JP2009185859A - Roller bearing unit and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent pre-load escape, and to improve rotational accuracy. <P>SOLUTION: A roller bearing unit includes: two roller bearings 10A, 10B having a plurality of rolling bodies 16 at intervals in the circumferential direction in a circular space between inner rings 12a, 12b and outer rings 14a, 14b arranged coaxially; a shaft 3 fitted and connected to the inner rings 12a, 12b of the two roller bearings 10A, 10B; a sleeve 5 with a through-hole 9 having the outer rings 14a, 14b of the two roller bearings 10A, 10B fitted and connected; and a ring-like spacer 7 sandwiched between the inner rings 12a, 12b of the two roller bearings 10A, 10B. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing unit and a manufacturing method thereof.

Generally, a rolling bearing unit rotates a cylindrical inner cylinder which is an inner member, a cylindrical outer cylinder which is an outer member disposed around the inner cylinder, and the inner cylinder and the outer cylinder relatively. And a pair of ball bearings that are freely supported. And a pair of ball bearing is each comprised from the inner ring | wheel, the outer ring | wheel, and the some ball provided so that rolling between these inner ring | wheels and outer rings was possible.
In such a rolling bearing unit, in order to ensure rigidity and improve rotational accuracy, the inner ring of the ball bearing is pressed in the axial direction so that preload is applied (for example, see Patent Document 1).

For example, in a rolling bearing unit used for a 3.5-inch class hard disk, in order to apply a preload to the inner ring, a protrusion that stops the outer ring of the ball bearing is usually provided on the inner diameter of the outer cylinder. On the other hand, in a small rolling bearing unit used for a 2.5-inch class hard disk or a 1.8-inch class hard disk, it is difficult to increase the accuracy of processing to provide a protrusion on the inner diameter of the outer cylinder. Therefore, in Patent Document 1, the inner diameter of the outer cylinder is made a hole without a protrusion, and a ring-shaped spacer is inserted between the outer rings of the upper and lower ball bearings in place of the protrusions, so that the interval between the ball bearings is increased. The inner ring can be pressed in the axial direction. As a result, the pair of ball bearings are bonded by the adhesive applied to the inner surface of the outer cylinder in a state where preload is applied.
JP 2002-257134 A

  However, since the spacer is restricted from moving in the radial direction by fitting to the inner surface of the outer cylinder, which is an outer member, in the state of the assembly before being assembled to the outer cylinder, the spacer in the radial direction Cannot be restricted. Therefore, there is a possibility that the spacer protrudes radially outward from the outer ring of the ball bearing when assembled to the outer cylinder. In that case, the adhesive on the inner surface of the outer cylinder is scraped or the spacer is not There is a problem that it interferes with assembly. If the adhesive is scraped or galling due to the spacer, there is an inconvenience that the rolling bearing unit is preloaded and the rotational accuracy is deteriorated.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a rolling bearing unit capable of preventing preload loss and improving rotational accuracy, and a method for manufacturing the same.

In order to achieve the above object, the present invention provides the following means.
The present invention relates to two rolling bearings containing a plurality of rolling elements spaced circumferentially in an annular space between an inner ring and an outer ring arranged coaxially, and the inner rings of these two rolling bearings. A first member that is bonded in a state in which the outer ring of the two rolling bearings is fitted, a second member having a fitting hole that is bonded in a state in which the outer ring of the two rolling bearings is fitted, and the two rolling bearings A rolling bearing unit including a ring-shaped spacer sandwiched between the inner rings is provided.

  According to the present invention, an assembly in which one rolling bearing, a spacer, and the other rolling bearing are assembled in order to the first member is fitted into the fitting hole of the second member to which the adhesive is applied. Thus, a rolling bearing unit is configured. In this case, since the movement of the spacer in the radial direction is restricted by the first member, the spacer does not protrude outward in the radial direction from the outer ring of the rolling bearing, and the adhesive on the inner surface of the fitting hole is scraped during fitting. It is possible to prevent the spacer and the spacer from interfering with the assembly.

  Further, since the distance between the inner rings of the two rolling bearings is determined by the length of the spacer, it is possible to easily apply preload only by pressing the outer rings in a direction in which they are brought close to each other. And the outer ring | wheel is adhere | attached on a fitting hole, and is maintained in the state which applied the preload. Thereby, preload loss can be prevented, and deterioration of the rotation accuracy of the rolling bearing unit can be prevented.

