JPS60227011A - Thrust bearing - Google Patents

Abstract

PURPOSE:To enable the captioned thrust bearing to bear impact load by interposing thrust collars between a rotary collar and a fixed receiver, said thrust collar having a spiral groove causing dynamic pressure effect on the face and back of the collar by unidirectional rotation of the spiral groove. CONSTITUTION:A thrust collar 13 is interposed between a rotary collar 11 keyed on a shaft 1 and a fixed receiver 12 supported on a spherical surface 5 of a fixed shaft 4, and one surface 13a of the thrust collar 13 is formed into a smooth one while the other surface 13b into a spherical one having a large radius R of curvature. These surfaces are accomodated in a bearing chamber 14 filled with a lubricating fluid therein. The thrust collar 13 has a spiral groove 15a in the surface 13a thereof such that a fluid is guided from a periphery of the thrust collar 13 to a pocket 16a located on the center of the bearing along the groove 15 owing to the rotation of the shaft 1 and the rotary collar 11 in the arrow direction and thereby it produces dynamic pressure effect between the rotary collar 11 and the thrust collar 13.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hydrodynamic thrust bearing with a helical groove used in submersible pumps, submersible motors, and other general thrust bearings.

(Prior art) A conventional spiral grooved thrust bearing involves cutting a spiral groove in only one direction on a fixed support surface that supports a rotating shaft, and interposing a fluid between these 24 relatively rotating surfaces to form a spiral groove. The shaft thrust was supported by generating dynamic pressure as the shaft rotated. (For example, see Japanese Patent Publication No. 41-12121.) However, such a spiral grooved thrust bearing,
Because spiral grooves were provided only on the bearing surface, it was said to be more vulnerable to impact loads and load fluctuations than the tailing pad type bearing shown in Figure 4. In FIG. 4, a disk 3 is fixed to an upper support 2 that rotates together with the rotating shaft 1, and a pin is mounted opposite the disk 3 so that it is supported by a spherical surface 5 with respect to the fixed shaft 4 and does not rotate. A pad 8 is attached to the upper part of a lower support 7 engaged with a pad 6 so as not to rotate.

In addition, in the conventional spiral grooved thrust bearing, when the rotation becomes high speed, the pump-in (
The inflowing fluid causes turbulence or cavitation,
There were drawbacks such as the dynamic pressure sometimes not being raised to the original value even when rotating at high speed.

(Problems to be Solved by the Invention) The present invention can eliminate the drawbacks of the above-mentioned prior art,
To withstand shock loads and load fluctuations applied to a spiral grooved hydrodynamic thrust bearing, and to prevent turbulence or cavitation in the fluid pumped in through the spiral groove even when rotating at high speeds. It is in.

(Means for Solving the Problems) The present invention provides a thrust collar in which spiral grooves are provided on the front and back surfaces to generate a dynamic pressure effect by rotation in one direction, or a land portion on the outer periphery in a spiral groove shape on one side. and a thrust collar with a through hole that connects both the front and back sides in the central pocket that shows the highest pressure.
It is characterized in that it is interposed between a rotating collar attached to a rotating shaft and a fixed collar, and as the rotating shaft rotates, the thrust collar is simultaneously rotated at a rotation speed less than the rotational speed of the rotating shaft.

(Function) With the above configuration, when the rotating collar is rotated by the rotating shaft, a dynamic pressure effect is generated in the spiral groove of the thrust collar that is in contact with the rotating collar, and a high pressure part of the fluid is formed in the central pocket. At the same time, the thrust collar itself also tries to rotate in the same direction due to the fluid friction force between the rotating collar and the thrust collar. Along with this rotation, the spiral groove formed on the back surface of the thrust collar similarly generates a dynamic pressure effect between the fixed cost and the dynamic pressure formed on both the front and back surfaces of the thrust collar, which makes the axial thrust effective. Supported by

At this time, when there is only one thrust collar, the thrust collar itself rotates at about half the number of rotations of the rotating collar.

Furthermore, if the back surface is a spherical seat, the contact area is large, so rotation occurs only on the smooth surface. This generates dynamic pressure in the pockets on the surface. This fluid pressure is also applied to the pocket on the back surface through the through hole, causing the spherical side to float, causing relative movement on the back surface with low frictional resistance, causing the thrust collar to rotate.

