WO2007074031A1

WO2007074031A1 - Synchronizing device

Info

Publication number: WO2007074031A1
Application number: PCT/EP2006/069357
Authority: WO
Inventors: Josef Schwuger; Kristina May
Original assignee: Schaeffler Kg
Priority date: 2005-12-23
Filing date: 2006-12-06
Publication date: 2007-07-05
Also published as: DE102005061977A1

Abstract

The invention relates to a device (1) for shifting at least one gear wheel (2, 3) by means of a sliding sleeve (9) which can be slid by a detent (5) from a neutral position into the direction of the gear wheel (2, 3), said sliding sleeve having teeth (8) for engaging and guide elements (26) between said teeth (8).

Description

Name of the invention

synchronizer

description

Field of the invention

The invention relates to a device for switching at least one gear wheel by means of a sliding from a neutral position of a synchronizer in the direction of the gear wheel sliding sleeve.

Background of the invention

Such devices are usually used as coupling elements in synchronizers manually switched motor vehicle transmissions. They connect a gear shaft rotationally fixed with a rotatably mounted on the transmission shaft gear. In this case, the sliding sleeve is arranged concentrically to the transmission shaft, rotationally fixed and slidable in the longitudinal direction of the transmission shaft and coupled with a gear wheel on a synchronizer body

Sliding sleeves are available in various designs. In most cases, they have on their inner lateral surface on an inwardly facing toothing, which engages in a counter-toothing of the synchronizer body and in the switched state in a toothing of the gear wheel. On the outer circumference of the sliding sleeve a guide for a shift fork is provided with the shift fork, the sliding sleeve is moved in the longitudinal direction on the synchronizer body until it is connected to the gear or moved back to its neutral position.

In the neutral position, the sliding sleeves are often axially locked by a locking lever. held ment, which is received in Synchronkόrper and usually spring-loaded acts on a recess. The recess is - depending on the design of the detent - on individual or all inwardly directed teeth of the sliding sleeve, the Riegelutzähnen formed. The locking element causes the sliding sleeve can only be moved axially after overcoming a defined resistance by the operator, when switching the gear, and does not move unintentionally and automatically in the axial direction. To different Rastpunkte z. For example, to define a neutral and a detent position or to define displacement forces and force profiles of different height, two or more recesses in the longitudinal direction of the tooth are often arranged one behind the other side or independently of the aforementioned locking elements act in other synchronizers pressure pieces or locking elements on the recesses of the after inwardly directed tooth. The plungers serve as an actuator for Vorsynchronisierung. In axial displacement of the sliding sleeve, the plungers are taken through them. They initiate the process of synchronization by acting on arranged between the gear and the synchronizer synchronizer rings.

The recess, in which the pressure piece is in the neutral position, serves to provide the user with haptic feedback when switching through the neutral position. It is not intended to fix the pressure piece firmly. During a gear change, the sliding sleeve is moved from the neutral position or from a second end position into a first end position, wherein the sliding sleeve via the pressure piece in a first movement step, the synchronization, an adjustment of the different speeds between the gear and the synchronizer body, initiates. In this case, a tilting movement of the sliding sleeve occurs in the radial and axial direction with respect to the synchronizer body on the further the sliding sleeve is disengaged, the larger becomes due to the smaller Abstύtzlänge between sliding sleeve and synchronizer body, the tilting of the tooth flanks and thus can cause problems in the movement of the sliding sleeve to the synchronizer ring or lead to the coupling body, because the tip circle of the sliding sleeve with the end faces of the Sync ring or the coupling body can collide. Another critical position is the deposit area of the sliding sleeve at the edges of the outer toothing of the synchronizer body.

One way to reduce the play between the sliding sleeve and synchronizer body, it is to provide the guide teeth on the synchronizer body with a larger tooth thickness and to increase the guide gaps on the sliding sleeve accordingly, so that there is a larger gap width. Such a design of the switching device leads to increased manufacturing and testing effort and high tooling costs.

Another way to reduce the tilting play, it is to modify the tooth base on the synchronizer body and provide a tip circle of the sliding sleeve, which has only very small tolerances. Due to this close tolerance, higher demands are placed on a method for finishing the tip diameter, which leads to higher costs. The modified tooth base on the synchronizer body also requires that modifications to the machining tools are required.

Object of the invention

The invention is therefore based on the object to provide a switching device in which the aforementioned disadvantages are eliminated.

Summary of the invention

According to the invention this object is achieved according to the features of the characterizing part of claim 1, characterized in that between two successive teeth of the sliding sleeve one or more guide elements are arranged. The guide elements compensate for the tolerances of the device in the installed state and thus reduce the games.

