HONING TOOL AND METHOD FOR MACHINING A BEARING PART

Abstract

A honing tool includes a honing stone holder and a branching lubricant duct arranged in the honing stone holder. The branching lubricant duct has a straight section, first and second diagonal sections connected to and positioned diagonally to the straight section, and first and second transition sections that adjoin the first and second diagonal sections, respectively, and are arranged in a first plane parallel to and spaced from the straight section. The duct also has first and second open end sections continuing from the first and second transition sections, respectively, and directed towards a second plane arranged parallel to the first plane and in which the straight section is situated. In an example embodiment, the honing tool includes a honing stone fixed in the honing stone holder between the first and second transition sections.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the United States National Phase of PCT Appln. No. PCT/DE2020/100865 filed Oct. 6, 2020, which claims priority to German Application No. DE102019129874.1 filed Nov. 6, 2019, the entire disclosures of which are incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to a honing tool that enables cooling lubricant to be supplied to a workpiece. The disclosure further relates to a method for machining a bearing part, in particular a wheel bearing, by honing.

BACKGROUND

A honing tool is known, for example, from DE 33 36 626 A1. The known honing tool is provided for connection to a pressurized honing oil source. The honing oil is intended to wash away abrasion from the work surface of a honing stone.

Another honing device that includes a supply duct for a cutting fluid is disclosed in CN 202399128 U. The supply duct for cutting fluid has an inlet and a double outlet.

A device known from DE 10 2009 040 062 A1 for finishing ring-shaped workpieces, in particular bearing rings, includes a device for short-stroke honing, which has an oscillation drive for generating oscillatory movements of a honing stone holder. Furthermore, a tool holder is provided, which is designed to accommodate a hard turning tool.

A further device for mechanical finishing of surfaces on rotationally symmetrical workpieces is described in DE 10 2007 054 897 B4. The workpiece to be machined can be a bearing ring for a double-row spherical roller bearing. A tool carrier of the known machining device can carry out both short-stroke oscillating movements and long-stroke oscillating movements with the aid of various drives.

SUMMARY

The present disclosure provides a honing tool and a method for machining, namely honing, of a bearing part, in particular a wheel bearing. The configurations and advantages explained below in connection with the machining method also apply analogously to the honing tool, and vice versa.

The honing tool includes a honing stone holder, in which a branching lubricant duct is situated, which has a first, straight section, two sections which are connected to and positioned diagonally to the first section, and two transition sections which adjoin these diagonally positioned sections and are arranged in a plane parallel to and spaced from the first section. Open end sections continue from the transition sections, said end sections being directed in the sense of surface normals towards a plane which is parallel to the aforementioned plane defined by the position of the transition sections and in which the first section of the lubricant duct is situated. The term transition sections was chosen for distinction from the other sections of the lubricant duct and does not imply any information about a deviating geometric design of the transition sections.

With this design of the lubricant duct in the honing stone holder, which describes a forked shape, it is possible to use one and the same honing tool, e.g., with unchanged mounting of the honing stone in the honing stone holder, for honing both rolling bearing raceways of an outer ring of a wheel bearing for a motor vehicle. With regard to movements of the honing tool and of the workpiece or bearing part, e.g., the wheel bearing outer ring, during machining, common processes can in principle be implemented during honing.

In general, the honing process includes the following steps:

providing a bearing part, e.g., a wheel bearing, namely a one-piece outer ring, through which two raceways for rolling elements are formed,

providing a honing tool which is formed from a cranked holder and a honing stone fixed therein. The longitudinal direction of the holder is given by a shaft of the holder and the honing stone is designed as an elongate cuboid that forms a right angle with the longitudinal direction of the holder. The holder is traversed by a lubricant duct branching out within the holder, the outlet openings of which lubricant duct are arranged next to the honing stone,

machining the first raceway of the outer ring with the honing tool. Cooling lubricant is passed through the lubricant duct and directed in the longitudinal direction of the honing stone onto the surface being machined, and

machining the second raceway of the outer ring with the honing tool. Again cooling lubricant is passed through the lubricant duct and directed in the longitudinal direction of the honing stone onto the surface being machined.

The indication “elongate cuboid” in connection with the honing stone refers to its basic shape. In the machining area in particular, the shape of the honing stone can deviate from a cuboid shape.