In the above invention, the outer rings may be bonded to the fitting holes of the second member in a state where preload is applied in a direction in which the outer rings of the two rolling bearings are close to each other.
According to such a configuration, since there is no gap between the inner and outer rings of each rolling bearing and the rolling elements, the rigidity of the rolling bearing unit can be ensured and the rotation accuracy can be improved.

  Further, in the above invention, the second member may have a convex portion at the end of the fitting hole in the fitting direction that protrudes toward the inner surface and abuts the end surface of the outer ring of one of the rolling bearings. Good.

  According to such a configuration, the outer ring of the other rolling bearing disposed on the opposite side in the axial direction with respect to the one rolling bearing in which the end face of the outer ring is abutted against the convex portion of the fitting hole of the second member. It is possible to apply preload to the two rolling bearings simply by pressing in the axial direction.

In the present invention, the outer ring is bonded to the inner ring of the first rolling bearing having a plurality of rolling elements in the annular space between the inner ring and the outer ring arranged on the same axis and spaced apart in the circumferential direction. A first step of fitting and bonding the first member coated with the agent, a second step of fitting the first member to a ring-shaped spacer, and an inner ring arranged coaxially Fitting the first member having an outer peripheral surface coated with an adhesive to the inner ring of a second rolling bearing having a plurality of rolling elements with a circumferential spacing in an annular space between the outer ring and the outer ring A third step of bonding in a state where the spacer is sandwiched between inner rings of the first rolling bearing and the second rolling bearing, and bonding to positions corresponding to the rolling bearings on the inner peripheral surface The first rolling bearing and the second rolling bearing in the fitting hole of the second member coated with the agent To provide a method of manufacturing a rolling bearing unit and a fourth step of adhering by fitting each said outer ring.

  According to the present invention, an assembly in which one rolling bearing, a spacer, and the other rolling bearing are assembled to the first member in this order is fitted into the fitting hole of the second member in which an adhesive is applied to the inner peripheral surface. A rolling bearing unit is configured by fitting. In this case, since the spacer is restricted from moving in the radial direction by the first member, it does not protrude outward in the radial direction from the outer ring of the rolling bearing. Therefore, the assembly can be fitted into the fitting hole of the second member without the adhesive on the inner surface of the fitting hole being scraped off or the spacer being in the way of assembly.

  In the above invention, a fifth step is provided in which the outer ring and the fitting hole of the second member are bonded to each other in a state where preload is applied in a direction in which the outer rings of the two rolling bearings are close to each other. Also good.

  According to such a structure, an outer ring | wheel can be adhere | attached on the fitting hole of a 2nd member in the state which eliminated the clearance gap between the inner and outer ring | wheels and rolling element of each rolling bearing. Therefore, a state in which a preload is applied can be maintained, and a rolling bearing unit with high rotational accuracy can be manufactured.

  According to the present invention, it is possible to prevent preload loss and to improve the rotation accuracy.

Hereinafter, a rolling bearing unit and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the rolling bearing unit 1 according to the present embodiment is a rolling bearing unit for a swing arm, for example. This rolling bearing unit 1 includes a first rolling bearing 10A and a second rolling bearing 10B (hereinafter referred to as a first rolling bearing 10A and a second rolling bearing 10B) that are arranged at predetermined intervals in the axial direction. In addition, it is referred to as “rolling bearings 10A and 10B”), a shaft (first member) 3 fitted to these rolling bearings 10A and 10B, and a through hole (fitting) for fitting the rolling bearings 10A and 10B. A cylindrical sleeve (second member) 5 having a hole 9 and a spacer (spacer) 7 sandwiched between the rolling bearings 10A and 10B are provided.

  The rolling bearings 10A and 10B are for rotating the shaft 3 and the sleeve 5 relatively. As shown in FIG. 2, the first rolling bearing 10 </ b> A is built in the inner ring 12 a and the outer ring 14 a arranged coaxially, and in an annular space between the inner ring 12 a and the outer ring 14 a with a circumferential interval. And a plurality of rolling elements 16.

A deep groove type or angular type inner ring raceway is provided on the outer peripheral surface of the inner ring 12a of the first rolling bearing 10A, and a deep groove type or angular type outer ring raceway is provided on the inner peripheral surface of the outer ring 14a. Yes.
Note that the second rolling bearing 10B has the same configuration as the first rolling bearing 10A, and a description thereof will be omitted.

