DE102015203273A1 - Switching element with electromechanical actuator - Google Patents

Abstract

The invention relates to a switching element (10) having an electromechanical actuating device which is designed as a spindle drive (11) comprising at least one electric motor (20) with an externally toothed pinion (22) non-rotatably connected to a motor shaft (21) of the electric motor (20). a gear rim (30) with internal toothing (31) and external toothing (32), at least one double pinion (42) rotatably mounted in a cage secured against rotation (40) and a cylinder (50) acting on the switching element (10) with one Helical teeth internal teeth (51). The double pinion (42) has two axially arranged one behind the other outer teeth (43, 44). Cylinder (50), cage (40) and gear rim (30) are arranged on the same central axis (60) axially adjacent to the switching element (10). The cylinder (50) is axially displaceable along the central axis (60) relative to the switching element (10), while the cage (40) and gear rim (30) are fixed in the axial direction relative to the pinion (22). The pinion (22) engages with its external toothing (23) in the outer toothing (32) of the gear rim (30). The switching element remote external toothing (43) of the double pinion (42) engages in the internal toothing (31) of the gear rim (30), while the switching element near outer toothing (44) of the double pinion (42) is designed as a worm toothing and in the internal toothing (51) of the cylinder (50) intervenes.

Description

The present invention relates to a switching element with a trained as a spindle drive electromechanical actuator, in particular for a motor vehicle transmission.

Electromechanically actuated switching elements of motor vehicle transmissions are widely known from the prior art.

From the US 7891261 B2 For example, a multi-plate clutch with a piston acting on the disk set is known, which can be hydraulically actuated and locked by an electric motor driven spindle drive in position "clutch closed". The actuation directions of pistons and electromotive actuator are the same.

From the DE 10 2006 049 281 A1 The applicant is aware of several variants of an internally operated dog clutch. Herein it is proposed to arrange the actuator provided for closing and opening the dog clutch centrally within the dog clutch and to form either as an electrically controllable electric motor or as a hydraulically controllable piston-cylinder unit.

From the DE 10 2006 049 283 A1 The Applicant several variants of an internally operated synchronization are known in which the actuator provided for actuating the synchronization is arranged centrally within the synchronization and optionally designed as an electrically controllable electric motor or as a hydraulically controllable piston-cylinder unit.

From the DE 19710121 C2 a device for the electromechanical switching of a gear change transmission is known, in which a spindle acts on a shift rod of the gear change transmission. To realize a switching movement of this shift rod, a translational movement of the shift rod is generated from a rotation of the spindle about its spindle axis. For this purpose, an electric motor and arranged in the power flow between the electric motor shaft and spindle electrically switchable coupling are provided. Depending on the switching position of this clutch, the rotational movement of the electric motor shaft is selectively convertible into a rotational or a translational movement of the spindle.

From the US 5024638 an automatic transmission with a plurality of wet-running Reibschaltelementen is known, which are actuated by means of individual electric motors. In this case, the respective friction switching element associated electric motor via a spur gear drives a corresponding switching element concentrically enclosing shift drum in the manner of a recirculating ball gear, said shift roller transmits axial forces on a release bearing of the corresponding Reibschaltelementes.

From the DE 10113300 A1 is another automatic transmission with electric motor actuated multi-plate clutches are known, which are preferably designed as wet-running switching elements, but can also be designed as dry-running switching elements. Each of these electromotively actuated clutches is associated with its own electric motor, which is arranged axially immediately adjacent to the disk pack to be actuated, has a housing-fixed stator and has an axially movable rotor. In this case, this rotor is rotatably connected to a spindle nut, which in turn is in threaded engagement with a spindle and acts via a plate spring on the outer disk of the disk pack to be actuated. The spindle in turn is fixedly connected to a shaft on which the inner disks of the disk pack to be actuated are arranged rotationally fixed. When the electric motor is energized, the rotor moves axially along the spindle in the direction of the disk pack to be actuated, and presses the outer disks of this disk pack against the inner disks of this disk pack.

From the DE 10 2012 220 073 A1 is a starting clutch with an electric motor-operated Zentralausrücker known, wherein a spindle drive is arranged in the power flow between the electric motor and the releaser.

The present invention has for its object to present a switching element with an alternative electromechanical actuator. In this case, the electromechanical actuator should be made compact and do not require more space than known hydraulic clutch actuators. Furthermore, the actuator should ensure good controllability when closing the switching element.

This object is achieved by a device having the features of patent claim 1. Further embodiments and developments of the invention will become apparent from the dependent claims.

