A high-frequency hydrostatic support actuator

Abstract

This utility model relates to the field of actuator technology and discloses a high-frequency hydrostatic support actuator, including a sleeve, and further including: a main shaft, which is slidably connected inside the sleeve, a piston chamber is opened inside the sleeve, a piston block is slidably connected inside the piston chamber, the piston block is fixedly connected to the main shaft, and a first annular sealing tooth is fixedly connected to the circumference of the piston block for sealing the circumference of the piston block and the inner wall of the piston chamber; a driving part for driving the piston block to slide is connected to the sleeve; a bearing, which is sleeved on the main shaft and located inside the sleeve, and a plurality of evenly distributed cavities are opened on the inner wall of the bearing, and an oil film support is formed between the cavities and the outer wall of the main shaft; this utility model, with the first annular sealing tooth structure on the piston block and the cavities opened in the bearing, can achieve non-contact support and maintain high-speed and high-frequency movement under near-zero friction, extending the service life and thus improving the working efficiency of the actuator.

Description

Technical Field

[0001] This utility model relates to the field of actuator technology, specifically a high-frequency hydrostatic support actuator. Background Technology

[0002] The actuator is a key actuator in a fatigue testing machine and an important component of the hydraulic system. Also known as a vibrator, the actuator is used for fatigue life testing and static mechanical property testing, and is the mechanism that applies loads.

[0003] Currently, the most widely used type is the high-frequency high-speed hydraulic actuator. Because the high-frequency high-speed hydraulic actuator is constantly in a high-frequency motion state, the internal piston wears very severely, greatly reducing its service life. After working for a long time, the actuator's working accuracy will decrease, seriously affecting normal working efficiency. Moreover, due to the sealing structure of the sealing ring, the friction is relatively large, which has a significant impact on the test results. Utility Model Content

[0004] This invention provides a high-frequency hydrostatic support actuator. By fixing a first annular sealing tooth structure on the piston block, non-contact operation between the piston block and the piston chamber can be achieved, reducing wear. By opening a chamber in the inner wall of the bearing bush, the hydraulic oil around the spindle is kept at high pressure by utilizing the pressure difference of the oil film in the chamber. Utilizing the principle of high-pressure suspension, the spindle achieves a suspended state, solving the problems of high friction and reduced working accuracy mentioned in the background art.

[0005] This utility model provides the following technical solution: A high-frequency hydrostatic support actuator includes a sleeve and further includes: a main shaft slidably connected inside the sleeve, a piston chamber formed inside the sleeve, a piston block slidably connected inside the piston chamber, the piston block being fixedly connected to the main shaft, and a first annular sealing tooth fixedly connected to the circumference of the piston block for sealing the circumference of the piston block and the inner wall of the piston chamber; a driving part for driving the piston block to slide is connected to the sleeve; and a bearing bush sleeved on the main shaft, the bearing bush being located inside the sleeve, and a plurality of evenly distributed chambers formed on the inner wall of the bearing bush, with an oil film support formed between the chambers and the outer wall of the main shaft.

[0006] As a preferred embodiment of this utility model, the outer wall of the bearing bush is provided with a first annular groove, and the plurality of chambers are connected to the first annular groove through a first hole. The sleeve is provided with an oil supply hole, which is connected to the first annular groove and is used to supply hydraulic oil to the chambers.

[0007] As a preferred embodiment of this utility model, the inner wall of the bearing bush is provided with an annular oil passage, the outer wall of the bearing bush is provided with a second annular groove, the second annular groove is connected to the annular oil passage through a second small hole, and the sleeve is provided with an oil outlet hole, the oil outlet hole is connected to the second annular groove, and the oil film flows from the chamber to the annular oil passage.

[0008] As a preferred technical solution of this utility model, a second annular sealing tooth is provided on the inner wall of the end of the bearing bush away from the piston block. The second annular sealing tooth is used to seal the inner wall of the bearing bush and the outer wall of the main shaft.

[0009] As a preferred embodiment of this utility model, the sleeve has an installation cavity, the bearing is connected to the installation cavity, and the outer wall of the bearing has a sealing groove, a sealing ring is fitted in the sealing groove, and the sealing ring abuts against the inner wall of the installation cavity.

[0010] As a preferred technical solution of this utility model, the driving unit includes at least two sets of oil pipes opened in the sleeve, the piston chamber is divided into a first chamber and a second chamber by a piston block, the two sets of oil pipes are respectively connected to the first chamber and the second chamber, and a two-stage electro-hydraulic flow servo valve is fixedly connected to the outer wall of the sleeve, the two-stage electro-hydraulic flow servo valve is used to change the movement state of the piston block.

