JP2003043849A - Roller bearing for supporting fixing roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict friction a shaft end of a fixing roller by sufficiently increasing tolerance for misalignment caused by flexure of the fixing roller. SOLUTION: The needle-like roller bearing for supporting the fixing roller has an inner ring 12 formed from an oil-containing sintered member in the inner diameter portion of which the shaft end 15 of the fixing roller 14 is fitted, an outer ring 11 on the outer diameter portion of which a mounting member is disposed, and needle-like rolls 13 interposed between the inner ring 12 and outer ring 11. The bearing freely rotatably supports the inner ring 12 relative to the outer ring 11. In the bearing, the inner diameter portion of the inner ring 12 has a taper 17 extending in the axial direction of the ring 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing for supporting a fixing roller, and more particularly to a rolling bearing for supporting a fixing roller which constitutes a part of a fixing device incorporated in an electrostatic transfer copying machine or a laser printer. .

[0002]

2. Description of the Related Art A fixing device incorporated in, for example, an electrostatic transfer copying machine or a laser printer is a device for fixing the toner charged and adhered on the paper to the paper, and includes a fixing roller and a pressure roller. Configured as the subject. The fixing roller has a heater inside, and the toner on the paper is fixed on the paper by heating the toner at a high temperature of up to about 250 ° C. by the heater. The pressure roller is disposed in parallel with the fixing roller while pressing the fixing roller, and rotates by being driven by the fixing roller. The pressure roller has a role of stabilizing the toner heated and fixed on the sheet by the fixing roller.

Deep groove ball bearings, small diameter ball bearings, miniature ball bearings and slide bearings are often used in the support structure of this type of fixing roller. The bearing used for the fixing roller support structure is required to be inexpensive, low torque, high temperature durability, and small space.

In response to these requirements, the various bearings have advantages and disadvantages. For example, a sliding bearing has an advantage that it is inexpensive, but has a large rotating torque and is compatible with a commonly used fixing roller made of aluminum. It is bad and it is difficult to absorb misalignment sufficiently.

Further, deep groove ball bearings, small diameter ball bearings, and miniature ball bearings have the advantage of having a small rotational torque, but are expensive as compared with slide bearings, and it is difficult to sufficiently absorb a large misalignment. However, when a small space is taken into consideration, the bearing size becomes smaller, so the allowable load becomes smaller.

Therefore, in order to solve the problems of deep groove ball bearings, small diameter ball bearings, miniature ball bearings and slide bearings described above, the fixing roller support structure is cheaper than deep groove ball bearings and requires a small space. It is desired to use needle roller bearings that are easy to handle and have a smaller rotating torque than sliding bearings. There are two types of needle roller bearings, one with an inner ring shown in FIG. 5 and the other without an inner ring shown in FIG.

As shown in FIG. 5, the needle roller bearing of the inner ring type has an outer ring 1 on which an attaching member is mounted on the outer diameter,
It has a structure in which a plurality of needle rollers 3 are arranged between the inner ring 2 and the inner ring 2 into which the shaft end 5 of the fixing roller 4 is fitted. Also,
As shown in FIG. 6, the needle roller bearing of the type without an inner ring includes an outer ring 1 having a mounting member attached to the outer diameter, and a fixing roller 4.
It has a structure in which a plurality of needle rollers 3 are arranged between the shaft end 5 and the shaft end 5. Although not shown, in both types of needle roller bearings, a plurality of needle rollers 3 are rotatably arranged at equal intervals in the circumferential direction by a cage.

[0008]

By the way, the needle roller bearings of both the inner ring type and the inner ring type as described above have the following problems when they are used for the supporting structure of the fixing roller 4.

The fixing roller 4 has a diameter of 12 mm, for example.
7 and 8 when the solid rollers below are used.
The fixing roller 4 by the load acting in the radial direction as shown in FIG.
Is large, and it is difficult to sufficiently absorb the misalignment due to this bending. Here, in order to speed up the fixing process, it is necessary to improve the fixing speed. However, if the heating temperature of the fixing roller 4 is raised to 250 ° C. or higher in order to improve the fixing speed, the power consumption will be reduced. As the number of the fixing rollers increases, the heat-resistant temperature of the parts near the supporting structure is exceeded, and it is very difficult to raise the heating temperature of the fixing roller 4.

The misalignment due to the bending of the fixing roller 4 varies depending on the material, shape, size, and magnitude of the load of the fixing roller 4, but the load is only from one direction.
The direction of bending is also fixed. In particular, there is a method of increasing the fixing load in order to improve the fixing speed. However, if the fixing load is increased, the bending of the fixing roller 4 is further increased and it becomes more difficult to absorb the misalignment.

