JPH109254A - Ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably and rotatably support a shaft which can be easily manufactured, and is not affected by the fluctuation in length in the axial direction. SOLUTION: Flat regulating walls 5, 6 in the radial direction to constrain the movement of a rolling element 4 in the radial direction of a rotary shaft 1 are formed opposite to each other on an inner ring 2 and an outer ring 3, and a flat regulating wall 7 in the thrust direction to constrain the movement of the rolling element in the thrust direction of the rotary shaft 1 is formed on either of the inner ring 2 or the outer ring 3. The regulating walls 5, 6 in the radial direction are provided from the position of the regulating wall 7 in the thrust direction over the range longer than the diameter of the rolling element 4, and an elastically deforming elastic pressing means 8 in which the rolling element 4 is pressed against and urged by the regulating wall 7 in the thrust direction is mounted in a space between the regulating walls 5, 6 in the radial direction adjacent to the rolling element 4. An extension part 11 for reinforcement in fitting a slip-off preventive flange 10 and a rotation drive transmitting member 12 is formed as necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a ball bearing,
In particular, the present invention relates to an improvement in a ball bearing effective for a shaft that expands and contracts in the axial direction by heating and cooling such as a fixing device used in a copying machine or a printer.

[0002]

2. Description of the Related Art Conventionally, a fixing device used in a copying machine or a printer employs a structure in which a rotating shaft such as a heating roll or a pressure roll is rotatably supported by a bearing. For example, if a sliding bearing is employed as this type of bearing, the sliding friction resistance between the bearing and the rotating shaft is large, so that the capacity of the driving motor must be increased accordingly and the motor cost increases. . Therefore, from the viewpoint of reducing the motor cost, there is a demand to use a ball bearing having a smaller frictional resistance than a plain bearing.

A ball bearing of this type is, for example, an outer ring and an inner ring having an L-shaped cross section having a radial raceway portion and a thrust raceway portion, the rolling elements (balls) being sandwiched and fitted to each other. Has already been proposed (for example,
-23821).

[0004]

However, in this type of ball bearing, it may be possible to reduce the size of the ball bearing itself as compared with the prior art in which the outer ring and the inner ring are manufactured by forging. Since the inner race must have a curved radial raceway portion and a thrust raceway portion with which rolling elements engage, respectively, even if pressing is performed instead of forging, a process for forming each raceway portion is performed. Is not so easy to manufacture.

Particularly, in a conventional ball bearing, a radial raceway portion and a thrust raceway portion are formed on the outer ring and the inner ring, respectively, and the rolling elements are restrained and supported by these raceways. No allowance for axial length fluctuation (elongation / contraction) is taken into account. For this reason, for example, if the heating roll of the fixing device is heated and its rotating shaft thermally expands in the axial direction, the rolling elements of the ball bearings are pressed against the thrust track portion unnecessarily strongly, and the rotation supportability of the ball bearings is reduced. Damaging concerns can arise. Therefore, the ball bearing cannot be used as it is as a bearing for a rotating shaft that expands and contracts in the axial direction by heating and cooling like a heating roll and a pressure roll of a fixing device used in a printer or a copying machine.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned technical problems, and can be easily manufactured, and has a novel structure for stably supporting the shaft for rotation without affecting the length variation in the axial direction. It provides a simple ball bearing.

[0007]

That is, the present invention provides:
As shown in FIG. 1A, in a ball bearing in which a plurality of rolling elements 4 are sandwiched and arranged between an inner ring 2 and an outer ring 3, and a rotating shaft 1 attached to the inner ring 2 or the outer ring 3 is rotatably supported, The inner ring 2 and the outer ring 3 are opposed to each other with planar radial direction regulating walls 5 and 6 for restricting the movement of the rolling element 4 in the radial direction of the rotating shaft 1, and one of the inner ring 2 and the outer ring 3 A flat thrust direction restricting wall 7 for restricting the movement of the rolling element 4 in the thrust direction of the rotating shaft 1 is formed, and the radial direction restricting walls 5 and 6 are moved from the thrust direction restricting wall 7 to the rolling element 4. The rolling element 4 is set over a range longer than the diameter dimension, and the rolling element 4 is provided with a thrust direction regulating wall 7 in a space between the radial direction regulating walls 5 and 6 adjacent to the rolling element 4.
Characterized in that an elastically deformable elastic pressing means 8 is loaded.

