DE102007036100A1 - Load switching element - Google Patents

Abstract

It is a load switching element (10) proposed which has a frictional and a form-locking switching element, which are connected in series and for closing the switching element (10) can be actuated by an actuator in this order.

Description

The The present invention relates to a power switching element according to the Preamble of claim 1.

Load switching elements are usually in automatic transmissions, for example used in automatic transmissions in planetary construction.

automatic transmission in planetary design include planetary gear sets and as frictional Multi-plate clutches and brakes trained load switching elements for Switching the planetary gear sets, with the switching elements in usually hydraulically operated by means of pistons. The Dimensioning of the switching elements, in particular with regard to the diameter and the number of fins and the piston depends here according to the maximum torque to be transmitted in the different gears of the transmission.

Especially with very large torques to be transmitted Become a very large diameter and a large Number of slats needed. This is for one thing the occurring drag torques of the shift elements in those gears, in which these are not switched very unfavorable. To the others must by oil pressure and piston area piston forces generated to be very large, resulting in in terms of printing resolution and controllability different friction moments and / or the filling speed the piston chambers proves to be unfavorable.

In some known planetary gears, such as. B. in the transmission according to EP 0 434 525 B1 or according to US 4,070,927 A a switching element is provided which is operated only in the first forward gear and in reverse gear and which must support a significantly higher torque especially in reverse than in the first forward gear. In gearbox according to EP 0 434 525 B1 this function is taken over by the brake D.

Of the present invention is based on the object, a load switching element indicate which can be small in size, for transmission of high torques is suitable, with lower forces can be controlled and in the open state lower drag torques has, as known from the prior art load switching elements.

These The object is achieved by the features of claim 1. Further advantages and advantageous Embodiments will become apparent from the dependent claims.

Therefore a load switching element is proposed, which is both a frictional as well as having a form-fitting mode of action. According to the Invention, the load switching element comprises a frictional and a positive switching element, preferably are connected in series and to close the switching element can be actuated by an actuator in this order. in this connection is a force an axially movable element (for example a piston) displaced, which via a transmission element both on a disk set of a frictional switching element as well as pushing on a slidable claw member.

The frictional switching element therefore comprises a plate pack, wherein the positive switching element comprises a claw assembly, comprising an axially displaceable and guided in the housing Claw element and a between the end plate of the plate pack and the claw member disposed transmission element having. Here are the frictional and the form-locking switching element by means of a hydraulically operated piston or a Any suitable with the jaw member operatively connected (preferably applied to the claw member) axially displaceable ren Actuator actuated such that the first frictional Switching element and from a defined piston or Aktuatorkraft the form-fitting switching element is actuated, whereby the claw member in a corresponding dog teeth a disk carrier of the disk pack is engaged is made, so that a positive connection becomes.

According to the Invention is the jaw member with a first side of the switching element in constant rotationally fixed connection and with the second side of the switching element in switchable torsionally strong operative connection, wherein the switchable operative connection any claw or sliding toothing can be. In addition, the claw element can also over the end plate of the disk pack to be rotatably connected to the first side.

Of the Actuator can also be used as a magnet, electric motor, piezo actuator intermediate mechanical transmission path formed be. Furthermore, the frictional switching element as Multi-plate clutch, multi-disc brake or designed as cone clutch be.

According to one advantageous embodiment of the invention is the transmission element as a spring, for example as a plate spring with non-linear characteristic or designed as a spiral spring, whereby in principle any other Spring is suitable as a transmission element.

The invention will be described below with reference to the attached figures explained in more detail by way of example. Show it:

1 : A schematic sectional view of a first embodiment of the invention in the frictional state;

2 : A schematic sectional view of the in 1 shown embodiment of the invention in the form-locking state;

3 : A schematic sectional view of a second embodiment of the invention in the frictional state;

4 : A schematic sectional view of the in 3 shown embodiment of the invention in the form-locking state; and

5 : A force-displacement diagram of the diaphragm spring (on the claw element) of the in 3 and 4 shown switching element according to the invention.

Referring to 1 includes the load switching element according to the invention 10 a frictional switching element comprising a plate pack 1 and a positive switching element comprising a jaw assembly consisting of a claw member or a claw sleeve 8th and one between the end fin 2 of the disk pack 1 and the claw sleeve 8th arranged and as a plate spring 3 formed transmission element, wherein the frictionally engaged and the positive-locking switching element by means of a hydraulically actuated piston 4 are actuated, such that first the frictional switching element and from a defined piston or Aktuatorkraft the positive switching element are actuated.