Accordingly, a switching element is proposed with an electromechanical actuator, which is designed as a spindle drive, comprising at least one electric motor whose motor shaft is rotatably connected to an externally toothed pinion, a gear rim with external teeth and internal teeth, at least one rotatably mounted in a cage against rotation stored Double pinion, as well as one for actuating the switching element on the Switching element acting cylinder with a designed as a worm gear internal teeth. In this case, the double pinion on two axially successively arranged external teeth.

Cylinder, cage and gear rim are arranged on the same central axis and spatially axially adjacent to the switching element, wherein the cylinder is axially displaceable along the central axis relative to the switching element, while the cage and the gear rim are fixed in the axial direction relative to the pinion. The cage is additionally secured against twisting, as already mentioned.

The external toothing of the pinion of the at least one electric motor engages in the external toothing of the gear rim. The switching element remote outer toothing of the double pinion engages in the internal toothing of the gear rim, while the switching element near outer toothing of the double pinion is formed as a worm toothing and engages in the likewise formed as a worm toothing internal toothing of the cylinder. Accordingly, a rotation of the motor shaft or the scribe generates a translational movement of the force acting on the switching element cylinder, which leads to actuation of the switching element. The axial forces occurring on the double pinion when the switching element is actuated can be supported on the cage in a structurally simple manner.

Preferably, the motor shaft is arranged axially parallel to the central axis of the gear rim, cage and cylinder.

In a preferred embodiment of the invention, the electric motor is spatially arranged on the side facing away from the switching element of the pinion, in a region axially adjacent to the cage. As an alternative to this, in terms of space, the electric motor can also be arranged on the side of the pinion facing the switching element, in a region radially above the cage.

The actuator according to the invention is characterized by a very compact design, which is suitable to replace a planned in an existing motor vehicle transmission hydraulic switching element actuator space neutral.

Compared to the known hydraulic switching element actuators, the actuator according to the invention operates energy-efficient: firstly, no time-consuming, leaking electro-hydraulic control is required to ensure the required switching quality when closing and opening the switching element. On the other hand, the actuator according to the invention consumes energy only during the switching process due to the self-locking of the worm gear used. Therefore, the actuator according to the invention is also particularly suitable for the control of such switching elements of a motor vehicle transmission, which should transmit torque in a start-stop system of the motor vehicle when the internal combustion engine of the motor vehicle is stationary or starting.

In addition, the actuator according to the invention is characterized by a very high power density: The proposed screw ratio allows despite using a comparatively small electromotive drive power a high contact pressure when closing the associated switching element.

In addition, the actuator according to the invention is characterized by a very good controllability when operating its associated switching element: Due to the provided screw ratio, the resolution of the axial movement of the cylinder acting on the switching element is very fine. Also, the actuator of the invention minimizes the known in hydraulic switching element actuators critical temperature dependence of the shift quality.

In the context of an advantageous embodiment of the invention it is proposed to provide a plurality of circumferentially distributed in the cage arranged double pinion to drive the cylinder, each of these double pinion engages with its switching element remote external teeth in the internal teeth of the gear rim and engages with its switching element near external teeth in the internal teeth of the cylinder. Compared to the design with only a double pinion, this allows to use smaller double pinions from the geometrical dimensions, without having to accept losses in the torque transmission capability. This embodiment thus further improves the compact design of the actuating device according to the invention. On the other hand, the use of a plurality of double pinions also causes a good centering of the cylinder acting on the switching element and thus a reduced tilting tendency of the cylinder upon actuation of the switching element, which in turn improves the sensitivity in controlling the switching element actuation.

In the context of a further advantageous embodiment of the invention it is proposed to provide a plurality of circumferentially spaced on the sprocket arranged electric motors for driving the sprocket, each of these electric motors on its motor shaft having a rotatably connected to the motor shaft externally toothed pinion, which is in meshing with the external teeth of the gear rim , As a result, the to be provided Torque required to close the switching element, distributed over several machines, which allows the use of smaller sized electric motors and thus further improves the compact design of the actuator according to the invention.

The switching element may be formed in any type, for example as a friction switching element, as a form-locking switching element or as a synchronization. Such types are well known in the art. If the switching element is designed, for example, as a multi-disc clutch, the cylinder of the spindle drive according to the invention can be arranged in a structurally simple manner coaxially with the disk set of the multi-disk clutch and act in the manner of a piston similar to the known hydraulic clutch actuators for actuating the multi-disk clutch axially on the disk set.

The use of the switching element according to the invention with its electromechanical actuator is not limited to the installation and use in a motor vehicle transmission.

