JPH1182493A - Hydrostatic bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the wear or seizure of a spherical surface and to improve the durability by providing a land part oil filler port having one end connected to an oil filler port in a land part between oil feeding grooves on the spherical surface, and supplying a lubricating oil-to the land part through it. SOLUTION: In the use of a bearing, a pressurized lubricating oil is supplied to an oil filler port 9 within a pin 5 from an external hydraulic device, and the lubricating oil is supplied into an oil feeding groove 7 through an oil filler port 10, a diaphragm 6, and an oil filler port 11. An oil pressure determined from the oil feeding pressure, the flowing characteristic of the diaphragm 6, the leakage characteristic of lubricating oil from the upper clearance 12 and lower clearance 13 between an inner ring 4 and an outer ring 3 is generated within the groove 7 to cause a spherical hydrostatic function between the circumferential surface 4a of the inner ring 4 and the inside surface 3a of the outer ring 3. Since a land part oil filler port 20 is provided in the center of a land part, the lubricating oil from the oil filler port 9 is supplied to the land part center through the oil filler port 20 to lubricate the spherical surface around it. Thus, the lack of lubricating oil in the land part is avoided, and the wear or seizure can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrostatic sliding bearing used for an oscillating mechanism or the like, and more particularly to a hydrostatic sliding bearing having a spherical seat in which an inner ring and an outer ring are in contact with each other on a spherical surface.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view along an axis showing a conventional example of a hydrostatic slide bearing with a spherical seat used in a swinging motion mechanism.

In FIG. 5, reference numeral 2 denotes a second shaft which is reciprocated by a hydraulic piston (not shown) or the like.
A second shaft housing 15 is fixed to the shaft.
The pin 5 is fixed to a fork of the shaft housing 15, and the inner race 4 is fixed to the outer periphery of the pin 5. on the other hand,
Reference numeral 1 denotes a first shaft, and the first shaft includes a first shaft housing 14.
Are fixed, and the outer race 3 is fixed inside the first shaft housing 14. The outer peripheral surface 4a of the inner ring 4 has a convex spherical surface, and the inner peripheral surface 3a of the outer ring 3 has a concave spherical surface. Here, since the clearance is provided between the outer peripheral surface 4a of the inner race 4 and the inner peripheral surface 3a of the outer race 3, that is, the upper clearance 12 and the lower clearance 13, the first shaft 1 is arranged with respect to the second shaft 2. It is possible to swing in a free direction.

[0004] On the outer peripheral surface 4a of the inner race 4, a plurality of oil supply grooves 7 are provided along the circumferential direction. This oil groove 7
In order to supply the lubricating oil, a lubrication hole 9 is drilled at the center of the pin 5, and a lubrication hole 10 extending from the lubrication hole 9 in the radial direction is drilled. The inner ring 4 is provided with a lubrication hole 11 communicating with the lubrication hole 10, and the lubrication groove 7 is communicated with the lubrication hole 11.
A throttle 6 is provided in the oil supply hole 11.

When the hydrostatic slide bearing device is used, pressurized lubricating oil is supplied to an oil supply hole 9 in the pin 5 from an external hydraulic device (not shown). The oil is supplied into the oil supply groove 7 through the throttle 6 and the oil supply hole 11. In the oil supply groove 7, a hydraulic pressure Pi determined by the oil supply pressure P and the flow characteristics of the throttle 6, the leakage characteristics of the lubricating oil from the upper clearance 12 or the lower clearance 15 between the inner ring 4 and the outer ring 3, and the like are generated. A spherical hydrostatic bearing function is provided between the outer peripheral surface 4a of the inner race 4 and the inner peripheral surface 3a of the outer race 3.

[0006]

In the conventional hydrostatic slide bearing with a spherical seat shown in FIG. 5, the second shaft 2 is driven by power from a drive source such as an external hydraulic piston (not shown).
Reciprocates to drive the first shaft 1 in a free direction via the spherical hydrostatic bearing, while a driven body (not shown) is mounted outside the first shaft 1. The force such as the inertial force of the driven body or the frictional force acting on the driven body appears as a force acting between the outer ring 3 and the inner ring 4.

