JPH01229114A - Unit bearing having no spacer and fixed position pre-loading method of said unit bearing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a unit bearing without a spacer suitable for use in a rotary actuator of a magnetic disk drive, and a method for preloading the unit bearing in position.

``Prior Art'' In recent years, small magnetic disk drives have become thinner and thinner, and the spacing between the unit bearings of a rotary actuator has become narrower. For example, as shown in FIG. A fixed position preloading method is known in which a thrust load is applied to the inner ring 3.3' by screwing a screw 5 onto the shaft 4 through a thin spacer 2 between the outer rings 1.1' and 1.1'.

Furthermore, as shown in FIG. A constant pressure preloading method that applies a thrust load using a highly elastic component such as an annular cylinder 15, the other end of which is housed in an annular cylinder 15, and the rear end surface of the cylinder 15 is in contact with the outer ring 1'. It has been known.

The former method has the advantage that it is a simple method of applying preload to the rolling bearing to increase its rigidity, and the latter has the advantage that the amount of preload does not change even if the position of the bearing changes somewhat during rotation of the bearing.

``Problem to be Solved by the Invention'' However, if the spacer 2 in the former is assembled so as to protrude from the outer ring 1.1', it may not be installed as specified when it is installed in a magnetic disk drive, and the inner ring 3 ' is screw 5
Since the inner ring 3 is press-fitted into the shaft 4 with the screwing force of Variations occur in the torque, which is the most important factor for actuator unit bearings.

In order to keep this torque value within a certain range, it is necessary to adjust and manage the screw 5, but this is extremely difficult.

Further, the latter has the disadvantage that it requires parts other than the bearing, such as the coil spring 13, and the dimensions around the bearing become large.

Therefore, it is an object of the present invention to provide a unit bearing and a fixed position preloading method for the bearing, which can facilitate the assembly of the unit bearing and the management of the constant required torque of the unit bearing.

"Means for Solving the Problem" In order to achieve the above object, in the present invention, one or both of the outer rings of two rolling bearings assembled to the shaft body face each other in close contact with the other outer ring. A unit bearing without a spacer, characterized in that the side protrudes axially beyond the width of the inner ring to maintain the bearing spacing, and one or both of the outer rings of the two bearings are attached to the shaft body, and the outer ring of one or both of the bearings is fixed to the shaft body. The side that faces and comes into close contact with the bearing protrudes axially beyond the width of the inner ring to maintain the bearing spacing, and then, after initially applying a constant preload to the inner ring of the bearing, the inner periphery of the inner ring is fixed to the outer periphery of the shaft. It is an object of the present invention to provide a method for preloading a unit bearing in place without a spacer, which comprises a step of preloading in place and adjusting it.

``Function'' Because the spacer and outer ring of the unit bearing are integrally formed, there is no possibility that the unit bearing will protrude from the outer periphery of the outer ring, unlike when there was a spacer, and when installed in a magnetic disk drive. There is no problem at all.

The inner ring is adhesively fixed to the shaft with a constant pressure preload applied to it, and the fixed position preload is applied, so that the desired constant torque value can be obtained after the unit bearing is completed.

"Example" Examples will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of a unit bearing according to the present invention, and FIG. 2 is a cross-sectional view showing another embodiment of the present invention.

In FIG. 1, an outer ring 101 of a rolling bearing 100 is formed with a wide portion 1011 projecting in the axial direction in order to maintain a distance from the outer ring 102 of the opposing rolling bearing 100, and an inner periphery 1012 of the wide portion 1011 is formed. is the inner circumference 1021 of the facing bearing, that is, the facing outer ring 102
It is formed to have the same inner diameter.

In the drawings, reference numerals 103 and 104 denote an inner ring, 105 and 106 a retainer for holding and guiding the balls 107 at a required interval, and 108 and 109 sealing plates 108' attached to the end faces of the outer rings 101 and 102.

109' is a sealing plate attached to opposite end surfaces of the outer rings 101 and 102, 110 is a shaft equipped with a flange,
130 is an adhesive, 140 is a jig with a guide 141 formed in the center, and 150 is a coil spring 153 fitted between a flanged pressing member 151 and an outer pressing member 152 that fits into the pressing member. This is a push jig.

