JPH04236817A - Sliding thrust bearing - Google Patents

Abstract

PURPOSE:To obtain a sliding thrust bearing which is so excellent in lubricity that an oil film does not break off even after being used for a long time. CONSTITUTION:In the internal surface of a hole 11 bored in a bearing body 6, so as to slidably fit around a shaft 4, at least a pair of grooves 13 and 14 are formed inclined to the axis line from different axis lines in such a way that one end of each groove reaches near a position 5 where the contact pressure between the above shaft 4 and bearing body 6 is large.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to sliding thrust bearings.

[0002] Rolling bearings using bearings are used in parts where the shaft and bearing slide at high speed. However, using a rolling bearing requires space and increases costs. Therefore, sliding bearings are used for parts that do not move at high speed.

0003

2. Description of the Related Art Conventional sliding thrust bearings simply have a hole formed in the bearing body to slidably fit into the shaft.

0004

[Problem to be Solved by the Invention] In a journal bearing that supports a rotating shaft, a wedge-shaped gap is formed between the shaft 100 and the bearing 101, as shown in FIG. Therefore, a so-called constricting flow of oil occurs, and the space between the shaft and the bearing is well lubricated.

However, in thrust bearings, such a narrowing flow of oil does not occur, so as shown in FIG. It is easy to get cut.

[0006] As a result, the thrust load gradually increases during long-term use, resulting in increased motion resistance and increased wear.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate such conventional drawbacks and to provide a sliding thrust bearing with good lubricity that does not cause oil film to run out even after long-term use.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the sliding thrust bearing of the present invention is slidably fitted with a shaft 4, as shown in FIG. 1 for explaining an embodiment. The inner surface of the hole 11 drilled in the bearing body 6 is inserted from a different side in the axial direction so that one end reaches the vicinity of the position 5 where the contact pressure between the shaft 4 and the bearing body 6 is large. It is characterized in that at least a pair of grooves 13 and 14 are formed at an angle.

Note that the grooves 13 and 14 may also be formed on opposite sides of the position 5 where the contact pressure is large, and a plurality of the grooves 13 and 14 may be formed at shifted positions in the axial direction. Good too.

Further, the bearing body 6 may be provided on a carriage 3 of a printer that carries the print head 2 and moves back and forth.

[0011]

[Operation] When the shaft 4 and the bearing body 6 are moved relative to each other in the axial direction, the oil in one of the grooves 13 is transferred to the shaft 4 and the bearing body due to the component force generated along the inner wall of the groove 13 due to the movement.
Move to the vicinity of position 5 where the contact pressure is large.

When the shaft 4 and the bearing body 6 are relatively moved in opposite directions, the oil in the other groove 14 is caused to move between the shaft 4 and the bearing body 6 due to the component force generated along the inner wall of the groove 13. Move to position 5 where the contact pressure is large.

[0013]

[Embodiment] An embodiment will be described with reference to the drawings.

FIG. 2 shows a printer in which a print head 2 is placed opposite a print sheet 50 wound around a platen roll 1. As shown in FIG.

The carriage 3 on which the print head 2 is mounted is slidably fitted onto a guide shaft (shaft) 4 fixed in parallel with the platen roll 1, and the guide shaft is moved by a space motor (not shown). It reciprocates along 4.

FIG. 1 shows a guide shaft 4 (hereinafter referred to as "shaft 4").
) and a sliding thrust bearing 10 provided on the carriage 3 so as to fit with the shaft 4 thereof.

The sliding thrust bearing 10 has a bearing body 6 through which a round hole 11 for fitting the shaft 4 is bored, and grooves 13 and 14 formed in the bearing body 6.

In this embodiment, the shaft 4 is fixed, and the bearing body 6 slides relative to it. Therefore, the load of the bearing body 6 and the loads of the carriage 3, print head 2, etc. are all applied to the upper surface portion 5 of the shaft 4, and the shaft 4 and the bearing body 6 exert a large contact pressure on the upper surface portion 5 of the shaft 4. have

Each of the grooves 13 and 14 is formed from different sides in the axial direction (
(from the right and left in the figure), it is formed at an angle with respect to the axis.

