DE102020127414A1 - Parking lock for a transmission and transmission and drive train - Google Patents

Abstract

The invention relates to a parking lock for a transmission. Known parking locks are often elaborately designed or take up a lot of space. A parking lock for a transmission is therefore proposed with a parking ratchet wheel that is operatively connected to an output of the transmission and a blocking element acting on the parking ratchet wheel, as well as an actuator and a control element, with the blocking element being mounted relative to a stationary element of the transmission and for blocking the output by means of the actuator can be switched between a free position and a locked position via the control element, with the parking lock wheel having an axial receptacle and the locking element having a corresponding axial engagement, with the receptacle on the parking lock wheel being able to be brought into engagement with the engagement on the locking element by the actuator using a worm drive element on the control element , The worm drive element converting a rotational movement of the control element into an axial movement of the blocking element.

Description

The invention relates to a parking lock for a transmission according to the preamble of claim 1. The invention also relates to a transmission, in particular for a motor vehicle according to the preamble of claim 9 and a drive train according to the preamble of claim 10.

Parking locks and transmissions or drive trains equipped with such a parking lock are used in particular in motor vehicles in connection with automatic transmissions or two-clutch transmissions or electric axle systems. The parking lock serves to lock an output of such a transmission in order to prevent the vehicle from rolling away by means of the chassis components connected to the output and the wheels of the motor vehicle. Such a parking lock can therefore be used in connection with a parking brake or as an alternative to it.

the DE 1 043 829 A discloses a parking lock in which a locking element is pivoted radially into a parking lock wheel. For this purpose, a claw in the locking element engages in the corresponding spaces between the claws on the parking lock wheel.

the DE 10 2005 015 161 A1 discloses a parking lock assembly for an automated transmission. A locking device is pushed axially into a parking ratchet wheel, the locking device and the parking ratchet wheel being designed as internally toothed and externally toothed gears, which then mesh. The teeth of the respective gears are each arranged radially.

the DE 10 2016 200 542 A1 describes a parking lock with an axial dog clutch. A locking element engages axially in a parking lock wheel. The parking lock is supported in its function by an axial spring.

the DE 10 2005 037 524 A1 describes a parking lock for a transmission, which is actuated with a lever mechanism. It is controlled via a ramp-like element, with the actual parking lock being implemented by means of locking elements that swing in radially.

The well-known parking locks are either complicated or very space-consuming.

The object of the invention is to improve the prior art.

The object is achieved by a parking lock according to independent claim 1. Advantageous refinements result from the dependent claims. In further aspects, the object is achieved by a transmission according to claim 9 and a drive train according to claim 10.

Because the parking lock wheel has an axial mount and the locking element has a corresponding axial engagement, the mount on the parking lock wheel being able to be brought into engagement with the locking element by the actuator using a worm drive element on the control element, with the worm drive element causing a rotational movement of the control element in a Transferred axial movement of the locking element, the parking lock can be built very compact and yet be designed with the axial recording and the axial engagement robust and fine-toothed enough so that appropriate forces can be transmitted.

The following terms are explained here:

An “output” of the transmission is, for example, an output shaft or an element of the transmission connected to an output shaft, with a connection to the output train in the direction of, for example, the wheels or an axle of a motor vehicle being established via the output. By means of such an output, both forces and torques introduced by an engine via the transmission and also a blocking of the output initiated by the parking lock can be passed on to other parts of the output train or the wheels.

A “parking lock wheel” can be any element that is mechanically, for example non-rotatably, operatively connected to the output. Such a parking ratchet wheel is used to interact with other components in such a way that, for example, when the parking ratchet wheel is rotationally blocked, the output of the transmission can no longer be moved in rotation and the output can therefore be blocked.

A "locking element" can be any component and any element that can act on the parking lock wheel, so that the parking lock wheel is inhibited or prevented from rotating, for example, so that the parking lock function is carried out correctly.

An "actuator" is, for example, a pneumatic or hydraulic cylinder, servomotor, lifting or actuating magnet, or any other device that performs a function in response to a control command, which then triggers a mechanical sequence.

For example, a "control element" can be a leverage or other mechanical cal device, which is suitable for transferring the movement emanating from the actuator to the blocking element in such a way that it is put into operation. For example, such a control element is an intermediate component which is arranged between the blocking element and the actuator.

A “fixed element” of the transmission is, for example, the housing or a component connected to the housing, in which the blocking element is mounted and accommodated in at least one of six possible degrees of freedom. In this way, the blocking element can transmit forces to the fixed element or forward forces that emanate from the parking lock wheel to the fixed element.

A "blocking" of the output describes a locking of the output in the sense of the complete restriction of, for example, free rotation of the parking lock wheel with the output.

