JPH0614538U - Sliding thrust bearing structure - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a sliding thrust bearing structure which has excellent wear resistance and enables a long life without specifying a material. [Structure] A sliding thrust bearing is composed of a shaft end 1a forming a curved surface of a shaft 1 and a receiving member 2 having a load plane 2a on which a thrust force acts by abutting the shaft end 1a. The load plane 2a of the receiving member 2 has a surface roughness of 5 to
The unevenness 3 of about 50S is formed. The unevenness 3 makes it possible to supply the lubricant 4 between the abutting shaft end 1a.
The load plane 2a of the receiving member 2 is provided with irregularities 5, 6 and 7 formed by grooves having a lattice shape, a vortex shape, or a concentric arc shape. The groove depth is approximately 5 to 50 μm.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sliding thrust bearing structure, and more particularly to a sliding thrust bearing structure that has excellent wear resistance and enables a long life without specifying a material.

[0002]

[Prior art]

 There is known a sliding thrust bearing structure including a shaft end having a curved surface and a receiving member having an abutting load surface that abuts the shaft end to receive the load.

As an example, a stainless steel shaft is formed with spherical surfaces having R1 to R10 and a surface roughness of 2S or less at the shaft end, and the receiving member is a wear-resistant polyacetal resin (for example, trade name “Delrin”), etc. A mirror-finished contact load surface with a surface roughness of 2S or less is formed on this surface, and a lubricant such as oil or grease is applied to this contact load surface to support the axial load of 0.1 to 5 kgf. Bearings for small mold motors are constructed.

[0004]

[Problems to be solved by the device]

 However, since a high surface pressure is generated between the shaft end forming the curved surface and the contact load surface of the receiving member due to the axial direction force, the lubricant is discharged from the contact portion and becomes in a non-lubricated state. In the case of abradable material, it causes troubles such as increased load loss due to friction and abnormal progress of abrasion, so the selection range of resin material is limited, and excessive cost burden due to expensive resin with abrasion resistance is avoided. I couldn't.

[0005]

[Means for Solving the Problems]

 In order to solve the above problems, the load plane of the bearing member of the sliding thrust bearing is provided with irregularities between the abutting shaft end and the supply of the lubricant.

[0006]

[Action]

 Due to the unevenness formed on the load plane of the receiving member, it is possible to supply the lubricant between the abutting shaft end and the lubrication of the abutting part with the valley depth of the unevenness as the wear limit.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a detailed view of essential parts of a sliding thrust bearing according to first to fourth embodiments of the present invention.

FIG. 1A is a vertical sectional view of a sliding thrust bearing according to the first embodiment. The sliding thrust bearing is composed of a shaft end 1a forming a curved surface of the shaft 1 and a receiving member 2 having a load plane 2a on which the thrust force acts by the contact of the shaft end 1a.

On the load plane 2a of the receiving member 2, the unevenness 3 having a surface roughness of about 5 to 50 S is formed. The unevenness 3 makes it possible to supply the lubricant 4 between the abutting shaft end 1a.

FIGS. 3B, 3D, and 3F are enlarged plan views of essential parts according to the second to fourth embodiments, and FIGS. 3C, 3E, and 3G are vertical sectional views thereof. The load plane 2a of the receiving member 2 is formed with irregularities 5, 6 and 7 each having a groove having a lattice shape, a vortex shape, or a concentric arc shape. The groove has a depth of about 5 to 50 μm, and its cross-sectional shape is V-shaped, U-shaped, rectangular, trapezoidal, bow-shaped or the like.

By using the vortex-shaped irregularities 6 in the rotation direction A of FIG. 3D, which is the centripetal direction, the supply of the lubricant is promoted.

The operation of the sliding thrust bearing structure configured as described above will be described below.

FIG. 2 is an explanatory view of the operation according to the embodiment of the present invention, in which (a), (b), and (c) show respective states at the beginning of use, a state of partial wear, and progress of wear.

The shaft end 1 a forming the curved surface of the shaft 1 in FIG. 1A abuts on the top of the unevenness 3 formed on the load plane 2 a of the receiving member 2. Therefore, the lubricant 4 penetrates into the gap formed by the unevenness 3, and the contact portion between the shaft end 1a and the load plane 2a is sufficiently lubricated from the beginning of use, so that wear and load loss are minimized.

Even when wear progresses from the initial state in FIG. 1A, as long as a part of the unevenness 3 facing the shaft end 1a remains, the contact portion is divided into large unevennesses and has a large size. Since the maximum limit of the depth is suppressed within the unevenness 3, the lubricant 4 penetrates through the gaps of the unevenness 3 and the contact portion is sufficiently lubricated.

