CN109268438B

CN109268438B - Hydraulic bushing

Info

Publication number: CN109268438B
Application number: CN201811273607.1A
Authority: CN
Inventors: 邹波; 丁行武; 刘桂杰; 张亚新; 姜其斌; 夏彰阳
Original assignee: Zhuzhou Times New Material Technology Co Ltd
Current assignee: Zhuzhou Times New Material Technology Co Ltd
Priority date: 2018-10-30
Filing date: 2018-10-30
Publication date: 2024-04-09
Anticipated expiration: 2038-10-30
Also published as: CN109268438A

Abstract

The present invention provides a hydraulic bushing comprising: a mandrel; a sleeve-shaped first runner body sleeved on the mandrel, a first rubber body is filled in a gap between the mandrel and the first runner body, a first runner for hydraulic fluid is formed on the outer surface of the first runner body, and two main liquid cavities for containing the hydraulic fluid are formed on the first rubber body in a radial opposite manner and are communicated with each other through the first runner; the outer sleeve is tightly sleeved on the radial outer side of the first runner body; and a seal assembly disposed axially outwardly of at least one of the first flow passage bodies, which together with the outer jacket defines an auxiliary fluid chamber for containing hydraulic fluid. The seal assembly includes a support ring sleeved on the mandrel that includes a radial projection within the auxiliary fluid chamber. The radial projection is in sealing contact with the inner surface of the outer sleeve, thereby dividing the auxiliary liquid chamber into a first subchamber axially outside and a second subchamber axially inside.

Description

Hydraulic bushing

Technical Field

The present invention relates to a hydraulic bushing for a vehicle, in particular a rail vehicle.

Background

Hydraulic bushings are a component widely used in vehicles (e.g., automobiles and railway vehicles), and are mainly mounted on a suspension or a bogie of the vehicle for buffering vibration and impact to improve the stability and safety of the running of the vehicle.

Chinese patent document CN108150536a discloses a hydraulic bushing. The hydraulic bushing comprises a mandrel, a first fluid sleeved outside the mandrel, and an outer sleeve tightly sleeved outside the first fluid. A gap between the mandrel and the first fluid is filled with a first rubber body, and a groove is formed on the outer surface of the first fluid. Two liquid cavities for containing liquid are formed on the first rubber body in a radial opposite mode, wherein the grooves and the outer sleeve enclose a flow channel, and the two liquid cavities are communicated through the flow channel. By means of the flowability between the hydraulic fluid in the two fluid chambers, the stiffness of the hydraulic bushing can be adjusted, so that an improved stability of the vehicle in driving, in particular when the vehicle is cornering, is achieved.

However, in the above hydraulic bushings, the range of stiffness and damping adjustment is still limited. Accordingly, it is desirable in the art to provide a hydraulic bushing having a stiffness and damping that can be varied over a greater range to provide greater stability and safety for the vehicle to travel.

Disclosure of Invention

The present invention aims to provide a novel hydraulic bushing which can realize a rigidity-changing function in both radial and axial directions.

According to the present invention, there is provided a hydraulic bushing comprising: a mandrel; a sleeve-shaped first runner body sleeved on the mandrel, a first rubber body is filled in a gap between the mandrel and the first runner body, a first runner for hydraulic fluid is constructed on the outer surface of the first runner body, two main liquid cavities for containing the hydraulic fluid are constructed on the first rubber body in a radial opposite manner, and the two main liquid cavities are communicated with each other through the first runner; the outer sleeve is tightly sleeved on the radial outer side of the first runner body; and a seal assembly disposed axially outwardly of at least one of the first flow passage bodies, the seal assembly and the jacket collectively defining an auxiliary fluid chamber for containing hydraulic fluid. The sealing assembly comprises a supporting ring sleeved on the mandrel, the supporting ring comprises a radial protruding part positioned in the auxiliary liquid cavity, and the radial protruding part is in sealing contact with the inner surface of the outer sleeve, so that the auxiliary liquid cavity is divided into a first subchamber positioned at the outer side in the axial direction and a second subchamber positioned at the inner side in the axial direction.

In a preferred embodiment, the radial projection is provided with a communication hole extending in the axial direction for communicating the first sub-chamber with the second sub-chamber.