A "release" is that position of the control element and/or the parking lock in which the output remains free to move and the parking lock is therefore inoperative.

A "locked position" is such a position of the control element and/or the parking lock in which the parking lock performs its function, namely in which the mobility of the output of the transmission is restricted or blocked.

A "receptacle" can be any technical configuration of the surface of the parking lock wheel which is suitable for absorbing and/or transmitting forces or moments in interaction with the locking element. For example, such a recording is a rough surface, a form-fitting configuration in the direction of the blocking element, or a comparable device.

An "intervention" can be any device corresponding to the receptacle, which can transmit forces or moments in cooperation with the receptacle from the locking element to the parking lock wheel or vice versa. The receptacle and the engagement are in particular aligned axially on the parking ratchet wheel and on the blocking element, ie aligned along the axis of a main shaft using the example of a conventional transmission with a main drive direction.

A “worm gear element” can be any element that is suitable for converting a rotational movement into an axial movement with a mechanism that acts in the manner of a worm gear. Examples of this are an element designed in the manner of a thread or an element acting on the principle of the wedge by means of rotation.

In one embodiment, the control element is ring-shaped and/or has a spiral-shaped end face in the axial direction, with the spiral-shaped end face acting axially on the blocking element.

Such a ring-shaped control element, in particular with a spiral end face for realizing the worm drive element, supports a compact design of the parking lock.

A "spiral end face" is, for example, the end face of a ring or a disk, which increases in the axial direction during rotation of such an element, ie, for example, an element with a thickness that continuously increases in the direction of rotation. Such a spiral end face can also be formed several times on the circumference in order to distribute forces.

An “axial direction” is a direction that runs along a main axis, for example, of the transmission and/or a rotating body in the transmission. This can also designate a direction that runs in a range from +10° to -10° to this reference axis. In particular, the direction of action is designated here, so that a force normal, for example a normal of a force of the spiral end face, can also run deviating from this axial direction. Angle specifications refer to a full angle of 360°.

In order to be able to transmit high forces from the blocking element to the parking ratchet wheel and to make the parking pawl particularly compact, the blocking element and/or the parking ratchet wheel is/are toothed on the face side. The toothing can be selected in such a way that certain operating parameters of the parking lock, for example a maximum permissible angular adjustment of the parking lock wheel after activating the parking lock, are maintained.

In a further embodiment, the control element is arranged on a common axis of action with the parking lock wheel and/or the blocking element.

By means of this axial arrangement along a common axis of action, the entirety of the parking ratchet wheel, control element and blocking element can be implemented in a very small space.

A "common axis of action" denotes a direction or an axis that essentially runs in common. They can do that Control and the parking ratchet wheel and / or the locking element also have slightly different axes in their effect. For example, there can be a deviation of -10° to +10° between the axis of engagement of the parking lock wheel and locking element and the effective axis of the control element or an axis of rotation of the control element. Angle specifications refer to a full angle of 360°.

In order to control the control element in a particularly effective, compact and reliable manner, the actuator acts on the control element in a tangential or essentially tangential direction.

"Substantially tangent" describes a direction that is tangent to the control or at an angle of +10° to -10° from this tangent direction. In particular, it can happen that the actuator is only in a specific position tangential to the control element and can also deviate from this tangential direction during its movement due to the geometric arrangement. Angle specifications refer to a full angle of 360°.

In one embodiment, the actuator has a mechanical energy storage device, with the locking element being able to be brought into engagement with the support of the mechanical energy storage device when the actuator is in an activated state.

Such an energy store can be used, for example, to design the actuator as a releasing element, so that the blocking element is activated by the energy stored by the mechanical energy store and then released, and the parking lock is set up in this way. For example, in the event of repairs with the actuator dismantled, it is ensured that the parking lock is activated and a safe state is thus achieved.

A "mechanical energy store" can be any element that is suitable for storing energy through the deformation of a solid, compression of a gas or a combination of these properties with other active principles and releasing it again when required. For example, such a mechanical energy store is a spring, a helical spring, a gas pressure spring, a pressure store or another similar device.

In the case of the actuator, in order to access elements that are compatible with other systems in a motor vehicle, the actuator is a linear drive that acts by an electric motor, magnetically, or hydraulically.

In a further embodiment, the blocking element has a mechanical energy store which acts on the blocking element in such a way that the blocking element is disengaged when the control element is released.

The blocking element can thus be equipped with a return spring, for example, which automatically presses the blocking element into the release position when the control element is in the appropriate position. This prevents the parking lock from being activated accidentally, for example by inertial forces.

A transmission, in particular for a motor vehicle, which is equipped with a parking lock of the above-described embodiments, can be built to be very compact and yet powerful. Furthermore, such a parking lock can be inserted into a transmission in a particularly compact manner.