As shown in FIG. 1, both the left-sloping groove 13 formed from the right side toward the upper left and the right-sloping groove 14 formed from the left side toward the upper right are both located in the axial direction. A plurality of grooves 13 and 14 are formed in parallel with each other at different angles, and similar grooves 13 and 14 are also formed on the opposite side (back side) across the upper surface portion 5 of the shaft.

FIGS. 3 and 4 show the operation of the above embodiment. As shown in FIG. 3, when the bearing body 6 moves to the right with respect to the fixed shaft 4, the oil 60 between the shaft 4 and the bearing body 6 is absorbed into the inner wall of the groove 13 upward to the left. The force generated along the axis pushes up the upper end of the groove 13 (i.e. the upper surface portion 5 of the shaft) as shown by arrow A.

Conversely, when the bearing body 6 moves to the left with respect to the fixed shaft 4, as shown in FIG. 4, the oil 60 between the shaft 4 and the bearing body 6 is Due to the force generated along the inner wall of the groove 14 which is upwardly oriented to the right, it is pushed up towards the upper end of the groove 13 (i.e. the upper surface portion 5 of the shaft) as shown by arrow B.

Therefore, when the bearing body 6 moves in either the left or right direction, the upper surface portion 5 of the shaft, which has a large contact pressure, is lubricated. Since a plurality of grooves 13 and 14 are formed on both sides of the upper surface portion 5 of the shaft, sufficient lubrication is achieved.

Note that the cross-sectional shape of the grooves 13 and 14 may have a wall surface perpendicular to the circumferential surface as shown in FIG. 5, or may have a wedge-like shape as shown in FIG. Then, the oil 60 is retained inside, and the lubricity is further improved.

Furthermore, the grooves 13 and 14 do not necessarily need to be exposed to the outside from the hole 11 of the bearing body 6, but may be formed at least on the inner surface of the hole 11.

Furthermore, the sliding thrust bearing of the present invention can be widely applied not only to printers but also to other devices.

[0027]

[Effects of the Invention] According to the sliding thrust bearing of the present invention,
By simply drilling a groove in a simple sliding thrust bearing without adding any special parts, it reliably lubricates the positions where the contact pressure between the shaft and bearing is high, providing light shaft support performance with low friction over a long period of time. It has an excellent effect that can maintain the

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment.

FIG. 2 is a perspective view of the printer of the embodiment.

FIG. 3 is an explanatory diagram of the operation of the embodiment.

FIG. 4 is an explanatory diagram of the operation of the embodiment.

FIG. 5 is a cross-sectional view of the groove of the example.

FIG. 6 is a cross-sectional view of a groove in another embodiment.

FIG. 7 is a sectional view of a journal bearing.

FIG. 8 is a sectional view of a conventional thrust bearing.

[Explanation of symbols]

4 Shaft 5 Upper surface portion of shaft (position with high contact pressure) 6 Bearing bodies 13, 14 Groove

Claims (4)

[Claims] 1. The shaft (4) is fitted into the inner surface of a hole (11) formed in the bearing body (6) so as to be slidably fitted to the shaft (4).
4) and the position where the contact pressure between the bearing body (6) is large (
5) At least a pair of grooves (13, 14
) is a sliding thrust bearing. 2. The sliding thrust bearing according to claim 1, wherein the grooves (13, 14) are also formed on the opposite side of the position (5) where the contact pressure is high. 3. The sliding thrust bearing according to claim 1, wherein a plurality of said grooves (13, 14) are formed with positions shifted in the axial direction. 4. The bearing body (6) is attached to the print head (2).
4. The sliding thrust bearing according to claim 1, wherein the sliding thrust bearing is provided in a carriage (3) of a printer that reciprocates while carrying the bearing.