In a preferred embodiment, the radial protrusion includes a plurality of communication holes uniformly distributed in the circumferential direction.

In a preferred embodiment, the sealing assembly further comprises a second rubber body vulcanized on the support ring such that the radial projections are in sealing contact with the inner surface of the outer sleeve by means of the second rubber body.

In a preferred embodiment, the second rubber body includes a first portion in sealing contact with an axial end of the first runner body, a second portion in sealing contact with an axial end of the outer jacket, and a third portion provided on the radial projection and in sealing contact with an inner surface of the outer jacket.

In a preferred embodiment, rigid gaskets are embedded in both the first and second portions of the second rubber body.

In a preferred embodiment, a hydraulic fluid filling channel is provided in the support ring for filling the auxiliary liquid chamber with hydraulic fluid.

In a preferred embodiment, the hydraulic fluid filling channel comprises a horizontal branch leading to an axially outer end of the support ring and a vertical branch leading to a first subchamber of the auxiliary liquid chamber.

In a preferred embodiment, the main liquid chamber and the auxiliary liquid chamber are not in communication with each other.

In a preferred embodiment, the cross-sectional area and the length of the first flow passage are determined according to the radial dynamic stiffness required of the hydraulic bushing, and the cross-sectional area and the length of the communication hole are determined according to the axial dynamic stiffness required of the hydraulic bushing.

The hydraulic bushing according to the invention has a variable stiffness characteristic both axially and radially, the extent of which stiffness varies in relation to the excitation amplitude and frequency. Due to the existence of the auxiliary liquid cavity, the damping effect of the hydraulic bushing in the axial direction is improved, and a better vibration reduction effect is achieved. Meanwhile, the communication between the two subchambers of the auxiliary liquid chamber of the hydraulic bushing is realized through the communication hole of the radial protruding part, so that the space in the auxiliary liquid chamber is fully utilized, and the rigidity-variable effect provided by the hydraulic bushing is further enhanced.

Drawings

The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings. Wherein:

fig. 1 schematically shows a cross-sectional view of a hydraulic bushing according to an embodiment of the invention.

Fig. 2 is an enlarged view showing an auxiliary fluid chamber area in the hydraulic bushing shown in fig. 1.

Fig. 3 shows the structure of the support ring without the rubber body vulcanized, in particular showing the hydraulic fluid filling channels in the support ring.

Fig. 4 shows the structure of the support ring with the rubber body vulcanized thereon.

In the drawings, like parts are denoted by like reference numerals. The figures are not drawn to scale.

Detailed Description

The invention will be further described with reference to the accompanying drawings. It should be noted that, herein, the terms "axial" and "radial" refer to the horizontal and vertical directions in fig. 1, respectively.

Fig. 1 schematically illustrates a hydraulic bushing 100 according to one embodiment of the invention. As shown in fig. 1, the hydraulic bushing 100 includes a mandrel 10, a first runner body 20 disposed radially outward of the mandrel 10, and an outer jacket 30 that is fitted radially outward of the first runner body 20 in a compressed manner. The first runner body 20 is generally configured in the form of a sleeve member. The mandrel 10 is typically a preform and in the embodiment shown in fig. 1 is configured in the form of a stepped shaft. The two ends of the spindle 10 can be connected, for example, to the bogie of a rail train, while the jacket 30 is connected to the positioning arm. An optional inner sleeve 15 may also be provided over the mandrel 10, as shown in fig. 1. The two axial ends of the outer sleeve 30 are bent radially towards the mandrel 10, forming a flange 32 to facilitate the sealing of the hydraulic bushing 100.

A gap between the mandrel 10 and the first fluid 20 is filled with a first rubber body 40. However, it is understood that where the inner sleeve 15 is provided, the first rubber body 40 may be filled between the inner sleeve 15 and the first fluid 20. On the first rubber body 40, two main liquid chambers 45 for receiving hydraulic fluid are provided, which are preferably configured to be diametrically opposed. That is, both of the main liquid chambers 45 extend only partially in the circumferential direction and are opposed in the radial direction. Grooves, which may be in the form of a spiral circumferential distribution, are formed on the outer surface of the first flow channel body 20. In the assembled state, the jacket 30 is pressed against the first flow channel body 20, so that the grooves on the first flow channel body 20 form a first flow channel 42 for the hydraulic fluid flowing therein. Both ends of the first flow passage 42 are respectively communicated with two main liquid chambers 45. In addition, a liquid injection hole (not shown) for injecting hydraulic fluid is formed in the outer jacket 30 in communication with the first flow passage 42.

