JP2000320649A - Gear with bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for a work to press in a bearing and a shaft by constituting a gear and the bearing integrally with each other and to provide a gear with a bearing to be decreased in the number of parts. SOLUTION: A gear 1 with a bearing comprises a gear 2; and a bearing 4 made of synthetic resin molded in a manner to be adhered to the inner peripheral surface of the bearing mounting hole 3 of the gear 2. The bearing 4 is provided with a radial bearing part 5 is provided with a cylindrical part adhered to the inner peripheral surface of the bearing mounting hole 3, and a plurality of bearing protrusions 8 situated in a dispersing state throughout the whole of the inner surface of the cylindrical part 6 and having a top face 7 forming a slide surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear with bearing,
The present invention relates to a gear and a synthetic resin bearing formed so as to be in close contact with the inner peripheral surface of a bearing mounting hole of the gear.

[0002]

2. Description of the Related Art Heretofore, there has been known an apparatus in which a gear is mounted on a shaft outer peripheral surface via a radial bearing.

[0003]

In this case, the press fitting of the radial bearing into the bearing mounting hole of the gear and the press fitting of the shaft into the radial bearing are indispensable operations, respectively. And the radial bearing are separate, and the number of parts increases accordingly.

[0004]

SUMMARY OF THE INVENTION The present invention makes the press-fitting operation unnecessary by integrating the gear and the bearing.
It is another object of the present invention to provide the gear with a bearing capable of reducing the number of parts.

[0005] To achieve the above object, according to the present invention,
The bearing comprises a gear and a synthetic resin bearing formed so as to be in close contact with the inner peripheral surface of the bearing mounting hole of the gear. The bearing has a radial bearing portion, and the radial bearing portion is provided on the inner peripheral surface of the bearing mounting hole. There is provided a gear with a bearing having a cylindrical portion that is in intimate contact and a plurality of bearing projections that are arranged in a scattered manner on the entire inner peripheral surface of the cylindrical portion and whose top surface is a sliding surface.

With the above-described structure, since the bearing is integrated with the gear, there is no need to press the bearing into the bearing mounting hole of the gear. Further, since the gear is mounted on the shaft by fitting the shaft into the radial bearing portion, the work of press-fitting the shaft into the bearing is not required. Further, the number of parts is reduced by integrating the bearing and the gear.

In addition, since the shaft is supported by a plurality of bearing projections, the contact area between the shaft and the radial bearing portion is reduced, and the area around each bearing projection becomes an oil reservoir. Friction is greatly reduced. Thus, the life of the bearing made of synthetic resin can be extended.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG.
The gear 2 comprises a steel gear 2 and a synthetic resin bearing 4 formed so as to be in close contact with the inner peripheral surface of the bearing mounting hole 3 of the gear 2. Referring also to FIGS. 2 and 3, the bearing 4 includes a radial bearing portion 5,
The radial bearing portion 5 is arranged in a cylindrical portion 6 which is in close contact with the inner peripheral surface of the bearing mounting hole 3, and is scattered around the entire inner peripheral surface of the cylindrical portion 6, and the top surface 7 is a sliding surface. Multiple bearing projections 8
Having.

In the illustrated example, the bearing projections 8 are located at the intersections of 64 of four virtual circles arranged at a predetermined interval in the axial direction and 16 virtual buses arranged at a predetermined interval in the circumferential direction. . The synthetic resin constituting the bearing 4 is polyimide,
Polyether ether ketone (PEEK) or the like is used.

With the above construction, the bearing 4 is mounted on the gear 2
Therefore, the work of press-fitting the bearing 4 into the bearing mounting hole 3 of the gear 2 is unnecessary. Further, since the gear 2 is attached to the shaft 9 by fitting the shaft 9 into the radial bearing portion 5, the work of press-fitting the shaft 9 into the bearing 4 is not required. Further, the number of parts is reduced by integrating the bearing 4 and the gear 2.

In addition, since the shaft 9 is supported by the plurality of bearing projections 8, the contact area between the shaft 9 and the radial bearing portion 5 is reduced, and an oil reservoir 10 is formed around each bearing projection 8. Therefore, the friction between the shaft 9 and the bearing 4 is greatly reduced. Thus, the life of the bearing 4 made of a synthetic resin can be extended.

