Transmission and Method for Adjusting the Circumferential Backlash of the Transmission

Abstract

A transmission has a housing, and a first and a second shaft, each of which has a bevel gearwheel. The two bevel gearwheels are in meshing engagement with one another. The first shaft with a first bevel gearwheel is designed as an axially adjustable shaft and, for this purpose, is supported by two rolling bearings on both sides of the bevel gearwheel, wherein each of the rolling bearings has a shaft-side inner ring and a housing-side outer ring. The shaft-side inner rings are provided in a defined axial position on the first shaft, while the housing-side outer rings of the rolling bearings are guided on respective housing-side support surfaces and are restricted from moving toward one another solely by the inner rings and the shaft. The axial position of the housing-side outer rings of the rolling bearings can be adjusted on the side facing away from the bevel gearwheel by respective adjusting devices. Each of the adjusting devices has an adjusting element with an external thread on the side of the respective outer ring facing away from the bevel gearwheel. The external thread is inserted into an internal thread in the housing. The internal thread and the external thread are designed as fine threads, preferably with a pitch of at most 0.75 mm.

Claims

1-11. (canceled)

12. A transmission, comprising: a. a housing; b. a first and a second shaft, each of which has a bevel gearwheel, c. the two bevel gearwheels are in meshing engagement with one another, d. the first shaft with a first bevel gearwheel is designed as an axially adjustable shaft and, for this purpose, is supported by two rolling bearings on both sides of the bevel gearwheel, e. each of the rolling bearings has a shaft-side inner ring and a housing-side outer ring, f. the shaft-side inner rings are provided in a defined axial position on the first shaft, g. the housing-side outer rings of the rolling bearings are guided on respective housing-side support surfaces and are restricted from moving toward one another solely by the inner rings and the shaft, and h. the axial position of the housing-side outer rings of the rolling bearings are adjustable on the side facing away from the bevel gearwheel by respective adjusting devices, wherein i. each of the adjusting devices has an adjusting element with an external thread on the side of the respective outer ring facing away from the bevel gearwheel, said external thread being inserted into an internal thread in the housing, and j. the internal thread and the external thread are designed as fine threads, preferably with a pitch of at most 3 mm.

13. The transmission as claimed in claim 12, wherein the pitch is at most 1.5 mm.

14. The transmission as claimed in claim 12, wherein the pitch is at most 0.75 mm.

15. The transmission as claimed in claim 12, wherein: a. at least one of the adjusting elements is designed as a closed cover.

16. The transmission as claimed in claim 12, wherein: a. at least one of the adjusting elements has a through opening for the passage of the first shaft.

17. The transmission as claimed in claim 16, wherein: b. the through opening is designed with a shaft seal for contact with the first shaft.

18. The transmission as claimed in claim 12, wherein: a. the adjusting elements are accessible from outside the housing with the transmission assembled.

19. The transmission as claimed in claim 12, wherein: a. at least one of the adjusting elements has a noncircular handling region for introducing an adjusting torque.

20. The transmission as claimed in claim 19, wherein: a. the noncircular handling region has at least two mutually paralleled torque introduction surfaces with either an internal or external hexagonal profile or with an internal or external square profile.

21. The transmission as claimed in claim 12, wherein: a. a counter element having an external thread for locking against the adjusting element is provided on the side of at least one of the adjusting elements facing away from the bevel gearwheel, or b. at least one of the adjusting elements is fixed in position relative to the housing by an adhesive joint, or c. a seal, in the form of an O-ring or other encircling sealing element composed of elastically deformable material, is provided between at least one of the adjusting elements and the housing.

22. The transmission as claimed in claim 12, wherein: a. an axially acting spring device is provided between one of the adjusting elements and the associated outer ring of the rolling bearing.

23. The transmission as claimed in claim 12, wherein: a. the two rolling bearings form a preloaded support arrangement, in an X arrangement.

24. The transmission as claimed in claim 12, wherein: a. the rolling bearings are taper roller bearings.

25. The transmission as claimed in claim 12, wherein: a. the internal thread and the external thread are designed as fine threads with a pitch of at most 0.5 mm.

26. The transmission as claimed in claim 12, wherein: a. the internal thread and the external thread are designed as fine threads with a pitch of at most 0.35 mm.

