JP2679789B2 - Floating bearing - Google Patents

Description

TECHNICAL FIELD The present invention relates to bearings, and more particularly to novel floating bearings that can replace conventional ball bearings. “Prior Art and Its Problems” The ball bearing has excellent features such as a structure that can receive loads in both thrust and radial directions, a small coefficient of friction, and a high load. On the other hand, however, since the bearing uses rolling friction, the generation of noise due to ball rolling cannot be avoided. Further, since all of them are made of metal parts, and particularly balls require strict dimensional accuracy, there is a drawback that the cost of precision processing and assembly is high and heavy. "Object of the Invention" The present invention has an object to obtain a bearing which is inferior to a ball bearing in load bearing capacity but is superior to the ball bearing in terms of quietness, weight and cost. "Outline of the Invention" The present invention relates to a tubular outer ring; a tubular inner ring; inserted between the outer ring and the inner ring, the inner and outer surfaces of which are in sliding contact with each other.
A cylindrical bush with an axial length shorter than the axial length of the inner ring;
A pair of radially inward thrust members provided on the outer ring that determine the axial position of the inner ring, the axial position of the pair of thrust members with respect to the outer ring, and the interval between them are unique regardless of the axial position of the inner ring. The inner ring, the outer ring and the thrust member are made of a metal material; the bush is made of a resin material; and the pair of thrust members and a slide member are provided on both end faces of the inner ring. A resin coating in contact therewith is provided; For example, one of the pair of thrust members is an inner flange integrally formed with the outer ring, and the other is sandwiched between a step portion formed on the outer ring and a retaining ring that is locked to the outer ring and positioned on the outer ring. The thrust plate can be made up of Alternatively, each of the pair of thrust members can be composed of a pair of thrust plates which are sandwiched between a step formed on the outer ring and a retaining ring locked on the outer ring and positioned on the outer ring. According to this floating bearing, since the sliding surfaces of the inner and outer surfaces of the bush are constituted by the contact surface of the resin material and the metal material, excellent sliding characteristics are obtained, and the friction is low and the cost is low. Further, the effect of vibration absorption (vibration absorption) by the resin material can be expected. Furthermore, the axial length of the bush is shorter than the axial length of the inner ring, and the position of this inner ring is regulated by the thrust member that is positioned on the outer ring, so that the force in the thrust direction can be reliably received without the bush. You can Furthermore, since the inner ring has the resin coating on both end surfaces that come into contact with the pair of thrust members, it is also excellent in quietness. BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the accompanying drawings. FIG. 1,
FIG. 2 shows a first embodiment of the floating bearing according to the present invention. This floating bearing consists of 1 outer ring and 1 inner ring
2, a bush 13, a thrust plate (thrust member) 14, and a retaining ring (snap ring) 15. The outer ring 11, the inner ring 12, and the thrust plate 14 are all made of a metal material such as bearing steel. Outer ring 11
Has a tubular portion 11a and an inward flange (thrust member) 11b extending inward from one end of the tubular portion 11a, and is fixed to a bearing housing (not shown). This outer ring
Further, 11 is an annular thrust plate locking step portion 11c having a diameter larger than the inner diameter of the tubular portion 11a at the end opposite to the inner flange 11b, and a dropout having a diameter larger than the thrust plate locking step portion 11c. It has a retaining ring locking groove 11d. The inner ring 12 has a supported shaft fixed to the inner periphery thereof by, for example, press fitting, and has a tubular (annular) shape. Its inner diameter is
It is smaller than the inner diameters of the inner flange 11b and the thrust plate 14. Bush 13 is basically a polyacetal nylon,
A resin material such as PPS can be used, but a resin material with excellent wear resistance and friction characteristics is preferable. Specifically, it can be composed of a polyimide resin called quinel, a polyester resin called Ekonol S, a polyamide-imide resin called Torlon, a resin material obtained by adding PTFE to the above resin, or a PTFE resin. The bush 13 has a clearance of an appropriate size between the inner surface of the tubular portion 11a and the outer surface of the inner ring 12, and is in sliding contact with both. This clearance may be selected, for example, between 30 μm and 150 μm on the basis of diameter. In this embodiment, the outer ring side is 40 μm and the inner ring side is 90 μm. The thrust plate 14 is fitted into the thrust plate locking step portion 11c of the outer ring 11, and further the retaining ring locking groove 11d.
It is sandwiched and supported between the retaining ring 15 fitted to the inner ring 12 and the step portion of the thrust plate locking step portion 11c to regulate the axial positions of the inner ring 12 and the bush 13. The axial position of the thrust plate 14 is independently determined by the step portion of the retaining ring locking groove 11d and the retaining ring 15, and is independent of the axial positions of the inner ring 12 and the bush 13. Further, the axial length l1 of the bush 13 is set shorter than that l2 of the inner ring 12. This is because it is difficult to improve the machining accuracy of the inner surface c of the connecting corner portion of the tubular portion 11a of the outer ring 11 and the inner flange 11b, and the inner ring 12 is more effective than the bush 13 to receive the thrust load. This is because it is advantageous. Further, if the axial length of the bush 13 is made shorter than that of the inner ring 12, there is an advantage that the accuracy of the bush 13 in the longitudinal direction may be rough. And in order to avoid contact between metals, this inner ring
A resin coating 16 such as Teflon (tetrafluoroethylene resin) is coated on both end surfaces of 12, that is, the contact surfaces of the inner flange 11b and the thrust plate 14. The floating bearing of the above structure has an outer ring 11 and an inner ring 12
When a relative rotation occurs between the bushes, the bush 13 makes sliding contact with the inner peripheral surface of the tubular portion 11a and the outer peripheral surface of the inner ring 12. Since this sliding contact is performed by contact between the metal material and the resin material, good sliding characteristics can be obtained, and galling, wear, etc. are unlikely to occur. Further, the load in the thrust direction applied between the outer ring 11 and the inner ring 12 is received by the contact between both end faces of the inner ring 12, the tubular portion 11a and the thrust plate 14. Since the resin coating 16 is formed on both end surfaces of the inner ring 12 to avoid contact between metals, sliding contact in the thrust direction is also made by contact between the metal material and the resin material, and thus in the radial direction, Excellent friction characteristics can be obtained in both thrust direction. Since it is in sliding contact, it is more quiet than ball bearings that use rolling contact, and because the structure is simple and the number of components is small, it is cheap and lightweight. Although the load bearing capacity is slightly inferior to the ball bearing, the floating bearing can be sufficiently used for a bearing used under a light load. Furthermore, the thrust plate 14 has a retaining ring locking groove.
Since it is sandwiched and supported by 11d and the retaining ring 15, even if the end faces of the inner ring 12 and the bush 13 are worn, they will not tilt. Therefore, the inner ring 12 and the bush 13 are not given harmful rotation resistance by the thrust plate 14 even if they are unevenly worn. FIG. 3 shows a second embodiment of the present invention. In this embodiment, without forming the inner flange 11b on the outer ring 11, the thrust plate locking step 11c and the retaining ring locking groove 11d are formed on the right and left sides of the outer ring 11, and the thrust plate retaining step 11c and the retaining ring are formed. A thrust plate 14 and a retaining ring 15 are fitted in the ring locking groove 11d to lock the inner ring 12 and the bush 13 respectively. A resin coating 16 is formed on both end surfaces and the inner peripheral surface of the inner ring 12 except the outer peripheral surface. In this embodiment, the inner surface of the inner ring is also coated with resin. This is a portion that does not directly participate in sliding, but it is provided for the advantage of being extremely simple in manufacturing if the resin cover is formed by spray coating while masking the outer peripheral surface of the inner ring with a holding jig. And when press-fitting this inner ring to the supported shaft,
In particular, it can be expected to have the effect of elastically supporting the shaft without causing any trouble. The other parts are the same as those of the first embodiment, and the same parts are designated by the same reference numerals. According to this embodiment, in addition to the advantages of the first embodiment, the advantage that the inner ring 12 and the bush 13 can be attached and detached from both sides of the outer ring 11 is obtained. Therefore, for example, when it is necessary to replace the inner ring 12 or the bush 13, the replacement work can be performed from either the outer ring 11, and the directionality is lost. "Effects of the Invention" As described above, the floating bearing of the present invention is excellent in quietness as compared with the ball bearing by rolling contact because the bearing is composed of a sliding bearing in which a metal material and a resin material are in contact with each other. In particular, sliding contact between a metal material and a resin material has excellent friction characteristics, and galling and abnormal wear hardly occur. Furthermore, the axial length of the bush is shorter than the axial length of the inner ring, and the position of this inner ring is regulated by a pair of thrust members positioned on the outer ring, so that the force in the thrust direction is reliably received without the bush. be able to. Furthermore, since both end surfaces of the inner ring are provided with a resin coating that is in sliding contact with the pair of thrust members, it is also excellent in quietness. Further, since the structure is simple and the number of parts is small, it can be provided at low cost and is lightweight. Therefore, it can be expected to be widely used as a bearing with a light load.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view showing a first embodiment of a floating bearing according to the present invention, FIG. 2 is a right side view of FIG. 1, and FIG. 3 is a second side view of the present invention. It is a longitudinal section showing an example. 11 ... Outer ring, 11a ... Cylindrical part, 11b ... Inner flange (thrust member), 11c ... Thrust plate locking step, 11d
...... Detachment ring locking groove, 12 ...... Inner ring, 13 ...... Bush, 14 ...... Thrust plate (thrust member), 15 ......
Lock ring, 16 ... Resin coating.

