WO2009118218A1

WO2009118218A1 - Device for reducing rattling noise in multi-speed manual transmissions

Info

Publication number: WO2009118218A1
Application number: PCT/EP2009/051532
Authority: WO
Inventors: Friedrich Ehrlinger; Stefan Renner; Jürgen RAUTER
Original assignee: Zf Friedrichshafen Ag
Priority date: 2008-03-26
Filing date: 2009-02-11
Publication date: 2009-10-01
Also published as: DE102008000820A1

Abstract

The invention relates to a device for reducing rattling noise in a multi-speed manual transmission comprising at least one reverse gear and multiple forward gears, having at least two countershafts (10, 20). For this purpose, the power flow is conducted to a central gear wheel (1) disposed on a main shaft (3) by way of two gear wheels (11, 21) disposed on the countershafts (10, 20), and at least one gear wheel (1, 11, 21, 31, 41) has a conical gearing in at least one gear of the multi-speed manual transmission. The gear wheel (1, 11, 21, 31, 41) having the conical gearing, or a gear wheel (1, 11, 21, 31, 41) meshing therewith, is further supported in an axially displaceable manner, and is axially prestressed by means of an elastic element (5, 37, 47) such that the gearings meshing with one another are pressed against each other.

Description

Device for reducing rattle noise in multistage transmissions

The present invention relates to a device for reducing rattle noise in multi-stage transmissions with at least two countershafts, according to the preamble of patent claim 1.

Known from the prior art are multi-stage manual transmission with two countershafts and a central main shaft. Arranged on the main shaft main shafts loose in Umfangsgehchtung on the main shaft and are only rotatably connected to the main shaft during operation in the associated gear stage to transmit torque. The main shafts are therefore also called idler gears.

The main shaft gears are mounted in the radial direction with play on the main shaft to allow load balancing between the power flows through the two countershafts. The main shaft gears, which engage in the teeth of the countershaft gears, are radially guided by the teeth of the countershaft gears within their radial range of motion on the main shaft. That is, each mounted on the main shaft movable main shaft centered under load in the teeth of the countershaft gears. This is the case when the associated gear is engaged and engaged and the drive motor operates in push or pull operation. As a result, an optimal load balance between the countershafts is achieved in the torque transmission. The main shaft wheels, which are not assigned currently engaged gear stages are in no-load condition. In the load-free state, the main shaft wheels float within the backlash, ie they have freedom of movement in the radial direction and in the circumferential direction. In the axial direction, the main shaft gears are guided for example by thrust washers on the main shaft, wherein the main shaft is disposed between two arranged on the main shaft thrust washers. Due to manufacturing tolerances and required for oil lubrication column, there is also play in the axial direction.

Due to the movable mounting of the main shaft gears in the radial direction and by the axial play, however, creates an unpleasant rattle noise during operation, because the gears of the non-load gear stages undergoing accelerations in Umfangsshchtung, in the axial and radial directions, excited by manufacturing inaccuracies and by Torsional vibrations from the input and / or output. By these accelerations, the main shaft wheels are moved in the described range of motion so that they strike against the adjacent components. For example, the tooth flanks of the meshing teeth strike against each other in the course of their backlash, causing the rattle noise of non-load gear stages to be mainly caused.

To reduce the rattle noise has already been proposed a variety of solutions. For example, from DE102004057126A1 a device for reducing the axial movement of the main shaft gears in a transmission with at least two countershafts is known, wherein an arranged on the main shaft pressing device for at least one of the main shaft gears presses the associated main shaft in the axial direction against a thrust washer. This should, among other things, unwanted rattling noises are avoided.

The present invention is based on the object of further improving a multi-stage transmission with two countershafts with respect to the reduction of rattle noise. This object is achieved by a device having the features of patent claim 1. Advantageous developments of the device according to the invention are claimed in the dependent claims.

The inventive device for reducing rattle noise is provided for a multi-stage transmission with at least one reverse gear and multiple forward gears, which further comprises two countershafts. The power flow is guided via two arranged on the countershafts gears on a centrally disposed on the main shaft gear.

The invention is characterized in that at least one gear in at least one gear stage of the multi-speed transmission has a conical toothing that the gear with the conical toothing or a gear meshing with this gear is mounted axially displaceable, and that the gear with the conical toothing and the be meshed with this gear meshing gear by at least one elastic element in the axial direction against each other.