[0011] As a preferred embodiment of this utility model, stepped holes are provided at both ends of the sleeve, and channels are provided in the stepped holes. One end of the channels is connected to the first cavity and the second cavity respectively, and the oil pipe is connected to the other end of the channels through the stepped holes.

[0012] As a preferred embodiment of this utility model, the end of the oil supply hole away from the first annular groove is connected to the oil pipe.

[0013] As a preferred technical solution of this utility model, an end cap is sleeved on the main shaft, and the inner wall of the end cap is detachably connected to the end face of the stepped hole.

[0014] As a preferred embodiment of this utility model, a retaining ring is fixedly connected to the inner wall of the end cap, and the end of the bearing bush away from the piston block abuts against the retaining ring.

[0015] Compared with the prior art, this utility model provides a high-frequency hydrostatic support actuator, which has the following beneficial effects: 1. In this high-frequency hydrostatic support actuator, by fixing the first annular sealing tooth structure on the piston block, the piston block and the piston chamber can operate without contact, reducing wear. A chamber is opened in the inner wall of the bearing bush, and the pressure difference of the oil film in the chamber is used to keep the hydraulic oil around the spindle at high pressure. By using the principle of high-pressure suspension, the spindle can achieve a suspended state and maintain high-speed and high-frequency motion with almost zero friction, extending its service life and thus improving the working efficiency of the actuator.

[0016] The parts not mentioned in this device are the same as or can be implemented using existing technology. This utility model has a first annular sealing tooth structure on the piston block and a cavity in the bearing bush, which can achieve non-contact support and maintain high-speed and high-frequency movement with almost zero friction, thus extending the service life and improving the working efficiency of the actuator. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, the elements or parts are not necessarily drawn to actual scale.

[0018] Figure 1 This is a three-dimensional schematic diagram of the present invention; Figure 2 This is a schematic cross-sectional view of the present invention. Figure 3 This is an exploded view of the present invention; Figure 4 This is a cross-sectional view of the sleeve of this utility model; Figure 5 This is a cross-sectional view of the bearing bush of this utility model.

[0019] In the diagram: 1. Main shaft; 101. Piston block; 2. Sleeve; 201. Piston chamber; 202. Mounting chamber; 203. Oil pipe; 204. Oil outlet; 205. Stepped hole; 206. Channel; 207. Oil supply hole; 3. Bearing; 301. Chamber; 302. Annular oil passage; 303. First annular groove; 304. Second annular groove; 305. Second annular sealing tooth; 4. End cap; 5. Two-stage electro-hydraulic flow servo valve. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Example: Reference Figures 1-5 A high-frequency hydrostatic support actuator includes a sleeve 2 and a main shaft 1, which is slidably connected inside the sleeve 2. Both ends of the main shaft 1 extend beyond the outer side of the sleeve 2, meaning it can apply loads bidirectionally during use. A piston chamber 201 is provided inside the sleeve 2, and a piston block 101 is slidably connected inside the piston chamber 201. The piston block 101 is fixedly connected to the main shaft 1, and a first annular sealing tooth is fixedly connected to the circumference of the piston block 101. The first annular sealing tooth seals the circumference of the piston block 101 against the inner wall of the piston chamber 201. During use, by fixing the first annular sealing tooth to the piston block 101, non-contact operation can be achieved between the piston block 101 and the inner wall of the piston chamber 201. There is no physical contact between the piston block 101 and the inner wall of the piston chamber 201; sealing is achieved through gap control. Therefore, there is no friction or wear, making it suitable for high-speed / high-frequency operation. To reduce wear on the piston block 101 and improve its service life, a drive unit is connected to the sleeve 2 to drive the piston block 101 to slide. Through the drive unit, the piston block 101 can be driven to reciprocate within the piston chamber 201, which is convenient to use. The bearing 3 is sleeved on the main shaft 1 and is located inside the sleeve 2. Multiple evenly distributed chambers 301 are formed on the inner wall of the bearing 3. There are two to six chambers 301, preferably four, which are evenly distributed in a circle. The area of ​​the four chambers 301 accounts for three-quarters of the area of ​​the inner wall of the bearing 3. There is a small gap between the outer wall of the main shaft 1 and the inner wall of the bearing 3. The fluid forms a stable "oil film" in the gap, which completely floats the main shaft 1 and achieves non-contact support. Therefore, an oil film support is formed between the chambers 301 and the outer wall of the main shaft 1. The thickness of the oil film is 10-50μm, preferably 30μm.

