JPH0115991Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a rotary joint that connects a flow path on a rotating side and a stationary side when supplying working fluid such as pressure oil to a rotating body. .

[Conventional technology] A conventional rotary joint is shown in FIG.

Reference numeral 1 denotes a rotating shaft, and the rotating shaft 1 has passages 2, 3, and 4 that are open at both ends, respectively, formed on the end surface fixed to a rotating body (not shown) and on the outer peripheral surface. , 3 and 4 are provided with grooves 5, 6, and 7 that extend around the circumferential surface thereof. 8 is a sleeve rotatably fitted to the rotating shaft 1, and grooves 9, 10, 11 that match the grooves 5, 6, 7 are formed on the inner peripheral surface of the sleeve.
Further, communicating holes 12, 13, and 14 communicating with the grooves 9, 10, and 11 are passed through the sleeve 8. 15 is a housing that fits into the sleeve 8 and has bearings 16 and 17 fitted at both ends;
The housing 15 and the sleeve 8 are fixed, and the housing 15 is provided with guide holes 18, 19, 20 that match the communication holes 12, 13, 14, and a mounting seat 21 to which an oil supply pipe (not shown) is connected is fixed. ing.

Note that 22 is a seal ring, and a seal 23 is attached thereto. Further, 24 indicates a seal.

In the rotary joint described above, the housing 15
is fixed to the equipment, and the rotating shaft 1 is fixed to the rotating body.
The pressure fluid supplied is through the guide holes 18, 19, 20, communication holes 12, 13, 14, grooves 5, 6, 7 and grooves 9, 1.
It is supplied to a predetermined device through a space surrounded by 0 and 11 and flow paths 2, 3, and 4. With this configuration, the sealing of the sliding surfaces, that is, the sealing between the rotating shaft 1 and the sleeve 8, is achieved by optimizing the gap between them. 4
It is possible to seal the gap.

[Problems to be Solved by the Invention] However, it is difficult to finish the sleeve 8 with high accuracy over the entire length in the axial direction, and it is also expensive. For this reason, it is difficult to obtain an appropriate gap,
There was a problem with a seizure phenomenon or an increase in the amount of leakage.

In addition, as other conventional rotary joints, there is a type that does not have the above-mentioned sleeve and a piston ring is provided between the housing and the rotating shaft to seal the sliding surface. Since the rotary shaft is provided with a groove for the piston ring, there is a problem in terms of strength due to stress concentration, etc. Furthermore, the sliding surfaces of the piston ring and the housing wear out, increasing leakage. Therefore, there have been problems such as the need for frequent replacement and maintenance.

The present invention aims to eliminate such problems, reduce the number of parts to be processed with high precision, improve sealing performance, and prevent seizure.

[Means for Solving the Problems] The present invention involves fitting a plurality of floating rings having a short axial length to a rotating shaft with an appropriate narrow gap to seal a pressure fluid, and forming a gap between the floating rings. A sleeve piece that fits with the rotating shaft with a large gap is arranged on the housing, and the floating ring at both ends is supported with a gap by a bearing holder for supporting the bearing, so that each flow between the sleeve pieces is A spacer having a longer axial length than the floating ring and regulating a gap between each sleeve piece in the axial direction is arranged between the floating ring and the housing and overlapped with a gap on the outer peripheral side of the floating ring. Each floating ring is fixed to the sleeve piece so as to be prevented from rotating by a rotation preventing member, and the floating ring between each sleeve piece and the sleeve piece and between each floating ring at both ends and the bearing holder are fixed to the sleeve piece so as to prevent rotation. An elastic body is sandwiched between the floating rings in a compressed state so that one end face of each floating ring and the end face of the opposing sleeve piece can be brought into close contact with each other. The present invention relates to a rotary joint characterized in that the sleeve piece communicates with the passageway through a communication hole bored in the sleeve piece.

