JP2012233536A - Outer race for bearing, its manufacturing method and grinding wheel for orbital surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outer race for a bearing, its manufacturing method and a grinding wheel of an orbital surface which can simplify a procedure of mounting the grinding wheel by decreasing the number of the grinding wheels and reducing cost.SOLUTION: The outer race 3 has a first inner orbital surface 3a which rotates the rolling element 4 of one side row having larger pitch circle diameters among double row having rolling elements 4, 5 which are circumferentially arranged with a plurality of spherical bodies having different pitch circle diameters. and a second inner orbital surface 3b which rotates the rolling element 5 of the other side row having smaller pitch circle diameter. The second inner orbital surface 3b specifies the ratio of d/dof the orbital base diameter din the first inner orbital surface 3a to the orbital base diameter dof the same as 1.1≥d/d≥1, and is formed with the orbital surface rotating the rolling element 5 of the other side row having a larger spherical diameter than that of the rolling element 4 of the one side row.

Description

  The present invention relates to a bearing rotating wheel, a method of manufacturing the same, and a grinding wheel for a raceway surface.

  As a conventional wheel bearing device, an inner member that can rotate around a central axis, an outer member (outer ring) disposed on the outer periphery of the inner member, and between the outer ring and the inner member. There is one provided with interposing double row rolling elements (for example, Patent Document 1).

  The inner member includes a hub ring and an inner ring, and is disposed so as to be rotatable on the central axis. The hub wheel has a wheel mounting flange and an outer raceway surface on the outer peripheral surface. The inner ring has an outer raceway surface on the outer peripheral surface, and is attached to the outer peripheral surface of the vehicle inner side end portion of the hub wheel.

  The outer ring rolls the rolling elements of the vehicle inner side row between the outer raceway surface of the hub wheel and the first inner raceway surface for rolling the rolling elements of the vehicle outer side row between the outer raceway surface of the hub wheel and the outer raceway surface of the inner ring. The second inner raceway surface to be moved is attached to the vehicle inner side via a knuckle of a suspension device. The track bottom diameter of the first inner track surface is set to be larger than the track bottom diameter of the second inner track surface.

  The double row rolling elements are made of bearing balls having a predetermined spherical diameter, and the rolling elements in each row are held by a cage so as to be able to roll.

  The rolling elements in one side row (vehicle outer side row) are disposed on the vehicle outer side so as to be interposed between the outer raceway surface of the hub wheel and the first inner raceway surface. A seal member interposed between the outer peripheral surface of the hub wheel and the inner peripheral surface of the outer ring is disposed on the vehicle outer side of the rolling elements in the one side row.

  The rolling elements of the other side row (vehicle inner side row) are disposed on the vehicle inner side so as to be interposed between the outer raceway surface of the inner ring and the second inner raceway surface. On the vehicle inner side of the rolling elements in the other side row, a magnetic encoder for detecting the rotational speed of the wheel is disposed between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring.

  With the above configuration, when the wheel rotates, this rotation is transmitted to the hub wheel and the inner ring, and the hub wheel rotates together with the inner ring.

  By the way, the manufacture of the outer ring in this type of wheel bearing device is the inner peripheral surface of the cylindrical outer ring forming member, the first part which becomes the first inner raceway surface, and the second inner raceway surface. This is performed by polishing the second portion to be with a grindstone.

Japanese Patent Laying-Open No. 2011-5963 (FIG. 3)

  However, according to the manufacture of the outer ring in the above-described wheel bearing device, a plurality of grindstones are required when forming the first inner raceway surface and the second raceway surface.

  That is, in the outer ring forming member, when polishing the first part serving as the first inner raceway surface and the second part serving as the second inner raceway surface, a grinding stone for grinding the first part, A grindstone for polishing the second part is required. This is because, when a single grindstone having two grindstone portions having different outer diameters is used, the first inner raceway surface and the second inner raceway surface having different raceway bottom diameters are formed. This is because, since the peripheral speeds of the respective grindstone portions are different from each other, a difference occurs in the surface roughness of each inner raceway surface after polishing, and therefore it is necessary to prevent this difference from occurring.

  As a result, there is a problem that the number of grindstones is increased, and not only the mounting work for attaching the grindstone to the polishing machine body is complicated, but also the cost is increased.

  Accordingly, an object of the present invention is to provide a bearing outer ring, a method for manufacturing the same and a raceway surface grindstone that can reduce the number of grindstones, thereby simplifying the grindstone mounting operation and reducing the cost. There is.

  In order to achieve the above object, one aspect of the present invention provides the bearing outer ring, the manufacturing method thereof, and the raceway grindstone of (1) to (5).

