JPH0735139Y2 - Hydrodynamic bearing - Google Patents

Description

[Detailed description of the device]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic pressure bearing that allows easy removal of air from the inside and is easy to assemble.

[Prior art]

Conventionally, a dynamic pressure bearing as shown in FIG. 3 has been known. Reference numeral 1 is a shaft, 2 is a sleeve, 3 is a thrust receiver, 4 is a housing, 5 is a groove for generating a dynamic pressure formed on the outer peripheral surface of the shaft 1, and the shaft 1 is housed in a sleeve 2 to form a groove 5. It is supported in the radial direction by the dynamic pressure generated by, and is supported by the thrust receiver 3 mounted on the housing 4 so as to be located below the shaft 1 in the thrust direction. The sleeve 2 is inserted into the insertion hole 4a of the housing 4, and the thrust receiver 3 is fitted into the lower fitting hole 4b of the insertion hole 4a, so that the lubricant 6 is sufficiently retained. The lower end portion of is sealed by a thrust receiver 3. In addition,
The thrust receiver 3 is made of a synthetic resin or the like having low friction.

[Problems to be solved by the device]

Due to the nature of the dynamic pressure bearing, the gap between the shaft 1 and the sleeve 2 is very small, and when the thrust receiver 3 is fitted into the housing 4, the internal air is compressed. As a result, repulsive force is generated, the workability of assembling the thrust receiver 3 is deteriorated, and bubbles escape through the gap while pushing away the lubricant between the shaft 1 and the sleeve 2, so that the bearing performance of the radial portion is reduced. May have a negative effect on. Therefore, the object of the present invention is to allow the internal air to be removed when the thrust receiver is assembled, so that the assembling performance is good, and no air bubbles are generated in the lubricant. The object of the present invention is to provide a dynamic pressure bearing in which the holding of the bearing is reliably performed.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention accommodates a shaft in a sleeve in a housing, and generates dynamic pressure by a groove provided on at least one of an inner peripheral surface of the sleeve and an outer peripheral surface of the shaft, thereby axially moving in the radial direction. A thrust bearing is provided in the housing so as to be positioned below the shaft, and in a dynamic pressure bearing configured to support the shaft in the thrust direction, the thrust bearing is provided on the outer periphery of the thrust bearing. The inside and outside of the thrust receiver communicate with each other until the thrust receiver is fitted in a predetermined position of the housing, while the thrust receiver is covered by the housing when the thrust receiver is fitted in a predetermined position of the housing. It is characterized by the provision of a groove that does not communicate with the.

[Action]

According to this invention, when the thrust receiver is fitted into the housing, the air inside is discharged through the groove,
Air is never compressed. Therefore, the thrust bearing can be easily assembled, and no bubbles are generated in the lubricant. Also, after the thrust bearing is completely fitted into the housing, the groove is completely covered by the housing,
Since the inside and the outside of the thrust receiver are shut off from each other, the lubricant does not flow out through the groove and no foreign matter enters.

【Example】

The present invention will be described in detail below with reference to an embodiment shown in FIGS. 1 and 2. The same parts as those in the conventional example shown in FIG. 3 are designated by the same reference numerals, and different parts will be mainly described. In FIGS. 1 and 2, reference numeral 13 is a thrust receiver, and an air bleeding groove 14 is formed on the outer peripheral portion thereof. The groove 14 is formed in a V-shaped cross-section such that the groove 14 is deeper from the lower edge of the outer periphery of the thrust receiver 13 to the upper edge of the outer periphery. Therefore, when the thrust receiver 13 is fitted into the fitting hole 4b of the housing 4, the air inside is discharged to the outside through the groove 14 during the fitting as shown by the one-dot chain line in FIG. Even if the fitting is advanced, the internal air is not compressed. Therefore, the repulsive force is not generated, and the assembling work of the thrust receiver 13 to the housing 4 can be easily performed. Further, no bubbles are generated in the lubricant 6. On the other hand, when the thrust receiver 13 is completely fitted in the fitting hole 4b and is in a state of a solid line, the lower end of the groove 14 is covered with the wall surface of the fitting hole 4b so that the inside and outside of the thrust receiver 13 are separated from each other. The shaft 1 is shut off and the lower end of the shaft 1 is sealed by a thrust receiver 13. For this reason, the lubricant 6 will not come out of the air vent groove 14 after assembly, and dust and foreign matter will not enter the air vent groove 14 inside. In the above embodiment, the V-shaped groove 14 is deeper and larger toward the upper side.
Since it is provided with a large groove at the beginning of the thrust receiver 13
Air can be smoothly extracted through the gap in 14.
On the other hand, in the final stage of the fitting, there is no problem because it passes through a small gap at the lower end of the groove 14, but there is little air to be discharged and the fitting speed is slow. The groove 14 for bleeding air in the above embodiment is an example, and other shapes can be appropriately adopted. In the above embodiment, the sleeve and the housing have separate structures, but the sleeve and the housing may have an integrated structure.

[Effect of device]

As is apparent from the above, according to the present invention, the inside and outside of the thrust receiver communicate with each other on the outer peripheral surface of the thrust receiver until the thrust receiver is fitted into the housing at a predetermined position.
A groove for air bleeding is provided which is covered by the housing when fitted in a predetermined position of the housing and does not communicate the inside and the outside of the thrust receiver. Therefore, when assembling the thrust receiver into the housing, the internal air is not compressed to generate a repulsive force, the assembling work becomes easy, and the bubbles do not come out from between the shaft and the sleeve after assembling. Since the bearing performance of the radial portion is not adversely affected and the groove is sealed after the assembling, it is possible to prevent the lubricant from leaking from the air bleeding groove and the entry of foreign matter.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an embodiment of the present invention, FIG. 2 is a perspective view of a thrust receiver, and FIG. 3 is a sectional view of a conventional example. 1 ... Axis, 2 ... Sleeve, 3,13 ... Thrust receiver, 4 ...
… Housing, 4b …… Mating hole, 5 …… Groove, 6 …… Lubricant, 14 …… Groove for bleeding air.

Claims (1)

[Scope of utility model registration request] 1. A shaft is housed in a sleeve in a housing, and dynamic pressure is generated by a groove provided on at least one of an inner peripheral surface of the sleeve and an outer peripheral surface of the shaft to support the shaft in a radial direction. In a dynamic pressure bearing configured to support the shaft in the thrust direction by providing a thrust receiver on the housing so as to be located on the lower side, the thrust receiver is provided on the outer periphery of the thrust receiver at a predetermined position of the housing. The inner and outer sides of the thrust receiver are communicated with each other until they are fitted in the housing, and when the thrust receiver is fitted in a predetermined position in the housing, the grooves are covered by the housing and do not communicate between the inner and outer sides of the thrust receiver. A dynamic pressure bearing characterized by being provided with.