Likewise, a drive train, in particular for a motor vehicle, which is equipped with a transmission according to such an embodiment, can be designed to be very compact and powerful.

• 1 eine schematische Darstellung einer Parksperre in einer Freistellung, in einer isometrischen Ansicht,
• 2 eine schematische Darstellung einer Parksperre in einer Sperrstellung in einer isometrischen Ansicht, sowie
• 3 eine Draufsicht auf eine Parksperre in axialer Richtung.

The invention is explained below using exemplary embodiments. Show it

• 1 a schematic representation of a parking lock in an exemption, in an isometric view,
• 2 a schematic representation of a parking lock in a locked position in an isometric view, and
• 3 a plan view of a parking lock in the axial direction.

A parking lock 101 has a parking lock wheel 103 with an axle mount 102 . An output shaft (not shown) of a transmission is inserted in a rotationally fixed manner in the axle mount 102, so that the parking lock wheel 103 is connected to the output shaft in a positive or non-positive manner. The parking lock wheel 103 is freely rotatable with the output shaft in the transmission. The output axle directs the forces and torques of the transmission to an axle drive of a vehicle (not shown).

The parking lock wheel 103 has claws 104 on its end face, which are designed in the form of axial teeth. The parking lock gear and the output shaft can rotate about an axis 131 .

A claw wheel 105 with claws 106 arranged axially opposite the parking lock wheel 103 is arranged on the same axle 131 . The claws 104 of the parking ratchet wheel 103 and the claws 106 of the claw wheel 105 are mutually configured such that the claw wheel 105 can mesh with one another when displaced along the axis 131 in the direction of the parking ratchet wheel 103 . The parking lock wheel 103 and the claw wheel 105 can then form a rotationally fixed connection.

The claw wheel 105 is in an exemption, so that the claws 106 and the claws 104 are disengaged ( 1 ).

Restoring springs 109 are arranged between the claw wheel 105 and the parking lock 103 and can push the claw wheel 105 away from the parking lock wheel 103 . In order to bring the claw wheel 105 into engagement with the parking lock wheel 103, these return springs 109 must be compressed in the opposite direction to their effective direction.

An activation wheel 107 is arranged on the same axle 131 . The activation wheel 107 is ring-shaped and has a flag 121 for its activation. The activation wheel 107 is axially fixed, but arranged in a non-rotating manner about the axis 131 .

Furthermore, the activation wheel has end faces 123 which interact with projections 122 of the claw wheel 105 . The end faces 123 are designed in such a way that they run spirally in relation to the axis 131. The thickness of the activation wheel 107 thus varies around the circumference in the direction of the axis 131 in the region of each end face 123.

The claw wheel 105 has balls 108 on its outside, which form an axial bearing 110, so that the claw wheel 105 is accommodated in a housing 151 of the transmission so that it can move axially. Furthermore, grooves 112 are arranged on the activation wheel 107, which accommodate the claw wheel 105 in a rotationally fixed but axially movable manner in the housing 151 of the transmission (not shown).

An actuator 111 is arranged acting on the lug 121 of the activation wheel 107 ; the actuator 111 is a servo-motor linear drive which acts on the lug 121 in such a way that the activation wheel 107 performs a rotary movement as a result of the action of the actuator 111 .

For this purpose, the actuator 111 has a piston 113 which is in contact with the vane 121 on one side. For this purpose, the end face of the piston 113 is spherical, that is to say spherical-convex, in order to enable contact which is as friction-free as possible.

The actuator 111 is constructed in its interior in such a way that the piston 113 is held in an extended position of the actuator 111 via a locking catch (internal structure not shown) in this extended position.

On an opposite side of the lug 121, a ram 115 acts on the lug 121. The ram 115 is arranged tangentially to the activation wheel 107 in its effective direction, just like the actuator 111. The plunger 115 is mounted in a bearing 119 which is accommodated in the housing 151 of the gear and is acted upon by a spring 117 .

The spring 117 is arranged in such a way that the direction of action of the relaxing spring 117 is in the direction of activation of the parking lock 101, i.e. counter to the direction of action of the actuator 111.

The function of the parking lock 101 is explained below:

In an exemption ( 1 ) the dog wheel 105 is spaced from the parking lock wheel 103, and is held in this position by the springs 109. The parking lock wheel 103 with the drive shaft can thus rotate freely in the transmission or, for example, transmit drive forces.

The actuator 111 is not activated, the flag 121 of the activation wheel 107 is in an almost vertical position.

The activation wheel 107 is in such a position that it has a comparatively small thickness compared to the projections 122 of the claw wheel 105 and therefore no forces are transmitted to the claw wheel 105 either.