  The shaft 3 is a cylindrical member having a through-hole 21 in the center, and is provided with a flange-like flange portion 23 protruding outward in the radial direction over the entire circumference at one end in the axial direction. A first rolling bearing 10A, a spacer 7, and a second rolling bearing 10B are fitted into the shaft 3 in this order from the flange portion 23 side. The end surface of the inner ring 12a of the first rolling bearing 10A is abutted against the flange portion 23, the spacer 7 is abutted against the first rolling bearing 10A, and the second rolling bearing 10B is abutted against the spacer 7. The outer peripheral surface of the shaft 3 and the inner rings 12a and 12b of the rolling bearings 10A and 10B are bonded with an adhesive.

  The inner peripheral surface of the through-hole 9 of the sleeve 5 and the outer rings 14a and 14b of the rolling bearings 10A and 10B are pressed by the adhesive in a state where the outer rings 14a and 14b of the rolling bearings 10A and 10B are pressed toward each other. It is glued. As a result, the rolling bearings 10A and 10B are preloaded, and the inner rings 12a and 12b and the outer rings 14a and 14b and the rolling elements 16 are brought into contact with no gap.

  The spacer 7 is a ring-shaped member that is sandwiched between the inner ring 12a of the first rolling bearing 10A and the inner ring 12b of the second rolling bearing 10B, and has an inner diameter that is substantially the same as the outer diameter of the shaft 3. is doing. The outer diameter of the spacer 7 is smaller than the inner diameter of the outer rings 14a and 14b of the rolling bearings 10A and 10B. For example, the outer diameter of the spacer 7 is equal to or slightly larger than the outer diameter of the inner rings 12a and 12b of the rolling bearings 10A and 10B. ing.

Hereinafter, the manufacturing method of the rolling bearing unit 1 of this embodiment comprised in this way is demonstrated.
First, an adhesive is applied to a position corresponding to the inner ring 12a of the first rolling bearing 10A on the outer peripheral surface of the shaft 3. Then, the shaft 3 is fitted to the inner ring 12a of the first rolling bearing 10A. The inner ring 12a of the first rolling bearing 10A and the shaft 3 are bonded together with the end face of the inner ring 12a of the first rolling bearing 10A abutting against the flange portion 23 of the shaft 3.

  Subsequently, the shaft 3 fitted to the first rolling bearing 10 </ b> A is fitted to the spacer 7. Since the inner diameter dimension of the ring-shaped spacer 7 is substantially the same as the outer diameter dimension of the shaft 3, the movement of the spacer 7 in the radial direction can be limited by the shaft 3.

  Next, an adhesive is applied to a position corresponding to the inner ring 12b of the second rolling bearing 10B on the outer peripheral surface of the shaft 3. Then, the shaft 3 is fitted to the inner ring 12b of the second rolling bearing 10B.

  Since the outer diameter of the spacer 7 is the same as or slightly larger than the outer diameter of the inner rings 12a and 12b of the rolling bearings 10A and 10B, the distance between the inner rings 12a and 12b of the first rolling bearing 10A and the second rolling bearing 10B is large. The spacers 7 are bonded together with the spacers 7 sandwiched therebetween. Thereby, the assembly 25 assembled in the order of the first rolling bearing 10A, the spacer 7, and the second rolling bearing 10B on the shaft 3 is completed.

  Next, an adhesive is applied to the through hole 9 of the sleeve 5 to fit the assembly 25 from the flange portion 23 side of the shaft 3. Specifically, an adhesive is applied to positions corresponding to the outer ring 14a of the first rolling bearing 10A and the outer ring 14b of the second rolling bearing 10B on the inner peripheral surface of the through hole 9 shown in FIG. The assembly 25 is fitted into the through hole 9 in the order of the outer ring 14a of the first rolling bearing 10A and the outer ring 14b of the second rolling bearing 10B.

  In this case, since the movement of the spacer 7 in the radial direction is restricted by the shaft 3, the spacer 7 does not protrude outward in the radial direction from the outer rings 14a and 14b of the rolling bearings 10A and 10B. Therefore, the adhesive applied to the inner surface of the through-hole 9 can be fitted without being scraped by the spacer 7 or the spacer 7 being in the way of assembly.

  Subsequently, before the assembly 25 and the sleeve 5 are completely bonded, a preload is applied to the rolling bearings 10A and 10B. In this case, since the distance between the inner rings 12a and 12b of the rolling bearings 10A and 10B is determined by the length of the spacer 7, it is possible to simply apply the preload simply by pressing the outer rings 14a and 14b in the direction in which they approach each other. Can do.

