阅读说明：本技术 密封件的组装装置及密封件的组装方法 (Assembling device and assembling method for sealing member ) 是由 森田贤一 山崎大介 泽野充 上本隆文 于 2019-01-31 设计创作，主要内容包括：在车轮用轴承装置用的滚道构件(外圈构件)中,为了抑制密封件具有的唇部相对于密封面的过盈量的偏差,以滚动体为基准,将密封件安装到外圈构件的轴向的端部。组装装置(40)是用于将环状的密封件(15)通过压入而安装到车轮用轴承装置用的外圈构件(12)的轴向的端部(17)的装置。该组装装置(40)具备：柱状的引导构件(41),具有沿周向连续的接触面(44),该接触面(44)从在外圈构件(12)形成的外滚道面(12a)的相反侧与沿着该外滚道面(12a)设置的多个滚珠(13)接触；按压构件(42),在轴向上沿着引导构件(41)向所述轴向的端部(17)侧移动,从而沿轴向按压密封件(15)而将密封件(15)压入到轴向的端部(17)；基准构件(43),限制按压构件(42)相对于引导构件(41)的轴向的移动行程。(In a raceway member (outer ring member) for a wheel bearing device, a seal is attached to an axial end portion of the outer ring member with reference to rolling elements in order to suppress variation in interference between a lip portion of the seal and a seal surface. The assembly device (40) is a device for attaching an annular seal (15) to an axial end portion (17) of an outer ring member (12) for a wheel bearing device by press fitting. The assembly device (40) is provided with: a columnar guide member (41) having a contact surface (44) that is continuous in the circumferential direction, the contact surface (44) being in contact with a plurality of balls (13) that are provided along an outer raceway surface (12a) formed on an outer ring member (12) from the opposite side of the outer raceway surface (12 a); a pressing member (42) that moves in the axial direction along the guide member (41) toward the axial end (17) and presses the seal (15) in the axial direction to press the seal (15) into the axial end (17); and a reference member (43) that limits the axial movement stroke of the pressing member (42) relative to the guide member (41).)

1. An assembling device for a seal, which is used for mounting an annular seal to an axial end portion of a first raceway member for a wheel bearing device by press fitting, comprising:

a columnar guide member having a contact surface continuous in a circumferential direction, the contact surface being in contact with a plurality of rolling elements provided along a raceway surface formed on the first raceway member from an opposite side of the raceway surface;

a pressing member that moves along the guide member in an axial direction toward an end portion in the axial direction, and presses the seal in the axial direction to press the seal into the end portion in the axial direction; and

and a reference member that limits an axial movement stroke of the pressing member with respect to the guide member.

2. The seal assembly of claim 1,

the contact surface has the same specification as a raceway surface formed in the second raceway member for the wheel bearing device and contacting the rolling elements.

3. The seal assembly device of claim 1 or 2,

the rolling bodies are balls, and the rolling bodies are balls,

the guide member has a cylindrical guide surface provided near a radially inner side of each of the plurality of balls provided along the raceway surface, in addition to the contact surface.

4. The assembling device of a sealing member according to any one of claims 1 to 3,

the reference member has a reference surface capable of pressing the pressing member toward the first raceway member side and capable of coming into contact with an axial end surface of the guide member on a side opposite to a side where the contact surface is provided,

the moving stroke is a stroke from when the reference member presses the pressing member to when the reference member cannot press the pressing member due to the reference surface contacting the axial end face.

5. A method of assembling a seal, in which an annular seal is press-fitted and attached to an axial end portion of a first raceway member for a wheel bearing device, comprising the steps of:

a preparation step of arranging a plurality of rolling elements along a raceway surface formed on the first raceway member;

a fixing step of bringing a contact surface of a guide member into contact with the plurality of rolling elements from an opposite side of the raceway surface to make the first raceway member, the rolling elements, and the guide member in a state in which they cannot be displaced relative to each other; and

a press-fitting step of moving a pressing member in an axial direction toward an end portion side in the axial direction along the guide member, thereby pressing the seal member with the pressing member and press-fitting the seal member into the end portion in the axial direction,

in the press-fitting step, the pressing member is moved by a predetermined axial stroke relative to the guide member.

Technical Field

The present invention relates to a seal assembly device and a seal assembly method.