In this way, a fluid film is formed on both the front and back surfaces of the thrust collar, creating a cushioning effect, and the rotation speed of the thrust collar (i.e., the bearing rotation speed) is reduced.
The rate of inflow pumped in through the spiral groove is reduced accordingly.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. 1st
The figure is a longitudinal cross-sectional view of a single thrust collar with a spherical back surface showing an embodiment of the present invention, and FIG. 2 is a plan view of the thrust collar taken along the line A-A in FIG. Figure 3 shows the shape of the spiral groove on the back side. In the figure, one thrust collar 13 is interposed between the rotational force 2-11 keyed to the shaft 1 and the fixed part 12 supported on the spherical surface 5 of the fixed shaft 4, and the thrust collar 130 The surface (front surface) 13a is smooth, and the other surface (back surface) 16b
are formed into a spherical shape machined with a large radius of curvature R, and are housed in a bearing chamber 14 filled with lubricating fluid.

As shown in FIG. 2, the thrust collar 13 has a spiral groove 15a (black part in the figure) on its surface 13a.
By the rotation of the shaft 1 and the rotating collar 11 in the direction of the arrow, fluid is guided from the periphery of the thrust collar 13 along the groove 15 to the central pocket 16a (the black part in the figure forms a recess), and the rotation occurs. Collar 11 and Thrust Collar 13
It is oriented in such a way that a dynamic pressure effect is produced between the two.

On the other hand, the spiral groove 15b on the back surface 13b of the thrust collar 16 is shown in FIG.
As 3 itself rotates in the same direction as the rotating shaft 10 rotations due to fluid friction with the rotating collar 11, the groove 1 rotates from the peripheral part.
5b<G, the pocket portion 16b is formed in the direction in which the fluid flows into the pocket portion 16b. In the case of this embodiment, since the thrust collar 13 tries to rotate in the same counterclockwise direction as the rotating shaft 1 when viewed from above (the direction of the hour hand when viewed from below), the direction of the spiral groove 15b on the back surface 13b is determined when viewed from the back surface. , a spiral groove 15a on the surface 15a shown in FIG.
are formed in the same direction. In addition, in the figure, 1B indicates a land portion left on the outer periphery. In addition, pocket portions L6a and 16 are formed at the center of both the front and back sides of the thrust collar.
Since the hole 17 of 10 μm to 2111 mm passing through b is drilled in the center where the highest pressure is exhibited, the pressure on both sides of the thrust collar is balanced.

At the beginning of rotation, the thrust collar generates movement on the smooth surface → dynamic pressure fluid → brings pressure to the pocket portion 16b on the back side through the through hole 17 in the pocket portion (the land portion 18 acts as a seal). (Do not leak pressure.)
The back side of the first spherical surface rises and the thrust collar 13 begins to rotate.

In this embodiment, the thrust collar 13 has wear resistance,
SiC (silicon carbide) with excellent corrosion resistance and heat resistance is used, and high lead bronze containing 8% carbide is used for the rotating collar 11 and fixed cost 12. Although the ceramic material that constitutes the thrust collar has excellent corrosion resistance, it has poor workability, so it
Although it is not easy to process extremely shallow spiral grooves of m (micron meters), in the present invention, after shielding with a spiral resin mask of a predetermined shape, fine alumina abrasive material is applied onto the resin mask. Spiral grooves can be formed in an extremely short time using the shot blasting method. Regarding the method of forming spiral grooves,
It is described in the specification of Japanese Patent Application No. 58-1215157 related to the earlier application.

According to this embodiment, when the rotating shaft 1 is rotated in the direction of the arrow with a load applied to it, the thrust collar 13 itself also rotates at the rotation speed of the rotating shaft or less, and the spiral grooves 15a and 15b on both the front and back surfaces of the thrust collar 13 rotate. Apply lubricating oil from the periphery to pocket part 1
6a and 16b, dynamic pressure is generated, and a liquid film of a required thickness is formed between the opposing surfaces to support the thrust load.