The invention will be explained in more detail below with reference to the attached figure, in which a preferred embodiment of the switching element according to the invention is shown with its electromechanical actuator

In the figure with reference numerals 10 is a switching element in a simplified representation, here exemplified as a friction switching element in the design of a multi-plate clutch with a disk set 70 , With reference number 11 is designated as a spindle drive electromechanical actuator of this switching element 10 , This spindle drive 11 includes an electric motor 20 , a gear wreath 30 a cage 40 and a cylinder 50 ,

The electric motor 20 has a motor shaft 21 on, on its motor shaft 21 one with an external toothing 23 provided pinion 22 arranged and rotationally fixed with the motor shaft 21 connected is. The gear wreath 30 has an internal toothing 31 and an external toothing 32 on. The cage 40 has four circumferentially spaced recesses 41 on. In each of these recesses 41 is a double pinion 42 used, such that the double pinion 42 can rotate around its central axis and that on the double pinion 42 occurring axial forces on the cage 30 be supported. Each of the four double pinions 42 has two seen in the axial direction one behind the other arranged external teeth 43 . 44 on. The cylinder 50 has an internal toothing 51 on and acts with one of its faces then when the switching element 10 closed and closed, on the disk pack 70 of the switching element 10 ,

cylinder 50 , Cage 40 and gear wreath 30 are on the same central axis 60 arranged, spatially seen axially adjacent to the disk set 70 , Here is the cylinder 50 axially along the central axis 60 relative to the disk pack 70 slidable while the cage 40 and the gear wreath 30 in the axial direction relative to the pinion 22 of the electric motor 20 are fixed and the cage 40 additionally secured against rotation. The motor shaft 21 is axially parallel to the central axis 60 of gear wreath 30 , Cage 40 and cylinders 50 is arranged. In order to achieve the leanest possible design of the actuator, the electric motor 20 spatially seen on the lamella package 60 opposite side of the pinion 22 is arranged, in an area axially adjacent to the cage 30 ,

The external toothing 23 of the pinion 22 stands with the external teeth 32 of the gear wreath 30 in meshing. Here are the external teeth 32 of the gear wreath 30 and the external teeth 23 of the pinion 22 designed as a so-called normal toothing, so that a rotation of the pinion 22 a rotation of the gear rim 30 entails. The switching element remote external teeth 43 each of the four double pinions 42 stands with the internal toothing 31 of the gear wreath 30 in meshing. Here are the internal teeth 31 of the gear wreath 30 and the switching element remote external teeth 43 the double pinion 42 also formed as a normal toothing, so that a rotation of the gear rim 30 a rotation of the double pinions 42 entails. The switch element near external toothing 44 each of the four double pinions 42 stands with the internal toothing 51 of the cylinder 50 in meshing. Here are the internal teeth 51 of the cylinder 50 and the switch element near external teeth 44 the double pinion 42 formed as a so-called worm toothing, so that a rotation of the double pinion 42 an axial movement of the cylinder 50 entails.

To the switching element 10 to close, the electric motor 20 so energized that the motor shaft 21 in rotation with direction of rotation 24 brought. The spindle drive 11 sets the motor shaft rotation in a translatory movement 52 of the cylinder 50 then, by the translation of the spindle drive 11 increased drive torque of the electric motor 20 as axial force in the closing direction of the switching element 10 on the disk pack 60 of the switching element 10 transfers. Is the switching element 10 sufficiently closed, so is the in the disk pack 70 built frictional engagement sufficiently high, to that of the switching element 10 To transmit transmitted torque safely, so is the energization of the electric motor 20 shut off, taking the self-locking of the worm gearing the contact pressure level in the disk set 70 maintains.

To the previously closed switching element 10 to open, becomes the electric motor 20 again energized, but with respect to the closing reverse polarity reversal. This results in a rotation of the motor shaft 21 with direction of rotation 25 that translate into a translatory movement 53 of the cylinder 50 is implemented and to open the switching element 10 leads.