(1) A first rolling element having a large pitch circle diameter of a plurality of rolling elements formed by arranging a plurality of spheres in a circumferential direction having different pitch circle diameters. a second raceway surface for rolling a rolling element on the other side column having a raceway surface, and smaller pitch circle diameter, the second track surface, said first raceway surface and the raceway bottom diameter d ₂ The ratio d ₂ / d ₁ to the track bottom diameter d ₁ is 1.1 ≧ d ₂ / d ₁ ≧ 1 and the other side having a larger sphere diameter than the rolling element of the one side row A bearing outer ring formed of a raceway surface that rolls the rolling elements in a row.

(2) In the outer ring for a bearing according to (1), the first raceway surface is a raceway surface for rolling the number of rolling elements in the one side row larger than the number of rolling elements in the other side row. It is formed with.

(3) A method for producing a bearing outer ring by polishing a material used as a bearing outer ring according to (1) or (2), wherein the first raceway surface is formed by polishing the material. A method for manufacturing a bearing outer ring, wherein the step of polishing and the step of polishing the material to form the second raceway surface are performed in a single polishing step.

(4) A grindstone used in the method for manufacturing a bearing outer ring according to (3) above, wherein the material is polished to form the first raceway surface, and the material is polished. And a second grindstone portion forming a second raceway surface.

  According to the present invention, the number of grindstones can be reduced, and the grindstone mounting operation can be simplified and the cost can be reduced.

Sectional drawing shown in order to demonstrate the whole wheel bearing apparatus to which the outer ring for bearings concerning the 1st Embodiment of this invention was applied. Sectional drawing shown in order to demonstrate the principal part of the wheel bearing apparatus to which the outer ring for bearings concerning the 1st Embodiment of this invention was applied. Sectional drawing shown in order to demonstrate the grindstone used for the manufacturing method of the outer ring | wheel for bearings concerning the 1st Embodiment of this invention. Sectional drawing shown in order to demonstrate the wheel bearing apparatus to which the outer ring for bearings concerning the 2nd Embodiment of this invention was applied.

[First embodiment]
(Whole configuration of wheel bearing device)
FIG. 1 shows the entire wheel bearing device. FIG. 2 shows a main part of the wheel bearing device. As shown in FIGS. 1 and 2, the wheel bearing device 1 includes, for example, a driven wheel bearing device, and an inner member 2 that can rotate around a central axis O and an outer periphery of the inner member 2. An outer member (outer ring) 3 arranged and double row rolling elements 4 and 5 interposed between the outer ring 3 and the inner member 2 are provided, and a vehicle body (not shown) and a wheel (not shown) are provided. ).

(Configuration of the inner member 2)
The inner member 2 includes a hub ring 6 and an inner ring 7, and is disposed on the central axis O so as to be rotatable.

  The hub wheel 6 has two large and small body portions 6a, 6b (large diameter body portion 6a, small diameter body portion 6b) having different outer diameters, and an intermediate diameter (body body) interposed between the two body portions 6a, 6b. A step portion 6c as a body portion that is smaller than the outer diameter of the portion 6a and larger than the outer diameter of the body portion 6b), and is disposed around the inner periphery of the outer ring 3 through the inner ring 7. For example, it is formed by a round shaft-shaped formed body made of carbon steel for machine structure. In the present embodiment, JISS55C is used as the material of the hub wheel 6. The hub wheel 6 is formed with a first recess 6d that opens to the vehicle outer side and a second recess 6e that opens to the vehicle inner side.

  The large-diameter trunk portion 6a is disposed on the vehicle outer side of the hub wheel 6 (left side in FIG. 1). The large-diameter trunk portion 6a is integrally provided with a plurality of (for example, four in this embodiment) wheel mounting flanges 60a that project on the outer peripheral surface of the large-diameter body portion 6a on the vehicle outer side and mount wheels (not shown). It has been. The plurality of wheel mounting flanges 60a are provided with bolt insertion holes 600a through which the bolts with serrations 8 as wheel mounting bolts are press-fitted and inserted.

  The small-diameter body portion 6b has an annular recess 60b for attaching the inner ring 7 on the outer peripheral surface, and is disposed on the vehicle inner side (right side in FIG. 1) of the hub wheel 6. The concave portion 60b is formed by plastically deforming (caulking) the opening end portion (opening end portion of the second concave portion 6e) of the cylindrical shaft member that becomes the hub wheel 6.

