Pressure balanced rotary union

Abstract

The application relates to the technical field of rotary joints, and discloses a pressure balance type rotary joint which comprises a shell, a rotating body arranged in the shell, a medium channel with a closed left end arranged in the rotating body, a connecting channel arranged on the side surface of the shell and vertically distributed with the medium channel, a plurality of flow guide holes arranged on the side surface of the medium channel and communicated with the connecting channel, a left end cover arranged on the left end of the shell and connected with the shell, an annular sealing body arranged in the left end cover, a rotating seal between the annular sealing body and the left end of the rotating body, a closed balance cavity formed between the annular sealing body and the left end of the rotating body, and a throttling channel arranged at the center of the left end of the rotating body and used for connecting the balance cavity and the medium channel. In the application, the rotating body is balanced under pressure, the sealing elements are not prone to wear, the overall structure is more stable, and the service life is longer.

Description

Technical Field

[0001] This invention relates to the field of rotary joint technology, and more particularly to a pressure-balanced rotary joint. Background Technology

[0002] A rotary joint is a sealing device that connects and seals fluid media from a stationary pipeline to a rotating or reciprocating device, thereby providing heating or cooling media for the rotating mechanism. For direct rotary joints, the two ends form right angles. When a high-pressure medium flows inside, because the inner end of the rotating body is closed, the medium flows out from the inner sidewall of the rotating body. This causes the high-pressure medium to exert pressure on the inner end of the rotating body, resulting in pressure imbalance and affecting operational stability. The seal between the rotating body and the housing is also prone to wear due to uneven pressure. Summary of the Invention

[0003] In order to solve the above-mentioned problems in the prior art, the present invention provides a pressure-balanced rotary joint with stable rotating body under pressure and long overall service life.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A pressure-balanced rotary joint includes a housing and a rotating body disposed within the housing. The left end of the rotating body is located inside the housing, and the right end of the rotating body extends outside the housing. A medium channel with its left end closed is provided inside the rotating body. A connecting channel perpendicularly distributed to the medium channel is provided on the side of the housing. A plurality of guide holes communicating with the connecting channel are provided on the side of the medium channel. A left end cover connected to the housing is provided at the left end of the housing. An annular sealing body is provided inside the left end cover. The annular sealing body and the left end of the rotating body form a rotational seal, and a closed balance cavity is formed between the annular sealing body and the left end of the rotating body. A throttling channel for connecting the balance cavity and the medium channel is provided at the center of the left end of the rotating body.

[0005] A balance chamber is constructed at the left end of the medium channel. The medium in the medium channel enters the balance chamber through the throttling channel, so that the left end face of the medium channel and the left end face of the rotating body are subjected to medium pressures in opposite directions, thereby achieving pressure balance, making the rotation of the rotating body more stable, reducing wear on the seals, and extending the overall service life.

[0006] Preferably, the inner wall of the housing is provided with supporting protrusions on both sides of the guide hole. The rotating body passes through the protrusions to form a clearance fit. The part between the two supporting protrusions forms an annular cavity. The guide hole is connected to the annular cavity, and the connecting channel is connected to the annular cavity.

[0007] Preferably, the inner wall of the supporting convex ring is provided with a first sealing ring, the outer wall of the rotating body is provided with an annular groove corresponding to the first sealing ring, and the inner hole of the first sealing ring is provided with a convex ring adapted to the annular groove.

[0008] Preferably, a limiting protrusion is provided on the outer side of the left end of the rotating body, a thrust bearing is provided between the limiting protrusion and the left supporting protrusion, a ball bearing is provided on the right side of the supporting protrusion on the right side of the rotating body, a right end cover is provided on the right end of the housing, and the rotating body extends out of the housing through the right end cover.

[0009] Preferably, a second sealing ring is provided between the outer side of the limiting protrusion ring and the inside of the housing, and a third sealing ring is provided between the right end cover and the outer wall of the rotating body.

[0010] Preferably, the third sealing ring is configured as two sets, with an elastic gasket between the two sets of third sealing rings.

[0011] Preferably, the left end face of the medium channel is configured as a conical surface, the left end face of the rotating body is configured as a spherical surface protruding to the left, the right end face of the annular sealing body abuts and seals against the spherical surface, and the cross-sectional area of ​​the balance cavity is equal to the cross-sectional area of ​​the medium channel.