Background

In a vehicle such as an automobile, a wheel bearing device (hub unit) is used to support a wheel. The wheel bearing device includes an outer ring member (first raceway member), an inner shaft member (second raceway member), and a plurality of rolling elements arranged between the outer ring member and the inner shaft member. A seal is attached to the outer ring member in order to prevent impurities from entering between the outer ring member and the inner shaft member (inside the bearing in which the rolling elements are provided) from the outside on one axial side on which the wheel is mounted. The seal member has a lip portion made of rubber, and the lip portion is in contact with the sealing surface of the inner shaft member. Patent document 1 discloses a conventional vehicle bearing device.

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 2007-224941

Disclosure of Invention

Problems to be solved by the invention

Fig. 6 is a sectional view of the outer ring member and the seal. The seal 91 is press-fitted to an axial end 98 (hereinafter referred to as "outer ring end 98") of the outer ring member 99. When attached, the position of the seal 91 is controlled with reference to an end surface 97 (hereinafter referred to as "first end surface 97") of the outer ring end 98. When the mounting position of the seal 91 is deviated, interference of the lip 92 with respect to the seal surface 93 shown by a two-dot chain line in fig. 6 is deviated. When the interference of the lip 92 varies, the pressing force of the lip 92 against the seal surface 93 is not fixed for each product, and the sealing performance becomes uneven. Further, the torque (sliding friction torque) generated by the contact of the lip portion 92 with the seal surface 93 is not fixed.

Here, the interference (pressing force) of the lip 92 with the seal surface 93 is greatly affected by the relative position in the axial direction of the outer ring member 99 and the inner shaft member 94. Therefore, the mounting position of the seal 91 to the balls 95 may be managed with reference to the balls 95 interposed between the outer ring member 99 and the inner shaft member 94.

However, conventionally, as described above, the seal 91 is attached with reference to the first end face 97. In this case, the following elements 1 to 3 increase the variation in the relative position (dimension La in fig. 6) between the ball 95 and the seal 91 in the axial direction.

Element 1: a deviation due to a manufacturing error of the axial dimension Lb of the outer ring member 99.

Element 2: the deviation (dimension Lc) in the axial direction of the inner peripheral side outer raceway surface 96 of the outer ring member 99.

Element 3: the press-fitting position (dimension Ld) of the seal 91 is based on the first end surface 97 of the outer ring end 98.

That is, the axial dimension Lb of the element 1 is a distance between the first end surface 97 and an end surface 100 (hereinafter, referred to as "second end surface 100") on the opposite side in the axial direction. The first end surface 97 is polished with reference to the second end surface 100. Further, the outer raceway surface 96 of the element 2 is polished with the second end face 100 as a reference. Therefore, even if the seal 91 is pressed accurately with respect to the first end face 97, that is, even if the error in the dimension Ld of the element 3 is 0, if manufacturing errors occur in the position of the first end face 97 with respect to the second end face 100 (the first element) and the position of the outer raceway surface 96 with respect to the second end face 100 (the second element), the relative positions of the balls 95 and the seal 91 in the axial direction (the dimension La in fig. 6) vary. Sometimes the errors overlap and the deviation may increase. As a result, the interference of the lip 92 with the seal surface 93 varies.

Therefore, an object of an aspect of the present invention is to provide a seal assembly device capable of attaching a seal to an end portion in an axial direction of an outer ring member with reference to a rolling element in order to suppress variation in interference between a lip portion of the seal and a seal surface, and an assembly method performed by the assembly device.

Means for solving the problems

An aspect of the present invention relates to a seal assembly device for attaching an annular seal to an axial end portion of a first raceway member for a wheel bearing device by press fitting, the seal assembly device including: a columnar guide member having a contact surface continuous in a circumferential direction, the contact surface being in contact with a plurality of rolling elements provided along a raceway surface formed on the first raceway member from an opposite side of the raceway surface; a pressing member that moves along the guide member in an axial direction toward an end portion in the axial direction, and presses the seal in the axial direction to press the seal into the end portion in the axial direction; and a reference member that limits an axial movement stroke of the pressing member with respect to the guide member.