  The step 6c includes an outer raceway surface 60c for rolling the rolling elements 4 in the vehicle outer side row of the double row rolling elements 4 and 5, and an outer raceway surface 60c interposed between the outer raceway surface 60c and the wheel mounting flange 60a. Thus, a seal surface 61c is provided as a receiving surface that receives the seal member 9 on the vehicle outer side. The outer raceway surface 60c is formed of a curvature surface (orbital surface) that matches the spherical surface of the rolling element 4 in one side row (vehicle outer side row).

  On the other hand, the inner ring 7 has an outer raceway surface 7a for rolling the rolling elements 5 in the vehicle inner side row of the double row rolling elements 4 and 5, and an encoder mounting surface 7b for mounting a magnetic encoder (not shown). And is fixed in the recess 60b of the hub wheel 6, and is entirely formed of a cylindrical molded body made of, for example, high carbon chromium bearing steel. In the present embodiment, JISSUJ2 is used as the material of the inner ring 7. The outer raceway surface 7a is formed of a curvature surface (track surface) that matches the spherical surface of the rolling elements 5 in the other side row (vehicle inner side row).

(Configuration of outer ring 3)
The outer ring 3 includes a first inner raceway surface 3a for rolling the rolling elements 4 in one side row (vehicle outer side row) of the double row rolling elements 4 and 5, and the rolling on the other side row (vehicle inner side row). A second inner raceway surface 3b for rolling the moving body 5 is provided, and is fixed to the vehicle inner side via a knuckle (not shown) as a component of a suspension device (not shown). It is formed of a cylindrical molded body made of carbon steel for industrial use. In the present embodiment, JISS55C is used as the material of the outer ring 3. The outer ring 3 is equipped with a cap (not shown) that covers the vehicle inner side opening.

The first inner raceway surface 3a is formed by a raceway surface in which n ₁ rolling elements 4 in the vehicle outer side row are arranged and rolled in the circumferential direction. Further, the first inner raceway surface 3a is formed by a curvature surface (track surface) that matches the spherical surface of the rolling element 4 in the vehicle outer side row.

The second inner raceway surface 3b rolls by arranging n ₂ (n ₁ > n ₂ ) rolling elements 5 in the vehicle inner side row, which are fewer than n ₁ , in the circumferential direction. It is formed with a curvature surface (orbital surface) that matches the spherical surface of the rolling elements 5 in the row. The second inner raceway surface 3b, the track bottom diameter _{d 2} and the first ratio _d 2 / _{d 1} is the inequality 1 ≦ _d 2 / _{d 1} ≦ 1 the raceway bottom diameter _{d 1} of the inner raceway surface 3a with a ratio satisfying .1, it is formed in the raceway surface having a curvature greater than the radius of curvature R ₁ of the first inner raceway surface 3a radius _{R 2 (R 1 <R 2} ).

Thereby, when it is going to form the outer ring | wheel 3 which has the 1st inner track surface 3a and the 2nd inner track surface 3b using the single grindstone (dedicated track surface grindstone) 100 mentioned later, it is conventional. In this case, the peripheral speed does not change between the two grindstone portions, and the surface roughness of the inner raceway surfaces 3a and 3b after polishing does not vary. This is because the ratio d ₂ / d ₁ between the track bottom diameter d ₁ of the first inner track surface 3 a and the track bottom diameter d ₂ of the second inner track surface 3 b is d ₂ / d ₁ = 1. Of course, it has also been confirmed when the ratio d ₂ / d ₁ is inequality 1 <d ₂ / d ₁ ≦ 1.1.

(Configuration of double row rolling elements 4 and 5)
The rolling elements 4 in one side row (vehicle outer side row) are composed of a plurality of bearing balls (spheres) arranged in the circumferential direction with the dimension of the sphere diameter D ₁ , and the outer raceway surface of the hub wheel 6. It is disposed between 60c and the first inner raceway surface 3a, and is held by the cage 10 so as to be able to roll. The pitch circle diameter P ₁ of the rolling elements 4 in the one side row is set to be larger than the pitch circle diameter P ₂ (P ₁ > P ₂ ) of the rolling elements 5 in the other side row. Thereby, the action point distance of the wheel bearing device 1 can be increased and the rigidity thereof can be increased. On the vehicle outer side of the rolling elements 4 in one side row, a seal member 9 is disposed between the seal surface 61c of the hub wheel 6 and the vehicle outer side opening inner peripheral surface of the outer ring 3.

The rolling elements 5 in the other side row (vehicle inner side row) are set to a dimension of a sphere diameter D ₂ (D ₁ <D ₂ ) larger than the sphere diameter D ₁ in the circumferential direction (the rolling element 4 in the one side row). And a plurality of bearing balls (spheres) arranged in a circumferential direction different from the circumferential direction of the inner ring 7 and disposed between the outer raceway surface 7a of the inner ring 7 and the second inner raceway surface 3b. And is held by the cage 11 so that it can roll.