When the rail train runs in a straight-line section snakelike-resistant running stage, the wheel pair can bear high-frequency vibration, and when the rail train runs in a low-speed curve, the rim of the wheel pair can be abutted against the steel rail, and the vibration frequency is obviously reduced. Under the two conditions, the movement of the wheels drives the mandrel 10 and the outer sleeve 30 to move relatively, so that the main liquid cavity at the front and the main liquid cavity at the rear expand and contract respectively. In this way, hydraulic fluid can flow between the two main fluid chambers 45 through the first flow passage 42, thereby adjusting the rigidity of the hydraulic bushing 100 accordingly, so that the train keeps running stably. This varying stiffness is an important property of the hydraulic bushing 100.

The above-described features and functions of the hydraulic bushing are known in the art, for example, see the applicant's chinese patent document CN108150536a, which is incorporated herein by reference.

According to the present invention, as shown in fig. 1, both ends of the first flow path body 20 in the axial direction are closed by the seal assembly 50 so as to form a closed chamber for containing hydraulic fluid, i.e., the main liquid chamber 45. The seal assembly 50 includes a rigid support ring 60 that is mounted on the mandrel 10. In the illustrated embodiment, the mandrel 10 is configured as a stepped shaft, and therefore, the support ring 60 is preferably mounted at the stepped structure of the mandrel 10 so as to be well positioned and more stably supported. A second rubber body 70 is vulcanized onto the support ring 60, and rigid gaskets 55, 56 (see fig. 2) are embedded in the second rubber body 70. In this way, the support ring 60 and the gaskets 55, 56 are formed in one piece by the second rubber body 70.

As shown more clearly in fig. 2, the vulcanized second rubber body 70 includes two axially spaced apart portions, an inner portion 72 adjacent the axial end of the first runner body 20 and an outer portion 74 adjacent the axial end of the jacket 30. With this arrangement, the inner portion 72 of the second rubber body 70 forms a seal with the outer surface of the axial end of the first fluid 20, while the outer portion 74 of the second rubber body 70 forms a seal with the axial end of the outer sleeve 30 (specifically, the inner surface of the flange 32 formed at the axial end of the outer sleeve 30). In this way, a closed auxiliary fluid chamber 80 is formed between the inner portion 72 of the second rubber body 70, the outer portion 74 of the second rubber body 70, the support ring 60 and the outer jacket 30, in which hydraulic fluid can be contained. Unlike the main fluid chamber 45, however, the auxiliary fluid chamber 80 within each seal assembly 50 is configured to extend completely in the circumferential direction, i.e., the auxiliary fluid chamber 80 extends circumferentially through 360 degrees. The auxiliary liquid chamber 80 is not connected to the main liquid chamber 45.

In the preferred embodiment as shown, the support ring 60 also includes a radially outwardly extending tab 62. The tab 62 is axially located between an inner portion 72 and an outer portion 74 of the second rubber body 70. According to the invention, the projections 62 of the support ring 60 are located in the auxiliary liquid chamber 80 and extend radially outwardly until they are in sealing contact with the inner surface of the outer jacket 30.

Preferably, as shown in fig. 2, a third portion 76 of the second rubber body 70 is also provided on the projection 62 of the support ring 60. In this way, the support ring 60 is brought into sealing contact with the inner surface of the casing 30 by the third portion 76 of the second rubber body 70, thereby dividing the auxiliary liquid chamber 80 into two first and second subchambers 82, 84 axially adjacent to each other. As shown, the first subchamber 82 of the auxiliary liquid chamber 80 is axially outboard and the second subchamber 84 is axially inboard.