In such technical means, the present invention is widely applied to ball bearings in general, and particularly to a ball bearing for rotatingly supporting a rotating shaft 1 whose axial length fluctuates due to heating and cooling. Effective. And the inner ring 2
The outer ring 3 and the outer ring 3 may be manufactured by an appropriate method such as utilizing molding or quenching and hardening. However, the radial direction regulating walls 5 and 6 and the thrust direction regulating wall 7 formed on the inner ring 2 and the outer ring 3 are flat. Therefore, the inner race 2 and the outer race 3 can be easily manufactured by press working without forming the radial raceway portion and the thrust raceway portion as before. Here, from the viewpoint of obtaining a sufficient supporting rigidity by a simple manufacturing method, a plate material for manufacturing the inner ring 2 and the outer ring 3 is formed by deep drawing to have at least a substantially L-shaped cross section, and the inner ring 2 and the outer ring 3 are formed. It is preferable that one of the substantially L-shaped sections is used as the radial direction regulating walls 5 and 6, and the other of the substantially L-shaped section is used as the thrust direction regulating wall 7 or the elastic pressing means pressing wall 9.

In the present invention, as the elastic pressing means 8, a leaf spring such as a wavy ring may be used,
An elastic body such as an elastic rubber may be appropriately selected, for example, but the elasticity of the elastic pressing means 8 and the size of the space in which the elastic pressing means 8 is loaded are determined by heating and cooling the rotating shaft 1. It is necessary to allow the range in which the length fluctuates, and to select such an extent that the rotation is stably supported.

Further, as a structure for preventing the shaft from coming off with respect to the ball bearing, a known method may be used.
Is attached to the rotating shaft 1, and the retaining flange 1 extends in the radial direction of the rotating shaft 1 inside the inner ring 2.
0 and the end of the rotating shaft 1
It is preferable to make it contact 0.

Further, as a mounting structure of the ball bearing, the ball bearing is usually closely fitted to the bearing portion of the support frame, but from the viewpoint of restricting the fitting position of the ball bearing, for example, the outer ring 3 It is preferable that a positioning flange protruding in the radial direction of the rotating shaft 1 is formed on the outer periphery, and this positioning flange is brought into contact with the support frame surface. Also, from the viewpoint of more reliably preventing the rotation of the ball bearing, a fixing flange extending in the radial direction of the rotating shaft 1 is provided on a part of the outer ring 3 and fixed to the support frame via the fixing flange with a screw or the like. Is preferred.

In order to apply a rotational driving force to the rotating shaft 1, a normal rotating drive transmitting member 12 is attached to the rotating shaft 1 as shown in FIG. Is a hollow thin shaft, for example, the inner ring 2
Is attached to the rotating shaft 1, the inner ring 2 is formed with an extended portion 11 extending in the thrust direction of the rotating shaft 1. The extended portion 11 reinforces the peripheral surface of the rotating shaft 1, and It is preferable that the rotation drive transmission member 12 is fixed to a corresponding portion with a screw or the like.

Next, the operation of the above technical means will be described. For example, in FIG. 1A, the rolling element 4 of the ball bearing is rotatably rolled by the radial direction regulating walls 5, 6, the thrust direction regulating wall 7, and the elastic pressing means 8.
It is restrained and held in between. Therefore, the inner ring 2 or the outer ring 3
The rotating shaft 1 attached to the shaft is rotatably supported as the rolling element 4 rolls. If the axial length of the rotary shaft 1 changes due to, for example, heating or cooling, the inner ring 2 or the outer ring 3 moves in the axial direction (thrust direction) of the rotary shaft 1 with the change in the axial length of the rotary shaft 1. ), But the moving allowance of the inner ring 2 or the outer ring 3 is absorbed by the elastic deformation of the elastic pressing means 8, so that the rolling elements 4 still have the radial direction regulating walls 5, 6 and the thrust direction regulating wall. 7 and the elastic pressing means 8 are held so as to be able to roll, so that the rotating operation of the rotating shaft 1 does not become unstable.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the accompanying drawings. First Embodiment FIG. 2 shows a first embodiment in which a ball bearing to which the present invention is applied is used for a roll supporting portion (for example, a supporting portion of a heating roll of a fixing device). In FIG. 1, reference numeral 20 denotes a roll shaft composed of, for example, a heating roll of a fixing device.
0 are rotatably supported by a pair of support frames 21 via ball bearings 22, respectively.

In this embodiment, as shown in FIGS. 3 and 5, the ball bearing 22 is formed with a ring-shaped inner ring 30 that is fitted and in close contact with the roll shaft 20 and is slightly larger than the inner ring 30. The vehicle includes a ring-shaped outer ring 40 and a plurality of rolling elements (balls) 50 that are rotatably accommodated in a space between the inner ring 30 and the outer ring 40.

