuating element (8) and a second cavity (13) in the guide sleeve is formed on a second side of the actuating element (8), wherein the guide sleeve (9) is arranged below the parking lock wheel (4) in an installed state, so that lubricant can collect in the first cavity (12) and the second cavity (13), and wherein a fluid connection (14) connects the first cavity (12) at least indirectly with the second cavity (13) with a cross-sectional area (A14) which is at least 5% of the cross-sectional area (A9) of the guide sleeve (9). The invention furthermore relates to a drive assembly with such a parking lock unit (2).

Description

TECHNICAL FIELD

[0001] The present application relates to a parking lock unit for a drive train of a motor vehicle and to a transmission assembly or an electric drive assembly with such a parking lock unit. BACKGROUND

[0002] Parking lock units for vehicle transmissions are generally known, for example for automatic transmissions or for electric drive assemblies. The parking lock unit here assumes the function of locking or releasing the drive train as required. Vehicle transmissions are used essentially for the speed adaptation between a drive source, for example an internal combustion engine or an electric machine, and a lower rotational speed of the vehicle wheels.

[0003] From WO 2020 001794 A1 a transmission assembly for an electric drive of a motor vehicle is known. The transmission assembly comprises a drive shaft, a reduction transmission, a power split unit with an input component and two output components arranged in a transmission housing, and a parking lock unit arranged in a parking lock housing. The parking lock unit comprises a parking lock wheel in the power path between the drive shaft and the output components and a controllable locking element which can be brought into selective engagement with the parking lock wheel in order to lock it. The parking lock housing is liquid-tightly sealed with respect to the transmission housing, so that a transmission oil sump and a parking lock oil sump are separated.

[0004] From WO 2018 001476 A1 an electric drive assembly with a parking lock is known. The motor shaft of the electric motor has a free, protruding shaft end which is introduced into a parking lock housing and with which a locking wheel is connected in a torque-proof manner. The parking lock housing forms a common space together with the housing assembly.

[0005] From DE 10 2010 029 400 A1 a parking lock assembly for a drive train of a motor vehicle is known, which has a locking mechanism and an actuator for actuating the locking mechanism. The locking mechanism comprises a locking element which can be moved linearly by the actuator, which is guided in a guide sleeve. SUMMARY

[0006] The present application is based on the task of providing a parking lock unit for a transmission unit of a motor vehicle which enables a fast engagement speed of the parking lock and which is robust and service-friendly. Furthermore, it should be the task of the present application to propose a transmission assembly with such a parking lock unit, whose drive train can be correspondingly quickly locked or released.

[0007] To solve the problem a parking lock unit for a drive train of a motor vehicle is presented, comprising a parking lock wheel which is torsionally connectable with an element of the drive train, a locking element which is selectively engageable and disengageable with the parking lock wheel, a controllable actuator, and an axially adjustable actuating element which is axially guided in a guide sleeve and cooperates with the locking element, wherein a first cavity in the guide sleeve is formed on a first side of the actuating element and a second cavity in the guide sleeve is formed on a second side of the actuating element, wherein a fluid connection is provided which at least indirectly connects the first cavity with the second cavity, wherein the fluid connection has a cross-sectional area which is at least 5% of the cross-sectional area of the guide sleeve.

[0008] The advantage is that the lubricant can quickly escape from the area of movement of the actuating element through the fluid connection when the actuating element is moved into the first cavity when actuating the parking lock unit. Due to the fluid connection having a cross-sectional area which is at least 5% of the cross-sectional area of the guide sleeve, particularly a particularly short actuation time for the switch of the parking lock is achieved, even when the vehicle or the drive assembly is in a ramped position. The cross-sectional area can also be larger, for example at least 7.5% or at least 10% of the cross-sectional area of the sleeve. Alternatively or additionally, the cross-sectional area of the fluid connection can also be at least 10% of the maximum cross-sectional area of the actuating element.

[0009] The actuating element is arranged axially movably in the guide sleeve, wherein the first cavity is formed on a first axial side of the actuating element and the second cavity is formed on a second axial side of the actuating element. When the actuating element is moved in a first direction, the first cavity correspondingly decreases and the second cavity correspondingly increases, and vice versa, thus forming a piston-like assembly. For a quick switch it is important that the lubricant located in front of the actuating element in the direction of movement can as quickly as possible escape from this area into another area of the parking lock housing, for example the area located behind the actuating element in the direction of movement. The actuating element can have a conical actuating face from which the locking element is pressed away or towards the parking lock wheel depending on the position of the actuating element.