  Then, the outer rings 14 a and 14 b are bonded to the through holes 9 of the sleeve 5 in a state in which the outer rings 14 a and 14 b of the rolling bearings 10 A and 10 B are preloaded. Thereby, since the clearances between the inner rings 12a and 12b and the outer rings 14a and 14b of the rolling bearings 10A and 10B and the respective rolling elements 16 are eliminated, the rigidity of the rolling bearing unit 1 can be ensured and the rotation accuracy can be improved. Moreover, since it maintains in the state which applied the preload by adhesion | attachment, preload loss can be prevented and the deterioration of the rotation precision of the rolling bearing unit 1 can be prevented.

In addition, the rolling bearing unit 1 and its manufacturing method according to the present embodiment can be modified as follows.
For example, as shown in FIG. 5, the sleeve 5 is at the end in the fitting direction (in other words, at the position where the axial position of the flange portion 23 of the shaft 3 becomes the same when the rolling bearing unit 1 is assembled). The protrusion 31 may protrude from the inner surface side of the through hole 9 and may have a protrusion 31 that abuts the end surface of the outer ring 14a of the first rolling bearing 10A.

  In this modification, the outer ring 14a of the first rolling bearing 10A of the assembly 25 is fitted into the through hole 9, and the end surface of the outer ring 14a is bonded to the convex portion 31. By doing in this way, the first rolling bearing 10A and the first rolling bearing 10A and the first rolling bearing 10A and the first rolling bearing 10A and the second rolling bearing 10B disposed on the opposite side in the axial direction can be simply pressed in the axial direction. A preload can be applied to the second rolling bearing 10B. Therefore, the rolling bearing unit 1 can be manufactured more easily.

It is the schematic which shows the rolling bearing unit which concerns on one Embodiment of this invention. FIG. 2 is a schematic diagram showing a first rolling bearing (second rolling bearing) of the rolling bearing unit of FIG. 1. Schematic which shows the assembly of the rolling bearing unit of FIG. Fig. 2 is a schematic view showing a sleeve of the rolling bearing unit of Fig. 1. It is the schematic which shows the whole rolling bearing unit which concerns on the modification of one Embodiment of this invention.

Explanation of symbols

1 Rolling bearing unit 3 Shaft (first member)
5 Sleeve (second member)
7 Spacer (spacer)
10A 1st rolling bearing 10B 2nd rolling bearing 12a, 12b Inner ring 14a, 14b Outer ring

Claims (5)

Two rolling bearings containing a plurality of rolling elements spaced circumferentially in an annular space between an inner ring and an outer ring arranged on the same axis;
A first member to be bonded in a state of being fitted to the inner ring of these two rolling bearings;
A second member having a fitting hole to be bonded in a state in which the outer rings of the two rolling bearings are fitted;
A rolling bearing unit comprising a ring-shaped spacer sandwiched between the inner rings of the two rolling bearings.   The rolling bearing unit according to claim 1, wherein the outer rings are bonded to the fitting holes of the second member in a state where preload is applied in a direction in which the outer rings of the two rolling bearings are close to each other.   The said 2nd member has the convex part which protrudes in an inner surface side at the terminal of the fitting direction of the said fitting hole, and abuts the end surface of the outer ring | wheel of one of the said rolling bearings. Rolling bearing unit. An adhesive is applied to the outer peripheral surface of the inner ring of the first rolling bearing that incorporates a plurality of rolling elements in the annular space between the inner ring and the outer ring that are arranged on the same axis and spaced apart in the circumferential direction. A first step of fitting and bonding the first member;
A second step of fitting the first member into a ring-shaped spacer;
An adhesive is applied to the outer peripheral surface of the inner ring of the second rolling bearing that incorporates a plurality of rolling elements in the annular space between the inner ring and the outer ring that are arranged on the same axis and spaced apart in the circumferential direction. A third step of fitting the first member and adhering in a state where the spacer is sandwiched between inner rings of the first rolling bearing and the second rolling bearing;
Each outer ring of the first rolling bearing and the second rolling bearing is fitted into a fitting hole of a second member coated with an adhesive at a position corresponding to the rolling bearing on the inner peripheral surface. A rolling bearing unit manufacturing method comprising a fourth step of bonding.   5. The rolling according to claim 4, further comprising a fifth step of bonding the outer ring and the fitting hole of the second member in a state where preload is applied in a direction in which the outer rings of the two rolling bearings are close to each other. Manufacturing method of bearing unit.

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