Here, the inner race 30 is formed into a substantially L-shaped cross section by deep drawing a metal circular ring member, and the inner ring 30 extends in the direction along the peripheral surface of the roll shaft 20 in the substantially L-shaped cross section. The extending portion is defined as a radial direction regulating wall 31 of the rolling element 50, and the portion extending in the radially outward direction of the roll shaft 20 of the substantially L-shaped section is a position regulating wall 3 of a wavy plate spring 62 described later.
In addition, a retaining flange 33 is formed on the inner peripheral edge of the radial direction regulating wall 31 in a radially inward direction of the roll shaft 20, and the peripheral edge of the end of the roll shaft 20 is brought into contact with the retaining flange 33. It is like that.

The outer race 40 is formed into a substantially L-shaped cross-section by deep drawing a metal circular ring member, and extends in a direction along the peripheral surface of the roll shaft 20 in the substantially L-shaped cross-section. A flat portion (a portion facing the radial direction regulating wall 31 of the inner ring 30) is defined as a radial direction regulating wall 41 of the rolling element 50,
A portion of the substantially L-shaped section extending in a radially outward direction of the roll shaft 20 (a portion facing the position regulating wall 32 of the inner race 30) is defined as a thrust direction regulating wall 42 of the rolling element 50, and further, a radial direction regulating wall 41. Roll shaft 20 on the outer periphery
The positioning flange 43 is formed so as to extend outward in the radial direction, and the positioning flange 43 is brought into contact with the inner wall surface of the support frame 21.

Further, the rolling element 50 is disposed so as to be able to roll on the radial direction regulating wall 31 of the inner ring 30, the radial direction regulating wall 41 of the outer ring 40, and the thrust direction regulating wall 42. A space is formed between the position regulating wall 32 and the position regulating wall 32. A ring-shaped rolling element pressing plate 61 is disposed in this space, and a ring-shaped wavy plate spring 62 is loaded between the rolling element pressing plate 61 and the position regulating wall 32. The moving body pressing plate 61 is constantly pressed toward the rolling element 50 side. In this embodiment, as shown in FIGS. 4A and 4B, a plurality of, for example, 4
One peak P1 is formed, and 45
A valley P0 is formed at a position displaced by a degree to form a wavy leaf spring.

Further, in the present embodiment, a lubricant (not shown) is provided in a space between the inner ring 30 and the outer ring 40.
A link-shaped resin cap 70 is fixed to the outer peripheral edge of the radial direction regulating wall 41 of the outer ring 40, and the lubricant is retained, and the inner ring 30, the outer ring 40 and the rolling elements 50 are assembled. Is to be maintained.

Next, a method of manufacturing the ball bearing according to the present embodiment will be described. First, the inner ring 30 and the outer ring 40 are formed by deep drawing a ring-shaped member. The rolling element 50, the rolling element pressing plate 61, and the corrugated leaf spring 62 may be incorporated between them, and the cap 70 may be fixed to the outer ring 40 after the lubricant is filled.

If the roll shaft 20 is rotatably supported by the ball bearing manufactured as described above, as shown in FIG. 5A, the rolling element 5 sandwiched between the inner ring 30 and the outer ring 40 is formed.
Numerals 0 are disposed in contact with four positions of the radial direction regulating walls 31 and 41 and the thrust direction regulating wall 42 and the rolling element pressing plate 61. At this time, the respective contact portions of the rolling elements 50 are flat and are not formed in a curved shape like the conventional radial orbital and thrust orbital portions, but the rolling elements 50 are formed by the inner ring 30 and the outer ring 40. The roll shaft 20 is rotatably supported by a ball bearing in order to contact and roll in a state in which the position is restricted.

When the roll shaft 20 is thermally expanded, for example, and its axial length increases, the inner ring 30 of the ball bearing follows the elongation d of the roll shaft 20, as shown in FIG. It moves by d in the axial direction of the shaft 20. However, the movement of the inner ring 30 is absorbed by the elastic compressive deformation of the wavy plate spring 62, and the rolling elements 50 are fixed to the radial direction restricting walls 31, 41 and the thrust direction restricting wall 42 and the rolling element pressing member. The state where it is kept in contact with the four positions of the plate 61 is maintained. At this time, if the elastic coefficient of the wavy plate spring 62 is set to be small, the compressive elastic force applied to the rolling element 50 can be suppressed to a small value, so that even if the inner ring 30 moves in the axial direction of the roll shaft 20, the rolling element A situation in which a particularly strong pressing force acts on 50 does not occur. Therefore, the rotation supporting performance of the ball bearing can be favorably maintained without being affected by the elongation deformation of the roll shaft 20. If the wavy leaf spring 62 is incorporated in a compressed state, it works effectively against the contraction deformation of the roll shaft 20.