[0010] The guide sleeve is fixedly connected to the parking lock housing, for example form-fittingly, force-fittingly and / or materially, wherein the guide sleeve is preferably oriented horizontally in the installed state of the parking lock unit. The guide sleeve can have a first sleeve section which is closed around, in particular an end section, which is moved into a bore of the parking lock housing, and a second sleeve section which is coupled thereto with a longitudinal slit into which the locking element can be moved in a release position. The closed sleeve section exists in a first movement direction and is part of the first cavity. The slit-open second sleeve section exists in a second direction and is part of the second cavity.

[0011] According to one embodiment, the parking lock unit and the transmission unit can be sealed relative to one another and have separate lubricants. By means of the separate parking lock lubricant, a defined oil supply of the contact area between the parking lock wheel and the locking element can be achieved when the parking lock is put in, which advantageously acts on the engagement speed. Furthermore, different lubricants can be used for the transmission and the parking lock, which are individually matched to the respective requirements. With regard to maintenance, the two lubricants can be replaced individually according to wear. Alternatively, it is also possible for the parking lock unit and the transmission unit to be fluidically connected to one another and to use a common lubricant, which lubricates both units.

[0012] The parking lock unit can be designed in principle in any way, wherein for moving the actuating element electromechanical, electromagnetic or hydraulic actuators can be used. According to one exemplary embodiment, an axially movable actuating element can be moved by an actuator in a first axial direction and loaded by spring means in a second, opposite direction. The actuating element in particular cooperates with the locking element such that the actuating element releases the locking element when moved in the first axial direction and loads the locking element into a closed position when moved in the second axial direction. In the closed position, the locking element engages form-fittingly into the locking wheel, so that the locking wheel and the drive train connected thereto is blocked. In the released state, the locking wheel can be freely rotated, so that a rotational movement introduced into the transmission unit is transmitted to the output member. The locking wheel can be connected with any torque-transmitting element of the drive train, for example a shaft.

[0013] According to one possible design, the actuating mechanism can have a spindle which can be driven in both directions by the actuator about an axis of rotation. By means of a spindle nut, the actuating element can be moved axially in a first direction against the restoring force of a spring via the spindle nut by a spindle twist. The spindle can have a centrifugal disc which, when the spindle is rotated, centrifugally lubricates the lubricant in the direction of the contact area between the parking lock wheel and the locking element.

[0014] The level of the lubricant in the installed position of the transmission assembly in the rest state is preferably below the active area of the parking lock wheel in the vertical direction, which is defined by the parking lock wheel when it is rotated. Thereby, splashing of the parking lock wheel in the lubricant is avoided. In particular, the level of the lubricant can be in the rest state in the horizontally installed position of the transmission assembly in the lower half, in particular in the lower third, of the guide sleeve.

[0015] The locking element can be designed according to a first possibility in the form of a pivotably mounted locking pawl or according to a second possibility in the form of a linearly movable locking pin. A spring means can be provided, which loads the locking element into a released position. The locking element has engagement means which are designed such that they can engage form-fittingly into a contour of the locking wheel or be released therefrom.

[0016] Several embodiments of the fluid connection and combinations thereof between the first and second chamber are possible.

[0017] According to a first embodiment, the fluid connection comprises at least one longitudinal recess which is formed in a peripheral section of the actuating element and which is set back radially inwardly with respect to the outer guide surface of the actuating element. Upon axial movement of the actuating element, lubricating oil flows from the first chamber through the longitudinal recess in the sleeve in the direction of the second chamber. Preferably, the actuating element has a plurality of longitudinal recesses, for example two, three or four, which are distributed regularly on the periphery, in particular. Between two recesses which are adjacent in the peripheral direction, one guide surface section each is formed, with which the actuating element is axially guided in the guide sleeve.

[0018] According to a further embodiment, the fluid connection can have at least one longitudinal bore through the actuating element, through which lubricant can flow between the first and second chamber depending on the direction of movement of the actuating element. The longitudinal bore can be designed as a central bore, wherein a longitudinal element which is drivingly connected to the actuator can be guided through the bore, for example a spindle or a coupling rod. In the case of the longitudinal bore and the longitudinal element, an annular gap is formed in this case as the fluid connection through which the parking lock lubricant can flow. The cross-sectional area of the annular gap is at least 5% of the cross-sectional area of the guide sleeve or at least 10% of the cross-sectional area of the actuating element.

[0019] The fluid connection can have, according to a further embodiment, at least one transverse bore in the actuating element, through which lubricant can flow from one chamber to the other upon movement of the actuating element. The actuating element can have two guide sections which are arranged axially offset from one another and which jointly act with the guide sleeve. An annular groove is configured axially between the guide sections, into which at least one transverse bore opens.