The guide elements are manufactured separately according to claim 4 and are thus particularly easy and inexpensive to manufacture. They are arranged in tooth spaces of the sliding sleeve distributed on the circumference of the synchronizer body. The number of guide elements is limited only by the existing tooth gaps. The arrangement of the guide elements in the tooth gaps around the rotation axis is possible in any way; In particular, two adjacent tooth spaces can also be provided with guide elements.

Due to manufacturing tolerances, the components sliding sleeve, synchronizer body and coupling body have different gap widths or tooth widths. The resulting from these manufacturing tolerances game is compensated according to the invention by suitably selected guide elements. The guide elements are sorted depending on the gap width existing on the sliding sleeve. In particular, in the mass production of such switching devices, this has the advantage that the ever-changing tolerances can be compensated by different guide elements, as always different types of guide elements are kept. The provision of guide elements of different sizes is relatively inexpensive. Due to their simple geometric structure, they are easy to manufacture and sort.

Due to the thus reduced game between the guide elements and the root diameter of the synchronizer body, the sliding sleeve can tilt less, because the sliding sleeve is held even when disengaging in an achskonstanten position to the synchronizer body. Furthermore, the guide elements have a positive effect on the transmission of the torque between the synchronizer body and the coupling body.

In an advantageous embodiment of the invention, the synchronizer body has enlarged tooth gaps, in which engage the guide elements. The enlarged tooth gaps are arranged uniformly on the circumference of the synchronizer body and can for example also be realized by the absence of a tooth. The guide element is either loose or firmly inserted between the synchronizer body and sliding sleeve. Is it used firmly It can either be cohesively connected to the sliding sleeve or with the synchronizer body. The material bond can be realized for example by welding or gluing. The rolling elements are preferably made of steel.

In a further advantageous embodiment of the invention, the guide elements are arranged distributed uniformly over the circumference. The use of multiple, uniformly arranged guide elements enables effective transmission of torque.

In a further development of the invention, the guide elements are designed as rolling elements. As rolling elements, for example, balls or cylindrical rolling elements such as needles or rollers can be used. Preferably, the length of the needles is shorter than the width of the sliding sleeve.

Of course, all the developments mentioned above can also be combined with each other.

Brief description of the drawings

The invention will be explained in more detail below with reference to an embodiment. The accompanying drawings show:

1 shows a longitudinal section of a part of a synchronizing device,

FIG. 2 shows a cross section of a switching device according to the invention,

3 shows a longitudinal section of the inventive switching device according to FIG. 2 along Ill-Ill, FIG.

Figure 4 is an enlarged view of the interlocking teeth of

Sliding sleeve and the synchronizer body of Figure 2 with a

Guide element 5a shows a perspective oblique view of a sliding sleeve according to the invention,

FIG. 5b shows an oblique view of a synchronizer according to the invention,

FIG. 6 shows an enlarged illustration of the region VI from FIG. 5a,

FIG. 7 shows a perspective oblique view of a part of a second embodiment of the switching device according to the invention and FIG

Figure 8 is a perspective oblique view of a portion of a third embodiment of the switching device according to the invention.

Detailed description of the drawings

In Figure 1, 1 denotes a shaft of a gearbox for motor vehicles, on which two gear wheels 2 and 3 are freely rotatably mounted. Between these two gear wheels 2 and 3, a synchronizer 4 is arranged, via which either one of the two gear wheels 2 or 3 can be coupled to the shaft 1. In this way, the gearbox is switched to different gear ratios.

The synchronizing device 4 has a synchronizer body 5, which engages in rotation in a toothing 6 of the shaft. Furthermore, the synchronizer body 5 is provided at its outer periphery with an external toothing 7, in which teeth 8 engage an internal toothing of a sliding sleeve 9. In the synchronizer body 5 a pressure piece 10 is further guided with a compression spring 1 1, the element 12 receives a spherical, in the longitudinal direction on the pressure piece 10 projecting locking element. The spherical detent element 12 protrudes from the synchronizer body 5 to approximately the tip circle of the external toothing 7. In a neutral position of the synchronizer 4, is switched to none of the two possible gear ratios and thus the two gear wheels 2 and 3 free rotate relative to the shaft 1, the locking element 12 engages in a locking groove 13 formed in the internal toothing 8 of the sliding sleeve 9.

On both sides of the pressure piece 10 synchronizer rings 14 and 15 are arranged, the outside have a locking teeth 16 and 17 and inside a friction surface 18 and 19. The friction surfaces 18 and 19 of the synchronizer rings 14 and 15 cooperate with correspondingly formed friction surfaces 20 and 21 which are formed on the gear wheel 3 and a non-rotatably connected to the gear wheel coupling ring 22.