According to this assembly device, the contact surface of the guide member is brought into contact with the plurality of rolling elements provided along the raceway surface from the opposite side to the raceway surface, and the first raceway member, the rolling elements, and the guide member are prevented from being displaced relative to each other. The pressing member is moved in the axial direction along the guide member toward the end portion of the first raceway member in the axial direction, and the seal is pressed by the pressing member and is pressed into the end portion in the axial direction. At this time, the pressing member is moved in the axial direction by a predetermined movement stroke with respect to the guide member based on the reference member. Accordingly, the seal can be attached to the end portion in the axial direction of the first raceway member with reference to the rolling elements provided along the raceway surface of the first raceway member.

Preferably, the contact surface has the same specification as a raceway surface formed in the second raceway member for a wheel bearing device and contacting the rolling elements. With this configuration, the state in which the rolling elements are interposed between the first raceway member and the second raceway member of the wheel bearing device is reproduced in the assembly device using the guide member.

Preferably, the rolling elements are balls, and the guide member has a cylindrical guide surface provided on the radially inner side of each of the plurality of balls provided along the raceway surface, in addition to the contact surface. According to this configuration, the guide member, the plurality of balls, and the first track member are aligned.

Preferably, the reference member has a reference surface capable of pressing the pressing member toward the first track member and capable of contacting an axial end surface of the guide member on a side opposite to a side on which the contact surface is provided, and the moving stroke is a stroke from when the reference member presses the pressing member to when the reference member cannot press the pressing member due to the contact of the reference surface with the axial end surface. In this case, when the reference member presses the pressing member and the reference surface of the reference member comes into contact with the axial end surface of the guide member, the seal is mounted at a predetermined position at the axial end of the first raceway member.

The method for assembling a seal, in which an annular seal is press-fitted and attached to an axial end portion of a first raceway member for a wheel bearing device, includes: a preparation step of arranging a plurality of rolling elements along a raceway surface formed on the first raceway member; a fixing step of bringing a contact surface of a guide member into contact with the plurality of rolling elements from an opposite side of the raceway surface to make the first raceway member, the rolling elements, and the guide member in a state in which they cannot be displaced relative to each other; and a press-fitting step of moving a pressing member in an axial direction toward an end portion side in the axial direction along the guide member, thereby pressing the seal member with the pressing member and press-fitting the seal member to the end portion in the axial direction, wherein in the press-fitting step, the pressing member is moved by a predetermined axial stroke with respect to the guide member.

With this assembly method, the seal can be attached to the end portion in the axial direction of the first raceway member with reference to the rolling element in a state of being in contact with the raceway surface of the first raceway member. Also, the assembling method is performed by, for example, the assembling apparatus.

Effects of the invention

According to the aspect of the present invention, the seal can be attached to the end portion of the first raceway member in the axial direction with respect to the rolling element.

Drawings

Fig. 1 is a cross-sectional view showing an example of a wheel bearing device.

Fig. 2 is a sectional view illustrating the assembly apparatus (preparation step).

Fig. 3 is a sectional view illustrating the assembly apparatus (fixing step).

Fig. 4 is a sectional view illustrating the assembly apparatus (press-fitting step).

Fig. 5 is a sectional view illustrating the assembly apparatus (press-fitting step).

Fig. 6 is a sectional view of the outer ring member and the seal.

Detailed Description

[ concerning a bearing device for a wheel ]

Fig. 1 is a cross-sectional view showing an example of a wheel bearing device. The wheel bearing device (hub unit) 10 is attached to a suspension device (joint) provided on the vehicle body side of the automobile, and rotatably supports a wheel. The wheel bearing device 10 includes an outer ring member 12 as a first raceway member, an inner shaft member 11 as a second raceway member, balls 13 as rolling elements, a cage 14, a first seal 15 provided on one axial side, and a second seal 16 provided on the other axial side. In the wheel bearing device 10, the axial direction is a direction parallel to a central axis C0 (hereinafter, referred to as a bearing central axis C0) of the wheel bearing device 10. The radial direction is a direction orthogonal to the axial direction.