According to the Invention, the claws of the positive Switching element or the claw sleeve have any shapes and executed as Stirnklauen, round claws or pointed claws be. Furthermore, it can be provided that the claws directly the driving teeth form on the plate carriers. For a sheet metal plate carrier can on the outside the lamellae track and on the Inside the teeth lie and vice versa.

Of further, the claws have a sufficiently large gap on, so the claws with the highest possible probability be inserted; Also, the claws can be axially conical be shaped so that they are as possible in the single track position big gap and in the end position no play have more. In head to head position of a claw and increase the torque to be transmitted occurs according to design slip in the slats; after a slight twist locks the spring-loaded Claw one.

ever according to the safety philosophy of the overall gear can the dog teeth be designed so that as long as moment is transmitted at short-term pressure drop, the claw remains meshed or is rejected.

In the example shown, the piston pushes 4 after filling and applying the piston 4 over the spring 3 to the disk pack 1 according to the predetermined oil pressure in the piston chamber 9 on the case 11 Guided claw socket 8th , By the axial movement of the piston 4 gets over the claw element 8th and the preloaded diaphragm spring 3 a direct power transmission to the disk pack 1 Ensures the lamellae package 1 pressed against the frictional switching element to generate a friction torque and thus the torque to be transmitted is adjusted by means of frictional engagement, as in 1 illustrated.

Due to the design of the transmission element as a spring 3 becomes the control quality of the switching element 10 in the frictional range advantageously not impaired. The diaphragm spring can be designed with or without slotting.

Here, the friction torque in the disk set 1 be regulated or controlled by modulation of the pressure. Furthermore, after completion of the shift, the pressure can be increased to a first holding pressure, wherein the positive-locking switching element is not yet switched.

Another increase in oil pressure in the piston chamber 9 results from a defined piston force or from a defined path of the piston 4 in an axial shortening of the jaw assembly (the spring 3 is further compressed), consisting of claw sleeve 8th and plate spring 3 , such that the dog teeth 7 the claw sleeve 8th in a toothing 6 on the inner disk carrier 5 of the disk pack 1 or of the frictional switching element engages, whereby a positive connection is made. This state of the switching element according to the invention is the subject of 2 , The insertion of the claw is preferably carried out in defined gears and a required holding function.

In the case of a tooth-on-tooth position between dog teeth 7 the claw sleeve 8th and the gearing 6 on the inner disk carrier 5 can be waited until a differential speed occurs in the switching element and hit the teeth on gaps. In addition, the teeth of the teeth can be flat, rounded or sharpened as already explained.

By reducing the pressure, the claw is first designed, with a torque transmission through the disk pack 1 continues to take place; by further reduction of pressure is the disk set 1 slipping, below a threshold value for the pressure of the piston 4 brought into its initial position and the switching element 10 is opened.

According to an advantageous embodiment of the invention, a (not shown) return mechanism is provided which results in that when opening the switching element of the piston 4 or the actuator and the claws muffle 8th are returned to the starting position and the switching element is quickly fully opened. Here, the return mechanism on the Endlamelle 2 of the disk pack 1 and / or the spring 3 and / or the piston 4 or act the actuator.

In another embodiment of the invention, this is between the claw sleeve 8th and the end fin 2 arranged transmission element as a nonlinear spring 3 executed as in 3 and 4 shown, which the inventive switching element frictional state ( 3 ) and in the form-locking state ( 4 ).

Here is the force-displacement ratio of the nonlinear spring 3 designed so that the spring 3 hardly deformed at low force and only at significant increase in the spring 3 deformed so far that the dog teeth 7 the claw sleeve 8th in the counter-toothing 6 on the inner disk carrier 5 of the disk pack 1 can indent. Advantageously, the force-displacement ratio of the spring 3 on the jaw element on a degressive course, as shown 5 illustrated. In other embodiments, the force-displacement ratio of the spring 3 have a progressive course.

By the concept of the invention is a load switching element provided, which cost can be produced and mounted and compared to off the stand the art known switching elements is small and with lower forces can be controlled. Furthermore, points it in the opened state low Schleppmomente on.