[0020] According to a further embodiment, the fluid connection can have at least one radial opening in the guide sleeve and a housing bore in the parking lock housing which is fluidically connected thereto, into which the guide sleeve is seated. Upon movement of the actuating element in a first direction, lubricant can flow through the radial opening and the housing bore to the lock wheel, and upon movement in a second direction, the lubricant flow is correspondingly rotated.

[0021] The fluid connection can have, according to a further embodiment, an external channel which is coupled at the parking lock housing, wherein a first end of the channel is fluidically connected to the first chamber and a second end of the channel opens into another housing region in which the hydraulic pressure is less than in the first chamber.

[0022] The parking lock unit can be used in any drive assembly, for example in an electric drive assembly or an automatic transmission of a motor vehicle.

[0023] The above-mentioned tasks are furthermore solved by a drive assembly, in particular for an electric drive, comprising a reduction gear which can convert an introduced torque into a slow (langsame, sometimes also called low speed), a differential gear which can transmit a rotational movement introduced by the reduction gear onto two output wheels on a differential housing, and a parking lock unit which can be designed according to one or more of the above-mentioned embodiments. The above-mentioned advantages of a particularly fast switching time of the parking lock with the drive assembly are achieved, in particular even when the vehicle is inclined with respect to the horizontal. BRIEF DESCRIPTION OF DRAWINGS

[0024] Preferred embodiments are explained below with reference to the drawings. Therein:

[0025] Figure 1A A parking lock unit according to the application in a first embodiment is shown in a sectional view;

[0026] Figure 1B A parking lock unit from Figure 1A is shown in a cross section through the actuating element;

[0027] Figure 1C An actuating element from Figure 1A and 1B is shown in a perspective view;

[0028] Figure 1D A parking lock unit from Figure 1A is shown in a position inclined by about 15° from the horizontal;

[0029] Figure 2 An actuating element for a parking lock unit according to Figure 1A , 1 B in a modified embodiment is shown in a perspective view;

[0030] Figure 3A A parking lock unit according to the application in another embodiment is shown in a sectional view;

[0031] Figure 3B An actuating element from Figure 3A is shown as a detail in a longitudinal section;

[0032] Figure 4A A parking lock unit according to the application in another embodiment is shown in a sectional view;

[0033] Figure 4B A parking lock unit from Figure 4A is shown in a cross section through the actuating element;

[0034] Figure 4C An actuating element from Figure 4Aa control element of the 4B;

[0035] Figure 5 a parking lock element according to the application in another embodiment is shown in a sectional view;

[0036] Figure 6 a parking lock unit according to the application in another embodiment is shown in a sectional view;

[0037] Figure 7A a drive assembly according to the application with a parking lock unit according to the application in another embodiment is shown in a sectional view according to Figures 1A-1D

[0038] Figure 7B a drive assembly according to the application in another embodiment is shown in a sectional view according to sectional line 7B-7B from Figure 7A DETAILED DESCRIPTION

[0039] the following jointly described Figures 1A-1D a parking lock unit 2 according to the application for a drive train of a motor vehicle is shown in a first embodiment. In general, a park lock is used to optionally lock a drive member in a drive train of a motor vehicle, so that the motor vehicle is prevented from unintentional rolling away when a drive source does not provide torque for use.

[0040] The parking lock unit 2 comprises a park lock housing 3, a lock wheel 4, which is connected in a torque-proof manner to a shaft 5, a lock element 6, which is movably supported in the park lock housing 3, and a control mechanism with an axially adjustable control element 8, which cooperates with the lock element 6 and is axially guided in a guide sleeve 9, and a controllable actuator 7, which is drivingly connected to the control element 8. The parking lock unit 2, which can also be referred to as a park lock assembly, is filled with a lubricant 10, the level of which is present as a dashed line L in the horizontal (Niveau, sometimes also referred to as level) in the horizontal filling position.

[0041] The level L of the lubricant 10 is in the horizontal filling position of the parking lock unit 2, or of a drive assembly comprising the parking lock unit, in a stationary state below the range of action of the park lock wheel 4. It can be recognized that the lubricant level L is currently arranged in the lower half or lower third of the guide sleeve 9. A particularly high efficiency results therefrom.