According to the present invention, a communication hole 90 extending in the axial direction is opened in the radially outwardly projecting protrusion 62 of the support ring 60, thereby communicating the first sub-chamber 82 and the second sub-chamber 84 of the auxiliary liquid chamber 80 adjacent to each other in the axial direction with each other. In this way, hydraulic fluid can flow between the first subchamber 82 and the second subchamber 84 of the auxiliary liquid chamber 80. Along with the flow of the hydraulic fluid, the rigidity of the hydraulic bushing 100 in the axial direction can be changed in a larger range, the effect of changing the rigidity of the hydraulic bushing 100 in the axial direction is enhanced, and the purposes of low-frequency low rigidity and high-frequency high rigidity in the axial direction are achieved.

In addition, when the hydraulic bushing 100 is subjected to an axial sinusoidal excitation, the radially outwardly projecting projections 62 of the support ring 60 will produce an axial back and forth movement, squeezing the first and second subchambers 82, 84 on the left and right sides thereof. In this way, an internal high pressure may be created in one subchamber (e.g., first subchamber 82) and an internal low pressure may be created in the other subchamber (e.g., second subchamber 84) accordingly, such that hydraulic fluid may flow from the subchamber having the internal high pressure (e.g., first subchamber 82) into the subchamber having the internal low pressure (e.g., second subchamber 84). The hydraulic bushing 100 produces an axially varying stiffness due to the pressure differential existing between the two subchambers. This further enhances the axial stiffness-changing effect of the hydraulic bushing 100 for the purposes of axial low frequency low stiffness and high frequency high stiffness.

In addition, since the support ring 60 is brought into sealing contact with the inner surface of the outer jacket 30 by the third portion 76 of the second rubber body 70, the third portion 76 of the second rubber body 70 can also provide a varying displacement in the radial direction. This also contributes to a certain degree to the stiffness variation in the radial direction of the hydraulic bushing 100.

In addition, the hydraulic fluid is allowed to flow between the first sub-chamber 82 and the second sub-chamber 84 of the auxiliary fluid chamber 80 through the communication hole 90 opened in the radial protrusion 62, so that it is unnecessary to add an additional auxiliary flow path body in the auxiliary fluid chamber 80, thereby making it possible to fully utilize the space in the auxiliary fluid chamber 80. In this way, the resulting hydraulic bushing 100 has a more compact structure. In particular, when the product is subjected to an axial load, the hydraulic fluid flows back and forth between the first subchamber 82 and the second subchamber 84 of the auxiliary liquid chamber 80 through the communication holes, so that the hydraulic fluid generates a damping effect at the time of passing through the inlet, outlet and intra-hole passages of the communication holes 90. This is reflected in the loss of along-way pressure and local pressure caused by the flow of hydraulic fluid through the above-mentioned areas. This further enhances the effect of the variable stiffness in the axial direction of the hydraulic bushing 100.

Without wishing to be bound by any theory, according to the invention the communication hole 90 in the auxiliary fluid chamber 80 is mainly used to provide axial stiffness to the hydraulic bushing 100, while the first flow channel 42 in the main fluid chamber 45 is mainly used to provide radial stiffness to the hydraulic bushing 100. Therefore, geometric parameters such as the cross-sectional area and the length of the first flow passage 42 and the communication hole 90 may be designed according to the requirements for radial rigidity variation and axial rigidity variation of the hydraulic bushing 100.

In a preferred embodiment, six communication holes 90 spaced apart from each other are uniformly provided on the support ring 60 in the circumferential direction. In this way, the mobility of the hydraulic fluid between the first subchamber 82 and the second subchamber 84 of the auxiliary liquid chamber 80 is improved, thereby further improving the responsiveness of the hydraulic bushing 100 to axial stiffness changes.

In accordance with the present invention, rigid shims 55 and 56 are embedded within the outer and inner portions 74 and 72, respectively, of the rubber body 70, thereby providing a degree of axial rigidity to the hydraulic bushing 100. In addition to providing axial rigidity, the gasket 56 can compress the adjacent second rubber body 70 to fully secure the sealing effect of the hydraulic fluid in the main 45 and auxiliary 80 fluid chambers. The insert 55 can then form a seal against the auxiliary liquid chamber 80 together with the flange 32 of the metal jacket 30 and the outer portion 74 of the second rubber body 70 located therebetween. Thereby, the sealability of the auxiliary liquid chamber 80 is further improved.