[Function] Each short floating ring that fits on the rotating shaft with a narrow gap is rotated by a rotation prevention member within an annular space formed by a sleeve piece, a spacer, and another sleeve piece or bearing holder. While being stopped and in close contact with the end face of the sleeve piece or bearing holder by the elastic body, slight movement is easily maintained.

Therefore, an appropriate sliding gap is always maintained to prevent seizure, and sealing is ensured at the close contact portion of the end face.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

Figures 2 and 3 are an embodiment of the present invention,
In the figure, the same components as in FIG. 1 are given the same reference numerals.

Sleeve pieces 25, 26, 27 having communicating holes 12, 13, 14 are fitted between the rotating shaft 1 and the housing 15 with a large gap relative to the rotating shaft 1. Between each sleeve piece 25 and 26, 26 and 27, a floating ring 28, 2 having a short axial length is provided.
9 is sandwiched between the rotating shaft 1 so as to form a narrow gap suitable for sealing the working fluid, and between the housing 15 and the floating rings 28, 29, the axes of the floating rings 28, 29 are A spacer 30 that is slightly longer than the length of the sleeve pieces 25 , 26 , and 27 and that regulates the gap in the axial direction of the sleeve pieces 25 , 26 , 27 is placed in a direction perpendicular to the axis of the rotating shaft 1 , that is, on the outer peripheral side of the floating rings 28 , 29 . It is arranged so as to overlap the floating rings 28 and 29 with a slight gap.

Further, bearings 1 are provided at both ends of the housing 15, respectively.
The movement of each sleeve piece 25, 26, 27 in the axial direction is restrained by fitting the sleeve pieces 6, 17 and the bearing holders 31, 32, and further pressing both the bearing holders 31, 32 with the seal rings 22, 22'. do.

Furthermore, the sleeve piece 25 and the bearing holder 31
Floating rings 33 and 34 are provided between the sleeve piece 27 and the bearing holder 32, respectively.

Like the floating rings 28 and 29, the floating rings 33 and 34 have a short length in the axial direction and are fitted to the rotating shaft 1 so as to form a narrow gap suitable for sealing the working fluid. ing. The floating rings 33 and 34 are fitted into the inner circumferential sides of the bearing holders 31 and 32, and the outer circumferential edges of each of the bearing holders 31 and 32 are in contact with the outer circumferential edges so that they function similarly to the spacer 30. A slight gap is provided between the bearing rings 33 and 34.

FIG. 3 shows the details of the mounting structure of the floating ring 28, in which the floating ring 28 is fixed so as to be prevented from rotating by a rotation preventing member such as a pin 35 provided protruding from the end surface of the sleeve piece 25, and the floating ring 28 is fixed so as to be prevented from rotating. piece 26 and floating ring 28
An elastic body such as a spring 26 is sandwiched between the floating ring 28 and the sleeve piece 2 in a compressed state.
The surface facing 5 can be brought into close contact. The floating rings 29, 33, and 34 also have a similar mounting structure.

The sliding surface of each floating ring 28, 29, 33, 34 having a short axial length with respect to the rotating shaft 1, and the surface that comes into close contact with the sleeve pieces 25, 26, 25, 27, respectively, that is, the surface provided with a spring. The opposite surface and the surface of the sleeve pieces 25, 26, 27 that the floating rings 28, 29, 33, 34 are in close contact with are finished with ultra-precision.

In the present invention having the above configuration, the seal in the axial direction of the sliding surface of the rotating shaft 1 is provided by the floating ring 2.
This is done by maintaining the gap g between the rotating shaft 1 and the floating ring 28, 29, 33, 34 and the sleeve piece 25, 26, 25, 27. Each end surface contact part a
Both parts are finished with ultra-precision finishing, and the spring 36 brings the two parts into close contact with each other, so this part provides a fluid seal.