If the load capacity based on the static pressure of the spherical hydrostatic bearing is larger than the inertia force of the driven body or the frictional force acting on the driven body, the outer ring 3 and the inner ring 4 come into contact with each other. I will not do it. However, when the force such as the inertial force or the frictional force exceeds the load capability based on the static pressure, as shown in FIG.
Becomes extremely small, and the inner peripheral surface 3a of the outer race 3 and the outer peripheral surface 4a of the inner race 4 come into contact with each other. FIG. 6 shows a state in which the upper clearance 12 is extremely small.

However, as described above, the first shaft 1 can swing in a free direction, and depending on the device, the swing angle of the first shaft 1 with respect to the second shaft 2 is large, and the cycle of the swing is also large. May be shorter. In such a case, as shown in FIG. 7, a shortage of lubricating oil occurs in the land portion 17 surrounded by the oil supply groove 7, particularly in the center portion thereof, and abnormal wear and seizure due to this are observed.

In order to prevent such a problem from occurring, it has been proposed to increase the pocket pressure Pi as a method for increasing the load capacity based on the static pressure between the outer ring 3 and the inner ring 4. Need to be increased. However, when the oil supply pressure P is increased, the amount of oil consumed becomes large, which causes a problem that the scale of the oil supply hydraulic device and the driving power increase.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hydrostatic bearing in which an inner ring and an outer ring are fitted on a spherical surface without increasing the capacity of a hydraulic device for lubrication. An object of the present invention is to improve the durability of a bearing by preventing occurrence of shortage and accompanying wear and seizure of a spherical surface.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The gist of the invention is to provide an inner ring connected to one shaft via a pin joint, and an inner ring connected to the other shaft. With the connected outer ring, the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring are formed into a spherical surface and fitted, and lubricating oil is supplied through an oil supply hole to an oil supply groove formed on the spherical surface. In the configured hydrostatic bearing device, a land portion formed between the lubrication grooves on the spherical surface has a land portion lubrication hole, one end of which is connected to the lubrication hole. The lubricating oil is supplied to the land.

According to the above means, lubricating oil is supplied through the oil supply hole to the land oil supply hole opened in the land portion of the spherical surface where the inner ring and the outer ring fit, and diffused from the oil supply hole to the land. Provided for lubrication. As a result, a sufficient amount of lubricating oil is supplied to the lands where lubricating oil shortage has conventionally been liable to occur, thereby avoiding lubricating oil shortage and causing abrasion and seizure of the spherical surface. Is prevented.

It is preferable that the land oil supply hole be opened at the center of the land from the viewpoint of the lubricating oil diffusion surface at the land.

Further, in addition to the above-mentioned means, the present invention also includes that a land portion oil supply groove is provided around the opening of the land portion oil supply hole of the land portion so as to communicate with the opening.

According to this means, the lubricating oil supplied to the land from the land oiling hole is easily diffused to the entire land through the land oiling groove, and the effect of preventing shortage of lubricating oil in the land is further enhanced. Can be

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. 1 to 3 show a first embodiment of the present invention. FIG. 1 is a cross-sectional view of a hydrostatic slide bearing with a spherical seat taken along a swing center line. FIG. 2 is an operation explanatory view corresponding to FIG. FIG. 2 is a plan view of the inner race seen through from the direction of arrow Z in FIG. 1.