With regard to the design of an outer ring of a wheel bearing, reference is made, for example, to DE 10 2009 051 930 A1. Wheel bearings with more than two rows of rolling elements, as disclosed, for example, in DE 10 2010 055 405 A1, can also be machined with the honing tool.

The cranked shape of the honing stone holder, which allows honing both raceways of a commercially available wheel bearing, is evident both in the overall shape of the honing stone holder and in the course of the partially split lubricant duct running in the honing stone holder. The honing stone may be fixed in the honing stone holder between the two transition sections of the lubricant duct lying in a common plane and parallel to the first section. For fixing the honing stone, a pressure block that is arranged inside the honing stone holder and can be adjusted with a screw mechanism may be used.

The two end sections of the lubricant duct, from which the cooling lubricant used in the honing emerges, are typically aligned in the longitudinal direction of the honing stone and thus transversely to the shaft of the honing stone holder. The first straight section of the lubricant duct, i.e., running in the shaft, is typically longer than any other section of the lubricant duct. In contrast, the two end sections may be the shortest sections of the lubricant duct.

The two diagonally positioned sections may be connected to the first section via a transverse section oriented orthogonally to the first section. In a manner that is advantageous in terms of manufacturing technology, as far as the manufacture of the honing stone holder is concerned, the transverse section, like the two diagonally positioned sections, is closed on one side by a screw.

The honing tool can be used particularly efficiently in that it can be attached to and partially inserted into the outer ring from the same end face of the outer ring one after the other for machining the first raceway of an outer ring and for machining the second raceway of the outer ring. The machined bearing part for a wheel bearing is typically a rolling bearing designed as a two-row ball bearing.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, an exemplary embodiment of the disclosure is explained in more detail by means of a drawing. In the figures:

FIG. 1 shows a honing stone holder of a honing tool in a perspective view,

FIG. 2 shows the honing stone holder in a sectional view,

FIG. 3 shows the machining of a wheel bearing outer ring with the honing tool in a first machining phase, and

FIG. 4 shows the machining of the wheel bearing outer ring by the honing tool in a second machining phase.

DETAILED DESCRIPTION

A honing tool, identified as a whole by reference sign 3, is provided for machining a workpiece 2, namely the wheel bearing outer ring. The arrangement sketched in FIGS. 3 and 4, which comprises the workpiece 2, i.e., the wheel bearing part, and the honing tool 3, is referred to as a whole as a machining arrangement 1. In FIG. 3, a pressure roller 6 can also be seen, which absorbs radial forces.

The workpiece 2 to be machined has a flange 4 which, when the wheel bearing is installed, is connected to a wheel carrier. Bores in the flange 4 are denoted by 5. The flange 4 is connected in one piece to a cylindrical section 12 in which a first raceway 10 and a second raceway 11 are formed, which are to be machined with the honing tool 3. In the finished state of the wheel bearing, balls roll as rolling elements on the raceways 10, 11 in a manner known per se. Overall, the wheel bearing, which comprises the wheel bearing part 2, is designed as a double-row angular contact roller bearing in an O-arrangement. With regard to the basic construction of such a wheel bearing, reference is made to the prior art cited at the outset.

The honing tool 3 comprises a honing stone holder 7, shown in isolation in FIGS. 1 and 2, which is also referred to as a holder for short. When using the honing tool 3, a honing stone 8 is fixed in the holder 7 with the aid of a pressure block 9. The honing stone holder 7 is traversed by a duct, denoted as a whole by 16, partially split into two arms, i.e., a lubricant duct, which will be discussed in more detail below.

A cooling lubricant 13, which is also referred to as lubricant for short and is used for honing, is passed through the duct 16. The lubricant 13 is introduced through a connection piece 18 into a straight, long section 17 of the duct 16. The first, straight section 17 of the duct 16 runs through a shaft 15 of the honing stone holder 7. At its end opposite the connection piece 18, the shaft 15 merges into a widened section 19. In this widened section 19 there is a transverse duct 20 which adjoins the first section 17 and is also assigned to the duct 16. The two ends of the transverse duct 20 are connected to diagonal ducts 23, 24, which are located in an intermediate section 22 which bends obliquely from the area of the holder 7 formed from the shaft 15 and the widened section 19 connected thereto.

The transverse duct 20, which is also referred to as a transverse section, is designed as a blind hole closed by a screw 21 on a side surface of the holder 7. In a corresponding manner, the two diagonal ducts 23, 24, i.e., diagonally positioned sections of the lubricant duct 16, are closed by screws 25, 26.