Therefore, the unevenness 3 is not affected by the material of the receiving member during the period from the partial wear state of FIG. 1B to the wear progress state of FIG. Also, load loss is kept to a minimum.

FIG. 3 is a diagram for explaining the operation according to the prior art, and (a), (b) and (c) show the states of a small wear state at the beginning of use and a state of progress of wear in comparison with the present invention.

The shaft end 1 a forming the curved surface of the shaft 1 in FIG. 1A abuts on the load plane 2 b of the smoothed receiving member 2. At this time, the lubricant 4 is discharged near the center of the contact portion due to the contact pressure, and sliding is performed without lubrication.

The unlubricated sliding causes wear to proceed, and the contact portion rapidly expands the contact area through the small wear state shown in FIG. It becomes difficult for the lubricant 4 to penetrate into the vicinity of the center of the contact portion, and a large load loss occurs, and the wear region expands at an accelerating rate, and the wear state of FIG.

FIG. 4 is a wear characteristic diagram showing the amount of wear in the thrust direction with respect to the bearing operation time. The test conditions are as follows: normal temperature air, thrust load 0.1 to 5 kgf, grease lubrication, 2000 rpm, forward / reverse switching interval 30. Seconds.

As shown in the characteristic line diagram C1, the measurement result of the wear amount of the bearing structure according to the present invention is reduced to about 1/5 to 1/6 of the characteristic line diagram C2 according to the conventional technique. (Specifically, A1 = 10 to 25 μm and A2 = 50 to 150 μm after T1 = 250 hours).

As described above, the unevenness that allows the lubricant to be supplied is formed on the load plane of the resin-made receiving member that is in contact with the shaft end that is finished in the curved surface and the thrust force acts, so that the progress of wear can be improved. Since lubricity is ensured without being involved, wear is minimized over a long period of time. Therefore, the load loss can be suppressed to be small without being restricted by the resin material, and the life can be extended.

A specific application example of the sliding thrust bearing structure having the above characteristics will be described below.

FIG. 5 is a vertical sectional view of a vertical motor to which the present invention is applied. The upper shaft end 1a of the fixed vertical shaft 1 made of stainless steel is in contact with the load plane 2a of the resin-made receiving member 2 to form a sliding thrust bearing structure. The shaft end 1a is finished into a spherical surface, and the load plane 2a of the receiving member 2 is formed with the above-mentioned unevenness that enables the supply of the lubricant between the shaft end 1a and the abutting shaft end 1a.

The receiving member 2 supports the coil 12 via the rotor base 11. The coil 12 is provided so as to face the fixed magnet 13. Reference numerals 14 and 15 denote radial bearings that support the top and bottom of the rotor base 11 so as to be rotatable with respect to the shaft 1.

The coil 12 receives a rotational driving force and an attraction force between the coil 12 and the magnet 13, and the attraction force acts as a thrust load of the sliding thrust bearing structure together with the weight on the rotor side. At this time, since the lubricant is supplied through the unevenness formed on the load plane 2a of the receiving member 2, the lubrication is ensured for a long period of time with the valley depth of the unevenness as the wear limit, and the load loss is minimized. Is maintained at the limit.

[0028]

[Effect of device]

 As described above, according to the present invention, since the unevenness is formed on the loading plane of the receiving member on which the thrust load acts, it becomes possible to supply the lubricant with the valley depth of the unevenness as the wear limit, and the above wear The load loss can be kept to a minimum over a long period of time until the limit is reached.

Therefore, the receiving member is not limited to a wear-resistant and expensive material, and it is possible to obtain a sliding thrust bearing having a low cost and a long life.

[Brief description of drawings]

FIG. 1 is a detailed view of essential parts of a sliding thrust bearing structure according to first to fourth embodiments of the present invention.

FIG. 2 is an explanatory view of the operation according to the embodiment of the present invention.

FIG. 3 is an operation explanatory view according to a conventional technique.

FIG. 4 is a wear characteristic diagram showing the amount of wear in the thrust direction with respect to the bearing operating time.

FIG. 5 is a vertical sectional view of a vertical motor to which the sliding thrust bearing structure according to the present invention is applied.

[Explanation of symbols]

1 ... Shaft, 1a ... Shaft end, 2 ... Receiving member, 2a ... Load plane,
3, 5, 6, 7 ... unevenness, 4 ... lubricant.

Claims (1)

[Scope of utility model registration request] 1. A sliding thrust bearing structure comprising a shaft end having a curved surface and a bearing member which is a load plane on which the shaft end abuts and a load in the thrust direction acts on the bearing plane. A sliding thrust bearing structure, characterized in that a concavo-convex portion is formed between the contacting shaft end and a lubricant supply source.