On the other hand, when the thrust of the gear is received by, for example, thrust washers attached to the shaft on both sides of the gear, thrust bearings are arranged between both end faces of the gear and both thrust washers. If such means are adopted, an increase in the number of parts is unavoidable.

In order to solve such a problem, the bearing 4
The two end faces 11, 1 of the gear 2 are provided at both ends of the cylindrical portion
2, the flange-shaped thrust bearing portions 13 in close contact with each other,
It has 14. Each of the thrust bearing portions 13 and 14 has at least one oil groove 15 on its outer surface. In the illustrated example, in each of the thrust bearing portions 13 and 14, eight oil grooves 15 are formed at regular intervals on the circumference and from the inner peripheral edge to the outer peripheral edge.

As clearly shown in FIGS. 2, 3 and 4, eight projections 16 are provided on the inner surfaces of the thrust bearings 13 and 14 so as to be located between two adjacent oil grooves 15.
The convex portions 16 are fitted into eight concave portions 17 opened on both end surfaces 11 and 12 of the gear 2, thereby forming the gear 2.
The rotation of the bearing 4 is stopped.

With the above configuration, the thrust of the gear 2 can be supported by, for example, a thrust washer via the respective thrust bearings 13 and 14. Further, since the space between the thrust bearings 13 and 14 and the thrust washers is sufficiently lubricated by the oil supplied from the oil grooves 15, the thrust bearings 13 and 14 made of synthetic resin are used.
Life can be extended.

With the clearance between the shaft 9 and the radial bearing 5 set to 10 to 50 μm and the gear 2 fixed, the shaft 9 is rotated while supplying oil between the shaft 9 and the radial bearing 5. When the rotation speed was gradually increased, it was found that the oil around the shaft 9 was skipped by the high-speed rotating shaft 9 at about 6000 rpm and disappeared, and that the shaft 9 was floating and rotating with the clearance. This is extremely effective in extending the life of the radial bearing portion 5.

The gear 2 may be made of a synthetic resin such as polyamide, and in this case also, the bearing 4 is structured as described above.

[0018]

According to the first aspect of the present invention, by integrating the gear and the bearing, it is possible to eliminate the need for press-fitting the bearing and the shaft and to reduce the number of parts. Can be provided. In addition, since this bearing has a structure capable of greatly reducing friction with the shaft, the life of the bearing is prolonged despite being made of synthetic resin.

Further, according to the second aspect of the present invention, it is possible to provide a gear with a bearing in which the advantage of reducing the number of parts in the above effects is further enhanced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of a gear with a bearing.
1 corresponds to a cross-sectional view taken along line 1-1.

FIG. 2 is a side view of the bearing alone and corresponds to a view taken in the direction of arrow 2 in FIG.

FIG. 3 is a longitudinal sectional side view of a bearing unit, which corresponds to a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a longitudinal sectional front view of a gear with a bearing.
Corresponds to a sectional view taken along line 4-4 of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gear with bearing 2 Gear 3 Bearing mounting hole 4 Bearing 5 Radial bearing part 6 Cylindrical part 7 Top surface 8 Bearing projection 11,12 End face 13,14 Thrust bearing part 15 Oil groove

Claims (2)

[Claims] 1. A bearing (4) comprising a gear (2) and a synthetic resin bearing (4) molded so as to be in close contact with an inner peripheral surface of a bearing mounting hole (3) of the gear (2). Has a radial bearing portion (5), and the radial bearing portion (5) has a cylindrical portion (6) closely contacting the inner peripheral surface of the bearing mounting hole (3) and an inner peripheral surface of the cylindrical portion (6). A bearing-equipped gear characterized by having a plurality of bearing projections (8) which are arranged in a scattered pattern as a whole and whose top surface (7) is a sliding surface. 2. The bearing (4) is provided with the cylindrical portion (6).
At both ends (11, 1) of the gear (2).
Flange-shaped thrust bearings (1)
3, 14) and each flange-shaped thrust bearing (1
3. The gear with bearing according to claim 1, wherein the gears (3, 14) have at least one oil groove (15) on their outer surface.