JPH07296455A - Bearing mechanism - Google Patents

Abstract

PURPOSE:To finely adjust a gap in the thrust direction by providing and screw- fitting an outer screw part on an outer circumference of a radial bearing and an inner screw part on an inner circumference of a holding member for fitting the radial bearing to a chassis. CONSTITUTION:A small diameter part 29 of a bearing holder 25 is inserted into a hole 31 of the chassis 30, and its tip 28 is calked and fixed to the chassis. The radial bearing 20 is screwed into the holder 25, and an end part 27 of the holder 25 and an end part 23 of the bearing 20 are positioned in the same plane. A shaft 12 of a flywheel 11 is inserted into a washer and then into a hole 22 of the bearing 20. A thrust bearing 35 is stuck to a recessed part 41 of a bottom plate 40, and the shaft end 14 of the flywheel 11 is borne by fixing the flywheel to the chassis 30 with screws 45. The bearing 20 is turned to go out and in from the end part 27 of the holder 25 so as to be adjusted to a setting dimension A, and is then fixed with a sticking agent. By this constitution, the fine adjustment of the gap between the end part 23 of the bearing 20 and the washer 36 becomes very simple, and also working and assembling errors of constituting members can be absorbed by the adjusting function, thus improving the yield and the quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing mechanism, for example, a flywheel bearing structure of a tape feeding mechanism of a cassette tape reproducing apparatus.

[0002]

2. Description of the Related Art A conventional bearing mechanism will be described with reference to the drawings. FIG. 3 is a cross-sectional view showing a bearing mechanism of a capstan shaft which sandwiches a tape together with a pinch roller in a conventional cassette tape reproducing apparatus and sends the tape by its constant speed rotation.

A flywheel 71 bearing mechanism 70 includes a flywheel 71, a radial bearing 76, a bearing holder 80,
The chassis 85, the thrust bearing 95, the washer 96, the bottom plate 90 and other members are included. Flywheel 7
1, a V-shaped groove 73 on which a rubber belt connected to a drive (motor) side pulley is hooked is formed on a disk-shaped outer periphery,
At the center of the disc, a rubber pinch roller (not shown) and a shaft 72 for sandwiching the tape and transporting the magnetic tape are press-fitted. The flywheel 71 is an important structure for transporting the magnetic tape at a constant speed.
Since the surface roughness of the directly affects the reproduced sound, precise processing and assembly are required.

The radial bearing 76 has a cylindrical shape and an outer diameter 78.
Is formed to have a size capable of press-fitting into the hole 82 of the bearing holder 80 (the outer diameter 78 is slightly larger than the hole 82). Further, the inner diameter 79 of the radial bearing 76 forms a holding portion for the shaft 72 of the flywheel 71, so that the flywheel 71 always maintains a smooth rotation, the material is oil-impregnated metal or resin material having a small friction resistance. Are used.

The bearing holder 80 has a cylindrical shape and has a hole 82 formed in the inner diameter to press fit with the radial bearing 76, and the small diameter portion 81 provided all around the outer diameter is slightly smaller than the hole 86 of the chassis 85. , There is a caulking allowance. The material is brass or the like and is formed by turning. The chassis 85 is a member for mounting a mechanical component such as the bearing holder 80, and has a mounting hole 86 for the bearing holder 80 and a mounting screw hole 87 for the bottom plate 90. A plated steel plate or the like is used as the material, and is formed by pressing or the like.

The thrust bearing 95 is a portion that receives a force acting in the axial direction of the flywheel 71 (downward in the drawing).
A material such as polyamide resin is used to reduce the contact resistance with the second end 74. The washer 96 is provided between the flywheel 71 and the radial bearing 76 so that the disk surface 75 of the flywheel 71 and the end 77 of the radial bearing 76 do not come into direct contact with each other. A material such as a polyamide resin having a low contact resistance is used as the material.

The bottom plate 90 has a recess 91 for mounting the thrust bearing 95 and a mounting hole 92 for mounting on the chassis 85. A plated steel sheet or the like is used as the material, and is formed by press working or the like. Next, the assembling method will be described. The end 77 of the radial bearing 76 is press-fitted into the hole 82 of the bearing holder 80 to such an extent that it slightly projects from the end 83 of the bearing holder 80. Then, the small diameter portion 81 of the bearing holder 80 is inserted into the hole 86 of the chassis 85, and the tip 84 of the insertion portion is caulked to be fixed to the chassis 85. Next, flywheel 7
1. Insert the washer 96 into the shaft 72 of No. 1 and set the radial bearing 76
It is inserted into the hole 79. Then, the thrust bearing 95 is attached to the recess 91 of the bottom plate 90, and is screwed to the chassis 85 with the screw 97 so as to hold the shaft end portion 74 of the flywheel 71.

