JP2008095911A - Ball bearing and manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small ball bearing capable of bearing a small diameter shaft. <P>SOLUTION: The ball bearing comprises an outer ring, a spherical member, and a plurality of retainer members, the outer ring including two or more lines of recessed groove raceways formed on the inside thereof for supporting the spherical members to be rollable over the whole circumference. An open part allowing entrance and exit of the retainer member to and out of the outer ring is formed on at least one axial side of the hollow part of the outer ring. Each retainer is formed of an elastically deformable material, and the retainer member includes a hallow part for retaining the spherical member. The hallow part includes a narrow diameter part narrowed more than the diameter of the spherical member in the side separating from the outer ring. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a simple ball bearing having no inner ring and a method for manufacturing the same, in which an outer ring can rotatably support a shaft member via a spherical member.

Conventional general ball bearings are in contact with the inner ring surface of the outer ring and the outer ring in which the grooved raceway is formed over the entire circumference of the inner diameter part so that the spherical member can roll. A spherical member, a retainer member that holds the spherical member, and an inner ring having a groove groove formed on the entire outer circumference so that the spherical member can roll (for example, a patent) Reference 1).
JP 2001-81492 A

Recently, with the increasing demand for small ball bearings for bearing small-diameter shafts, the limitations of conventional general ball bearing configurations described above have been pointed out, and it is extremely difficult to provide ball bearings that meet the above requirements. Was in the situation. In order to meet the above requirements, the applicant considered eliminating the inner ring and configuring the ball bearing with the configuration of the outer ring, the spherical member, and the retainer member. In this way, it is possible to reduce the portion occupied by the inner ring, to make it smaller, and to configure a small ball bearing that supports a smaller-diameter shaft.
However, such ball bearings have the following drawbacks because there is no inner ring. That is,

(1) In the bearing that has eliminated the inner ring, it is assembled once in the state of the outer ring + spherical member + retainer member, and then the inner shaft is assembled. In a conventional ball bearing with both inner and outer rings, the circumferential positioning of the ball member is performed by the retainer member, and the radial ball is held without any problem by sandwiching it with the inner and outer rings. I was able to hold. However, in the bearings that do not use the inner ring described above, the spherical ring member cannot be sufficiently held in the state of the outer ring + spherical member + retainer member before the inner shaft is assembled. become.

(2) When supporting the shaft member inserted inside the spherical member, the inner ring has a sufficient width in the axial direction in the case of having a conventional inner ring, so it is inserted inside the spherical member. The shaft member that was inserted could be stably supported without displacement in the axial direction, but the shaft member inserted inside the spherical member was a shaft if the inner ring was eliminated. It tends to be inclined with respect to the direction, and the axis of the shaft member tends to be displaced.
An object of the present invention is to solve these problems and to provide a small ball bearing capable of bearing a small-diameter shaft by constituting a ball bearing without an inner ring.

In order to achieve the above object, the present invention includes an outer ring, a spherical member arranged in contact with the inner diameter portion of the outer ring, and a retainer member that holds the spherical member, and the shaft member can be rotated relative to the outer ring via the spherical member. A ball bearing that does not have an inner ring that can be supported by the outer ring, and that the spherical member is allowed to roll over the entire circumference of the inner diameter portion of the outer ring. A plurality of rows of concave groove tracks for supporting the outer ring, and an open portion that allows the retainer member to freely enter and exit the outer ring on at least one axial side of the hollow portion of the outer ring. A plurality of retainer members are provided corresponding to the grooves, and each retainer member is made of an elastically deformable material. Each retainer member is provided with a space portion for holding the spherical member, and at least the outer ring is provided in the space portion. On the side away from It is provided with a small diameter which is smaller than the diameter of the serial spherical member.
The present invention also relates to a method of manufacturing a ball bearing having no inner ring that can rotatably support a shaft member via a spherical member on an outer ring, the spherical member and an inner diameter portion extending over the entire circumference. The spherical member has a plurality of rows of groove grooves for supporting the spherical member in the axial direction and the radially outward direction so that the spherical member can roll, and the retainer member is disposed at least on one side in the axial direction of the inner hollow portion. Elasticity having an outer ring having an open part that allows entry and exit, and a space part for holding a spherical member, and a narrow-diameter part that is narrower than the diameter of the spherical member at least on the side away from the outer ring. A plurality of retainer members made of a deformable material, the step of holding the spherical member in the space of each retainer member, and an inner diameter portion of the outer ring formed in at least one axial direction. From the open part A step of inserting one of the plurality of retainer members together with the spherical member, and further inserting the retainer member together with the spherical member to a position where the spherical member coincides with the corresponding concave groove track of the outer ring. Inserting the remaining retainer member into the inner ring portion of the outer ring, and further inserting the remaining retainer member into the inner ring portion of the outer ring until the spherical member that holds the retainer member fits into the corresponding groove groove of the outer ring. The plurality of retainer members are assembled to the outer ring together with the spherical member by the step of pushing into the outer ring.
Further, according to the present invention, the space portion that holds the spherical member provided in each retainer member has a narrow-diameter portion that is narrower than the diameter of the spherical member on both the side away from the outer ring and the side closer to the outer ring. Is provided.