[0012] Therefore, in this invention, the rotating body is under balanced pressure, the various seals are not easily worn, the overall structure is more stable, and the service life is longer. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of one structure of the present invention.

[0014] Figure 2 for Figure 1 A sectional view.

[0015] Figure 3 This is a cross-sectional view of the shell.

[0016] Figure 4 This is a schematic diagram showing the fit between the rotating body and the annular seal.

[0017] In the figure: housing 10, connecting channel 11, supporting convex ring 12, annular cavity 120, first sealing ring 13, convex ring 130, rotating body 20, medium channel 200, guide hole 201, conical surface 202, spherical surface 203, annular groove 204, throttling channel 21, limiting convex ring 22, second sealing ring 220, thrust bearing 23, ball bearing 24, left end cover 30, right end cover 40, third sealing ring 41, elastic washer 42, annular sealing body 50, balance cavity 500. Detailed Implementation

[0018] To make the technical problems to be solved, the technical solutions, and the beneficial technical effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and several exemplary embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0019] It should be understood that the terms "first," "second," etc., used herein are for descriptive purposes only and should not be construed as indicating or implying relative importance, nor should they be construed as implicitly specifying the number of technical features indicated. Features specified as "first" or "second" may expressly or implicitly indicate that at least one of those features is included.

[0020] like Figures 1-4 The pressure-balanced rotary joint shown includes a housing 10 and a rotating body 20 disposed within the housing 10. The left end of the rotating body 20 is located inside the housing. The left end of the housing 10 is provided with a left end cover 30, and the right end of the housing is provided with a right end cover 40. The right end of the rotating body 20 extends out of the housing after passing through the right end cover. The rotating body 20 is provided with a medium channel 200 that is closed at the left end. The side of the housing 10 is provided with connecting channels 11 that are perpendicular to the medium channel. The side of the medium channel 200 is provided with a plurality of guide holes 201 that communicate with the connecting channels.

[0021] The left end cover 30 is provided with an annular sealing body 50, which rotates and seals with the left end of the rotating body 20. The annular sealing body 50 and the left end of the rotating body form a closed balance cavity 500. The center of the left end of the rotating body 20 is provided with a throttling channel 21 for connecting the balance cavity and the medium channel.

[0022] In some embodiments, the left end face of the medium channel 200 is configured as a conical surface 202, the left end face of the rotating body 20 is configured as a spherical surface 203 protruding to the left, and the right end face of the annular sealing body 50 abuts against the spherical surface for sealing. The cross-sectional area of ​​the balance cavity is equal to the cross-sectional area of ​​the medium channel. The annular sealing body adopts an annular end face sealing ring, with its left end face closed and its right end face fitting and sealing against the spherical surface 203, resulting in good sealing performance. The high-pressure medium in the medium channel enters the balance cavity through the throttling orifice. The medium in the balance cavity exerts a rightward pressure Fa on the spherical surface 203 at the left end of the rotating body, and the medium in the medium channel exerts a leftward pressure Fb on the conical surface 202 at the left end of the medium channel. Since the cross-section of the balance cavity and the cross-section of the medium channel are equal, the medium pressure in the balance cavity is equal to the medium pressure in the medium channel, thus making Fa=Fb. In some embodiments, the orifice diameter of the throttling channel is set to 1-3 mm. When the medium pressure in the medium channel changes, the medium pressure in the balance chamber can be gently (delayed) changed through the small-diameter throttling channel, preventing excessive pressure changes in the balance chamber from causing seal failure. This allows the rotating body to achieve a dynamic pressure balance. Furthermore, the spherical surface 203 and the conical surface 202 can reduce the axial runout generated when the rotating body rotates. The medium pressure on the spherical surface 203 and the conical surface 202 can drive the rotating body to rotate coaxially, further reducing wear on the seal.

[0023] The inner wall of the housing 10 is provided with supporting protruding rings 12 on both sides of the guide hole. The rotating body 20 passes through the protruding rings to form a clearance fit. The area between the two supporting protruding rings forms an annular cavity 120. The guide hole 201 communicates with the annular cavity 120, and the connecting channel 11 communicates with the annular cavity 120. The inner wall of the supporting protruding rings 12 is provided with a first sealing ring 13. The outer wall of the rotating body 20 is provided with an annular groove 204 corresponding to the first sealing ring. The inner hole of the first sealing ring 13 is provided with a protruding ring 130 that matches the annular groove.