   ────────────────────────────────────────────────── ─── Continuation of front page    (56) Bibliography Reference: Sho 55-6598 (JP, U)                 Actual public Sho 42-20922 (JP, Y1)                 Actual public Sho 40-17126 (JP, Y1)

Claims (1)

(57) [Claims] Cylindrical outer ring; Cylindrical inner ring; Cylindrical bushing inserted between the outer ring and the inner ring, the inner and outer surfaces of which are in sliding contact with each other and whose axial length is shorter than the axial length of the inner ring; A pair of radially inward thrust members provided on the outer ring that determine the axial position, the axial position of the pair of thrust members with respect to the outer ring, and the interval between them are unique regardless of the axial position of the inner ring. The inner ring, the outer ring and the thrust member are made of a metal material; the bush is made of a resin material; and the pair of thrusts are provided on both end faces of the inner ring. A floating bearing, which is provided with a resin coating that is in sliding contact with a member. 2. In the floating bearing according to claim 1, one of the pair of thrust members is an inner flange integrally formed with the outer ring, and the other is a step portion formed on the outer ring, and the thrust member is locked to the outer ring. Floating bearing, which is a thrust plate that is sandwiched between the retaining rings and positioned on the outer ring. 3. In the floating bearing according to claim 1, each of the pair of thrust members has a step portion formed on the outer ring and a pair of thrust members which are sandwiched by a retaining ring engaged with the outer ring and positioned on the outer ring. Floating bearing that is a thrust plate. 4. The floating bearing according to claim 1, wherein the inner race is further provided with a resin coating on its inner peripheral surface.