Since the present invention does not have an inner ring, a small diameter shaft can be supported, and it can be manufactured in a small size and at a low cost. Further, in a ball bearing without an inner ring, since the spherical member cannot be stably held before the retainer member and the spherical member are inserted into the inner diameter portion of the outer ring, the assembly is not easy. Since the assembly is completed only by inserting the retainer member + the spherical member into the inner diameter portion of the outer ring, the assembly is extremely simple. Further, since the retainer members are arranged in a plurality of rows, the shaft member inserted inside can be stably supported, and the axial line of the shaft member is not displaced.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 shows a cross-sectional view of a simple ball bearing 2 suitable for a small-diameter shaft bearing according to the present invention. The ball bearing 2 includes an outer ring 4, two retainer members 6 and 7 having the same structure, and a spherical member 8 made of a steel ball or the like, and has no inner ring. Opening portions 10 and 12 are formed on the left and right sides of the cylindrical hollow portion of the outer ring 4 so that the retainer member 6 can be inserted in the axial direction from either the left or right direction.

The outer ring 4 is composed of a cylindrical member, and in this embodiment, the outer ring 4 uses polyacetal (POM). Since the outer ring 4 does not need to be particularly deformed, various materials such as metal can be used. Two rows of concave groove tracks 14 and 15 having an arc-shaped cross section are formed over the entire circumference at positions spaced from both ends of the inner diameter portion of the outer ring 4. In addition, the cross-sectional shape of the concave groove tracks 14 and 15 is not limited to the circular arc shape, and various shapes such as a tapered inclined surface are conceivable. The concave groove tracks 14 and 15 are configured to support the spherical member 8 in the axial direction and the radially outer direction so that the spherical member 8 can roll. These groove grooves 14 and 15 are not particularly limited to the two-row arrangement, and a plurality of rows can be provided on the outer ring 4, and a retainer member can be provided corresponding to the number of rows. The retainer members 6 and 7 are constituted by cylindrical members made of a resin such as nylon that can be elastically deformed.

The retainer members 6 and 7 are set to a size that can be inserted into the inner diameter portion of the outer ring 4 with a slight gap. A plurality of space portions 16 are formed in the retainer members 6 and 7 at substantially equal intervals, and the spherical member 8 can be held in each space portion 16. The space portion 16 is formed by a concave curved wall surface having substantially the same curvature as the spherical surface of the spherical member 8 and opened in the radial direction of the retainer member 6, and is formed on the outer peripheral surface of the retainer member 6 in the space portion 16. The opening side and the side opening to the inner peripheral surface of the retainer member 6 on the opposite side are the narrow diameter portion 16a narrower than the diameter of the spherical member 8 on the side approaching the outer ring 4, and the outer ring 4 It has a narrow-diameter portion 16b that is narrower than the diameter of the spherical member 8 on the far side.

FIG. 1 shows a state in which two retainer members 6, 7 are assembled to the outer ring 4. A spherical member 8 is rotatably held in each space 16 of the retainer members 6, 7, and a part of each spherical member 8 is shown. Are fitted in the plural rows of concave grooves 14 and 15 of the outer ring 4.
Next, an assembly manufacturing process of the ball bearing 2 will be described with reference to FIG.

"First step"
Prepare the outer ring 4, the two retainer members 6 and 7, and the required number of spherical members 8 (see FIG. 3A), and push the spherical member 8 into each space 16 of the retainer members 6 and 7. The spherical member 8 is inserted and arranged. The spherical member 8 inserted into each space portion 16 of the retainer members 6, 7 is prevented from coming off from the space portion 16 in the radial direction of the retainer members 6, 7 by the narrow diameter portions 16 a, 16 b of the space portion 16. It is held by the retainer members 6 and 7 (see FIG. 3B).

"Second process"
The two retainer members 6 and 7 are inserted into the inner diameter portion of the outer ring 4 from the retainer member opening portions 10 and 12 formed in the axial direction together with the spherical member 8 (see FIG. 3C). At the time of this insertion, the spherical member 8 is pushed by the inner diameter portion of the outer ring 4, and the retainer members 6 and 7 are deformed against the elasticity by this pressing force, and move in the direction of the central axis of the outer ring 4.