The outer ring member 12 has a cylindrical outer ring main body 21 and a fixing flange 22 extending radially outward from the outer ring main body 21. Outer raceway surfaces 12a and 12b are formed on the inner peripheral side of the outer ring body 21. The outer ring member 12 is attached to a knuckle (not shown) as a vehicle body side member via the flange portion 22, and the wheel bearing device 10 including the outer ring member 12 is fixed to a vehicle body. In a state where the wheel bearing device 10 is fixed to the vehicle body, the flange portion 27 side for wheel attachment, which will be described later, of the inner shaft member 11 is located on the vehicle outer side. That is, one axial side on which the flange portion 27 is provided is a vehicle outer side, and the other axial side opposite thereto is a vehicle inner side.

The inner shaft member 11 has a hub shaft (inner shaft) 23 and an inner ring 24 attached to the other axial side of the hub shaft 23. The hub axle 23 includes a shaft body portion 26 provided radially inward of the outer ring member 12 and a flange portion 27 provided on one axial side of the shaft body portion 26. The shaft portion 26 is a shaft portion that is long in the axial direction. The flange portion 27 extends radially outward from one axial side of the shaft portion 26. A wheel and a brake disk (not shown) are attached to one surface (flange surface) 31 of the flange 27 in the axial direction. A seal surface 29 is provided between the shaft body portion 26 and the flange portion 27.

The inner race 24 is an annular member and is fitted and fixed to the small diameter portion 39 on the other axial side of the shaft portion 26. A (first) inner raceway surface 11a is formed on the outer peripheral surface of the shaft body portion 26, and a (second) inner raceway surface 11b is formed on the outer peripheral surface of the inner race 24.

A plurality of balls 13 are arranged between the outer raceway surface 12a and the inner raceway surface 11a on one axial side. A plurality of balls 13 are arranged between the outer raceway surface 12b and the inner raceway surface 11b on the other axial side. The balls 13 are arranged in two rows between the outer ring member 12 and the inner shaft member 11. The outer raceway surfaces 12a and 12b and the inner raceway surfaces 11a and 11b have concave circular arc shapes in cross section, respectively. The balls 13 are in point contact with the outer raceway surfaces 12a and 12b and the inner raceway surfaces 11a and 11b, respectively, with a contact angle therebetween.

The first seal 15 is attached to an end portion 17 (hereinafter referred to as "outer ring end portion 17") on one axial side of the outer ring member 12. As shown in an enlarged view in fig. 1, the first seal 15 includes a metal core rod 35 and rubber lips 30a and 30b fixed to the core rod 35. On the inner shaft member 11 side, the seal surface 29 includes an annular seal surface 29a, a cylindrical seal surface 29b, and a rounded surface 29 c. The annular seal surface 29a contacts a lip portion 30a of the seal 15 extending toward the flange portion 27. The cylindrical seal surface 29b faces a lip portion 30b of the seal 15 extending toward the shaft body portion 26 side. The annular seal surface 29a is a surface that is generally perpendicular to the bearing center axis C0. The cylindrical seal surface 29b is a surface along a cylindrical surface parallel to the bearing center axis C0 as a whole. The rounded surface 29c is a surface connecting the annular seal surface 29a and the cylindrical seal surface 29 b. The first seal 15 prevents impurities such as muddy water from entering the bearing provided with the balls 13 from between the outer ring member 12 and the inner shaft member 11 on one axial side. The second seal 16 prevents impurities such as muddy water from entering the bearing from between the outer ring member 12 and the inner shaft member 11 on the other axial side.

[ concerning the assembly device 40 ]

Fig. 2 is a sectional view illustrating an assembling apparatus 40 for press-fitting an annular first seal 15 (hereinafter, simply referred to as "seal 15") to the outer ring end 17. The assembly device 40 includes a guide member 41, a pressing member 42, and a reference member 43.

The postures of the outer ring member 12 and the assembling device 40 when the seal 15 is attached to the outer ring end 17 will be described. In the present embodiment, the seal 15 is attached to the outer ring end 17 in a state where the outer ring member 12 is in the posture shown in fig. 2. That is, the mounting work is performed in a state where the center axes of the outer ring member 12 and the seal 15 are aligned with the vertical direction. In the assembly apparatus 40, the center axes of the guide member 41, the pressing member 42, and the reference member 43 are aligned. The center axis (the center axis of the assembly device 40) and the center axes of the outer ring member 12 and the seal 15 are set to the same reference line C1, and the mounting operation is performed. When the seal 15 is attached, the outer ring member 12 is placed on a work table, not shown. Further, a plurality of balls 13 are provided along the outer raceway surface 12a on one axial side of the outer race member 12. These balls 13 are held by the cage 14 at intervals in the circumferential direction. In this state, the seal 15 is attached to the outer ring end 17 by press fitting.