The intermeshing teeth are so far pushed into each other until the tooth flanks of the conical gear are present on the opposite tooth flanks. Due to the conicity of the at least one gear and the axial pressing against each other of this gear with the opposite gear the backlash is taken from the respective gear pair and thereby eliminates the cause of the disturbing rattles noises. Particularly in the operating phases in which the respective gear stage is not in the power flow, the elastic element pushes the tooth flanks together. The elastic element is deformed accordingly and the axially displaceable gear is shifted as soon as the associated gear stage is switched into the power flow. Then this is positioned with radi- Alem game mounted on the main shaft, central gear so between the meshing with him gears of the countershafts that the load balancing described above acts.

According to a first preferred embodiment, only the gear wheel arranged centrally on the main shaft, the main shaft wheel, has the conical toothing. It is also axially slidably mounted only the main shaft of the respective gear and the main shaft is pressed by an elastic member in the axial direction in the meshing with him, axially fixed gears.

This preferred embodiment takes into account the fact that the arranged on the countershaft gears are advantageously rigidly connected to the associated countershaft in order to ensure a uniform load balance between the two countershafts permanently. Characterized in that in this embodiment, only the main shaft is movably mounted, the countershaft gears can be rigidly mounted on its countershaft or the teeth are made directly and integrally with the countershaft. For the purposes of this patent application gear teeth produced directly on a shaft should also be encompassed by the term gear.

However, according to another preferred embodiment of the invention, it is also possible that both the main shaft wheel and the meshing with him gears have a conical toothing, and that one or all of the said gears are mounted axially displaceable and by an elastic member in the axial direction the respective opposite gear are pressed. The opposite gears each have an opposing conicity.

A further preferred embodiment provides that only the reverse gear stage has at least one gear with the conical toothing. Accordingly, all the gears of the forward gear stages are provided with a conventional, non-conical toothing.

Surprisingly, it has been found that the rattle noise in all grades are significantly reduced by this measure. This is due to the fact that the rattle noise in all gears is mainly caused by vibrations in the reverse gear. By minimizing the backlash in backlash, especially in the backlash-free load operation, therefore, the rattle noise of the entire multistage transmission is reduced, i. even with a relatively large backlash having, not running under load forward gear steps are much less likely to rattle. Thus, a significant reduction of the annoying rattling noises of the entire transmission can be achieved inexpensively with little design effort. It is therefore not necessary to reduce the backlash in all gear stages of a multi-stage gearbox in order to achieve the desired noise reduction target.

The advantage of the measures used to reduce the rattle noise only in the reverse gear is also very large, because a vehicle transmission is mainly operated in one of the forward gears, while the reverse gear runs along with no load and causes rattle noise in a conventional transmission. Especially in these periods of predominant operating phases, the advantages of the present invention come to fruition.

Particularly preferred is an embodiment in which only the direction of rotation of the main shaft reversing intermediate wheels of the reverse gear stage have a conical shape, are axially displaceable and are pressed by a respective elastic element in the axial direction in the intermeshing with the intermediate gears. The advantage of this embodiment of the invention tion is again that the gears or gears on the countershafts can be rigidly mounted on the shaft, and that the main shaft of the reverse gear in the axial direction must have only enough play that sufficient mobility is maintained in the radial direction to the described Allow load balancing. Both features contribute to a durable, solid design.

In contrast, it is also possible that the main shaft and the intermediate gears of the reverse gear stage have a conical shape, that the mutually engaged gears each have an opposing conicity, and that the main shaft or the intermediate wheels of the reverse gear are axially displaceable and each having an elastic Element are pressed in the axial direction in the opposite teeth.

Likewise, all the gears of the reverse gear stage may have a conical shape, wherein the meshing gears each having an opposing conicity, and wherein at least one of the gears in each gear chain of the reverse gear is axially displaceable and from an elastic member in the axial direction in the opposite Toothing is pressed.

Said elastic element is preferably a disc spring. Also other elastic elements, such as e.g. Rubber rings are used.

The invention is suitable for multi-speed transmission both with straight-toothed, and with helical gears. Spur-toothed gears are simple and inexpensive to manufacture and cause in operation no axial forces that need to be compensated by other design measures. Helical gears ensure quiet, noisy poor running and thus an even longer life of the components of the entire drive train.

The conical toothing on the respective gears is preferably designed as Beveloidverzahnung.

Due to the described design and arrangement of the components of the load balance between the countershafts in both the forward gears, as well as in reverse gear is maintained.

In addition to minimizing the rattle noise increased by the invention, the life of the components of the entire drive train, because the gears of all non-lying in the power flow grades no longer beat so strong and so often against each other. This also results in a smoother running of the entire drive train.

Embodiments of the invention are illustrated in the figures and will be described in more detail below. Show it:

1 shows a detail of a multi-speed transmission with a first embodiment according to the invention of a gear stage for the reverse gear in a schematic representation.