[0008]

[Problems to be Solved by the Invention] Now, the flywheel 7
In the bearing mechanism 70 of No. 1, the gap B between the end 77 of the radial bearing 76 and the washer 96 is set to an appropriate dimension (ideally, the minimum necessary size at which the end 77 of the radial bearing 76 and the washer 96 do not contact). Otherwise, excessive backlash will occur in the thrust direction of the flywheel 71, or the gap between the end 77 of the radial bearing 76 and the washer 96 will be too small to make contact, resulting in uneven rotation of the flywheel 71 and deterioration in sound quality. Moreover, in the worst case, the rotation may stop and the reproduction may be impossible.

However, since the conventional bearing mechanism is not provided with an adjusting function after assembly, processing errors and assembly errors of individual assembled members are accumulated. Therefore, in order to make the clearance B between the end portion 77 of the radial bearing 76 and the washer 96 appropriate, it is required to improve the processing accuracy and the assembly accuracy of each assembly member. Therefore, there is a problem in that work efficiency and yield are reduced, which is disadvantageous in terms of cost.

In addition, the thrust bearing has a screw structure,
It is also possible to move and adjust the thrust bearing after assembly to adjust the gap B between the end 77 of the radial bearing 76 and the washer 96, but the flywheel 71 moves and the positional relationship with the drive shaft changes. Therefore, there is a problem that unevenness in rotation of the flywheel 71 occurs, which leads to deterioration of reproduced sound quality.

The present invention solves the above-mentioned problems.
An object of the present invention is to provide a bearing mechanism that can adjust the clearance in the thrust direction without changing the positional relationship of the flywheel.

[0012]

SUMMARY OF THE INVENTION The present invention achieves the above-mentioned object, and a radial bearing for rotatably supporting a rotary shaft of a rotary body and restricting the radial direction of the rotary body, and a radial bearing for the chassis. In a bearing mechanism comprising a holding member attached to the radial bearing and a thrust bearing that rotatably supports the rotating shaft and regulates the axial direction, and an outer threaded portion formed on the outer periphery of the radial bearing and an inner portion of the holding member. The radial bearing and the holding member are coupled to each other by screwing the outer screw portion and the inner screw portion, and the radial bearing is positionally adjustable with respect to the chassis. It is characterized by

The holding member comprises a male screw portion formed on the outer periphery of the holding member and a female screw portion formed on the chassis. The holding member and the chassis are connected to each other by screwing the male screw portion and the front female screw portion. The position of the holding member can be adjusted with respect to the chassis. Alternatively, the radial bearing and the holding member are integrally formed.

[0014]

According to the present invention, when the radial bearing screwed to the holding member is rotated, the radial bearing moves in and out of the holding member, and the relative positional relationship between the radial bearing and the thrust bearing. Changes. Therefore, it is possible to adjust the dimension in the thrust direction.

Further, according to the second invention, when the holding member screwed into the chassis is rotated, the holding member moves in and out of the chassis, and the radial bearing is press-fitted into the holding member. And the relative positional relationship between the thrust bearing and the thrust bearing changes. Therefore, it is possible to adjust the dimension in the thrust direction. Alternatively, according to the third aspect of the invention, the radial bearing and the holding member are integrated so that the number of constituent members is reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a sectional view showing a bearing mechanism. Reference numeral 10 denotes a bearing mechanism for the flywheel 11, which includes a flywheel 11, a radial bearing 20, a bearing holder 25, a chassis 30, and a thrust bearing 3.
5, the washer 36, the bottom plate 40 and the like.

The flywheel 11 has a disc-shaped outer periphery on which a rubber belt connected to a drive (motor) pulley is hooked.
A groove 13 is formed, and at the center of the disk, a pinch roller (not shown) and a shaft 12 for sandwiching the tape and transporting the magnetic tape are press-fitted. Flywheel 11
It is an important structure for transporting magnetic tape at a constant speed,
Since the concentricity of the shaft 12 and the V-shaped groove 13, the surface runout of the V-shaped groove 13, the movement of the rotational center of gravity, and the surface roughness of the shaft 12 directly affect the reproduced sound, precise processing and assembly are required. It

The radial bearing 20 has a cylindrical shape, and has an outer diameter on which a screw portion 21 to be screwed into a screw hole 26 of a bearing holder 25 is provided.
In addition, a groove 24 is formed in the end portion to engage with a tool for rotating the radial bearing 20. Inner diameter 22 of radial bearing 20
Is a shaft supporting portion of the shaft 12 of the flywheel 11, and an oil-impregnated metal having a small friction resistance or a resin material is used as the material so that the flywheel 11 always maintains a smooth rotation.