According to the invention, a hydraulic fluid filling channel 95 is also provided on the support ring 60. As shown in fig. 3, the hydraulic fluid filling channel 95 comprises a horizontal branch 96 leading to the axial end of the support ring 60, and a vertical branch 94, one end of which communicates with the horizontal branch 96 and the other end of which leads to the auxiliary liquid chamber 80. In this way, after the hydraulic bushing 100 is assembled, hydraulic fluid may be injected into the auxiliary fluid chamber 80 using the hydraulic fluid injection passage 95. After the injection is completed, the horizontal branch 96 of the hydraulic fluid filling channel 95 may be plugged, for example, using a plug (not shown). Alternatively, the hydraulic fluid charging passage 95 may also be sealed by driving steel balls into the inlet of the horizontal branch 96.

As shown in fig. 2, the vertical branch 94 of the hydraulic fluid filling channel 95 is arranged to open into the first sub-chamber 82 of the auxiliary liquid chamber 80, which is axially outside. Therefore, the structure can be simplified, the processing difficulty is reduced, and the cost is saved.

It should be noted that seal assemblies are required to be provided at both axial ends of the first fluid. Both seal assemblies may be seal assemblies 50 as described above, or only one of the seal assemblies 50 may be used as described above while the other is a conventional seal. Such a conventional seal need only provide a sealing effect to form a closed main liquid chamber, as will be readily devised by those skilled in the art.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

1. A hydraulic bushing, comprising:

a mandrel;

a sleeve-shaped first runner body sleeved on the mandrel, a first rubber body is filled in a gap between the mandrel and the first runner body, a first runner for hydraulic fluid is constructed on the outer surface of the first runner body, two main liquid cavities for containing the hydraulic fluid are constructed on the first rubber body in a radial opposite manner, and the two main liquid cavities are communicated with each other through the first runner;

the outer sleeve is tightly sleeved on the radial outer side of the first runner body; and

a seal assembly disposed axially outwardly of at least one of the first flow bodies, the seal assembly and the outer jacket collectively defining an auxiliary fluid chamber for containing hydraulic fluid;

wherein the sealing assembly comprises a support ring sleeved on the mandrel, the support ring comprises a radial protruding part positioned in the auxiliary liquid cavity, the radial protruding part is in sealing contact with the inner surface of the outer sleeve, so as to divide the auxiliary liquid cavity into a first subchamber positioned at the outer side in the axial direction and a second subchamber positioned at the inner side in the axial direction,

the radial protruding portion is provided with a communication hole extending along the axial direction and used for communicating the first subchamber with the second subchamber.

2. The hydraulic bushing of claim 1, wherein said radial protrusion includes a plurality of communication holes uniformly distributed in a circumferential direction.

3. The hydraulic bushing of claim 1, wherein said seal assembly further includes a second rubber body vulcanized on said support ring such that said radial projection is in sealing contact with an inner surface of said outer sleeve by said second rubber body.

4. A hydraulic bushing according to claim 3, wherein the second rubber body includes a first portion in sealing contact with an axial end of the first runner body, a second portion in sealing contact with an axial end of the outer sleeve, and a third portion provided on the radial projection and in sealing contact with an inner surface of the outer sleeve.

5. The hydraulic bushing of claim 4, wherein rigid shims are embedded within both the first and second portions of said second rubber body.

6. A hydraulic bushing according to any of claims 1-5, wherein a hydraulic fluid filling channel is provided in said support ring for filling said auxiliary fluid chamber with hydraulic fluid.

7. The hydraulic bushing of claim 6, wherein said hydraulic fluid charging passage includes a horizontal branch leading to an axially outboard end of said support ring, and a vertical branch leading to a first subchamber of said auxiliary fluid chamber.

8. The hydraulic bushing according to any one of claims 1-5, wherein said main fluid chamber and said auxiliary fluid chamber are not in communication with each other.

9. The hydraulic bushing according to any one of claims 1 to 5, wherein a cross-sectional area and a length of the first flow passage are determined according to a radial dynamic stiffness required of the hydraulic bushing, and a cross-sectional area and a length of the communication hole are determined according to an axial dynamic stiffness required of the hydraulic bushing.