In FIG. 1, reference numeral 2 denotes a second shaft reciprocated by a hydraulic piston (not shown) or the like.
A second shaft housing 15 is fixed to the shaft.
The pin 5 is fixed to a fork of the shaft housing 15, and the inner race 4 is fixed to the outer periphery of the pin 5. on the other hand,
Reference numeral 1 denotes a first shaft, and the first shaft includes a first shaft housing 14.
Are fixed, and the outer race 3 is fixed inside the first shaft housing 14. The outer peripheral surface 4a of the inner ring 4 has a convex spherical surface, and the inner peripheral surface 3a of the outer ring 3 has a concave spherical surface. The two slide-contact each other to form a spherical hydrostatic bearing. here,
Since the outer peripheral surface 4a of the inner race 4 and the inner peripheral surface 3a of the outer race 3 are arranged with a clearance, that is, an upper clearance 12 and a lower clearance 13, the first shaft 1 is free with respect to the second shaft 2. It is possible to swing in the direction. The above basic configuration is shown in Figs.
This is the same as the conventional one shown in FIG.

In the embodiment of the present invention, an oil supply hole, an oil supply groove, and the like for supplying lubricating oil to a spherical surface of the spherical hydrostatic bearing where the inner ring and the outer ring are in contact with each other are improved.

That is, in FIG. 1, reference numeral 7 denotes an oil supply groove formed in the outer peripheral surface 4a of the inner ring 4;
As shown in FIG. 5, the groove is continuous on the outer peripheral surface 4a. Reference numeral 17 denotes a land portion surrounded by the continuous oil supply groove.

Reference numeral 9 denotes an oil supply hole formed in the center of the pin 5 in the axial direction, and a lubricating oil inlet is provided on one side (left side in FIG. 1), and a stopper 8 is provided on the other side. It is blocked. Two (or more than two) oil supply holes 10 are formed in the pin 5 in the radial direction from the oil supply hole 9, and the inner ring 4 is provided with a radial direction communicating with the oil supply hole 10 of the pin 5. The fuel supply hole 11 is formed. The outlet end of the oil supply hole 11 is connected to the oil supply groove 7 of the outer peripheral surface 4a. Reference numeral 6 denotes a throttle provided in the oil supply hole 11 of the inner ring 4.

Reference numeral 20 denotes a land portion oil supply hole. The land portion oiling hole 20 is formed substantially at the center of the inside of the inner ring 4, and is opened substantially at the center of the land portion 17 on the outer peripheral surface 4 a of the inner ring 4. Further, the land portion oil supply hole 20 penetrates through the inside of the inner ring 4 from the opening to the outer peripheral surface 4a, further penetrates the inside of the pin 5, and is connected to the oil supply hole 9 of the pin 5. A throttle 6 is provided in the land oil supply hole 20 as in the oil supply hole 11.

When the hydrostatic slide bearing with a spherical seat having the above-mentioned configuration is used, pressurized lubricating oil is supplied to an oil supply hole 9 in the pin 5 from an external hydraulic device (not shown). Is supplied into the oil supply groove 7 through the oil supply hole 10, the throttle 6, and the oil supply hole 11. In the oil supply groove 7, a hydraulic pressure Pi determined by the oil supply pressure P and the flow characteristics of the throttle 6, the lubricating oil leakage characteristics from the upper clearance 12 or the lower clearance 13 between the inner ring 4 and the outer ring 3, and the like are generated. Outer peripheral surface 4 of inner ring 4
a and the inner peripheral surface 3a of the outer ring 3 has a spherical static pressure function.

In the hydrostatic bearing according to this embodiment, when the second shaft 2 is caused to reciprocate by power from a drive source such as an external hydraulic piston (not shown), the above-mentioned spherical hydrostatic bearing is used to move the second shaft 2 through the spherical hydrostatic bearing. The first shaft 1 is driven in a free direction, while the first shaft 1 drives a driven body connected thereto.

At the time of driving, a force such as an inertial force of the driven body or a frictional force acting on the driven body appears as a force acting between the outer wheel 3 and the inner wheel 4. If the load capacity based on the static pressure of the spherical hydrostatic bearing is larger than the inertia force of the driven body or a force such as a frictional force acting on the driven body,
The outer ring 3 and the inner ring 4 do not come into contact with each other. However, when the force such as the inertial force or the frictional force exceeds the load capacity based on the static pressure, the upper clearance 12 or the lower clearance 13 becomes extremely small as shown in FIG. And the outer peripheral surface 4a of the inner ring 4 comes into contact with each other. FIG. 2 shows a state in which the upper clearance 12 is extremely small.