Further, according to the present embodiment, the inner ring 30,
Since the outer ring 40 is manufactured by deep drawing, the strength of the inner ring 30 and the outer ring 40 can be sufficiently obtained by utilizing work hardening by drawing. For this reason, the inner ring 30,
As a method for manufacturing the outer ring 40, heat treatment such as quenching and hardening is not required.

Further, in the present embodiment, when the inner ring 30 is deep-drawn, the retaining flange 33 is formed at the same time, so that a separate component such as a retaining ring is not required, and the roll shaft 20 is not required. Is prevented from falling off. Furthermore, in the present embodiment, when the outer ring 40 is drawn, the positioning flange 43 is formed at the same time, so that the positioning operation when the ball bearing is fitted into the bearing hole of the support frame 21 can be easily performed. It is possible to do.

Second Embodiment FIG. 6 shows a second embodiment in which a ball bearing to which the present invention is applied is used for a roll supporting portion (for example, a supporting portion of a heating roll of a fixing device). In the figure, the basic configuration of the ball bearing is substantially the same as that of the first embodiment, but the configuration of the inner ring of one of the ball bearings is different from that of the first embodiment. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted here. That is, an extended cylindrical portion 34 extending in the thrust direction (axial direction) of the roll shaft 20 is formed on the inner ring 30 of one of the ball bearings, and the peripheral surface of the roll shaft 20 is reinforced by the extended cylindrical portion 34. At the same time, a drive gear 35 is fitted to a portion corresponding to the extended cylindrical portion 34 and fixed with a stopper 36 such as a screw. Therefore, according to the present embodiment, even if the roll shaft 20 has a hollow thin-walled structure, the extended tubular portion 34 reinforces the rigidity of the roll shaft 20 and has sufficient support for fixing the drive gear 35. It is designed to ensure rigidity.

Third Embodiment FIG. 7 shows a third embodiment in which a ball bearing to which the present invention is applied is used for a roll support portion (for example, a support portion of a heating roll of a fixing device). In the figure, the basic configuration of the ball bearing is substantially the same as that of the first embodiment, but the configuration of the outer ring of the ball bearing is different from that of the first embodiment. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted here. That is, as shown in FIGS. 7A and 7B, the outer ring 40 has a positioning flange 43 on the outer peripheral edge thereof, and the positioning flange 43.
Is further projected outward to form a fixed flange 44,
A screw insertion hole 45 is formed in a part of the fixing flange 44, and the fixing flange 44 is fixed to the support frame 21 through the screw insertion hole 45 with a stopper 46 such as a screw.

Therefore, according to the present embodiment, the outer race 40
Are firmly fixed to the support frame 21 and are prevented from rotating, so that when the roll shaft 20 rotates, the inner ring 30 and the rolling elements 50
Even if a rotational force acts on the outer ring 40 through the
Zero movement is reliably prevented. If the ground wire is fastened together to the stopper 46 of the fixed flange 44, it is possible to release the static electricity generated on the roll shaft 20.

[0028]

As described above, according to the present invention, the radial and thrust direction regulating walls of the inner ring and the outer ring, and the elastic pressing means loaded in the space between the inner and outer rings. Even if the rotating shaft is expanded and contracted by, for example, heating and cooling, the rolling element is restrained and held so as to be able to roll, and the length variation of the rotating axis is absorbed by the elastic pressing means, and the contact rolling property of the rolling element is reduced. Since the rotation shaft is maintained, the rotation supportability of the rotation shaft can always be kept satisfactorily without being affected by the fluctuation in the axial length of the rotation shaft. Therefore, it is most suitable as a ball bearing that supports a rotating shaft that expands and contracts in the length direction by heating and cooling, such as a heating roll or a pressure roll of a fixing device used in a printer or a copying machine.

Further, according to the present invention, it is not necessary to form a radial raceway portion and a thrust raceway portion on the inner ring and the outer ring, so that it is not necessary to perform machining for forming the raceway portion on the inner ring and the outer ring. In addition, the inner ring and the outer ring can be easily manufactured only by press working, and the manufacturability of the ball bearing can be simplified accordingly.

Further, in the present invention, if the inner ring and the outer ring are subjected to deep drawing, it is possible to obtain a thin and sufficiently strong inner ring and outer ring by utilizing the work hardening by the deep drawing. . For this reason, without using a manufacturing method such as forging, and without the need for heat treatment such as quenching, the size of the inner ring and outer ring can be easily reduced and thinned, and the manufacturing process of the inner ring and outer ring can be improved. It can be simplified.