Further, due to the bending of the fixing roller 4, the inner ring 2
Since the load is applied (on one side) only at the inner diameter of or the axial end portion of the needle roller 3, the shaft end portion 5 of the fixing roller 4 is extremely worn (scratched) due to an excessive load. The occurrence of this wear becomes particularly noticeable when a soft material such as aluminum is used as the material of the fixing roller 4, and it becomes difficult to use the fixing roller 4 made of the soft material.

Therefore, the present invention has been proposed in view of the above problems, and an object of the present invention is to sufficiently absorb misalignment due to bending of the fixing roller and to cause wear generated at the shaft end portion of the fixing roller. To provide a rolling bearing for supporting a fixing roller capable of suppressing the above.

[0013]

As a technical means for achieving the above object, the present invention has an inner ring in which an axial end portion of a fixing roller is fitted in an inner diameter and a mounting member in an outer diameter. In a rolling bearing for fixing roller support, comprising an outer ring and a rolling element interposed between the inner ring and the outer ring and rotatably supporting the inner ring with respect to the outer ring, the inner diameter of the inner ring is a convex curved surface along the axial direction. It is characterized by having a part. The convex curved surface portion of the inner ring is preferably tapered or spherical.

By forming the tapered or spherical convex curved surface portion on the inner diameter of the inner ring as described above, even if the axial end portion of the fixing roller is bent by the load acting in the radial direction of the fixing roller, The misalignment due to the bending of the fixing roller can be sufficiently absorbed, and the abrasion generated at the shaft end portion of the fixing roller can be suppressed. Misalignment can also be absorbed by forming the outer diameter of the outer ring into a convex curved shape along the axial direction.

In the above structure, if the flange portion is formed at the axial end portion of the inner ring, the axial load can be applied by the flange portion. Further, if the inner ring is made of an oil-impregnated sintered material, it is not necessary to seal grease inside the bearing, and a grease seal structure is not required.

As the rolling bearing according to the present invention,
A needle roller bearing in which the rolling element is a needle roller is suitable. The needle roller bearing has a merit that it is cheaper than a deep groove ball bearing when used for a fixing roller support structure, can easily accommodate a small space, and has a rotational torque smaller than that of a sliding bearing.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a rolling bearing for supporting a fixing roller according to the present invention will be described in detail below.

The rolling bearing for supporting the fixing roller of the embodiment shown in FIG. 1 is a needle roller bearing of the type with an inner ring, and has an inner ring 12 into which the shaft end of the fixing roller is fitted, and an outer ring to which the fixing roller is mounted. An outer ring 11 on which a member is mounted and the inner ring 12
The needle roller 13 (rolling element) is interposed between the outer ring 11 and the outer ring 11, and the fixing roller is rotatably supported by the needle roller bearing with respect to the mounting member. In this embodiment, the inner ring 12 is formed with a tapered portion 17 on the inner diameter thereof, the diameter of the taper portion 17 increasing toward both axial ends thereof.

The inclination angle θ of the taper portion 17 is preferably, for example, about 2 to 8 ° in consideration of the state in which the shaft end portion of the fixing roller is bent by the load acting in the radial direction of the fixing roller. If the inclination angle θ of the taper portion 17 is smaller than 2 °, it is difficult to sufficiently absorb the misalignment due to the bending of the fixing roller, and the shaft end portion of the fixing roller is likely to be worn. On the contrary, the inclination angle θ of the taper portion 17
Is greater than 8 °, the axial end portion of the inner ring 12 is reduced, and the axial end portion necessary for processing cannot be secured.

Although the tapered portion 17 is formed on the inner diameter of the inner ring 12 in this embodiment, the present invention is not limited to this, and the spherical portion 17 having a predetermined radius of curvature R as shown in FIG. It is also possible to form ', and another convex curved surface portion including the tapered portion 17 and the spherical surface portion 17' may be formed.

FIG. 3 shows a supporting structure of the fixing roller 14 using the needle roller bearing of FIG. Outer ring of needle roller bearing 11
The outer diameter of the fixing roller 14 is fixed to the housing 16, and the shaft end portion 15 of the fixing roller 14 is fitted into the inner diameter of the inner ring 12. In the needle roller bearing of this embodiment, the taper portion 17 is formed on the inner diameter of the inner ring 12, so that the fixing roller 14
Even if the shaft end portion 15 of the fixing roller 14 is bent by the load acting in the radial direction of the fixing roller 14, misalignment due to the bending of the fixing roller 14 is sufficiently absorbed, and the fixing roller 14
It is possible to suppress wear that occurs in the shaft end portion 15 of the.
By suppressing this abrasion, it becomes easy to use the fixing roller 14 made of a soft material such as aluminum.