However, the first shaft 1 can swing in a free direction. For this reason, depending on the device, the swing angle of the first shaft 1 with respect to the second shaft 2 may be large and the period thereof may be short. In such a case, contact slip occurs between the outer ring 3 and the inner ring 4 under severe sliding conditions, and the lubricating oil is insufficient at the land portion 17 surrounded by the lubrication groove 7, especially at the center of the land remote from the lubrication groove 7. Is easy to occur.

However, in the embodiment of the present invention, since the land oiling hole 20 is opened at the center of the land 17, the lubricating oil from the oiling hole 9 passes through the land oiling hole 20 and is landed. It is supplied to the central part of the part 17 and is used for lubrication of the spherical surface near the part. In this way, the lubricating oil shortage in the land portion 17 is avoided, thereby preventing the occurrence of wear and seizure.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, a land oil groove 21 is provided radially at the opening of the land oil hole 20 to the land 17. Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals. In this embodiment, the lubricating oil flows through
7, and the effect of preventing oil shortage can be further enhanced.

[0028]

The present invention is configured as described above.
According to the present invention, since the land oiling hole is opened in the land portion of the spherical surface where the inner ring and the outer ring fit, the lubricating oil is diffused from the land oiling hole to the land portion to provide lubrication to the land portion. Thus, the shortage of lubricating oil in the land is avoided. Therefore, it is possible to prevent wear and seizure of the spherical surface due to the lubricating oil of the land portion, and it is possible to extend the life of the bearing.

Further, since it is not necessary to increase the oil supply pressure to make up for the lubricating oil shortage, the capacity of the hydraulic device can be increased,
Lubrication performance can be maintained without increasing the manufacturing cost due to the increase in size.

According to the second aspect of the present invention, the lubricating oil supplied to the land from the land oil supply hole is easily diffused into the land through the land oil groove, thereby preventing shortage of lubricating oil in the land. Can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a hydrostatic slide bearing with a spherical seat according to a first embodiment of the present invention, taken along a swing center line.

FIG. 2 is an operation explanatory view corresponding to FIG. 1;

FIG. 3 is a plan view of the inner race seen through from the direction of arrow Z in FIG. 1;

FIG. 4 is a diagram corresponding to FIG. 3, showing a second embodiment of the present invention.

FIG. 5 is an equivalent view of FIG. 1 showing a conventional hydrostatic slide bearing with a spherical seat.

FIG. 6 is an operation explanatory view corresponding to FIG. 5;

FIG. 7 is a plan view of the inner race seen through from the direction of arrow Y in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st axis 2 2nd axis 3 Outer ring 3a Inner peripheral surface (outer ring) 4 Inner ring 4a Outer peripheral surface (inner ring) 5 Pin 6 Restrictor 7 Oil supply groove 9 Oil supply hole (pin center) 10 Oil supply hole (pin) 11 Oil supply hole (inner ring) 12) Upper clearance 13 Lower clearance 14 First shaft housing 15 Second shaft housing 17 Land 20 Land lubrication hole 21 Land lubrication groove

Claims (2)

[Claims] An inner race connected to one shaft via a pin joint and an outer race connected to the other shaft are formed by forming the outer peripheral surface of the inner race and the inner peripheral surface of the outer race into spherical surfaces. In a hydrostatic bearing device configured to supply lubricating oil through an oil supply hole to an oil supply groove formed on the spherical surface, a land portion formed between the oil supply grooves on the spherical surface A hydrostatic bearing device, wherein one end is opened to a land oil supply hole connected to the oil supply hole, and lubricating oil is supplied to the land from the land oil supply hole. 2. The hydrostatic bearing device according to claim 1, wherein a land oil groove is provided around the opening of the land oil hole in the land, the land oil groove being communicated with the opening.