Further, in the present invention, a retaining flange extending in the radial direction of the rotating shaft is formed inside the inner ring attached to the rotating shaft so that the end of the rotating shaft is brought into contact with the retaining flange. This makes it possible to prevent the rotation shaft from falling off without using a separate component such as a retaining ring.

Further, in the present invention, an extended portion extending in the thrust direction of the rotating shaft is formed on the inner race attached to the rotating shaft, and the extended surface reinforces the peripheral surface of the rotating shaft and a portion corresponding to the extended portion. If the rotary drive transmitting member is fixed to the rotary shaft, the mounting strength of the rotary drive transmitting member can be sufficiently secured even if the rotary shaft has a hollow thin-walled shape. The force can be transmitted reliably and stably.

[Brief description of the drawings]

FIG. 1A is an explanatory diagram showing one embodiment of the configuration of a ball bearing according to the present invention, and FIG. 1B is an explanatory diagram showing another embodiment of the configuration of the ball bearing according to the present invention.

FIG. 2 is an explanatory diagram showing a ball bearing according to the first embodiment.

FIG. 3 is an exploded perspective view of the ball bearing according to the first embodiment.

4A is an explanatory plan view showing details of a waving ring of the ball bearing according to Embodiment 1, and FIG. 4B is an explanatory side view thereof.

5 (a) is a detailed view of a V portion in FIG. 2, and FIG. 5 (b) is a detailed view of a V portion in FIG. 2 of the ball bearing when the rotating shaft is thermally expanded.

FIG. 6 is an explanatory diagram showing a ball bearing according to a second embodiment.

7A is an explanatory diagram showing a ball bearing according to Embodiment 3, and FIG. 7B is an arrow view as viewed from the direction of arrow B in FIG. 7A.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotating shaft, 2 ... Inner ring, 3 ... Outer ring, 4 ... Rolling element, 5, 6
... Radial direction restriction wall, 7 ... Thrust direction restriction wall, 8 ...
Elastic pressing means, 9: elastic pressing means pressing wall, 10: retaining flange, 11: extension, 12: rotary drive transmission member, 20: roll shaft, 30: inner ring, 31: radial direction regulating wall, 32: position regulation Wall, 33 ... retaining flange,
34 ... Extended cylindrical part, 35 ... Drive gear, 40 ... Outer ring, 41
... Radial direction restriction wall, 42 ... Thrust direction restriction wall, 4
Reference numeral 3: positioning flange, 50: rolling element, 61: rolling element pressing plate, 62: corrugated plate spring

Claims (4)

[Claims] A plurality of rolling elements (4) are sandwiched and arranged between an inner ring (2) and an outer ring (3), and a rotating shaft (1) attached to the inner ring (2) or the outer ring (3) is rotated. In the ball bearing for dynamic support, the inner ring (2) and the outer ring (3) have a planar radial direction regulating wall (5, 6) in which the movement of the rolling element (4) in the radial direction of the rotating shaft (1) is restricted. ) Are formed opposite to each other, and one of the inner ring (2) and the outer ring (3) is provided with a rotating shaft (1).
Forming a planar thrust direction regulating wall (7) for restricting the movement of the rolling element (4) in the thrust direction, and from the position of the thrust direction regulating wall (7) to the radial direction regulating wall (5, 6). Is set over a range longer than the diameter of the rolling element (4), and the rolling element (4) is restricted in the thrust direction in the space between the radial direction regulating walls (5, 6) adjacent to the rolling element (4). A ball bearing comprising an elastically deformable elastic pressing means (8) pressed against a wall (7). 2. The inner ring (2) and the outer ring (3) according to claim 1, wherein the inner ring (2) and the outer ring (3) are formed into at least a substantially L-shaped cross section by deep drawing a plate material. One of the substantially L-shaped sections is used as a radial direction regulating wall (5, 6), and the other of the substantially L-shaped section is used as a thrust direction regulating wall (7) or an elastic pressing means pressing wall (9). A ball bearing. 3. The inner ring (2) according to claim 1, wherein the inner ring (2) is mounted on the rotating shaft (1).
A ball, wherein a retaining flange (10) extending in the radial direction of the rotating shaft (1) is formed inside the shaft, and an end of the rotating shaft (1) is brought into contact with the retaining flange (10). bearing. 4. The inner ring (2) according to claim 1, wherein the inner ring (2) is attached to the rotating shaft (1).
Has an extension (1) extending in the thrust direction of the rotary shaft (1).
1) is formed, and the peripheral surface of the rotary shaft (1) is reinforced by the extension (11), and the rotation drive transmission member (12) is fixed to a position corresponding to the extension (11). And ball bearings.