JPS6165909A - Plastic linear plain bearing - Google Patents

Abstract

PURPOSE:To erase a shortage of lubricant due to clawing by the inclination of a moving body and delete the catching of its edge during motion by providing a carrier at the mid-part of a bearing hole in parallel with an axial center and inclining both ends of the carrier. CONSTITUTION:A plastic linear plain bearing 1 is cylindrically formed with its peripheral surface 11 fitted to and held by a supporter and a circular hole 12 serving as a bearing hole forming the bearing surface which is in sliding contact with the peripheral surface 21 of an axis 2 via a lubricant at the position of an axial center. The circular hole 12 has a cylinder surface 13 serving as a carrier parallel to the axial center at the mid-part and an inclining face 14 of curvature at both ends, continuous smoothly to the cylinder surface 13.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention provides that either the shaft body or the bearing support body (1)
When the moving body of the bearing support or the shaft body reciprocates in the axial direction via the bearing, for example, a mirror slide of a copying machine, a lamp slide, a printer, a plotter, a magnetic desk head, an optical desk. This relates to a plastic linear sliding bearing that is effective as a support bearing for a head. [Prior art] Linear sliding bearings that have been conventionally used for this type of application include, for example, bearings as shown in 31A and 4th J. It is held on a support 1a, and together with the support 1a, a shaft 2a
The plastic bearing 3a, which moves upward in the axial direction (1!7I), has a circular hole 31a that forms a sliding bearing surface between the outer peripheral surface of the shaft and the circular hole 31a that has the same diameter over its entire length. The end edge 32a has only a thread surface fit to eliminate sharp edges, and no other measures have been taken.

Therefore, as shown in FIG. 4, for example, when the support 1a is tilted, the edge 32a of the bearing 3a scrapes off lubricant, such as oil, adhering to the outer surface of the shaft 2a. As a result, the lubricant on the bearing surface becomes insufficient and the torque increases. At the same time, during movement, another problem arises in that the edge 32a gets caught on the outer surface of the shaft member, which further increases the torque and prevents smooth movement. It had the disadvantage of being inhibited.

[Problems that non-invention attempts to solve]

This invention eliminates the lack of %M fit due to the above-mentioned tln (moisturization due to the tilt of the viewing body) and scraping of the agent, and also prevents the 44 edges from getting caught at the time of movement. Weird torque!! Eliminate noise and smooth transition Φ
May you have strength 1. It's ours.

[Means for solving the problem] This invention is based on the hollow body &
l bearing u! In the receiving hole, the center part of the receiving hole is made into a receiving surface parallel to the axis, and both subsequent ends are curved or tapered surfaces that widen toward the end surface. It's another thing.

[Saku] (4) With the above configuration, it is possible to prevent the edge of the bearing's bearing hole from being caught or the lubricant from being scraped off due to one jet of the moving body, and also to prevent the lubricant from being scraped off on the inclined surface. The small wedge-shaped space formed by the wedge-shaped space creates a wedge effect that draws the lubricant adhering to the surface of the shaft to the receiving surface parallel to the axis of the central region. 1) Improving the lubrication performance of the bearings and reducing finger torque.

[Explanation of Examples]

Next, two representative embodiments of the FLAN, KNAC, and CNC linear sliding bearings of the present invention will be described.

In explaining this embodiment, the parts around the bearing explained in the above Q'>prior art will be omitted, and the slip will be explained by illustrating only the bearing.

In the example, ■ is a molded (injection molded) plastic part', 'near dimension support, outer periphery 1i1) fitted and held by support 1Bk (not shown), and support center position. A circular hole 12 serving as a bearing hole forms a bearing surface in contact with the outer circumferential surface 21 of the shaft 2 through a lubricant rFt between the shaft 2 and the outer peripheral surface 21.
It is formed into a planar body with a distance of 'Jffl'. Furthermore, 1i
A hollow body (Yo, be?: B lik I) is sometimes made by cutting and sliding it from the entity that replaced it.

Part 1. The circular hole 121-1 as a bearing hole forming a bearing surface has a cylindrical surface 13 as two planes parallel to each other in the central region, and 1tiL at both ends thereof. A cylindrical part 13 is formed by a curved surface that is smoothly connected to the cylindrical part 13.

In the first embodiment, the bearing material is polyphenylene sulfide lH resin (PPs) or Boliete! It is made of plastic material such as Wrestlephone Jugetsu 1 (PES).

That is, the circular hole 12Vi, which is the bearing surface of the bearing 1 made of the general plastic material described below, leaves a cylindrical surface 13 in the central region, and has an inclined ifi 14 whose diameter increases toward the end surface at both ends. It is formed by pressing. and,
The size of the inclination 1) ffi14 is not just a chamfer of the edge part, but also a case where the bearing 1 is tilted in the axial direction (in the direction of the arrow) during use.
When the bearing reciprocates, the lubricant adhering to the outer surface 21 of the shaft body 1 is pulled into the cylindrical surface 13 by a wedge effect, and during the movement 1) 1, the bearing 4. The peripheral edges of both ends of the circular hole 12 are set so as not to catch on the outer circumferential surface 21 of the shaft body 2 even if it is tilted as shown in FIG. They are connected smoothly.