Fig. 2 shows a detail of a multi-speed transmission with a second embodiment according to the invention a gear stage for the reverse gear in a schematic representation and

Fig. 3 shows a detail of a multi-speed transmission with a third embodiment of a gear stage according to the invention for the reverse gear in a schematic representation. Fig. 1 shows an embodiment of the invention in the gear stage for reverse. The torque to be transmitted is guided by the two countershafts 10 and 20 via the intermediate wheels 31 and 41 on the main shaft 1 rotatably mounted on a central main shaft 3 about the central axis 2 thereof. Of the main shaft 3, only a portion is shown, which is cut off at both ends. The central main shaft 1 is mounted on the main shaft 3 with radial clearance 7, to allow a uniform load balance between the two countershafts 10 and 20. It has an outer contour with non-conical shape. The main shaft 1 is guided by at least one arranged on the main shaft thrust washer 4 in the axial direction.

Each of the countershafts 10 and 20 rotates about their respective central axis 12 and 22. Shown is only one end portion of the countershafts 10 and 20. The end portion of each countershaft 10 and 20 carries a toothing 1 1 and 21. In this embodiment, the teeth 1 1 and 21 executed directly on the respective countershaft 10, 20. However, it is also possible in each case to arrange a prefabricated gear rotatably on the countershafts 10 and 20. The outer contours of the teeth 1 1 and 21 on the countershafts 10, 20 have a non-conical shape in this embodiment.

The two intermediate wheels 31 and 41 are each rotatable on an intermediate wheel axle 33 and 43 about their respective center axes 32 and 42 and have a conical toothing. The Zwischenradachsen 33 and 43 are fixed or fixed to the housing in each case two bearings 34, 35 and 44, 45. The intermediate wheels 31 and 41 are mounted axially movably on their associated intermediate wheel axle 33, 43. In the illustrated embodiment, the intermediate wheels 31 and 41 for this purpose on the respective Zwischenradach- se 33, 43 by means of bearings 36, 46 are mounted. The bearings 36, 46 can, for example, be executed as a needle bearing. The axial movement of the intermediate wheels 31, 41 on the Zwischenradachsen 33, 43 is limited in both directions by the bearings 34, 35 and 44, 45, unless he is already restricted by the conical toothing of the idler gears 31, 41.

On each Zwischenradachse 33, 34 further comprises a plate spring 37, 47 is arranged, which presses the associated intermediate 31, 41 via an annular disc 38, 48 in the axial direction in the respective counter teeth of the main shaft 1 and the countershaft 10, 20. The disc springs 37, 47 and the annular discs 38, 48 are respectively disposed between the intermediate 31 and 41 and the bearing 35 and 45 and are based on the intermediate wheel 31, 41 facing away from the associated bearing 35, 45 from.

The taper of the intermediate wheels 31, 41 is directed so that the outer diameter decreases in the effective direction of the plate spring 37, 47. In this way, the conical intermediate wheels 31, 41 of the associated disc spring 37, 38 always pushed so far into the meshing with the intermediate gears teeth of the main shaft 1 and the countershafts 10, 20 that the tooth flanks of the intermeshing teeth abut each other and a backlash avoided becomes. As a result, a quieter running of the transmission is achieved and annoying rattling noises are avoided or at least significantly reduced.

The embodiment shown in Fig. 2 corresponds to a large extent to the embodiment of Fig. 1. Therefore, the same parts in the figures with the same reference numerals. To describe the same parts and their function, reference is made to the description of FIG.

In contrast to the exemplary embodiment according to FIG. 1, in the exemplary embodiment of FIG. 2, all the teeth of the illustrated gear stage of the reverse gear are made conical. On each Zwischenradachse 33, 34 is a plate spring 37, 47 is arranged, which presses the associated intermediate gear 31, 41 via an annular disc 38, 48 in the axial direction in the conical counter-teeth of the main shaft wheel 1 and the countershafts 10, 20.

The main shaft 1 is supported in the axial direction against the force exerted by the disc springs 37, 47 pressure on a thrust washer 4 from.

Also, the embodiment shown in Fig. 3 corresponds to a large extent to the embodiment of Fig. 1. Therefore, the same parts in Fig. 3 are provided with the same reference numerals as in Fig. 1. For description of the same parts and their function will be to the description of Fig. 1 referenced.

In contrast to the embodiment of FIG. 1, in the embodiment of FIG. 3, only the teeth of the main shaft 1 of the illustrated gear stage of the reverse gear are conical and it is also only the main shaft 1 axially slidably mounted.

Also, the elastic element for pressing against each other of the intermeshing teeth is assigned to the main shaft 1 here. Namely in the form of a plate spring 5, which is arranged on the main shaft 3 between an annular disc 6 and the main shaft 1. The plate spring 5 is supported in the axial direction via the annular disc 6 on the thrust washer 4 against the main shaft 1 from.