The structure of each part of the assembly apparatus 40 will be described. The guide member 41 is a column member, and has a linear cylindrical shape in the present embodiment. The guide member 41 has a small diameter portion 45, an intermediate diameter portion 46, and a large diameter portion 47 in this order from the lower side. The small diameter portion 45 has a smaller outer diameter than the medium diameter portion 46. The medium diameter portion 46 has a smaller outer diameter than the large diameter portion 47. The large diameter portion 47 has an axial end surface 48 at an upper end. The axial end surface 48 is a surface perpendicular to the central axis of the guide member 41 (the reference line C1). An annular stepped surface 49 is provided between the large diameter portion 47 and the intermediate diameter portion 46.

The diameter D1 of the outer peripheral surface 46a of the intermediate diameter portion 46 is (approximately) the same as the pitch circle diameter (pcd) of the plurality of balls 13 provided along the outer raceway surface 12 a. The diameter D2 of the outer peripheral surface 45a of the small diameter portion 45 is smaller than the pitch circle diameter (pcd) of the ball 13. The intermediate diameter portion 46 has a contact surface 44 continuous in the circumferential direction with the small diameter portion 45 side. The contact surface 44 of the present embodiment is a tapered surface. Therefore, the contact surface 44 can be in contact with the plurality of balls 13 provided along the outer raceway surface 12a over the entire circumference (see fig. 3). When the contact surface 44 contacts all of the plurality of balls 13, the guide member 41 cannot move axially downward and is positioned in the axial direction.

The contact surface 44 has the same specification as the inner raceway surface 11a of the inner shaft member 11 for the wheel bearing device 10 shown in fig. 1. The specifications are at least the pitch circle diameter (pcd) of the ball 13 to be contacted (see fig. 2) and the distance r from the point Q1 on the pitch circle of the ball 13 to be contacted to the contact point Q2 with the ball 13. The actual inner raceway surface 11a has a concave circular arc shape in cross section as described above. In the inner raceway surface 11a, the distance r is a radius of curvature thereof.

In this way, the guide member 41 has a circumferentially continuous surface, i.e., the contact surface 44. As shown in fig. 3, the contact surface 44 contacts the plurality of balls 13 provided along the outer raceway surface 12a from the opposite side of the outer raceway surface 12 a.

In the guide member 41, an axial dimension L1 from a contact position (contact point Q2) of the contact surface 44 with the ball 13 to the axial end surface 48, which is a surface on the opposite side in the axial direction from the side on which the contact surface 44 is provided, is set to a predetermined value. The contact surface 44 and the axial end surface 48 are machined (e.g., ground), and the axial dimension L1 is highly accurate.

The small diameter portion 45 of the guide member 41 further has a cylindrical guide surface 50 on the outer circumferential side, which can be in contact with the balls 13. In the present embodiment, the guide surface 50 is formed by the outer peripheral surface 45a of the small diameter portion 45. The diameter D2 of the guide surface 50 is slightly smaller than the diameter D3 of the inscribed circle of the plurality of balls 13 provided along the outer raceway surface 12 a. Therefore, as shown in fig. 3, the guide surface 50 is provided close to the radially inner side of each of the plurality of balls 13 provided along the outer raceway surface 12 a.

In fig. 2, the pressing member 42 is a linear cylindrical member that is fitted to the guide member 41 (the large diameter portion 47 and the medium diameter portion 46) with a gap. In the present embodiment, the pressing member 42 and the reference member 43 are separate members, but are integrally connected by a connecting member not shown. The pressing member 42 is movable along the guide member 41 (in the linear direction of the reference line C1).