[0042] ​​The axially movable operating element 8 in the guide sleeve 9 has a piston-like action, wherein on a first side of the operating element 8 a first cavity 12 in the guide sleeve 9 is formed and on the opposite second side of the operating element a second cavity 13 in the guide sleeve is formed. When the operating element 8 is moved in a first direction Rl, the first cavity 12 correspondingly decreases and the second cavity 13 correspondingly increases, and vice versa. In order that the lubricant 10 can escape as quickly as possible from the operating element 8 when the operating element 8 is moved to the cavity in which it is moved, a fluid connection 14 is provided in another region of the parking lock housing 3. The fluid connection 14 has a cross-sectional area which is preferably at least 5%, in particular at least 7.5% or at least 10% of the cross-sectional area of the guide sleeve 9 and / or at least 10% of the largest cross-sectional area of the operating element 8. The design of the fluid connection 14 is discussed in more detail further below.

[0043] In the present embodiment, the axially movable operating element 8 can be moved by the actuator 7 in a first axial direction Rl and loaded by spring means 15 in a second, opposite direction R2. The operating element 8 thus cooperates with the locking element 6 such that the operating element releases the locking element 6 when moved in the first axial direction Rl and loads the locking element 6 into a closed position when moved in the second axial direction R2.

[0044] The guide sleeve 9 is fixedly connected with the parking lock housing 3, in particular pressed into a corresponding bore 16 of the housing. In the installed state of the parking lock unit 2, the guide sleeve 9 is preferably oriented horizontally, so that the lubricant is distributed uniformly when the vehicle is located on a flat surface. The guide sleeve 9 has a first sleeve section 17 which is closed around, into which the operating element 8 is moved when actuated in the first direction Rl, and a second sleeve section 18, into which the operating element 8 is moved in the second direction R2 and which has a longitudinal slit 32. The guide sleeve 9 is supported axially against the parking lock housing 3, in particular with the interposition of a disc spring 19. The parking lock housing 3 optionally has a sleeve projection 20 arranged coaxially to the guide sleeve 9, into which the spring 15 and the drive element 22 which is movable by the actuator 7 in the form of a spindle axially extend. On the bottom side, the sleeve projection 20 can have a removable cover 21 which, if necessary, can be removed for a forced unlocking of the parking lock 2 in order to introduce a torque into the drive element 22. The spindle 22 is rotatably supported in the parking lock housing 3 about an axis of rotation X22 by means of a bearing 11.

[0045] The operating element 8 has a pressure face 27, in particular conical, for loading the locking element 6, and two guide sections 28, 28' with which the operating element is axially guided in the guide sleeve 9. An annular recess 29 is configured axially between the guide sections, which forms an annular space in the guide sleeve.

[0046] As can be recognized especially in Figure 1A The blocking wheel 4 has a plurality of peripherally distributed latching recesses 24 at the outer peripheral face, into which a blocking element 6 with a blocking tooth 25 can be engaged in a form-fit. The blocking element 6 can be shifted into a blocking position, in which it is form-fittingly connected with the blocking wheel 4, so that the blocking wheel 4 is prevented from rotational movement. In the release position, the blocking element 6 is moved outwardly relative to the blocking wheel 4, so that the blocking wheel 4 and the drive train connected therewith can be freely rotated.

[0047] The blocking element 6 is designed in the form of a blocking pawl, which is pivotably supported at one end in the parking lock housing 3 about a pivot axis X6. The blocking pawl 6 serves to either fix the blocking wheel 4 or the shaft 5 connected therewith, so that the drive train connected with the shaft 5 is prevented from rotational movement, or to release, so that the components of the drive train can be freely rotated. In order to shift the blocking pawl 6 from the blocking position into the release position, a spring element (not represented) can be provided. The spring element can be designed in the form of a leg spring, which can be supported with a first leg at the parking lock housing 3 and with a second leg at the blocking pawl 6.

[0048] At its opposite free end, the blocking pawl has an outer functional face 26, which cooperates with a conical pressure face 27 of the actuating element 8. The functional face 26 is inclined relative to a radial plane containing the rotational axis X6, which extends through the contact point between the functional face 26 and the pressure face 27. In this way, the translational movement of the actuating element 8 is converted into a pivoting movement of the blocking pawl 6. In order to guide the actuating element 8, a guide sleeve 9 is provided, into which the actuating element 8 with the guide sections 28, 28' is axially movably guided.

[0049] The actuator 7 is currently designed in the form of an electromechanical actuator, which can be controlled by an electronic control unit (not represented), for example an electric motor. However, it is apparent that the actuator can alternatively be designed, for example also in the form of an electromechanical, hydraulic or pneumatic actuator. The actuator 7 acts on the actuating element 8 in a first axial direction Rl. To this end, the actuator 7 acts via a rotatably driven spindle 22, which cooperates with a spindle nut 23, which is screwed thereon. The spindle nut 23 serves as an axial stop or support face for the actuating element 8. The actuating element 8 is loaded by a spring 15 in a second direction R2, that is to say relative to the spindle nut 23.