In this needle roller bearing, if the flange portion 19 is formed at the axial end portion of the inner ring 12, the axial load can be applied by the flange portion 19.
Further, as shown in FIG. 4, if the outer diameter of the outer ring 11 'is a convex curved surface shape along the axial direction, for example, a convex spherical surface shape having a predetermined radius of curvature r, the spherical surface portion 18 further absorbs misalignment. be able to. The outer ring 11 'is preferably made of a sintered material so that the spherical portion 18 can be easily formed.

If the inner ring 12 is made of an oil-containing sintered material, the oil (lubricating oil) contained in the inner ring 12 is supplied to the needle rollers 13 by rotation, so that each contact portion (fixing roller 14 And inner ring 12, inner ring 12 and needle rollers 13, outer ring 11
And the flange portion 19) of the inner ring 12 are easily lubricated, it is not necessary to seal grease inside the bearing, and a grease seal structure is not required. If the inner ring 12 is made of an oil-impregnated sintered material, it is easy to form a tapered or spherical convex curved surface portion.

[0024]

According to the present invention, by forming a tapered or spherical convex curved surface portion on the inner diameter of the inner ring, the axial end portion of the fixing roller is bent due to the load acting in the radial direction of the fixing roller. Even if it occurs, misalignment due to the bending of the fixing roller can be sufficiently absorbed, and the abrasion generated at the shaft end portion of the fixing roller can be suppressed, so that the life of the rolling bearing can be extended. Further, by suppressing the wear of the fixing roller, it becomes easy to use the fixing roller made of a soft material such as aluminum, and it is possible to provide a bearing having excellent versatility.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a needle roller bearing in which an inner ring has a tapered portion in an embodiment of a fixing roller supporting rolling bearing according to the present invention.

FIG. 2 is a partial cross-sectional view showing a needle roller bearing having a spherical portion formed on the inner diameter of the inner ring according to another embodiment of the present invention.

3 is a sectional view showing a fixing roller support structure using the needle roller bearing of FIG.

FIG. 4 is a cross-sectional view showing a needle roller bearing in which the outer diameter of the outer ring is a convex spherical shape in another embodiment of the present invention.

FIG. 5 is a partial cross-sectional view showing a needle roller bearing with an inner ring, which is a conventional example of a rolling bearing for supporting a fixing roller.

FIG. 6 is a partial cross-sectional view showing a needle roller bearing without an inner ring, which is a conventional example of a rolling bearing for supporting a fixing roller.

7 is a sectional view showing a fixing roller support structure using the needle roller bearing of FIG.

8 is a sectional view showing a fixing roller supporting structure using the needle roller bearing of FIG.

[Explanation of symbols]

11 outer ring 12 inner ring 13 Rolling elements (needle rollers) 14 Fixing roller 15 Shaft end 17 Tapered convex curved surface (tapered part) 17 'Spherical convex curved surface portion (spherical surface portion) 18 Spherical part of outer ring 19 Flange

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshiyuki Mizuno             Katsutaba, Kanie, Niigata, Kanie-cho, Kaifu-gun, Aichi Prefecture             No. 101 NTT Special Alloy Co., Ltd.             Within F term (reference) 2H033 AA23 BB01 BB18 BB28 BB36                 3J101 AA14 AA24 AA32 AA42 AA62                       BA53 BA54 BA56 BA57 BA70                       FA32 FA46 GA60                 3J103 AA02 BA03 DA05 GA58 GA66

Claims (6)

[Claims] 1. An inner ring having an inner diameter to which a shaft end of a fixing roller is fitted, an outer ring having an outer diameter to which a mounting member is mounted, and a rolling element interposed between the inner ring and the outer ring, A fixing roller supporting rolling bearing for rotatably supporting a fixing roller with respect to a mounting member, wherein an inner diameter of the inner ring has a convex curved surface portion along the axial direction. 2. The rolling bearing for supporting a fixing roller according to claim 1, wherein the convex curved surface portion of the inner ring is tapered or spherical. 3. The fixing roller supporting rolling bearing according to claim 1, wherein a flange portion is formed at an axial end portion of the inner ring. 4. The rolling bearing for supporting a fixing roller according to claim 1, wherein the inner ring is made of an oil-containing sintered material. 5. The rolling bearing for supporting a fixing roller according to claim 1, wherein the outer diameter of the outer ring has a convex curved shape along the axial direction. 6. The rolling bearing for supporting a fixing roller according to claim 1, wherein the rolling element is a needle roller.