The Switching element according to the invention can be at any automatic transmission systems, such. In planetary gears, Countershaft lathe gears, dual clutch transmissions or with continuously variable transmissions, in particular in the forward / reverse group be used by belt transmissions. Furthermore, can it in the range group of power split multi-range friction gears, Continuously variable hydrostatic transmissions or multi-range electric power splitters Be used geared.

Of course Every constructive training, especially every one, also falls spatial arrangement of the components of the invention Switching element in itself and to each other and as far as technically within the scope of the present claims, without the function of the switching element, as in the claims is indicated to influence, even if these training is not explicit are shown in the figures or in the description.

1

disk pack

2

end disk

3

Spring, transmission element

4

piston

5

Inner disk carrier

6

gearing

7

dog-tooth

8th

Dog sleeve, jaw member

9

piston chamber

10

switching element

11

casing

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 0434525 B1 [0005, 0005]
• - US 4070927 A [0005]

Claims (12)

Load switching element ( 10 ), characterized in that it comprises a frictional and a form-locking switching element, which are connected in series and for closing the switching element ( 10 ) are operable by an actuator in this order. Load switching element ( 10 ) according to claim 1, characterized in that the frictional switching element a disc pack ( 1 ) and in that the form-locking switching element has an axially displaceable and in the housing ( 11 ) guided claw element ( 8th ), which is connected to a first side of the switching element ( 10 ) in constant rotationally fixed operative connection and with the second side of the switching element ( 10 ) is switchable in rotatable operative connection, wherein the switchable operative connection is a claw or sliding teeth. Load switching element ( 10 ) according to claim 2, characterized in that the claw element ( 8th ) over the end plate ( 2 ) of the disk pack ( 1 ) is rotatably connected to the first side. Load switching element ( 10 ) according to claim 1, 2 or 3, characterized in that the frictional switching element a plate pack ( 1 ) and the form-locking switching element a jaw assembly, comprising a jaw member ( 8th ) and one between the end plate ( 2 ) of the disk pack ( 1 ) and the claw element ( 8th ) arranged transmission element ( 3 ), wherein the frictional and the form-locking switching element by means of a hydraulically actuated piston ( 4 ) or a suitable axially displaceable with the claw member ( 8th ) can be actuated in operative connection such that upon an axial displacement of the piston ( 4 ) or the actuator for closing the switching element ( 10 ) first the frictional switching element and from a defined piston or Aktuatorkraft the positive-locking switching element is actuated, whereby the dog teeth ( 7 ) of the claw element ( 8th ) in a corresponding dog teeth ( 6 ) of a disk carrier ( 5 ) of the disk pack ( 1 ) is engaged, so that a positive connection is made. Load switching element ( 10 ) according to claim 4, characterized in that the transmission element ( 3 ) is designed as a spring. Load switching element ( 10 ) according to claim 5, characterized in that the transmission element ( 3 ) is designed as a plate spring with non-linear characteristic or as a spiral spring. Load switching element ( 10 ) according to one of the preceding claims, characterized in that the actuator is designed as a magnet, electric motor or piezoelectric actuator with intermediate mechanical transmission path. Load switching element ( 10 ) according to one of the preceding claims, characterized in that the frictional switching element is designed as a multi-plate clutch, multi-disc brake or as a cone clutch. Load switching element ( 10 ) according to one of the preceding claims, characterized in that the claws of the positive-locking switching element are designed as face claws, round claws or pointed claws. Load switching element ( 10 ) according to one of the preceding claims, characterized in that the claws of the positive switching element directly the driving teeth on the plate carriers of the plate pack ( 1 ) form the frictional switching element, wherein in a sheet-plate carrier on the outside of the slats career and on the inside of the dog teeth is provided and vice versa. Load switching element ( 10 ) according to one of the preceding claims, characterized in that a return mechanism is provided, which leads to the fact that when opening the switching element ( 10 ) The piston ( 4 ) or the actuator and the claw element ( 8th ) are returned to the starting position. Load switching element ( 10 ) according to claim 11, characterized in that the return mechanism on the end plate ( 2 ) of the disk pack ( 1 ) and / or on the transmission element ( 3 ) and / or on the piston ( 4 ) or the actuator acts.