JPS6213528B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a highly accurate and extremely easy manufacturing method for a hydrodynamic slide bearing used for a rotating shaft that rotates in one direction.

Bearings for rotating shafts that are subject to heavy loads and impact loads are
Hydrodynamic slide bearings (also simply called slide bearings) are generally used. Conventionally, known structures of this hydrodynamic slide bearing include a simple cylindrical structure and a structure in which a split bearing metal is lined between the rotating shaft and the casing. However, with the simple cylindrical shape mentioned above, the minimum clearance between the rotating shaft and the inner circumferential surface of the bearing changes as the load changes, resulting in a reduction in rotational accuracy, especially at high speeds. For rotating devices, a specially shaped split bearing metal lining is used.

For example, as shown in the drawing showing the cross-sectional structure of such a conventional hydrodynamic sliding bearing, in this embodiment, a bearing ring divided into two parts is arranged around a rotating shaft 1 that rotates in the direction of the arrow in the drawing. 2 is located, and a casing 3 is located outside of the casing 3 that tightly contacts and fixedly supports the bearing metal 2. Since the shape of the casing 3 in the illustrated example is cylindrical, the outer circumferential surface 2a of the bearing metal 2 that is in close contact with the inner circumferential surface 3a of the casing 3 has a curvature corresponding to the curvature of the inner circumferential surface 3a of the casing 3. It is formed in a semicircular arc shape. The shape of the inner circumferential surface 2b of the bearing metal 2 is similar to that of the rotating shaft 1.
The inner peripheral surface 2b of the bearing metal 2 is machined so that it gradually approaches the outer peripheral surface of the rotating shaft 1 in the direction of rotation of the rotating shaft. A wedge-shaped gap is formed between 1 and the bearing metal 2, and this gap is filled with lubricating oil 4.

Therefore, when the rotating shaft 1 rotates counterclockwise in the direction of the arrow in the figure, the lubricating oil 4 is drawn into the narrow side of the wedge-shaped gap formed between the rotating shaft 1 and the bearing metal 2 due to its viscosity. Therefore, dynamic pressure is generated and the rotating shaft 1
rotates in a state where it floats above the bearing metal 2. In this case, in the figure, the left-right component of load fluctuations such as impact loads applied to the rotating shaft 1 is attenuated and absorbed by the dynamic pressure of the lubricating oil 4, so that high-precision rotation can be maintained. This is possible.

However, in a bearing lined with two or more split bearing metals as described above,
As can be easily imagined from the shape of their inner peripheral surfaces, manufacturing, assembly, etc. are extremely troublesome, and there is a risk that the cost will be extremely high.

In view of the drawbacks of conventional hydrodynamic slide bearings, the present invention is aimed at producing two-split type hydrodynamic slide bearings for rotating shafts that rotate in one direction with high precision and is extremely easy to manufacture. and to provide a method that allows assembly.

The structure of the method for manufacturing a hydrodynamic sliding bearing of the present invention that achieves this object is such that the bearing is interposed between a rotary shaft that rotates in one direction and a casing having an inner circumferential surface that supports the rotary shaft, and the outer circumferential surface is Dynamic pressure formed by a plurality of wedge-shaped bearing metals that are in close contact with the inner circumferential surface of the casing and whose inner circumferential surfaces gradually approach the outer circumferential surface of the rotating shaft as they move toward the rotational direction of the rotating shaft. In a sliding bearing, a circular hole eccentrically parallel to the central axis is bored in a rod-shaped bearing metal material having an outer peripheral surface corresponding to the inner peripheral surface of the casing, and the bearing metal material is inserted into the bearing metal material. The casing is characterized in that it is divided into two equal parts along a plane including the central axis and the central axis of the circular hole, one of which is reversed in direction, and these parts are brought into close contact with the inner circumferential surface of the casing.

In this case, a hole with a diameter slightly larger than the rotating shaft is drilled eccentrically to the bar material, which has an outer diameter slightly larger than the inner diameter of the casing, taking into account the cutting allowance when dividing. It is preferable to use a known means such as a wire saw or a diamond cutter to divide the bar into equal parts along a plane containing the central axis of the bar and the central axis of the hole parallel to the central axis, and then combine the bars upside down.
Further, the radius of the hole drilled in the bar needs to be larger than the sum of the radius of the rotating shaft and the eccentricity of the hole with respect to the bar. In general, round holes are very easy to machine, and it is easy to improve dimensional accuracy and finishing accuracy, so the hydrodynamic slide bearing according to the present invention can be expected to have high accuracy.

As described above, according to the method for manufacturing a hydrodynamic sliding bearing of the present invention, it is only necessary to divide a cylindrical bearing metal material with an eccentric hole into two equal halves and assemble them in opposite directions, which makes manufacturing extremely easy and at low cost. can do. Moreover, since it can be manufactured and assembled with high precision, it is possible to further promote stable rotation of the rotating shaft.

[Brief explanation of the drawing]

The drawing is a cross-sectional view showing the cross-sectional shape perpendicular to the axis of the hydrodynamic sliding bearing that is the object of the present invention, and the reference numerals in the drawing are: 1 is the rotating shaft, 1a is the outer circumferential surface of the rotating shaft, and 2 is the outer circumferential surface of the rotating shaft. 2a is the outer peripheral surface of the bearing metal, 2b is the inner peripheral surface of the bearing metal, 3 is a casing, 3a is the inner peripheral surface of the casing, and 4 is lubricating oil.

Claims (1)

[Claims] 1 A casing that is interposed between a rotating shaft that rotates in one direction and a casing that has an inner circumferential surface that supports the rotating shaft, and whose outer circumferential surface is in close contact with the inner circumferential surface of the casing and whose inner circumferential surface rotates in the rotational direction of the rotating shaft. In the method for manufacturing a hydrodynamic sliding bearing formed of a plurality of wedge-shaped bearing metals that gradually approach the outer circumferential surface of the rotating shaft, the outer circumferential surface corresponding to the inner circumferential surface of the casing is An eccentric circular hole is bored parallel to the central axis of a round bar-shaped bearing metal material, and the bearing metal material is equally spaced in a plane containing the central axis of the bearing metal material and the central axis of the circular hole. A method of manufacturing a hydrodynamic sliding bearing, characterized in that the bearing is divided into parts, one of which is reversed in direction, and the parts are brought into close contact with the inner circumferential surface of the casing.