As mentioned above, by using a thrust collar with spiral grooves in the same direction on both sides, it has become possible to divide the bearing rotation speed into two, so by stacking multiple thrust collars, various You can select an appropriate rotation speed (the fluid pressure value changes depending on the lubricant). Therefore, as the pump rotates at high speed, it passes through the spiral groove.
It is possible to prevent the incoming fluid from causing turbulence or cavitation. In addition, the cushioning effect of the liquid film formed on both surfaces of the thrust collar effectively acts against impact, so that it can withstand the impact fluctuation load well, and as mentioned above, stable bearing performance can be obtained at high speed rotation.

FIG. 5 is a schematic diagram of a thrust bearing testing device, in which one of the test bearings 21A and 21B is connected to a variable speed monitor (10 to 5000 rpm) 24 and a cipley 2.
The other bearing 21B is attached to the end of the rotating shaft 23 driven through a hydraulic cylinder (~10000 kg
f) 28, attached to the end of the thrust shaft 27 via the low F cell 30; In the figure, 22 is a bearing, 26 is a torque meter, and 29 is a hydraulic valve.

The results of testing the thrust bearing of the present invention using the thrust bearing testing apparatus shown in FIG. 5 above, with the members 21A and 21B used as rotating collars and fixed parts, and with the thrust collar interposed between them, will be exemplified.

Rotating collar 21A is 600Orp in 106C tap water
It was confirmed that the thrust collar was rotating at about half the rotation speed when the rotation speed was m. The thrust load at this time is 10
000 rgf. This is because the pressure on both the front and back surfaces was balanced by the through hole 17 in the center of the pocket, resulting in approximately the same number of rotations. Furthermore, it has been found that the collar shape on the fixed charge 21B side is spherical and can sufficiently serve as a universal support.

In the above embodiments, the shape of the thrust collar is described as having a smooth front surface and a spherical back surface, but it is of course not limited to these shapes. If it is made smooth, there is no need for through holes and there is relative operation on either side,
The striped collar rotates while forming a liquid film on both the front and back sides.

In addition, in Fig. 1, the rotating collar and fixed cost are shown housed in a bearing chamber filled with lubricating fluid, but this is also -
Of course, this is just a usage example.

(Effects of the Invention) As explained above, according to the present invention, the thrust force 2-
Because a liquid film is formed on both the front and back sides of the spiral grooved hydrodynamic bearing, it is able to withstand shock loads that are considered to be weaker than conventional tailed pand type bearings, and the spiral bearing's original characteristics By using fluid friction, power loss is reduced to approximately 115 or less at a thrust load of 5000 kgf compared to a tailing pad bearing, and the load capacity is improved to more than 5 times that of a tailing pad bearing. Shikaku lubricant 50 thibrobylene glycol,
Conventional bearings with an i-bearing diameter of φ86 (2000 rgf) have a bearing diameter of 10000 rgf (inventive bearings), and can withstand high-temperature environments well.While tailing pad bearings have a temperature of 1000C or less, the present invention can withstand temperatures of 200'C or more. In addition, in this invention, the thrust collar divides the rotational speed of the bearing into two, so it satisfies the high-speed rotational specifications and eliminates any dimensional tolerances or assembly defects (misalignment). However, by forming the bottom part into a swivel bearing, stable bearing performance can be achieved.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a thrust bearing showing an embodiment of the present invention, Fig. 2 is a view taken along the line A-A in Fig. 1, and Fig. 3 shows a spiral groove shape when the back surface is spherical. 4 are longitudinal sectional views of a conventional tailing pad type bearing, and FIG. 5 is a schematic diagram of a thrust bearing testing device. 1-m-rotation axis, 11--one rotation collar. 12-11 Fixed receiver + 15a * 15b---Spiral groove. ISa, 16b---pocket portion, 17---through hole. 1st-m-land club.

Claims (1)

[Claims] 1. A stator 2 having spiral grooves provided on the front and back surfaces thereof to produce a dynamic pressure effect by rotation in one direction.
- is interposed between a rotating collar attached to a rotating shaft and a fixed base, and as the rotating shaft rotates, the thrust collar is simultaneously rotated at a rotation speed equal to or lower than the rotating speed of the rotating shaft. 2 The thrust collar has one surface smooth and the other surface spherical, and the spiral groove on the spherical side leaves a land portion on the outer periphery, and a through hole communicating the front surface and the back surface is provided in the box part showing the highest pressure. A thrust bearing according to claim 1.