[0050] By rotating the spindle 22 in a first rotational direction, the spindle nut 23 screwed thereon is moved away from the actuator 7 in the first axial direction Rl. In the moved-away position from the actuator, the actuating element 8 is moved away relative to the pretensioning force of the spring 15 by the functional face 26 of the blocking pawl 6, so that the blocking pawl 6 is released and pivoted radially outwardly relative to the blocking wheel by the spring force of the pawl spring.

[0051] By rotating the spindle 22 in the opposite second direction of rotation, the spindle nut 23 is correspondingly moved in the axial opposite second direction R2, that is to say, towards the actuator 7. The handling element 8 is released and loaded by the spring 15 against the functional face 26 of the blocking pawl 6. When the tooth 25 is in the region of the gap of the blocking wheel, the handling element 8 acts on the blocking pawl 6 in the closing direction and loads it radially inwards. The tooth 25 is engaged in a form-fitting manner into one of the recesses 24 of the blocking wheel 4, so that the latter is rotationally blocked. For the purpose of re-latching, the spindle nut 33 is in turn moved in its first position. The spindle nut 23 is thus not rotationally coupled when the spindle 22 is rotated, the spindle nut being torsionally blocked in the longitudinal groove of the guide sleeve 9. The spring 15 is preferably designed in the form of a helical spring, which sits in the accommodation space of the handling element 8. The spring 15 is supported axially against the handling element 8 on the one hand and against the parking lock housing 3 on the other hand. The spindle 22 can optionally have a centrifugal disc 37, which centrifugally lubricates the contact area between the parking lock wheel 4 and the blocking element 6 when the spindle is rotated.

[0052] The parking lock unit 2 can furthermore have a blocking sensor, which acquires the switching position of the blocking element 6 and transmits a corresponding blocking signal to the control unit. The blocking sensor, which can be fixed in the parking lock housing 3, recognises whether the blocking element 6 is engaged in a form-fitting manner into the blocking wheel 4, is in a tooth-on-tooth position or is completely swung away from the blocking wheel 4.

[0053] In the following, different embodiments of the fluid connection 14 between the first chamber 12 and other regions of the parking lock unit 2 are discussed in more detail.

[0054] According to the embodiment shown in Figures 1A-1D , the fluid connection 14 comprises a plurality of circumferentially distributed longitudinal recesses 30 in the guide section 28'. Between two circumferentially adjacent recesses 30, one guide face section 31 is formed, with which the handling element is axially guided in the guide sleeve 9. When the handling element 8 is moved axially in the first direction, lubricating oil can flow from the first chamber 12 through the longitudinal recesses 30 into the circumferential recess 29 and from there through the longitudinal slit 32 of the guide sleeve into the region above the parking lock, from which the lubricant can reach the second chamber 13 behind the handling element 8. When the handling element 8 is moved in the second direction, lubricant can flow in the opposite direction from the second chamber 14 through the longitudinal slit 32 of the guide sleeve and the longitudinal recesses 30 in the handling cone to the first chamber 12.

[0055] The cross-sectional area A14 of the fluid connection 14 is formed in the present case by the sum of the cross-sectional areas of the longitudinal recesses 30. Here, the cross-sectional area A14 of the fluid connection 14 is at least 5% of the cross-sectional area A8 of the guide sleeve 9, preferably at least 10% of the sleeve cross-sectional area. The longitudinal recesses 30 are preferably designed such that their cumulative cross-sectional area A14 is at least 10% of the largest cross-sectional area A8 of the actuating element 8.

[0056] By means of the fluid connection 14 mentioned, the lubricant 10 is quickly accessible from the space in front of the actuating element 8 in the direction of movement. The hydraulic resistance built up by the lubricant is reduced, so that particularly fast reaction times of the parking lock 2 result. This applies in particular to operating states in which the vehicle or the parking lock is inclined relative to the horizontal normal position, as is shown in Figure 1D , which can result in a greater amount of lubricant being located directly in front of or behind the actuating element.

[0057] Figure 2 An actuating element 8 in a slightly modified embodiment is shown. The only difference from the embodiment according to Figures 1A-1D is that the longitudinal recesses 30 are designed in the form of circumferentially distributed grooves.

[0058] The parking lock unit 2 according to the application in another embodiment is shown in the following common description. Figure 3A and 3B A parking lock unit 2 according to the application in another embodiment is shown. This corresponds as far as possible to the embodiment according to Figures 1A-1D , reference being made to its description in the context of commonality. Here, identical or modified details are provided with identical reference symbols, as in Figures 1A-1D .