  On the vehicle inner side of the rolling element 5 in the other side row, a magnetic encoder for detecting the rotational speed of the wheel is formed between the outer peripheral surface (encoder mounting surface 7b) of the inner ring 7 and the vehicle inner side opening inner peripheral surface of the outer ring 3. It is arranged in between.

(Operation of the wheel bearing device 1)
The operation of the wheel bearing device 1 shown in the present embodiment is performed by transmitting the rotation to the hub wheel 6 and the inner ring 7 when the wheel rotates, and the hub ring 6 rotates together with the inner ring 7. In this case, the rolling elements 4 in the vehicle outer side row are between the outer raceway surface 60 c of the hub wheel 6 and the first inner raceway surface 3 a, and the rolling elements 5 in the vehicle inner side row are the outer raceway surface 7 a of the inner ring 7. And the second inner raceway surface 3b.

(Production method of bearing outer ring)
Next, a method for manufacturing the outer ring 3 shown in the present embodiment will be described with reference to FIG. FIG. 3 shows a grindstone.

  In the manufacturing method of the bearing outer ring shown in the present embodiment, each process of “formation of the first inner raceway surface” and “formation of the second inner raceway surface” is performed at the same time in a single polishing process. Since this step is performed as a step of “formation of inner raceway surface and second inner raceway surface”, this step will be described.

“Formation of first inner raceway surface and second inner raceway surface”
In the manufacturing method of the outer ring 3 shown in the present embodiment, as shown in FIG. 3, the first polishing target portion 200a in the bottomless cylindrical material 200 that becomes the outer ring 3 (shown in FIG. 1) is polished. The first grindstone portion 100a forming the first inner raceway surface 3a (shown in FIG. 1) and the second grinding target portion 200b in the material 200 are polished to form the second inner raceway surface 3b (shown in FIG. 1). The grindstone 100 having the second grindstone portion 100b for forming the above is used. The first grindstone portion 100a is formed with a curvature surface that conforms to the first inner raceway surface 3a, and the second grindstone portion 100b is formed with a curvature surface that conforms to the second inner raceway surface 3b.

Then, the grindstone 100 is arranged in the material 200 and rotated around the axis O ₁ , and the material 200 is rotated around the axis in the direction opposite to the rotation direction of the grindstone 100, thereby the first grindstone portion. The first polishing target part 200a of the material 200 is polished by 100a, and the second polishing target part 200b of the material 200 is polished by the second grindstone part 100b, respectively, and the first inner raceway surface 3a and the second inner raceway are polished. The outer ring 3 can be manufactured by simultaneously forming the surface 3b.

In this case, the ratio d ₂ / d ₁ between the track bottom diameter d ₁ of the first inner track surface 3 a and the track bottom diameter d ₂ of the second inner track surface 3 b is inequality d ₂ / d ₁ is 1 ≦ d ₂ / The outer ring 3 set to a ratio satisfying d ₁ ≦ 1.1 can be obtained.

  Therefore, in the present embodiment, the peripheral speed does not change between the two grindstone portions 100a and 100b of the grindstone 100 as in the prior art, and the surface roughness of the inner raceway surfaces 3a and 3b after polishing is different. There is nothing.

[Effect of the first embodiment]
According to the first embodiment described above, the following effects can be obtained.

  The number of grindstones can be reduced, and the grindstone mounting operation can be simplified and the cost can be reduced.

[Second Embodiment]
Next, a wheel bearing device to which a bearing outer ring according to a second embodiment of the present invention is applied will be described with reference to FIG. FIG. 4 shows the entire wheel bearing device. 4, the same or equivalent members as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the wheel bearing device 31 according to the second embodiment of the present invention is characterized in that the inner member 2 includes an inner ring 32 on the vehicle outer side and an inner ring 33 on the vehicle inner side.

  For this reason, the inner ring 32 on the vehicle outer side has an outer raceway surface 32a for rolling the rolling elements 4 in one side row between the first inner raceway surface 3a and is fixed in the recess 60b of the hub wheel 6. Has been. The outer raceway surface 32a is formed of a curvature surface that conforms to the spherical surface of the rolling element 4 in the vehicle outer side row.

  The inner ring 33 on the vehicle inner side has an outer raceway surface 33a for rolling the rolling elements 5 in the other side row between the second inner raceway surface 3b and a hub wheel adjacent to the inner ring 32 on the vehicle outer side. 6 is fixed in the recess 60b. The outer raceway surface 33a is formed of a curvature surface that matches the spherical surface of the rolling element 5 on the vehicle inner side.