Therefore, when the working fluid is supplied to each guide hole provided in the housing, each sleeve piece 25, 26, 2
7 through the communication holes 12, 13, 14, and flow into the channels 2, 3, 4 from the respective grooves of the rotating shaft 1. The flow path 3 system is sealed by the close contact between the floating ring 28 and the sleeve piece 25 and the close contact between the floating ring 29 and the sleeve piece 26, and the flow path 4 system is sealed by the close contact between the floating ring 28 and the sleeve piece 25, and the flow path 4 system is sealed by the close contact between the floating ring 28 and the sleeve piece 25, and the close contact between the floating ring 29 and the sleeve piece 26. Sealed by the close contact between the ring 29 and the sleeve piece 26 and the close contact between the floating ring 34 and the sleeve piece 27, each of the flow passages 2, 3, and 4 can be operated separately and independently without causing fluid leakage. It becomes possible to do so.

Each floating ring 28, 29, 33, 3
Since the sliding gap g between the rotating shaft 1 and the rotary shaft 1 is maintained at an appropriate value, lubrication can be ensured and seizure can be prevented by keeping the amount of fluid leakage constant.

The gaps between the sleeve pieces 25, 26, 27 and the rotating shaft 1 are larger than the gap g, and the floating rings 28, 29, 33, 34 are small parts with short lengths in the axial direction, ensuring high accuracy. The rotating shaft 1 Even if there is a difference in axis between the outer diameter and the inner diameter of the housing 15, it does not directly affect the gap g, and therefore the gap g can be easily managed.

[Effects of the invention] As described above, according to the rotary joint of the invention,
Various excellent effects can be achieved as described below.

() A sleeve piece is arranged between a plurality of floating rings that fit on the rotating shaft with a predetermined gap, so that the sleeve piece fits on the rotating shaft with a large gap, and the end face of each floating ring is connected to one of the adjacent floating rings. By bringing the sleeve piece into close contact with the end face using an elastic body such as a spring, it is possible to reliably seal the working fluid.

() Each floating ring is a small part with a significantly shorter axial length than a conventional sleeve, and the parts that are machined with high precision are the sliding surface between the floating ring and the rotating shaft, the floating ring and the sleeve. Only the contacting end surfaces of the pieces are sufficient.

() () Since high-precision processing can be reliably performed, sealing performance can be improved and seizure prevention can be achieved.

() With (), the high-precision machining range can be reduced, so machining costs can be significantly reduced.

() Since each floating ring is supported by a spacer or bearing holder with a gap in between, an appropriate narrow gap is always maintained for sealing the working fluid, making it possible to maintain a constant small amount of fluid leakage and prevent seizure at the same time. can.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of a conventional rotary joint, and FIGS. 2 and 3 are partial cross-sectional views of the rotary joint of the present invention. 1 is the rotating shaft, 2, 3, 4 are flow channels, 8, 19, 2
0 is a guide hole, 15 is a housing, 16, 17 are bearings, 25, 26, 27 are sleeve pieces, 28, 2
9, 33, 34 are floating rings, 30 is a spacer, 31, 32 are bearing holders, 35
indicates a pin, and 36 indicates a spring.

Claims (1)

[Scope of utility model registration request] A plurality of floating rings with short axial lengths are fitted to the rotating shaft with appropriate narrow gaps to seal the pressure fluid, and a sleeve piece that fits with the rotating shaft with a large gap is inserted between the floating rings. The floating rings are arranged and fitted into the housing, and the floating rings at both ends are supported by bearing holders for bearing support with a gap between them, and the floating rings are arranged between each floating ring between the sleeve pieces and the housing. A spacer having a longer axial length than the sleeve piece and regulating the axial gap between each sleeve piece is arranged overlappingly on the outer circumferential side of the floating ring with a gap in between, so that each floating ring is prevented from rotating by the sleeve piece. They are each fixed so as to be prevented from rotating by a member, and an elastic body is sandwiched in a compressed state between the floating ring between each sleeve piece and the sleeve piece, and between each floating ring at both ends and the bearing holder, respectively; One end face of each floating ring and the end face of the opposing sleeve piece can be brought into close contact with each other, and a communication hole formed in the sleeve piece connects the guide hole provided in the housing and the flow path bored in the rotating shaft. A rotary joint characterized by communicating through the joint.