LIST OF REFERENCE NUMBERS

10

switching element

11

electromechanical actuator of the switching element; spindle drive

20

Electric motor of the spindle drive

21

Motor shaft of the electric motor

22

Pinion of the electric motor

23

External toothing of the pinion

24

Direction of rotation of motor shaft and pinion when closing the

switching element

25

Direction of rotation of motor shaft and pinion when opening the

switching element

30

Gear rim of the spindle drive

31

Internal toothing of the gear rim

32

External toothing of the gear rim

40

Cage of the spindle drive

41

Recess of the cage

42

Double pinion of the spindle drive

43

external switching toothing of the double pinion

44

Close to switching element outer toothing of the double pinion

50

Cylinder of the spindle drive

51

Internal toothing of the cylinder

52

Direction of movement of the cylinder when closing the switching element

53

Direction of movement of the cylinder when opening the switching element

60

Central axis of gear rim, cage and cylinder

70

Disc pack of the switching element

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• US 7891261 B2 [0003]
• DE 102006049281 A1 [0004]
• DE 102006049283 A1 [0005]
• DE 19710121 C2 [0006]
• US 5024638 [0007]
• DE 10113300 A1 [0008]
• DE 102012220073 A1 [0009]

Claims (11)

Switching element ( 10 ) with an electromechanical actuating device, this actuating device being a spindle drive ( 11 ), comprising at least one electric motor ( 20 ), whose motor shaft ( 21 ) rotatably with an external toothing ( 23 ) having pinion ( 22 ), an internal toothing ( 31 ) and an external toothing ( 32 ) having gear rim ( 30 ), at least one in a cage ( 40 ) rotatably mounted double pinion ( 42 ), as well as one for actuating the switching element ( 10 ) on the switching element ( 10 ) acting cylinder ( 50 ) with an internal toothing designed as a helical gearing ( 51 ), whereby the cylinder ( 50 ), the cage ( 40 ) and the gear rim ( 30 ) on the same central axis ( 60 ) and spatially axially adjacent to the switching element ( 10 ) are arranged, wherein the cylinder ( 50 ) axially along the central axis ( 60 ) relative to the switching element ( 10 ) is displaceable, wherein the cage ( 40 ) and the gear rim ( 30 ) in the axial direction relative to the pinion ( 22 ) and the cage ( 40 ) is additionally secured against rotation, wherein the double pinion ( 42 ) two axially successively arranged external toothings ( 43 . 44 ), wherein the external toothing ( 23 ) of the pinion ( 22 ) of the at least one electric motor ( 20 ) in the external toothing ( 32 ) of the gear rim ( 30 ) engages, wherein the switching elements remote external teeth ( 43 ) of the double pinion ( 42 ) in the internal toothing ( 31 ) of the gear rim ( 30 ) engages, and wherein the switching elements near the outer teeth ( 44 ) of the double pinion ( 42 ) is designed as a worm gear and in the internal toothing ( 51 ) of the cylinder ( 50 ) intervenes. Switching element with electromechanical actuating device according to claim 1, characterized in that the motor shaft ( 21 ) paraxial to the central axis ( 60 ) of gear rim ( 30 ), Cage ( 40 ) and cylinders ( 50 ) is arranged. Switching element with electromechanical actuating device according to claim 1 or 2, characterized in that the electric motor ( 20 ) spatially seen on the switching element ( 10 ) facing away from the pinion ( 22 ) is arranged in an area axially adjacent to the cage ( 30 ). Switching element with electromechanical actuating device according to claim 1 or 2, characterized in that the electric motor is spatially arranged on the switching element facing side of the pinion, in a region radially above the cage. Switching element with electromechanical actuating device according to one or more of claims 1 to 4, characterized in that for driving the cylinder ( 50 ) several, in the cage ( 40 ) circumferentially distributed double pinion ( 42 ) are provided, each of these double pinion ( 42 ) with its switching elements remote external teeth ( 43 ) in the internal toothing ( 31 ) of the gear rim ( 30 ) engages and with its switching element-close outer toothing ( 44 ) in the internal toothing ( 51 ) of the cylinder ( 50 ) intervenes. Switching element with electromechanical actuating device according to one or more of claims 1 to 5, characterized in that for driving the ring gear several circumferentially distributed on the ring gear arranged electric motors are provided, each of these electric motors on its motor shaft having a rotatably connected to the motor shaft externally toothed pinion, the is meshed with the external teeth of the gear rim. Switching element with electromechanical actuating device according to one or more of claims 1 to 6, characterized in that the switching element ( 10 ) is designed as a friction switching element. Switching element with electromechanical actuating device according to claim 7, characterized in that the switching element ( 10 ) is designed as a multi-plate clutch. Switching element with electromechanical actuating device according to one or more of claims 1 to 6, characterized in that the switching element is designed as a form-locking switching element. Switching element with electromechanical actuating device according to one or more of claims 1 to 6, characterized in that the switching element is designed as a synchronization. Switching element with electromechanical actuating device according to one or more of the preceding claims, characterized in that it is designed as a switching element of a motor vehicle transmission.

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