[0024] A limiting protrusion ring 22 is provided on the outer side of the left end of the rotating body 20. A thrust bearing 23 is provided between the limiting protrusion ring 22 and the support protrusion ring 12 on the left side. A ball bearing 24 is provided on the right side of the support protrusion ring on the right side of the rotating body 20. A second sealing ring 220 is provided between the outer side of the limiting protrusion ring 22 and the inside of the housing. A third sealing ring 41 is provided between the right end cover 40 and the outer wall of the rotating body. The third sealing ring 41 is configured in two sets, and an elastic washer 42 is provided between the two sets of third sealing rings.

[0025] Rotational sealing is achieved between the rotating body and the housing through multi-stage sealing rings; the left end of the medium channel in the rotating power and the right end of the balance chamber are subjected to the same medium pressure, and the pressure is adaptively adjusted through the throttling channel, so that the axis of the rotating body maintains dynamic pressure balance during rotation, making the rotation more stable and smooth, with less axial runout, and the sealing rings are less prone to wear, thus improving the overall service life.

[0026] In the description of this invention, it should be understood that the directions or positional relationships indicated by up, down, left, right, inner end, outer end, one end, and the other end are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the purpose of more clearly describing the technical solutions of this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as limiting this invention.

[0027] Although specific embodiments of the invention have been described in detail herein, they are given for illustrative purposes only and should not be construed as limiting the scope of the invention. Various substitutions, alterations, and modifications can be conceived without departing from the spirit and scope of the invention.

Claims

1. A pressure-balanced rotary joint, comprising a housing and a rotating body disposed within the housing, wherein the left end of the rotating body is located inside the housing, the right end of the rotating body extends outside the housing, a medium channel with its left end closed is provided inside the rotating body, and connecting channels perpendicularly distributed to the medium channel are provided on the side of the housing, and a plurality of guide holes communicating with the connecting channels are provided on the side of the medium channel, characterized in that, The left end of the housing is provided with a left end cover connected to the housing. The left end cover is provided with an annular sealing body. The annular sealing body and the left end of the rotating body are rotatably sealed. The annular sealing body and the left end of the rotating body form a closed balance cavity. The center of the left end of the rotating body is provided with a throttling channel for connecting the balance cavity and the medium channel.

2. The pressure-balanced rotary joint according to claim 1, characterized in that, The inner wall of the housing is provided with supporting protrusions on both sides of the flow guide hole. The rotating body passes through the supporting protrusions to form a clearance fit. The part between the two supporting protrusions forms an annular cavity. The flow guide hole is connected to the annular cavity, and the connecting channel is connected to the annular cavity.

3. A pressure-balanced rotary joint according to claim 2, characterized in that, The inner wall of each supporting convex ring is provided with a first sealing ring, the outer wall of the rotating body is provided with an annular groove corresponding to the first sealing ring, and the inner hole of the first sealing ring is provided with a convex ring that matches the annular groove.

4. A pressure-balanced rotary joint according to claim 2 or 3, characterized in that, A limiting protrusion is provided on the outer side of the left end of the rotating body. A thrust bearing is provided between the limiting protrusion and the left supporting protrusion. A ball bearing is provided on the right side of the supporting protrusion on the right side of the rotating body. A right end cover is provided on the right end of the housing. The rotating body extends out of the housing through the right end cover.

5. A pressure-balanced rotary joint according to claim 4, characterized in that, A second sealing ring is provided between the outer side of the limiting protrusion ring and the inside of the housing, and a third sealing ring is provided between the right end cover and the outer wall of the rotating body.

6. A pressure-balanced rotary joint according to claim 5, characterized in that, The third sealing ring is configured in two sets, with an elastic gasket between the two sets of third sealing rings.

7. A pressure-balanced rotary joint according to claim 1, characterized in that, The left end face of the medium channel is configured as a conical surface, the left end face of the rotating body is configured as a spherical surface protruding to the left, the right end face of the annular sealing body abuts and seals against the spherical surface, and the cross-sectional area of ​​the balance cavity is equal to the cross-sectional area of ​​the medium channel.

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