[0059] The present embodiment according to Figure 3A and 3B is characterized in that the fluid connection 14 has a longitudinal bore 33 through the actuating element 8. The spindle 22 is guided through the longitudinal bore 33, wherein an annular gap 34 is formed between the spindle and the bore wall, through which the lubricant can flow. The cross-sectional area of the annular gap 34 is at least 5% of the cross-sectional area A9 of the guide sleeve 9 or at least 10% of the cross-sectional area A8 of the actuating element 8.

[0060] The parking lock unit 2 according to the application in another embodiment is shown in the following common description. Figures 4A-4C A parking lock unit 2 according to the application in another embodiment is shown. This corresponds as far as possible to the embodiment according to Figures 1A-1D , reference being made to its description in the context of commonality. Here, identical or modified details are provided with identical reference symbols, as in Figures 1A-1D .

[0061] The present embodiment according to Figures 4A-4CThe present embodiment is characterized in that the fluid connection 14 has a plurality of lateral bores 34 in the handling element, through which the lubricant can flow from one chamber to the other when the handling element is moved. The lateral bores 35 connect the outer peripheral face of the handling element 8 with the central bore 36. Here, two lateral bores 35 are arranged in the plane between the two guide sections 28, 28' and open into the circumferential recess 29 of the handling cone. The number and diameter of the lateral bores 35 are chosen such that the cumulative cross-sectional area A14 of the fluid connection 14 is at least 5% of the cross-sectional area A9 of the guide sleeve 9 or at least 10% of the cross-sectional area A8 of the handling element 8. In the present embodiment, two lateral bores 35 are provided, which are arranged opposite one another directly opposite, wherein it is clear that another number and arrangement can also be realized.

[0062] Figure 5 A parking lock unit 2 according to the application is shown in another embodiment. This corresponds as far as possible to the embodiment according to Figures 1A-1D , reference being made to the description thereof insofar as it is common. Here, identical or modified details are provided with identical reference symbols, as in Figures 1A-1D .

[0063] The present embodiment according to Figure 5 is characterized in that the fluid connection 14 comprises a radial opening 38 in the guide sleeve 9 and a housing bore 39 in the parking lock housing 3, which is fluidically connected thereto. When the handling element 8 is moved in the first direction R1, the lubricant can flow from the first chamber 12 in the direction of the lock wheel 4 through the radial opening 38 and the housing bore 39. The radial opening 38 and the housing bore 39 are dimensioned such that their cross-sectional area is at least 5% of the cross-sectional area of the guide sleeve 9 or at least 10% of the cross-sectional area of the handling element 8, respectively.

[0064] Figure 6 A parking lock unit 2 according to the application is shown in another embodiment. This corresponds as far as possible to the embodiment according to Figures 1A-1D , reference being made to the description thereof insofar as it is common. Here, identical or modified details are provided with identical reference symbols, as in Figures 1A-1D .

[0065] The present embodiment according to Figure 6 is characterized in that the fluid connection 14 has an external channel 40, which is coupled at the parking lock housing 3. Here, a first end of the channel 40 is coupled at the cover plate 21 and is thus fluidically connected with the first chamber 12. A second end of the channel 40 opens into a housing section above the first end in the region of the lock wheel 4. The cross-sectional area A14 of the channel of the fluid connection 14 is at least 5% of the cross-sectional area A9 of the guide sleeve 9 or at least 10% of the cross-sectional area A8 of the handling element 8.

[0066] In the following, a drive assembly 41 according to the application is described which is provided with a parking lock unit 2 according to the application. The parking lock unit corresponds to the embodiment described above and hereinafter with reference to the figures. In this connection, reference is made to the description thereof. Figure 7A and 7B A drive assembly 41 according to the application is shown which is provided with a parking lock unit 2 according to the application. The parking lock unit corresponds to the embodiment described above and hereinafter with reference to the figures. In this connection, reference is made to the description thereof. Figures 1A-1D The embodiment described above and hereinafter with reference to the figures. In this connection, reference is made to the description thereof. Here, identical details are provided with identical reference numerals.