27. A method for adjusting the circumferential backlash of a transmission as claimed in claim 12, the method comprising the steps of: a. fixing the shaft axially in position by screwing in the two adjusting elements, and b. rotating synchronously the adjusting elements in order to move the shaft axially via the threads while keeping a preload on the shaft constant.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The invention is described below by means of an illustrative embodiment, which is shown in the figures.

[0038] FIG. 1 shows a transmission according to the invention.

[0039] FIGS. 2 and 3 show, on an enlarged scale, partial areas of the transmission shown in FIG. 1 that are essential to the invention.

[0040] FIG. 4 shows an adjusting element of the transmission shown in FIGS. 1 to 3, in perspective.

[0041] FIG. 5 shows an alternative adjusting element in perspective.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0042] FIG. 1 shows a transmission 10 according to the invention, which is distinguished by two intermeshing bevel gearwheels 32, 42. FIGS. 2 and 3 show details of this transmission on an enlarged scale.

[0043] The transmission 10 has a housing 20, wherein all those sections of the transmission 10 which are fixed in location relative to one another after assembly are regarded as part of the housing. The housing 20 defines a housing interior, within which two nonparallel shafts 30, 40 are supported. The two intermeshing bevel gearwheels 32, 42 are secured on these shafts 30, 40.

[0044] In order to be able to adjust the circumferential backlash of the bevel gearwheels 32, 42 in accordance with the area of application, the first shaft 30 can be moved axially by means of adjusting devices 70, 80. The mode of operation of these adjusting devices 70, 80 is explained below.

[0045] The first shaft 30 is supported by means of two rolling bearings 50, 60, which are each designed as taper roller bearings and which are arranged in a preloaded X support arrangement.

[0046] The inner rings 52, 62 of these rolling bearings 50, 60 are slipped onto the first shaft 30 and each rest against shoulders on the shaft 30, with the result that the position thereof relative to one another and to the bevel gearwheel 32 in the axial direction is predetermined.

[0047] The outer rings 54, 64 of the rolling bearings 50, 60 rest on cylindrical supporting surfaces 22, 24 of the housing 20. The movement thereof toward one another is limited only by the rolling elements, the inner rings 52, 62 and the shaft 30. No stops are provided on the inside of the housing. The outward movement of the outer rings 54, 64 is limited by the adjusting devices 70, 80.

[0048] Each of the adjusting devices 70, 80 has an adjusting element 72, 82, which can be removed in the perspective view in FIG. 4.

[0049] The adjusting elements 72, 82 form covers with an external thread 74, 84, which are screwed into internal threads 26, 28 in the housing on opposite sides of the housing 20, at both ends of the shaft 30. In an outer edge region, the adjusting elements each press on the outer rings 54, 64 of the rolling bearings 50, 60, with the result that the outward movement thereof is limited and the rolling bearings can be braced against one another via the shaft 30.

[0050] On the outside thereof, the adjusting elements 72, 82 each have a handling region in the form of an external hexagonal profile 76, 86, thus allowing them to be rotated and thereby axially adjusted by means of generally available tools.

[0051] Assembly is preferably performed in such a way that, after the shaft 30 and the rolling bearings 50, 60 have been arranged in the housing, a first adjusting element 72, 82 is first of all screwed in. The other, opposite adjusting element is then screwed in, wherein a torque wrench can be used, thus ensuring that a defined prestress in the shaft 30 is achieved via the rolling bearings 50, 60.

[0052] Once this has been completed, the adjustment of the circumferential backlash can then take place by rotating the two adjusting elements 72, 82, preferably simultaneously and to the same extent. As a result, one of the adjusting elements presses axially on the outer ring of the rolling bearing associated therewith and moves the latter together with the shaft 30, while the other adjusting element simultaneously creates the axial space required for this movement. Since the threads 26, 28, 74, 84 are designed as fine threads, this adjustment can be performed in a very precise and controlled manner. The preset stress in the shaft 30 remains unchanged owing to the axially identical movement of the adjusting elements 72, 82.

[0053] Once the desired circumferential backlash has been achieved, the adjusting elements 72, 82 are preferably secured finally against rotation. This can be accomplished by adhesive bonding or, alternatively, by means of a counter element.

[0054] FIG. 5 shows an alternative embodiment of an adjusting element 172. This has a through opening 178, through which the shaft 30 can be passed out of the housing 20 of the transmission 10. Thus, this shaft can be used directly as an input or output shaft. An inward-oriented shaft seal 179 can be arranged in the through opening.