The pressing member 42 includes, in order from the lower side, a first cylindrical portion 61 having a large inner diameter (maximum), a second cylindrical portion 62 having a minimum inner diameter, and a third cylindrical portion 63 having a larger inner diameter than the second cylindrical portion 62. An annular receiving surface 64 is provided between the second cylindrical portion 62 and the third cylindrical portion. The stepped surface 49 of the guide member 41 can be in contact with the receiving surface 64. The guide member 41 is suspended from the pressing member 42 by the contact of the stepped surface 49 with the receiving surface 64. The guide member 41 and the pressing member 42 are relatively movable in the axial direction between the receiving surface 64 and the reference surface 55 of the reference member 43. The seal 15 attached to the outer ring end 17 is held at an end (first cylindrical portion 61) of the pressing member 42 in the axial direction by a holding mechanism (not shown). In a state where the seal 15 is held at the axial end portion (the first cylindrical portion 61) of the pressing member 42, the inner diameter of the seal 15 (the inner diameter of the lip portion 30 b) is in a relationship larger than the diameter D1 of the outer peripheral surface 46a of the intermediate diameter portion 46 of the guide member 41.

The pressing member 42 (first cylindrical portion 61) has an annular pressing portion 65 at an end (lower end) in the axial direction. The pressing portion 65 axially contacts the seal 15, and axially presses the seal 15. The seal 15 is pressed in the axial direction (downward in the present embodiment) by the pressing portion 65, and the seal 15 is pressed into the outer ring end portion 17 as shown in fig. 4 to 5. Fig. 4 shows a starting state in which pressing-in of the seal 15 to the outer ring end 17 is started. Fig. 5 shows a completed state in which the press-fitting of the seal 15 to the outer ring end 17 is completed. The sealing member 15 is fixed at the position where the press-fitting is completed. Thus, the pressing member 42 moves along the guide member 41 toward the outer ring end 17 in the axial direction, and the seal 15 can be pressed into the outer ring end 17 by pressing the seal 15 in the axial direction.

In fig. 2, an axial dimension L2 from an axial end surface (upper surface) 42b of the pressing member 42 to a distal end surface 65a of the pressing portion 65 is set to a predetermined value. The axial end face 42b and the distal end face 65a are machined (e.g., polished), and the accuracy of the axial dimension L2 is high.

The reference member 43 is a disk-shaped member. The reference member 43 is linearly movable (vertically movable in the present embodiment) along the reference line C1 by an actuator (not shown). The reference member 43 has a reference surface 55 and a pressing surface 56 on the lower surface side. The pressing surface 56 contacts and presses the axial end surface 42b of the pressing member 42. By this pressing, as shown in fig. 4 to 5, the seal 15 is pressed into the outer ring end 17.

The reference member 43 is lowered by the actuator, and as shown in fig. 5, the reference surface 55 comes into contact with the axial end surface 48 of the guide member 41. When the reference surface 55 comes into contact with the axial end surface 48, the reference member 43 cannot move any more in the axial direction (lower side). At this point, the movement (lowering) of the reference member 43 by the actuator is stopped. For example, when the reference member 43 cannot move, the load of the actuator increases, and therefore the load detection sensor provided in the actuator detects this and stops the operation of the actuator.

Both the reference surface 55 and the pressing surface 56 are machined (e.g., polished), and the accuracy of vibration or the like with reference to the reference line C1 is high. In the present embodiment, the pressing surface 56 and the reference surface 55 are provided on a common plane, but may be provided on different planes.

Thus, the reference member 43 can press the pressing member 42 toward the outer ring member 12 side. The reference member 43 has a reference surface 55, and the reference surface 55 is contactable with the axial end surface 48 of the guide member 41 on the side opposite to the side on which the contact surface 44 is provided.

[ concerning the assembling method ]

A method of assembling the seal 15 by the assembling device 40 having the above-described structure will be described. The assembling method includes a preparation step (see fig. 2), a fixing step (see fig. 3), and a press-fitting step (see fig. 4 and 5). The method comprises a preparation step, a fixing step and a pressing step.

[ preparation step ]

In the preparation step, as shown in fig. 2, the plurality of balls 13 are arranged along the outer raceway surface 12a of the outer ring member 12. The plurality of balls 13 are held by a cage 14. The outer ring member 12 is placed on the table with its center axis in the vertical direction. This state is referred to as a first state.