In contrast, the intermediate wheels 31 and 41 are axially non-displaceably mounted on the Zwischenradachsen 33 and 43 in the embodiment of FIG. The intermediate wheels 31 and 41 are on the Zwischenradachsen 33rd and 43 between each thrust washer 39, 49 and an annular disc 38, 48 and are held by them axially in position, wherein the annular disc 38, 48 in the axial direction of the adjacent bearing 35, 45 is supported.

REFERENCE CHARACTERS

1 main shaft wheel

2 central axis

3 main shaft

4 thrust washer

5 plate spring

6 ring disk

7 game

10 countershaft

11 toothing

12 central axis

20 countershaft

21 toothing

22 central axis

31 idler gear

32 central axis

33 intermediate wheel axle

34 bearings

35 bearings

36 bearings

37 plate spring

38 ring disk

39 thrust washer

41 intermediate wheel

42 central axis

43 intermediate wheel axle

44 bearings

45 bearings

46 bearings Disc spring washer Disc thrust washer

Claims

Patent Attorney

1. A device for reducing rattle noise in a at least one reverse gear and multiple forward gears having multi-stage transmission with at least two countershafts (10, 20), wherein the power flow via two on the countershafts (10, 20) arranged gears (11, 21) on a central Gear wheel (1) arranged on a main shaft (3) is guided, characterized in that at least one toothed wheel (1, 11, 21, 31, 41) has a conical toothing in at least one gear stage of the multistage transmission Gear (1, 11, 21, 31, 41) with the conical toothing or a gear meshing with this gear (1, 11, 21, 31, 41) is mounted axially displaceable, and that the gear (1, 11, 21, 31, 41) with the conical toothing and the gear meshing with this gear (1, 11, 21, 31, 41) are pressed against each other by at least one elastic element (5, 37, 47) in the axial direction.

2. Device according to claim 1, characterized Porsche Style n zei ch et, that only the centrally arranged on the main shaft gear (1) has the conical toothing, is mounted axially displaceable and by an elastic element (5) in the axial direction in the the gear wheel (1) arranged on the main shaft (3) is pressed by meshing gears (11, 21, 31, 41).

3. Device according to claim 1, characterized Porsche Style n zei ch et et, that the centrally arranged on the main shaft gear (1) and each meshing with this gear (11, 21, 31, 41) has the conical toothing, and that only the centrally arranged on the main shaft gear (1) is mounted axially displaceably and by an elastic member (5) in the axial direction in each meshing with him gear (11, 21, 31, 41) is pressed.

4. Device according to one of the preceding claims, characterized g e - ken n zei ch n et that only the reverse gear at least one gear (1, 11, 21, 31, 41) having the conical toothing.

5. Device according to claim 4, characterized Porsche Style n zei ch et, that only the direction of rotation of the main shaft (3) reversing intermediate wheels (31, 41) of the reverse gear stage have a conical shape, are axially displaceable and each of an elastic element (37 , 47) in the axial direction in the with the intermediate wheels (31, 41) meshing gears (1, 11, 21) are pressed.

6. Device according to claim 4, characterized Porsche Style n zei ch et, that the centrally on the main shaft (3) arranged gear (1) and the intermediate wheels (31, 41) of the reverse gear stage have a conical shape that the mutually engaged Each gear wheels have an opposing conicity, and that the centrally on the main shaft (3) arranged gear (1) or the intermediate wheels (31, 41) of the reverse gear are axially displaceable and each of an elastic member (5, 37, 47) in axial direction are pressed into the opposite teeth.

7. Device according to claim 4, characterized Porsche Style n zei ch et that all gears of the reverse gear stage (1, 11, 21, 31,41) have a conical shape, wherein the mutually engaged gears each have an opposing conicity, and that at least one of the gears (1, 11, 21, 31, 41) in each gear chain of the reverse gear is axially displaceable and is pressed by an elastic element (5, 37, 47) in the axial direction in the opposite teeth.

8. Device according to one of the preceding claims, characterized in that the elastic element (5, 37, 47) is designed as a disc spring.

9. Device according to one of the preceding claims, characterized g e - ken n zei ch n et, that the gears (1, 11, 21, 31,41) are straight teeth.

10. Device according to one of claims 1 to 8, characterized g e - ken n zei ch n et, that the gears (1, 11, 21, 31,41) are helically toothed.

11. Device according to one of the preceding claims, characterized g e ken n zei ch n et, that the conical gears (1, 11, 21, 31, 41) have Beveloidverzahnung.