The bearing holder 25 has a cylindrical shape and has an inner diameter formed with a screw hole 26 into which the radial bearing 20 is screwed. The outer diameter small diameter portion 29 is slightly smaller than the hole 31 of the chassis 30 to provide a caulking margin. ing. The material is brass or the like and is formed by turning. The chassis 30 is a member for mounting mechanical parts such as the bearing holder 25, and the mounting hole 31 of the bearing holder 25 and the mounting screw hole 32 of the bottom plate 40 are formed. A plated steel plate or the like is used as the material, and is formed by pressing or the like.

The thrust bearing 35 is a portion that receives a force acting in the axial direction of the flywheel 11 (downward in the figure).
A material such as polyamide resin is used to reduce the contact resistance with the second end portion 14. The washer 36 is provided between the flywheel 11 and the radial bearing 20 so that the surface 15 of the disc of the flywheel 11 and the end 23 of the radial bearing 20 do not come into direct contact with each other. As the material, a material such as polyamide resin having a low contact resistance is used.

The bottom plate 40 is formed with a recess 41 for mounting the thrust bearing 35, a mounting hole 42 for mounting on the chassis 30, and the like. A plated steel sheet or the like is used as the material, and is formed by press working or the like. First, the assembly method will be described. The small diameter portion 2 of the bearing holder 25 is inserted into the hole 31 of the chassis 30.
9 is inserted, the tip 28 of the insertion portion is caulked, and the chassis 30
Stick to. Then, the radial bearing 2 is attached to the bearing holder 25.
The end portion 27 of the threaded bearing holder 25 and the end portion 23 of the radial bearing 20 are substantially flush with each other. Next, the washer 36 is inserted into the shaft 12 of the flywheel 11 and into the hole 22 of the radial bearing 20. Then, the thrust bearing 35 is attached to the recess 41 of the bottom plate 40, and the flywheel 1
Screw 4 to chassis 30 so that shaft end 14 of
Screw with 5.

Next, a method for adjusting the thrust clearance of the flywheel 11 will be described. In the adjustment, in the assembled state, while rotating the radial bearing 20, the radial bearing 20 is taken in and out from the end 27 of the bearing holder 25, and the set dimension A (ideally, by changing the environmental temperature, etc. Adjusted so that the end 14 of the radial bearing 20 and the washer 36 do not come into contact with each other even if deformation occurs due to expansion and contraction of the fixed member), and after adjustment, secure the screws so that the screws do not loosen. It is fixed using an agent (for example, a semi-fixed state with a resin-based adhesive or the like).

As described in detail above, according to the present embodiment, the screwing portion of the radial bearing 20 and the bearing holder 25 serves as an adjusting function, and the end portion 23 of the radial bearing 20 and the washer 3 are provided.
Fine adjustment of the clearance A of 6 becomes very easy. Moreover, since the adjustment function can absorb the processing and assembling errors of the constituent members, the yield and quality can be improved, and the work efficiency can be improved. Therefore, it leads to cost reduction.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a sectional view showing the bearing mechanism. FIG. 2 shows the radial bearing 20, the bearing holder 25, and the radial bearing 20 of the first embodiment shown in FIG.
Since a part of the chassis 30 is changed and other parts are substantially the same, the same components as those in FIG.

The radial bearing 51 has a cylindrical shape and an outer diameter 52.
Is formed in such a size that it can be press-fitted into the hole 56 of the bearing holder 55. The inner diameter 22 of the radial bearing 51 forms a shaft support portion of the shaft 12 of the flywheel 11, and the material is oil-impregnated metal with low frictional resistance or resin material so that the flywheel 11 always maintains smooth rotation. Used.

The bearing holder 55 has a cylindrical shape and has a hole 56 formed in its inner diameter to be press-fitted into the radial bearing 51, and has a screw portion 57 screwed into a screw hole 62 of a chassis 60 in its outer diameter.
Further, a groove 59 with which a tool for rotating the bearing holder 55 is engaged is formed in the end portion. The material is brass or the like and is formed by turning. The chassis 60 is the bearing holder 5
5, which is a member for attaching mechanical parts such as 5, a screw hole 61 (a screw forming process after burring process) with which the bearing holder 55 is screwed, a mounting screw hole 62 of the bottom plate 40, and the like are formed. A plated steel plate or the like is used as the material, and is formed by pressing or the like.