The diagonally positioned sections 23, 24 each merge into a straight, short section 27, 28 shortly before the screws 25, 26. The two straight, short sections 27, 28 are also referred to as transition sections and define a plane which is arranged parallel to a plane in which the first, straight section 17 of the duct 16 is situated. Each of the short sections 27, 28 is closed by a screw 29, 30 which—based on the arrangement according to FIG. 1—is arranged on the underside of the honing stone holder 7.

Above the screws 29, 30, one end section 31, 32 branches off at right angles from the straight, short sections 27, 28. The cooling lubricant 13 emerges from the end sections 31, 32 in such a way that it is fed to the machining area along the honing stone 8. The two machining areas, which are in the form of the raceways 10, 11, are separated from one another by a central inner wall area 14. Due to the cranked shape of the honing stone holder 7 including the lubricant duct 16, each raceway 10, 11 can be reached from the same end face of the workpiece 2, wherein the lubricant 13 is supplied to the respective machining area in a targeted manner in each case.

REFERENCE NUMERALS

1 Machining arrangement

2 Bearing part, workpiece

3 Honing tool

4 Flange

5 Bore

6 Pressure roller

7 Holder, honing stone holder

8 Honing stone

9 Pressure block

10 First raceway

11 Second raceway

12 Cylindrical section of the workpiece

13 Lubricant

14 Central inner wall area

15 Shaft

16 Duct, lubricant duct

17 Straight, long section

18 Connector

19 Widened section

20 Transverse duct, transverse section

21 Screw

77 Intermediate section

23 Diagonally positioned section of the duct

24 Diagonally positioned section of the duct

25 Screw

26 Screw

27 Straight, short section, transition section

28 Straight, short section, transition section

29 Screw

30 Screw

31 End section

32 End section

Claims

1-8. (canceled)

9. A honing tool comprising: a honing stone holder; anda branching lubricant duct arranged in the honing stone holder, the branching lubricant duct comprising:a straight section;a first diagonal section connected to and positioned diagonally to the straight section;a second diagonal section connected to and positioned diagonally to the straight section;a first transition section that adjoins the first diagonal section and is arranged in a first plane parallel to and spaced from the straight section;a second transition section that adjoins the second diagonal section and is arranged in the first plane;a first open end section continuing from the first transition section and directed towards a second plane arranged parallel to the first plane and in which the straight section is situated; anda second open end section continuing from the second transition section and directed towards the second plane.

10. The honing tool of claim 9, further comprising a honing stone fixed in the honing stone holder between the first transition section and the second transition section.

11. The honing tool of claim 10, wherein: the honing stone comprises a longitudinal direction; andthe first open end section and the second open end section are oriented in the longitudinal direction.

12. The honing tool of claim 9, wherein: the straight section is longer than all other sections of the branching lubricant duct; andthe first open end section and the second open end section are shorter than all other sections of the branching lubricant duct.

13. The honing tool of claim 9, wherein: the branching lubricant duct further comprises a transverse section oriented orthogonally to the straight section; andeach of the first diagonal section and the second diagonal section is connected to the straight section via the transverse section.

14. The honing tool of claim 13, wherein each of the transverse section, the first diagonal section and the second diagonal section is closed on one side by a respective screw.

15. A method for machining a bearing part comprising: providing the bearing part comprising a first raceway and a second raceway for rolling elements;providing a honing tool formed from a cranked holder and a honing stone fixed therein, wherein: the cranked holder comprises: a shaft;a longitudinal direction extending along the shaft; anda branching lubricant duct with outlet openings arranged next to the honing stone;the honing stone is designed as an elongate cuboid that forms a right angle with the longitudinal direction; andmachining the first raceway with the honing tool, wherein a cooling lubricant is passed through the branching lubricant duct and directed in the longitudinal direction onto the first raceway; andmachining the second raceway with the honing tool, wherein the cooling lubricant is passed through the branching lubricant duct and directed in the longitudinal direction onto the second raceway.

16. The method of claim 15 wherein the bearing part is for a wheel bearing.

17. The method of claim 15 wherein the bearing part is an outer ring for a wheel bearing.

18. The method of claim 15, wherein: during the machining of the first raceway with the honing tool, the honing tool engages in the bearing part from a first end face; andduring the machining of the second raceway with the honing tool, the honing tool engages in the bearing part from the first end face.