On the other hand, in the outer ring 3, the ratio d ₂ / d ₁ between the track bottom diameter d ₁ of the first inner raceway surface 3 a and the track bottom diameter d ₂ of the second inner raceway surface 3 b is inequality d ₂ / d ₁ is 1. It is set to a ratio that satisfies ≦ d ₂ / d ₁ ≦ 1.1.

Further, in the double-row rolling elements 4 and 5, the rolling elements 4 in the vehicle outer side row and the rolling elements 5 in the vehicle inner side row have pitch diameters (the pitch circle diameter P ₁ of the rolling elements 4 in the vehicle outer side row). , Pitch circle diameters P ₂ : P ₁ > P ₂ ) of the rolling elements 5 in the vehicle inner side row are arranged different from each other. The sphere diameter D ₂ of the rolling elements 5 of the vehicle inner side row is set to larger than the sphere diameter D ₁ of the rolling elements 4 of the vehicle outer side row.

  Therefore, in the present embodiment, the peripheral speed does not change between the two grinding wheel portions 100a and 100b of the grinding wheel 100 during the production of the outer ring 3 as in the prior art, and the surface roughness of the inner raceway surfaces 3a and 3b after polishing is increased. There will be no difference.

[Effect of the second embodiment]
According to the second embodiment described above, the same effects as those shown in the first embodiment can be obtained.

  The bearing outer ring, the manufacturing method thereof, and the raceway surface grinding wheel of the present invention have been described based on the above embodiment, but the present invention is not limited to the above embodiment, and departs from the gist thereof. The present invention can be carried out in various modes as long as it is not, for example, the following modifications are possible.

  In the above-described embodiment, the case where the present invention is applied to a driven wheel bearing device has been described. However, the present invention is not limited to this, and the present invention can also be applied to a drive wheel bearing device in the same manner as the above embodiment.

DESCRIPTION OF SYMBOLS 1 ... Wheel bearing apparatus, 2 ... Inner member, 3 ... Outer ring, 3a ... 1st inner track surface, 3b ... Second inner track surface, 4 ... Rolling element of vehicle outer side row, 5 ... Vehicle inner side Rolling elements in row, 6 ... hub wheel, 6a ... large diameter barrel, 60a ... wheel mounting flange, 600a ... bolt insertion hole, 6b ... small diameter barrel, 60b ... concave, 6c ... step, 60c ... outside Track surface, 61c ... Seal surface, 6d ... First recess, 6e ... Second recess, 7 ... Inner ring, 7a ... Outer track surface, 7b ... Encoder mounting surface, 8 ... Bolt with serration, 9 ... Seal member, 10 , 11 ... Cage, 100 ... Grinding stone, 100a ... First grinding wheel part, 100b ... Second grinding wheel part, 200 ... Material, 200a ... First polishing target part, 200b ... Second polishing target part, 31 ... Wheel bearing device, 32 ... inner ring on vehicle outer side, 32a ... outer raceway surface, 3 ... the inner ring of the vehicle inner side, 33a ... outer raceway surface, O ... Rotation axis, O 1 _... axis, _{d 1, d} 2 _... orbital bottom diameter, _{D 1, D} 2 _... spherical diameter, _{P 1, P} 2 _... pitch circle diameter

Claims (4)

A first raceway surface that rolls rolling elements in one side row having a large pitch circle diameter among double row rolling elements formed by arranging a plurality of spheres in a circumferential direction having different pitch circle diameters; And a second raceway surface for rolling the rolling elements of the other side row having a small pitch circle diameter,
The second track surface has a ratio d ₂ / d ₁ between the track bottom diameter d ₂ and the track bottom diameter d ₁ of the first track surface of 1.1 ≧ d ₂ / d ₁ ≧ 1. An outer ring for a bearing formed of a raceway surface that rolls the rolling elements of the other side row having a spherical diameter larger than that of the rolling elements of the one side row.   2. The bearing outer ring according to claim 1, wherein the first raceway surface is formed by a raceway surface for rolling the number of rolling elements in the one side row larger than the number of rolling elements in the other side row. A method of polishing the material to be the outer ring for bearing according to claim 1 or 2, and manufacturing the outer ring for bearing,
A method of manufacturing an outer ring for a bearing, wherein the step of polishing the material to form the first raceway surface and the step of polishing the material to form a second raceway surface are performed in a single polishing step. A grindstone used in the method for manufacturing a bearing outer ring according to claim 3,
A first grindstone portion for polishing the material to form the first raceway surface;
A raceway surface grindstone comprising: a second grindstone portion that polishes the material to form a second raceway surface.

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