First, the assembling method will be described. Bearing holder 5
5, the end portion 54 of the radial bearing 51 is press-fitted to the extent that the end portion 54 of the bearing holder 55 slightly projects from the end portion 58. Then, the bearing holder 55 is screwed into the screw hole 61 of the chassis 60. Next, the washer 36 is inserted through the shaft 12 of the flywheel 11 and through the hole 53 of the radial bearing 51.
Then, the thrust bearing 35 is attached to the recess 41 of the bottom plate 40, and is screwed to the chassis 60 with the screw 45 so as to pivotally support the shaft end portion 14 of the flywheel 11.

Next, a method for adjusting the thrust clearance of the flywheel 11 will be described. The adjustment is performed by rotating the bearing holder 55 so that the clearance between the end portion 54 of the radial bearing 51 and the washer 36 becomes the set dimension A in the assembled state so that the screw does not loosen after the adjustment. It is fixed using a fixing agent (for example, a semi-fixed state with a resin adhesive or the like).

As described in detail above, also in this embodiment, the threaded portion between the bearing holder 55 and the chassis 60 serves as an adjusting function, and the end portion 54 of the radial bearing 51 and the washer 3 are adjusted.
Fine adjustment of the clearance A of 6 becomes very easy. Moreover, since the adjustment function can absorb the processing and assembling errors of the constituent members, the yield and quality can be improved, and the work efficiency can be improved. Therefore, it leads to cost reduction.

Further, the radial bearing and the bearing holder in the second embodiment shown in FIG. 2 are integrally molded to form a threaded portion on the outer diameter. Further, it is also possible to adopt a configuration in which it is screwed into a screw hole formed in the chassis, and in this case, the number of component parts is reduced and further cost reduction can be achieved. Further, a threaded portion is formed on the outer diameter of the radial bearing,
Threaded portions are also formed on the inner and outer diameters of the bearing holder, and screw holes into which the bearing holder is screwed are formed on the chassis. Further, by adjusting all the couplings of the radial bearing, the bearing holder and the chassis to be screwed together, an adjusting function is formed at two positions of the radial bearing and the bearing holder and between the bearing holder and the chassis. Therefore, a wider range of adjustment is possible.

[0031]

As described above, according to the bearing mechanism for a rotating body of the present invention, the radial bearing and the holding portion that holds the radial bearing, or the holding portion and the chassis are screwed together. The threaded portion fulfills the adjusting function.
Therefore, by rotating the radial bearing or the holding portion after assembling the bearing mechanism, the radial bearing moves in the axial direction of the rotating body, and the dimension adjustment in the axial direction becomes possible. And the assembly error can be absorbed. Therefore, the yield and quality are improved, and the work efficiency is improved, so that the cost can be reduced. Further, even if the adjustment dimension changes due to some factor after the assembly adjustment, readjustment can be easily performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a bearing mechanism of a first embodiment of the present invention.

FIG. 2 is a sectional view showing a bearing mechanism of a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a conventional bearing mechanism.

[Explanation of symbols]

 10, 50 · Bearing mechanism 11 ··· Flywheel 20, 51 · Radial bearing 25, 55 · Bearing holder 30, 60 · Chassis 35 · · · Thrust bearing 36 · · · Washer 40 · · · Bottom plate

Claims (3)

[Claims] 1. A radial bearing that rotatably supports a rotary shaft of a rotating body and restricts the radial direction of the rotary body, a holding member that attaches the radial bearing to a chassis, and a rotary member that rotatably supports the rotary shaft. In a bearing mechanism including a thrust bearing that regulates the axial direction, an outer threaded portion formed on the outer circumference of the radial bearing and an inner threaded portion formed on the inner circumference of the holding member, wherein the radial bearing and the A bearing mechanism, wherein the holding member is coupled to the outer screw portion and the inner screw portion by screwing, and the position of the radial bearing can be adjusted with respect to the chassis. 2. A radial bearing that rotatably supports a rotating shaft of a rotating body and regulates the radial direction of the rotating body, a holding member that attaches the radial bearing to a chassis, and a rotating member that rotatably supports the rotating shaft. In a bearing mechanism including a thrust bearing that regulates an axial direction, a male screw portion formed on the outer periphery of the holding member and a female screw portion formed on the chassis, wherein the holding member and the chassis are coupled to each other by the male screw. A bearing mechanism, characterized in that the position of the holding member can be adjusted with respect to the chassis by screwing a portion and the female screw portion. 3. The bearing mechanism according to claim 2, wherein the radial bearing and the holding member are integrally formed.