"3rd process"
The retainer members 6 and 7 together with the spherical member 8 are inserted further inwardly of the outer ring 4 until the spherical member 8 coincides with the corresponding concave groove tracks 14 and 15 of the outer ring 4. By this process, the spherical member 8 moves radially outward due to the return stress due to the deformation of the retainer members 6 and 7, and fits into the corresponding concave groove tracks 14 and 15 of the outer ring 4 (see FIG. 3D). .
The work of fitting the retainer member 6 to the outer ring 4 is performed using an appropriate tool.

  The assembly of the ball bearing 2 is completed by the above process. When the shaft member 18 is mounted on the ball bearing 2, the shaft member 18 is inserted into the inner diameter portion of the retainer members 6 and 7, as shown in FIG. By inserting the shaft member 18, the inner peripheral surfaces of the concave groove tracks 14 and 15 of the outer ring 4 and the spherical member 8 are arranged to face each other with an appropriate interval. In this state, the shaft member 18 is in point contact with the spherical member 8 at two positions having a predetermined interval in the axial direction, and is supported by the outer ring 4 through the spherical member 8 so as to be rotatable.

  As shown in FIG. 5, a ring-shaped inner wall portion 4b having a wall surface perpendicular to the axial direction and capable of locking the retainer members 6 and 7 is provided at the center of the inner diameter portion of the outer ring 4. May be. In the above embodiment, the opening portions 10 and 12 that open the retainer members 6 and 7 in the axial direction are formed on both sides of the outer ring 4 in the axial direction. However, as shown in FIG. It is good also as a structure which formed only in one side of this and formed the bottom wall part 4a integrally in the other side.

The bottom wall portion 4a is formed in a plane perpendicular to the axial direction of the outer ring 4, and a hole for loosely arranging the shaft member 18 is formed in the center portion. As shown in FIG. 6, when the outer ring 4 is made of a single wall, the outer ring 4 of the ball bearing 2 is fitted and disposed on the external member 20 for supporting the ball bearing 2, as shown in FIG. 6. The inner stopper surface 22 of the external member 20 can be received by the wall surface of the bottom wall portion 4a.

When the plastic external member 20 that supports the ball bearing 2 is made into a bottomed type as shown in FIG. 6, the thickness of the external member 20 is made uniform in order to prevent deformation due to expansion and contraction during plastic molding. It is necessary to do the meat removal on the bottom wall. A tubular ridge 24 is formed on the bottom wall by this thinning. If the bottom wall portion 4 a does not exist on the outer ring 4 side, the stopper end surface 22 of the protrusion 24 abuts on the end surface of the retainer member 7, and the ball is caused by frictional resistance between the retainer member 7 and the end surface of the protrusion 24. This adversely affects the rotation guide performance of the bearing 2.

However, this problem can be solved by providing the bottom wall portion 4 a on one side of the outer ring 4. Further, by providing the bottom wall portion 4 a on one side of the outer ring 4, it is possible to reduce the entry of dust into the outer ring 4. Other configurations of the inner wall type ball bearing 2 shown in FIG. 5 and the single wall type ball bearing 2 shown in FIG. 6 are the same as those of the embodiment shown in FIG. Corresponding relationships are shown with reference numerals. Moreover, the assembly manufacturing process of the inner wall type ball bearing 2 shown in FIG. 5 is the same as the assembly manufacturing process of the ball bearing 2 of the first embodiment as shown in FIG.
Next, an assembly manufacturing process of the single wall type ball bearing 2 will be described below with reference to FIG.

"First step"
Prepare the outer ring 4, the two retainer members 6 and 7, and the required number of spherical members 8 (see FIG. 7A), and push the spherical member 8 into each space 16 of the retainer members 6 and 7. The spherical member 8 is inserted and arranged. The spherical member 8 inserted into each space portion 16 of the retainer members 6, 7 is prevented from coming off from the space portion 16 in the radial direction of the retainer members 6, 7 by the narrow diameter portions 16 a, 16 b of the space portion 16. It is held by the retainer members 6 and 7 (see FIGS. 7A and 7B).

"Second process"
One retainer member 7 is inserted in the inner direction of the outer ring 4 together with the spherical member 8 from the retainer member opening 10 formed on one side of the outer ring 4 in the axial direction (see FIG. 7C). ). At the time of this insertion, the spherical member 8 is pushed by the inner diameter portion of the outer ring 4, and the retainer member 7 is deformed against the elasticity by this pressing force and moves in the direction of the central axis of the outer ring 4.

"3rd process"
The retainer member 7 is inserted together with the spherical member 8 inward of the outer ring 4 until the spherical member 8 coincides with the concave groove track 14 in front of the outer ring 4 (see FIG. 7D). At this time, due to the return stress due to the deformation of the retainer members 6, 7, the spherical member 8 moves radially outward and fits into the concave groove track 14 of the outer ring 4.

"4th process"
Next, the retainer member 7 together with the spherical member 8 is pushed further inwardly of the outer ring 4. At this time, the spherical member 8 held by the retainer member 7 is detached from the groove track 14 with the movement of the retainer member 7 (see FIG. 7E).