[0067] The drive assembly 41 comprises an electric motor 42 and a drive connection therewith a transmission assembly 43 with a reduction gear 44 and a differential gear 45. The electric motor 42 is accommodated in a housing section of a housing assembly 46 and comprises a stator supported in the housing, a rotor with a motor shaft 47 rotatably driven therearound a rotational axis X47. The motor shaft 47 has at the shaft end a drive pinion 48 which jointly with a gear wheel 49 forms a first transmission stage. The gear wheel 49 is rotatably supported on the shaft 5 with a bearing 50 and can be selectively coupled or decoupled from the shaft for transmitting torque via a coupling unit 53. The shaft 5, also referred to as intermediate shaft, is rotatably supported in the housing 46 about a rotational axis X5 by means of bearings 58, 58' and extends through an opening in an intermediate plate 60 of the housing 46. A drive pinion 54 is fixedly connected with the shaft 5 which jointly with an annular wheel 55 forms a second transmission stage. The annular wheel 55 is connected with a differential housing 56 of the differential gear 45 which is rotatably supported in the housing by means of bearings 59, 59'. The differential gear 45 further comprises a differential wheel set 57 accommodated therein with two side shaft wheels as output components which can be drivingly connected with side shafts of the vehicle.

[0068] The shaft 5 has adjacent to the outer bearing 58' a free projecting shaft end 52 which extends into a parking lock space 51. The parking lock space 51 is fluid-tightly sealed with respect to a transmission space 61 by means of a sealing element 62. The transmission space 61 is filled with a transmission lubricant, while the parking lock space 51 is filled with a separate parking lock lubricant 10. For pressure equalization between the transmission space 61 and the parking lock space 51 a pressure equalization channel can be provided. It is also possible in a modified embodiment that the transmission space and the parking lock space are connected with each other and use a common lubricant.

[0069] The drive assembly 41 or the transmission assembly 43 is characterized by a parking lock unit 2 which is arranged in the parking lock space 51. By means of the fluid connection 14, lubricant can be quickly brought from the movement area of the actuating element 8 to a distance therefrom. In particular, even when the vehicle or the transmission assembly 43 is in a ramped position, a particularly short actuation time for the switch of the parking lock 2 is achieved.