FIG. 2 shows another embodiment of the linear plain bearing. In this embodiment, the inclined surface 14 continuing to the cylindrical portion 13 in the central region of the circular hole serving as the bearing surface is tapered. It is formed by a surface. In this case, as a matter of course, the cylindrical portion 13 in the central region and the inclination yr-t which is the Taber surface
, -1'+414 are smooth and curved.

In addition, in this embodiment, in order to maintain effective lubrication performance of the bearing itself, the plastic material (base material) that serves as the base material is used.
Solid lubricants such as polyethylene tetrafluoride, molybdenum disulfide, graphite, and polyquine benzoyl polyester are mixed singly or in combination.

Therefore, when the bearing of this embodiment is used, even if there is no lubricant such as oil or grease, the mixed solid lubricant adheres to the surface of the shaft during use and contributes to lubrication of the bearing surface.

〔Effect of the invention〕

As described above, in the plastic linear sliding bearing of the present invention, the bearing surface for the shaft body leaves a carefully parallel bearing surface 1, for example, a cylindrical surface in the central region, and end surfaces It is an inclined surface that expands in diameter toward
Moreover, since the boundary portions on both sides are smoothly connected, for example, even if the bearing reciprocates in the axial direction while being inclined with respect to the shaft, 1) the shaft described in 1. The lubricant adhering to the surface of the bearing is not scraped off by the inner peripheral edge of the bearing hole of the bearing, and the slight wedge-like shape formed between the front inclined surface and the outer peripheral surface of the shaft body is prevented. A wedge effect is created that draws the lubricant on the outer surface m1 of the shaft body into the space, and as a result, the lubricant is actively introduced into the cylindrical portion, resulting in an increase in torque due to irreversible lubrication, instability, and
Not only can wear be prevented, but dynamic pressure is generated in the IH+ between the ILFT cylindrical portion and the outer surface of the shaft due to the squeezing effect when lubricant is introduced, contributing to torque reduction.

In addition, 1) By preventing the above-mentioned snagging, smoother fx movement is possible, and in combination with the above-mentioned effects, it is possible to further reduce torque and stabilize torque at the time of starting.

In this example, we will explain a general sliding bearing with a smooth circular hole that serves as the bearing surface.
However, it is also possible to form a dynamic pressure generating groove of any shape necessary for generating dynamic pressure on the other bearing surface, and the NIF, nqb receiving hole may be replaced with the circular hole of the embodiment. It may also be implemented as a non-circular shape.

In the embodiment g, hX is used for an example in which the bearing reciprocates, but it can be used in exactly the same way even in an example in which the shaft body reciprocates.

Furthermore, the bearing can be lubricated by using oil or grease, by using a solid lubricant as shown in the embodiment of FIG. 2 described in IF, or by using both of the above.

Porous materials may also be used as bearing materials.

In addition, reinforcing bodies made of metal may also be used.

Although the present invention is specifically applied to plastic bearings, it goes without saying that it can be similarly applied to metal bearings.

[Brief explanation of drawings]

1st IA#'i is a cross-sectional view of the main part showing the plastic linear sliding bearing of this invention, 2nd is a view corresponding to FIG. FIG. 4, which is a cross-sectional view of the main part of the device used, is a partial VH view when the bearing is tilted by 16 degrees in the third worst bearing device. Explanation of symbols of embodiments 1: Linear bearing 14: Inclined surface 1: Outside 1) 1
Part 2: Shaft 12; Circular hole (bearing hole) 21
;Outer peripheral surface 13 2 cylindrical surface (bearing surface) ゝ1 1. ＼ Niji／

Claims (7)

[Claims] (1) A hollow body having a bearing hole penetrating in the axial direction forming a sliding bearing surface between the outer peripheral part held by the bearing holding part of the support and the outer peripheral surface of the shaft, and the shaft In a plastic linear sliding bearing that reciprocates in the axial direction via a lubricant interposed between the outer peripheral surface of the bearing hole and the bearing surface of the bearing hole, the bearing hole as the bearing surface that penetrates in the axial direction is
A receiving surface parallel to the axis is left in the central region, and both ends of the receiving surface are
A plastic linear sliding bearing characterized by an inclined surface whose diameter increases toward the end surface to allow the bearing or shaft to tilt during use. (2) A plastic linear sliding bearing according to claim 1, in which the inclined surface is molded at the same time as the hollow body is molded. (3) A plastic linear sliding bearing according to claim 1, wherein the inclined surface is formed by processing after molding the hollow body. (4) A plastic linear sliding bearing according to any one of claims 1, 2, and 3, in which a groove for generating dynamic pressure is formed on the inner surface of the bearing hole. (5) A plastic linear sliding bearing according to any one of claims 1, 2, 3, and 4, wherein the lubricant is oil or grease. (6) A plastic linear sliding bearing according to any one of claims 1, 2, 3, and 4, wherein the lubricant is a solid lubricant mixed into a plastic base material. (7) A plastic linear sliding bearing according to any one of claims 1, 4, 5, and 6, wherein the bearing is formed by cutting a solid body.