JPH0240330Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a spiral groove thrust bearing used in superchargers, compressors, blowers, turbines, pumps, etc.

[Conventional technology]

Conventional thrust bearings of this type are shown in Figures 5 and 6.
As shown in the figure, a pressure generating section is constituted by spiral grooves 02 extending from an outer circumference 04 toward an inner circumference 05 and land sections 01 arranged alternately in the rotational direction with the spiral grooves 02.

Further, an inner peripheral land 03 for fluid damming is formed at the terminal end of the spiral groove 02.
The inner peripheral land 03 and the above-mentioned pressure generating section are integrally constructed.

The fluid flow generated along the spiral groove 02 is dammed by the land part 01, and finally the whole is dammed by the inner peripheral land 03, which has the function of absorbing the load applied to the bearing with an oil film. are doing.

In addition, Fig. 3 is a simplified version of the shape of the thrust bearing shown in Fig. 5, and Ri is the bearing inner radius,
Rg indicates the end radius of the spiral groove, and Ro indicates the outer radius of the bearing.

Furthermore, FIG. 4 shows the sliding surface temperature (Tem) distribution of this conventional thrust bearing.

[Problem that the invention attempts to solve]

In the conventional device configured as described above, the temperature of the sliding surface becomes higher toward the inner side in the radial direction, as shown in FIG. As a result, the viscosity of fluid such as oil decreases, reducing load capacity, and the inner land surface in particular thermally expands, raising the position of the inner land surface, reducing the thickness of the oil film with the thrust collar and causing seizure. There were problems such as the occurrence of

[Means for solving problems]

The present invention was devised in view of the above-mentioned conventional problems, and consists of forming the pressure generating part and the inner circumferential land part from members having different coefficients of thermal expansion, and joining them together.

[Effect]

Since the present invention is configured as described above,
By forming the high-temperature portion, that is, the inner peripheral land, from a member with a low coefficient of thermal expansion, expansion of the inner peripheral land can be suppressed without any deterioration of the pressure generation function and fluid damming function.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, A is a pressure generating portion formed by alternately arranging land portions 01 and spiral grooves 02 in the rotational direction, and the terminal end of the spiral groove 02 extends to the outer periphery of the inner peripheral land 03 for damming.

Reference numeral B designates an inner peripheral land portion, and the inner peripheral land portion B is formed by integrally forming the inner peripheral land 03 and a backing metal portion with a member having a low coefficient of thermal expansion, and is formed separately from the pressure generating portion A.

Note that the inner land portion B may of course be formed of ceramics, and the back surface of the inner land 03 may be coated with a highly compatible bearing alloy.

The pressure generating portion A is fitted and bonded to the inner peripheral land portion B by shrink fitting, adhesive, or other mechanical bonding methods. With this structure, abnormal thermal expansion of the inner land portion B exposed to high temperatures can be prevented, all of the above-mentioned conventional problems are eliminated, and stable bearing characteristics can be obtained. .

[Effect of idea]

According to the present invention, by forming the inner peripheral land portion with a material having a low coefficient of thermal expansion, it is possible to prevent swelling of the inner peripheral land portion due to thermal expansion in advance and reliably, thereby preventing seizures and other problems. It can produce various excellent results such as preventing damage.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the main parts showing an embodiment of the present invention, Fig. 2 is a cross-sectional view taken from Fig. 1, and Fig. 3 is the radial dimensions of the inner circumference, outer circumference, and groove end position of a conventional spiral groove thrust bearing. Fig. 4 is an explanatory drawing showing the temperature distribution of the sliding surface in the radial direction of the conventional bearing, Fig. 5 is an explanatory drawing showing the structure of the conventional spiral groove thrust bearing, and Fig. 6 is an explanatory drawing showing the structure of the conventional spiral groove thrust bearing. - It is a cross-sectional view. A...Pressure generating part, B...Inner peripheral land part, 2...
...Spiral groove, 3...Inner land.

Claims (1)

[Scope of utility model registration request] The pressure generating part formed by processing a spiral group and the inner circumferential land part which dams the flow of fluid are formed of members having different coefficients of thermal expansion, respectively, and the two members are bonded to each other. Spiral groove thrust bearing.