[0070] List of reference numerals

[0071] 2 parking lock unit

[0072] 3 parking lock housing

[0073] 4 locking wheel

[0074] 5 shaft

[0075] 6 locking element

[0076] 7 actuator

[0077] 8 actuating element

[0078] 9 guide sleeve

[0079] 10 lubricant

[0080] 11 bearing

[0081] 12 first chamber

[0082] 13 second chamber

[0083] 14 fluid connection

[0084] 15 spring

[0085] 16 bore

[0086] 17 closed sleeve section

[0087] 18 split sleeve section

[0088] 19 disc spring

[0089] 20 sleeve protrusion

[0090] 21 cover plate

[0091] 22 drive element

[0092] 23 spindle nut

[0093] 24 latching recess

[0094] 25 locking tooth

[0095] 26 functional face

[0096] 27 pressure face

[0097] 28, 28' guide section

[0098] 29 recess

[0099] 30 longitudinal recess

[0100] 31 guide face section

[0101] 32 longitudinal slit

[0102] 33 longitudinal bore

[0103] 34 annular gap

[0104] 35 transverse bore

[0105] 36 central bore

[0106] 37 centrifugal disc

[0107] 38 radial opening

[0108] 39 housing bore

[0109] 40 passage

[0110] 41 drive assembly

[0111] 42 electric motor

[0112] 43 transmission assembly

[0113] 44 reduction gear

[0114] 45 differential gear

[0115] 46 housing assembly

[0116] 47 motor shaft

[0117] 48 drive pinion

[0118] 49 gear wheel

[0119] 50 bearing

[0120] 51 parking lock space

[0121] 52 shaft end

[0122] 53 coupling unit

[0123] 54 drive pinion

[0124] 55 annular wheel

[0125] 56 differential housing

[0126] 57 differential wheel set

[0127] 58, 58' bearing

[0128] 59, 59' bearing

[0129] 60 intermediate plate

[0130] 61 transmission space

[0131] A cross-sectional area

[0132] L level

[0133] R direction

[0134] X axis

Claims

1. Parking lock unit for a drive train of a motor vehicle, comprising: a parking lock wheel (4), which can be connected in a torque-proof manner to an element of the drive train, a locking element (6), which can be brought into engagement or out of engagement with the parking lock wheel (4), a controllable actuator (7), and a control element (8), which can be adjusted axially by the actuator (7), is guided axially in a guide sleeve (9) and cooperates with the locking element (6), wherein a first cavity (12) in the guide sleeve is formed on a first side of the control element (8) and a second cavity (13) in the guide sleeve is formed on a second side of the control element (8), and wherein the guide sleeve (9) is arranged below the parking lock wheel (4) in an installed state of the parking lock unit, so that lubricant can collect in the first and second cavities (12, 13), characterized by a fluid connection (14), which connects the first cavity (12) at least indirectly with the second cavity (13), wherein the fluid connection (14) has a cross-sectional area (A14) which is at least 5% of a cross-sectional area (A9) of the guide sleeve (9), and wherein the cross-sectional area (A14) of the fluid connection (14) is at least 10% of a maximum cross-sectional area (A8) of the control element (8), so that lubricant (10) can flow quickly from the first cavity (12) or the second cavity (13), respectively, which is in front of the control element (8) in the direction of movement, when the control element (8) is moved. The guide sleeve (9) has a first sleeve section (17), which is closed circumferentially, and a second sleeve section (18), which has a longitudinal slit (32). A parking lock housing (3) is provided, which forms a liquid-tightly sealed parking lock space (51), in which the lubricant (10) is accommodated. The control element (8) can be moved by the actuator (7) in a first axial direction (Rl) and is loaded by spring means (15) in a second direction (R2) opposite the first direction, wherein the control element (8) releases the locking element (6) when moved in the first axial direction and loads the locking element (6) into a closed position when moved in the second axial direction. A drive element (22) is provided, which can be driven in rotation by the actuator (7) about an axis of rotation (X22). A level (L) of the lubricant (10) is in a rest state in the lower half of the guide sleeve (9) in a horizontally installed position of the parking lock unit. The fluid connection (14) comprises at least one longitudinal notch (30), which is formed in a peripheral section of the control element (8) and is set back radially inwardly with respect to an outer guide surface of the control element (8), so that lubricant can flow from the first cavity (12) through the at least one longitudinal notch (30) in the direction of the second cavity (13) when the control element (8) is moved axially. ​ 2. Parking lock unit according to claim 1, characterized in that ​ 3. Parking lock unit according to claim 1 or 2, characterized in that ​ 4. Parking lock unit according to claim 1 or 2, wherein ​ ​ 5. Parking lock unit according to claim 1 or 2, characterized in that ​ 6. Parking lock unit according to claim 1 or 2, characterized in that ​ 7. Parking lock unit according to claim 1 or 2, characterized in that ​ 8. Parking lock unit according to claim 7, characterized in that The actuating element (8) has a plurality of circumferentially distributed longitudinal recesses (30), wherein between each two circumferentially adjacent longitudinal recesses a guide surface section (31) of the actuating element (8) is formed.

9. Parking lock unit according to claim 1 or 2, characterized in that The fluid connection (14) comprises at least one longitudinal bore (33) through the actuating element (8), through which a lubricant can flow from the first chamber (12) in the direction of the second chamber (13) upon axial movement of the actuating element (8).

10. Parking lock unit according to claim 9, characterized in that A drive element (22) connected to the actuator (7) is guided through the longitudinal bore (33), wherein between the longitudinal bore (33) and the drive element (22) an annular gap (34) is formed, through which the lubricant (10) can flow.

11. Parking lock unit according to claim 1 or 2, characterized in that The fluid connection (14) comprises at least one transverse bore (35) in the actuating element (8), through which a lubricant (10) can flow from the first chamber (12) to an outer circumferential surface of the actuating element (8) upon axial movement of the actuating element (8).

12. Parking lock unit according to claim 11, characterized in that The actuating element (8) has two guide sections (28, 28') which are arranged axially offset from one another, wherein between the two guide sections (28) a circumferential recess (29) is configured, into which at least one transverse bore (35) opens.

13. The parking lock unit according to claim 3, characterized by The fluid connection (14) comprises at least one radial opening (38) in the guide sleeve (9) and a housing bore (39) in the parking lock housing (3) which is fluidically connected thereto, into which the guide sleeve (9) is seated, so that a lubricant (10) can flow from the first chamber (12) through the radial opening (38) and the housing bore (39) in the direction of the lock wheel (4) upon axial movement of the actuating element (8).

14. The parking lock unit according to claim 3, characterized by The fluid connection (14) comprises an external channel (40) which is coupled at the parking lock housing (3), wherein a first end of the external channel (40) is fluidically connected to the first chamber (12) and a second end of the external channel (40) opens into a housing region in which the parking lock wheel (4) is arranged.

15. A drive assembly for a motor vehicle, comprising: a reduction gear (43) designed to convert an incoming rotational movement into a slow rotational movement; a differential gear (45) with a differential housing (56) and two output wheels, wherein the differential gear (45) is designed to transmit a rotational movement introduced by the reduction gear into the differential housing (55) to the two output wheels; characterized in that the drive assembly has a parking lock unit (2) according to any one of claims 1 to 14.

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