[ fixed step ]

From the first state, the reference member 43 is lowered together with the guide member 41 and the pressing member 42. As shown in fig. 3, the contact surface 44 of the guide member 41 is in a state of contact with the ball 13 (second state). At this time, the guide surface 50 of the guide member 41 is guided by the plurality of balls 13, and the plurality of balls 13 are guided by the guide surface 50, thereby aligning the guide member 41, the plurality of balls 13, and the outer ring member 12. In the second state, the contact surface 44 is in contact with the plurality of balls 13. In this second state, the contact surface 44 may be in contact with all of the balls 13, but may be in contact with a part (a plurality of) of all of the balls 13 in the circumferential direction. Thus, the plurality of balls 13 are pressed by the contact surface 44 and contact the outer raceway surface 12 a. Therefore, the guide member 41 cannot move axially downward and is positioned in the axial direction. And is also positioned in the radial direction. In this way, in the fixing step, the contact surface 44 of the guide member 41 is brought into contact with the plurality of balls 13 from the opposite side of the outer raceway surface 12a, and the outer ring member 12, the plurality of balls 13, and the guide member 41 are set in a state in which they cannot be displaced relative to each other.

[ Press-in step ]

The axial dimension E of the space K1 formed between the reference surface 55 of the reference member 43 and the axial end surface 48 of the guide member 41 does not change (is fixed) from the first state shown in fig. 2 to the second state shown in fig. 3. When the reference member 43 is further lowered from the second state, the axial dimension E of the space K1 gradually decreases (see fig. 4). Fig. 4 shows a third state in which the reference member 43 presses the pressing member 42, and the pressing member 42 starts pressing the seal 15 into the outer ring end 17. When the reference member 43 is further lowered from the third state, the pressing member 42 moves along the guide member 41, and the seal 15 is pressed by the pressing member 42. In this way, in the press-fitting step, the pressing member 42 is moved in the axial direction toward the outer ring end portion 17 along the guide member 41, and the seal 15 is press-fitted to the outer ring end portion 17 by the pressing member 42 pressing the seal 15.

When the reference member 43 is lowered from the third state shown in fig. 4, the reference surface 55 is brought into contact with the axial end surface 48 as shown in fig. 5 immediately after that, and the axial dimension E of the space K1 becomes 0. This state is the fourth state. The reference member 43 cannot move toward the outer race end portion 17 side by the contact of the reference surface 55 with the axial end surface 48. Therefore, the movement of the pressing member 42 that moves integrally with the reference member 43 with respect to the guide member 41 is stopped. In this way, the axial movement stroke of the pressing member 42 with respect to the guide member 41 is limited by the reference member 43. The moving stroke is set to a value at which the axial dimension E of the space K1 becomes 0. That is, in the press-fitting step, the pressing member 42 is moved by a predetermined axial stroke (a value until the direction dimension E becomes 0) with respect to the guide member 41.

The moving stroke of the pressing member 42 limited by the reference member 43 is further explained. This moving stroke is a stroke from when the reference member 43 presses the pressing member 42 (when the third state shown in fig. 4 is started) to when the reference member 43 cannot press the pressing member 42 due to the contact of the reference surface 55 with the axial end surface 48 as shown in fig. 5. More specifically, the movement stroke is a stroke from the start of the pressing member 15 by the pressing member 42 by the reference member 43 (from the third state shown in fig. 4) to the point where the pressing member 42 cannot be pressed by the reference member 43 because the reference surface 55 comes into contact with the axial end surface 48 as shown in fig. 5.

The position of the seal 15 pressed into the outer ring end 17 by the press-fitting step is a predetermined press-fitting position. As described above, in the guide member 41, the axial dimension L1 from the contact position (contact point Q2) of the contact surface 44 with the ball 13 to the axial end surface 48 is set to a predetermined value. Further, in the pressing member 42, an axial dimension L2 from the axial end surface (upper surface) 42b to the distal end surface 65a of the pressing portion 65 is set to a predetermined value. Therefore, according to the assembling device 40 of the present embodiment, the seal 15 is attached to a predetermined position of the outer ring end portion 17 with reference to the balls 13 in a state of being in contact with the outer raceway surface 12 a.

The axial dimension L1 and the axial dimension L2 are highly accurate as described above. Therefore, the seal 15 is mounted at an accurate position on the outer race end 17 with reference to the balls 13 in a state of being in contact with the outer race surface 12 a. In the fourth state, the pressing member 42 is not in contact with the outer ring end 17.