If the activation wheel 107 and thus also the parking lock 101 are moved into a locked position, this is done by means of the actuator 111 as follows:

The piston 113 of the actuator 111 is retracted and the rotation of the activation wheel 107 is thereby released, the plunger 115 is extended by the relaxation of the spring 117. The spring 117 also pushes the piston 113 in the direction of a retracted position.

The activation wheel 107 is thus rotated about the axis 131 . The spring 117 on the plunger 115 supports the process. Due to their spiral arrangement on the activation wheel 107, the end faces 123 now act on the projections 122 of the claw wheel 105.

The dog wheel 105 is moved axially toward the parking lock wheel 103 . In this case, the dog wheel 105 is guided by means of the axial bearing 110 in the housing 151 of the transmission. This is done in a torsion-proof manner in relation to the transmission, which the grooves 112 the Prevent dog wheel 105 from rotating. The return springs 109 are thereby compressed, the claws 104 and 106 engage in one another. This creates a positive connection between dog wheel 105 and parking lock wheel 103.

Due to the rotationally fixed mounting of the dog wheel 105 in the housing 151 of the transmission by means of the grooves 112, the parking lock wheel 103 is thus prevented from rotating. Forces are transmitted via the claws 104 and the claws 106 and the claw wheel 105 by means of the grooves 112 to the housing 151 of the transmission.

Because the rotation of the parking lock wheel 103 is blocked in this way, the output shaft and thus the entire output train of the vehicle can no longer be moved in rotation, so that the vehicle is prevented from rolling away.

If the parking lock wheel 103 is in a position during the transfer of the parking lock 101 in such a way that teeth of the claws 104 and teeth of the claws 106 are directly opposite and the claw wheel 105 cannot engage in the parking lock wheel 103, then at the latest when the vehicle rolls slightly, For example, created a rotational position on a slope in which the parking lock 101 securely engages.

The deactivation of the parking lock 101 in the direction of an exemption ( 2 ) takes place in reverse order, namely by the actuator 111 being returned to its starting position, the activation wheel 107 being returned against the spring 117 and the claw wheel 105 being pressed back into the release position by the return springs 109.

The claws 104 and the claws 106 are then disengaged and the output shaft of the transmission can rotate freely.

Reference List

101

parking lock

102

axle mount

103

parking lock wheel

104

Nab

105

claw wheel

106

Nab

107

activation wheel

108

Bullet

109

return spring

110

thrust bearing

111

actuator

112

groove

113

Pistons

115

pestle

117

Feather

119

storage

121

banner

122

head Start

123

face

131

axis

151

Housing

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 1043829 A [0003]
• DE 102005015161 A1 [0004]
• DE 102016200542 A1 [0005]
• DE 102005037524 A1 [0006]

Claims (10)

Parking lock (101) for a transmission, with a parking ratchet wheel (103) operatively connected to an output (102) of the transmission and a locking element (105) acting on the parking ratchet wheel (103) as well as an actuator (111) and a control element (107) , wherein the blocking element (105) is mounted opposite a stationary element (151) of the transmission and can be switched between a free position and a blocking position to block the output (102) by means of the actuator (111) via the control element (107), characterized in that that the parking ratchet wheel (103) has an axial receptacle (104) and the locking element (107) has a corresponding axial engagement (106), the receptacle (104) on the parking ratchet wheel (103) having the engagement (106) on the locking element (107). the actuator (111) can be brought into engagement with the control element (107) using a worm gear element (123), the worm gear element (123) causing a rotational movement of the control element (107) in an a xiale movement of the locking element (105) transferred. Parking lock according to claim 1 , characterized in that the control element (107) is ring-shaped and/or has a spiral end face (123) in the axial direction, the spiral end face (123) acting axially on the blocking element (105). Parking lock according to claim 1 or 2 , characterized in that the blocking element (105) and/or the parking lock wheel (103) is or are toothed on the face side. Parking lock according to one of the preceding claims, characterized in that the control element (107) is arranged in a common axis of action (131) with the parking lock wheel (103) and/or the locking element (105). Parking lock according to one of the preceding claims, characterized in that the actuator (111) acts on the control element (107) in a tangential or essentially tangential direction. Parking lock according to one of the preceding claims, characterized in that the actuator (111) has a mechanical energy store (117), the blocking element (105) being supported by the mechanical energy store (117) and being engageable when the actuator (111) is in an activated state is. Parking lock according to one of the preceding claims, characterized in that the actuator (111) is a linear drive which acts by an electric motor, magnetically or hydraulically. Parking lock according to one of the preceding claims, characterized in that the locking element (105) has a mechanical energy store (109) which acts on the locking element (105) in such a way that the locking element (105) disengages when the control element (107) is released is. Transmission, in particular for a motor vehicle with a parking lock according to claims 1 until 8th . Drive train, in particular for a motor vehicle, with a transmission according to claim 9 .

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