Since the unit bearing of the present invention is constructed as described above, the adhesive 130 is applied to the outer periphery of the shaft 110 or the inner periphery 1041 of the inner ring 104 of the bearing 100' in advance, and then the unit bearing is inserted into the shaft 110 and the bearing is cured. Place it on the tool 140, and then press the flanged pressing member 151 and the outer pressing member 152.
By pressing the pushing jig 150 with the coil spring 153 inserted therebetween against the inner ring 104 and applying an external force in the direction of arrow 154, the elasticity of the coil spring 153 acts and a constant constant preload is applied.

After a predetermined period of time has elapsed and the adhesive 130 has hardened, the receiver is removed by removing the jig 140 and the pushing jig 150.
A fixed position preload is maintained between bearings 100 and 100'.

If you prepare the necessary data through experiments to ascertain the relationship between the pressure (elasticity) of the coil spring 153 and the practically required torque of the unit bearing, you can always apply a constant pressure to the bearing, so the torque The required value of is obtained.

FIG. 2 shows another embodiment of the present invention, with both bearings 100 and 100.
1/2 of the interval in the inner axial direction of the outer rings 101 and 102 of '
The sealing plate 108' of the bearing 100 and 100' protrudes one by one.
, 109' can be omitted, so the space volume of the opposing bearings can be increased.

Therefore, the amount of grease sealed between the bearings increases, and the life of the unit bearing becomes longer.

The rest is the same as in the first embodiment, the same parts are given the same reference numerals, and the explanation thereof will be omitted.

"Effects of the Invention" Since the present invention is configured as described above, it produces the effects described below.

Since the opposite sides of the outer ring of the unit bearing are closely attached and the inner ring of one bearing is fixed to the shaft, there is no displacement of the outer ring, no grease leakage, and the leakage prevention function can work effectively.

Furthermore, since the sealing plate inside the bearing can be omitted, the space of the bearing can be increased, and the lubrication function, which is related to the service life of the bearing, can be further improved due to the large amount of grease sealed therein.

In addition, the unit bearing of the present invention does not require parts such as spacers, screws, or coil springs, and female thread machining of the shaft, which eliminates the need for management of these parts and accuracy control, which has a significant effect on quality control. .

In addition, since the number of parts is small and assembly is easy, the working time can be shortened, and a great advantage can be obtained in terms of cost.

In particular, the unit bearing of the present invention can maintain the most important torque at a constant value by using both constant pressure preload and fixed position preload.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a unit bearing of the present invention, FIG. 2 is a sectional view showing another embodiment of the invention, FIG. 3 is a sectional view of a conventional example of a unit bearing using a spacer, and FIG. The figure is a sectional view showing a conventional example of a unit bearing using a coil spring. Description of symbols 100.100': Bearing 101.102: Outer ring 1011: Wide portion of outer ring 103.104: Inner ring 110: Shaft 130: Adhesive Patent applicant NSK Ltd. 130, contact;
I! Saij Figure 2 Procedural Amendments August 1, 1986

Claims (2)

[Claims] (1) The bearing spacing is maintained by making the side where one or both of the outer rings of two rolling bearings assembled on the shaft body face and come into close contact with the other outer ring protrude in the axial direction beyond the width of the inner ring. A unit bearing without a spacer, characterized by: (2) The unit bearing according to claim 1, wherein the outer rings of the two bearings protrude in the axial direction so that the outer rings come into close contact with each other, thereby making it possible to omit the inner shield of the bearings. (3) The side of one or both of the outer rings of the two bearings assembled on the shaft body faces and comes into close contact with the other outer ring, protruding in the axial direction beyond the width of the inner ring to maintain the bearing spacing; The fixed position preload of a unit bearing without a spacer according to claim 1, comprising the step of initially applying a constant pressure preload to the inner ring of the bearing, and then fixing the inner circumference of the inner ring to the outer circumference of the shaft to obtain a fixed position preload. Method.