"5th process"
Together with the spherical member 8, the retainer member 7 is inserted further in the direction toward the bottom wall 4 a of the outer ring 4 until the spherical member 8 matches the groove groove 15 on the bottom wall 4 a side of the outer ring 4. When the spherical member 8 coincides with the concave groove track 15, the spherical member 8 moves radially outward due to the return stress caused by the deformation of the retainer member 7, and is fitted into the concave groove track 15 of the outer ring 4 (FIG. 7F). reference).

"6th process"
The remaining retainer member 6 is inserted into the inner direction of the outer ring from the opening 10 of the outer ring 4 together with the spherical member 8 (see FIG. 7G).
"Seventh process"
Further, the retainer member 6 is pushed inward of the outer ring 4 so that the spherical member 8 is aligned with the concave groove track 14. At this time, due to the return stress due to the deformation of the retainer members 6, 7, the spherical member 8 moves in the radially outward direction and fits into the corresponding groove groove 14 in front of the outer ring 4 (see FIG. 7H).

The work of fitting the retainer members 6 and 7 into the outer ring 4 is performed using an appropriate tool.
The assembly of the ball bearing is completed by the above process. As shown in FIG. 6, a shaft member 18 is inserted into the ball bearing 2.

It is sectional drawing of the ball bearing which concerns on this invention. It is a side view of a ball bearing. It is explanatory drawing which shows the manufacturing process of a ball bearing. It is sectional drawing of the ball bearing with which the shaft member was mounted | worn. It is explanatory drawing which shows other embodiment of this invention. It is sectional drawing which shows other embodiment of a ball bearing. It is explanatory drawing which shows other embodiment of this invention.

Explanation of symbols

2 Ball bearing 4 Outer ring 4a Bottom wall portion 4b Inner wall portion 6 Retainer member 7 Retainer member 8 Spherical member 10 Opening portion 12 Opening portion 14 Concave groove raceway 15 Concave groove raceway 16 Space portion 16a Narrow diameter portion 16b Narrow diameter portion 18 Shaft member 20 External member 22 Stopper end face 24 Projection

Claims (4)

The outer ring includes a spherical member disposed in contact with the inner diameter portion of the outer ring, and a retainer member that holds the spherical member. The outer ring has an inner ring that can support the shaft member in a relatively rotatable manner via the spherical member. A plurality of concave groove raceways for supporting the spherical member in the axial direction and the radially outward direction of the outer ring so that the spherical member can roll over the entire circumference of the inner diameter portion of the outer ring. An open portion is provided on the at least one side in the axial direction of the hollow portion of the outer ring so as to allow the retainer member to enter and leave the outer ring, and a plurality of the retainer members are provided corresponding to the concave groove tracks. Each retainer member is made of an elastically deformable material, each retainer member is provided with a space portion for holding the spherical member, and the space portion has a diameter from the diameter of the spherical member at least on the side away from the outer ring. Narrow Ball bearings, characterized in that a small diameter that. The space portion that holds the spherical member provided in each retainer member is provided with a narrow-diameter portion that is narrower than the diameter of the spherical member on both sides of the side away from the outer ring and the side approaching the outer ring. The ball bearing according to claim 1. A ball bearing manufacturing method that does not have an inner ring that can rotatably support a shaft member via a spherical member on an outer ring, the spherical member rolling over the entire circumference of the spherical member and the inner diameter portion. Opening to allow the retainer member to freely enter and exit at least one side in the axial direction of the inner hollow portion having a plurality of grooves for supporting the grooves in the axial direction and the radially outward direction as possible. An elastic ring having an outer ring having a portion and a space portion holding the spherical member, and having a narrow-diameter portion narrower than the diameter of the spherical member on at least the side away from the outer ring. A plurality of retainer members, a step of holding the spherical member in the space of each retainer member, and an inner diameter portion of the outer ring from an open portion formed in at least one axial direction thereof. With spherical members A step of inserting one of the plurality of retainer members, and the retainer member together with the spherical member to a position where the spherical member coincides with a corresponding concave groove track of the outer ring, and further inward of the outer ring. Inserting and inserting the remaining retainer member into the inner diameter portion of the outer ring, and further pushing the remaining retainer member into the inner diameter portion of the outer ring until the spherical member holding the retainer member fits into the corresponding grooved track of the outer ring A method of manufacturing a ball bearing, wherein the plurality of retainer members are assembled to the outer ring together with the spherical member by a process. The space portion that holds the spherical member provided in each retainer member is provided with a narrow-diameter portion that is narrower than the diameter of the spherical member on both sides of the side away from the outer ring and the side approaching the outer ring. The method for manufacturing a ball bearing according to claim 3, wherein:

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