[ Assembly device 40 of the present embodiment ]

According to the assembly device 40 having the above-described configuration, the contact surface 44 of the guide member 41 contacts the plurality of balls 13 provided along the outer raceway surface 12a of the outer ring member 12 from the opposite side of the outer raceway surface 12a (see fig. 3). Accordingly, the outer ring member 12, the balls 13, and the guide member 41 are in a state in which they cannot be displaced relative to each other. The pressing member 42 is moved in the axial direction toward the outer race end 17 along the guide member 41 (see fig. 4 and 5). Thus, the seal 15 is pressed by the pressing member 42 and is press-fitted into the outer ring end portion 17. At this time, the pressing member 42 is moved in the axial direction by a predetermined movement stroke with respect to the guide member 41 by the reference member 43. Accordingly, the seal 15 can be attached to the outer race end portion 17 with reference to the balls 13 provided along the outer race surface 12 a.

In the fourth state shown in fig. 5, the reference member 43 is in a state of pressing the guide member 41 toward the balls 13. Therefore, the assembled state in which the balls 13 are interposed between the outer ring member 12 and the inner shaft member 11 of the wheel bearing device 10 (see fig. 1) is reproduced in the assembling device 40. In the assembling device 40, the balls 13 have a predetermined angle (contact angle) with respect to a plane perpendicular to the reference line C1, and are in contact with the outer raceway surface 12a and the contact surface 44. Therefore, the axial dimension from the seal 15 (the lip portion 30a) to the seal surface 29 (see fig. 1) has a predetermined value. According to this assembly apparatus 40, the mounting position of the seal 15 with respect to the ball 13 is fixed for each product.

The outer ring member 12 to which the seal 15 is attached in this way is combined with the inner shaft member 11, and the axial dimension from the seal 15 (the lip portion 30a) to the seal surface 29 (see fig. 1) is a predetermined value. As a result, the variation in the interference of the lip portion 30a with respect to the seal surface 29 can be suppressed. Therefore, the pressing force of the lip portion 30a against the seal surface 29 is constant for each product, and the sealing performance is uniformed. Further, the torque (sliding friction torque) generated by the contact of the lip portion 30a with the seal surface 29 is constant. By setting the torque to be small, loss due to friction can be suppressed.

In the present embodiment, as described above, the contact surface 44 of the guide member 41 has the same specification as the inner raceway surface 11a formed on the outer peripheral side of the inner shaft member 11 and in contact with the balls 13 shown in fig. 1. Therefore, the state in which the balls 13 are interposed between the outer ring member 12 and the inner shaft member 11 of the wheel bearing device 10 is reproduced by the assembly device 40 using the guide member 41. As a result, the seal 15 can be more accurately attached to the outer ring end 17.

Since the contact surface 44 of the guide member 41 has the same specification as the inner raceway surface 11a, although not shown, the guide member 41 may be divided into separate structures and the inner ring 24 (a structure in which the inner ring 24 is additionally machined) may be used as a part of the guide member 41. However, in this case, the first inner raceway surface 11a and the second inner raceway surface 11b need to have the same specifications.

The guide member 41 may be constituted by a split body that is split into a plurality of pieces in the circumferential direction. In this case, the contact surface 44 continuous in the circumferential direction of the guide member 41 is constituted by joining the divided bodies together.

The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is not limited to the above-described embodiments, and includes all modifications within the scope equivalent to the structure described in the claims. The rolling elements provided between the inner shaft member 11 and the outer ring member 12 may be rollers (tapered rollers) other than the balls 13. The wheel bearing device to which the seal 15 is assembled by the assembling device 40 of the present embodiment may be other than the one shown in fig. 1. For example, although not shown, the present invention can also be applied to a wheel bearing device in which a wheel and a brake disk are attached to the outer ring member 12 and the inner shaft member 11 is attached to the vehicle body side.

The present application is based on the japanese patent application filed on 2/1 in 2018 (japanese patent application 2018-016529), the contents of which are incorporated herein by reference.

Description of the reference symbols

10: wheel bearing device 11: inner shaft component (second raceway component)

11 a: inner raceway surface 12: outer ring component (first raceway component)

12 a: outer raceway surface (raceway surface) 13: rolling ball (Rolling element)

15: sealing member 17: end (outer ring end)

41: the guide member 42: pressing member

43: reference member 44: contact surface

48: axial end face 50: guide surface

55: datum plane