During a shift operation, an axial force is exerted on the respective synchronizer ring 14 or 15 during a corresponding locking synchronization via the pressure piece 10, so that it is driven by its friction surface 18, 19 from the corresponding friction surface 20, 21 and with respect to the latter during the synchronizing Synchronous body 5 is rotated by a certain angle. In this position, the locking teeth 16 blocks a further displacement of the sliding sleeve 9. This blocking effect is only canceled when a synchronization between the respective gear 2 and 3 and the shaft 1 is achieved. At this moment, the internal toothing 8 of the sliding sleeve 9 is moved through the locking toothing 16 or 17 and finally reaches into engagement with a coupling toothing 23 or 24.

Figures 2, 3 and 4 show a switching device according to the invention, in which at the periphery of the sliding sleeve 9 six guide elements 26 are arranged distributed uniformly over the circumference. The outer toothing 7 of the synchronizer body has a tooth space 25. The tooth gap 25 is formed in this case in that a tooth has been omitted in the outer toothing 7, so that the two adjacent teeth 30, 30 'have a distance about twice as large as they would have without the tooth gap 25. The teeth 8, 8 'of the sliding sleeve circumferentially always have the same distance from each other. In the tooth gap 25, a cylindrical guide member 26 is arranged, which is positively connected to the tooth flanks 31 of the teeth 8, 8 ', 8 "and the radially outwardly facing surface 32 of the synchronizer body 5 Diameter seen in the radial direction corresponds approximately to the height of the teeth 8. As can be seen from FIG. 4, the teeth 8, 8 'are thereby spaced from the synchronizer body 5 by a gap 33. The gap 33 has a very small amount, which can go to zero, so that on the one hand scarcely material wear by rubbing occurs and on the other hand, a tilting is prevented by an excessive gap. When disengaging the sliding sleeve from the neutral position, the gap 33 remains the same size, so that the distance between the sliding sleeve 9 to the synchronizer body 5 does not change.

FIGS. 5a, 5b and 6 show oblique views of a synchronizing device 4 according to the invention. In particular, it can be seen from FIG. 6 that the positive locking or material connection of the guide elements 26 with the sliding sleeve 9 does not have to take place over the entire length of the guide element 26, but also only in FIG In the connection between guide element 26 and sliding sleeve 9 or synchronous body 5, mixed forms of form and material connection are also possible, for which purpose the guide element 26 is welded, for example, only at one point of contact.

Figures 7 and 8 show further perspective views of synchronizing devices 4 with guide elements 26. The guide elements 26 are cylindrical in Figure 7 as rollers or needles 29 and in Figure 8 as balls 28. For larger manufacturing inaccuracies, it may be appropriate to arrange a plurality of balls 28 or needles 29 axially in succession in the tooth gap 25. The diameter of the individual guide elements need not necessarily be identical. LIST OF REFERENCE NUMBERS

1 shaft 30, 30 'external teeth

2 gear wheel 31 tooth flanks

3 gear wheel 32 surface

4 synchronizer 33 gap

5 synchronizer body 34 partial area

6 toothing

7 external toothing

8, 8 ', 8 "teeth

9 sliding sleeve

10 pressure piece

11 compression spring

12 locking element

13 locking groove

14 synchronizer ring

15 synchronizer ring

16 locking teeth

17 locking teeth

18 friction surface of 14

19 friction surface of 15

20 friction surface

21 friction surface

22 coupling ring

23 Clutch toothing

24 Clutch toothing

25 tooth gap

26 guide element

27 rolling elements

28 ball

29 needle

Claims

claims

1. Synchronizing device (4) for switching at least one gear wheel

(2, 3) with a coupling toothing (23) by means of a sliding sleeve (9) displaceable from a neutral position by a synchronizing body (5) provided with an outer toothing (7) in the direction of the gear wheel (2, 3), which teeth (8, 8 ', 8 ") for engagement with the Kupplungsge- toothing (23) of the gear wheel (2, 3) and the outer toothing (7) of the

Synchronizer (5), characterized in that between at least two successive teeth (8 ', 8 ") one or more guide elements (26) are arranged.

2. Synchronizing device according to claim 1, characterized in that the synchronizer body (5) tooth spaces (25), in which engage the guide elements (26).

3. Synchronizing device according to claim 1, characterized in that the guide elements (26) uniformly over the circumference of

Sliding sleeve (9) are arranged distributed.

4. Synchronizing device according to claim 1, characterized in that the guide elements (26) are formed separately.

5. Synchronizing device according to claim 1, characterized in that the guide elements (26) are designed as rolling elements (27).

6. Synchronizing device according to claim 5, characterized in that the rolling bodies (32) are formed as balls (28).

7. Synchronizing device according to claim 5, characterized in that the rolling bodies (26) are formed as needles (31).

8. Synchronizing device according to claim 1, characterized in that the connecting elements (26) are positively connected to the synchronizer body (5) and with the sliding sleeve (9).

9. Synchronizing device according to claim 1, characterized in that the connecting elements (26) are integrally connected to the sliding sleeve (9) or the synchronizer body (5).