[0022] Reference Figure 2 , Figure 4 and Figure 5A first annular groove 303 is formed on the outer wall of the bearing bush 3, and multiple chambers 301 are connected to the first annular groove 303 through a first hole. An oil supply hole 207 is formed on the sleeve 2, which is connected to the first annular groove 303 to supply hydraulic oil to the chambers 301. An annular oil passage 302 is formed on the inner wall of the bearing bush 3. Two sets of annular oil passages 302 are formed, located at both ends of the chambers 301 along the axis of the bearing bush 3. The two sets of annular oil passages 302 are connected to each other through connecting pipes between adjacent chambers 301. A second annular groove 304 is formed on the outer wall of the bearing bush 3, and the second annular groove 304 is connected to the annular groove 301 through a second small hole. The sleeve 2 is connected to the oil passage 302 and has an oil outlet 204. The oil outlet 204 is connected to the second annular groove 304. The oil film flows from the chamber 301 to the annular oil passage 302. This not only forms an oil film, but also allows for dynamic adjustment of the position of the spindle 1. In use, high-pressure oil is injected into the oil supply hole 207, passes through the first hole into the first annular groove 303, and then enters the chamber 301. The hydraulic oil in the chamber 301 flows into the annular oil passage 302 through the tiny gap between the bearing 3 and the spindle 1. Finally, it flows out of the sleeve 2 through the oil outlet 204 via the second annular groove 304. During the flow process, an oil film can be continuously formed, improving the performance.

[0023] Reference Figure 2 , Figure 3 and Figure 5 A second annular sealing tooth 305 is provided on the inner wall of the end of the bearing shell 3 away from the piston block 101. The second annular sealing tooth 305 is used to seal the inner wall of the bearing shell 3 and the outer wall of the main shaft 1. Both the first annular sealing tooth and the second annular sealing tooth 305 are labyrinth seals. A groove with an annular structure is formed between adjacent sealing teeth. A series of tortuous and meandering micro gaps are formed between the groove and the inner wall of the corresponding piston chamber 201 (outer wall of the main shaft 1). If the liquid wants to leak from the high-pressure side to the low-pressure side, it must change the flow direction multiple times and pass through the narrow throttling orifice, just like walking through a "maze", thereby greatly increasing the flow resistance, consuming the fluid kinetic energy, and reducing the leakage.

[0024] Reference Figure 2 , Figure 3 and Figure 5 An installation cavity 202 is provided inside the sleeve 2. The bearing shell 3 is connected inside the installation cavity 202. A sealing groove is provided on the outer wall of the bearing shell 3. There are at least two sets of sealing grooves, preferably two sets, which are located at both ends of the first annular groove 303 along the axial direction of the bearing shell 3. On the one hand, it can seal the space between the first annular groove 303 and the second annular groove 304. On the other hand, it can seal the bearing shell 3 and the installation cavity 202. A sealing ring is fitted inside the sealing groove, and the sealing ring abuts against the inner wall of the installation cavity 202.

[0025] Reference Figures 1-3 The drive unit includes at least two sets of oil pipes 203, preferably two sets, opened inside the sleeve 2. In use, the piston chamber 201 can be divided into a first chamber and a second chamber by the piston block 101. The two sets of oil pipes 203 are respectively connected to the first chamber and the second chamber. A two-stage electro-hydraulic flow servo valve 5 is fixedly connected to the outer wall of the sleeve 2. The model of the two-stage electro-hydraulic flow servo valve 5 is: MOOG-X761-S60J-4EPL. The two-stage electro-hydraulic flow servo valve 5 is used to change the movement state of the piston block 101. High-pressure oil is injected into the oil pipes 203 by an external hydraulic pump. The flow direction of the high-pressure oil can be controlled by the two-stage electro-hydraulic flow servo valve 5. At the current moment, one set of oil pipes 203 is oil inlet and the other is oil outlet, thereby driving the piston block 101 to move back and forth.

[0026] Reference Figure 2 and Figure 4 A stepped hole 205 is provided at both ends of the sleeve 2, and a channel 206 is provided in the stepped hole 205. One end of the two channels 206 is connected to the first cavity and the second cavity respectively, and the two oil pipes 203 are connected to the other end of the channel 206 through the corresponding stepped hole 205. In use, by connecting the oil pipe 203 to the piston cavity 201 through the channel 206, and the channel 206 is connected to the end face of the piston cavity 201, even if the end face of the piston block 101 is abutting against the end face of the piston cavity 201, the piston block 101 can be pushed away from the current end face during the next start-up, which can increase the stroke of the piston block 101 in the piston cavity 201.

[0027] Reference Figure 2 The end of the oil supply port 207 furthest from the first annular groove 303 is connected to the oil pipe 203. When the high-pressure oil in the oil pipe 203 flows into the stepped hole 205, a small portion of the hydraulic oil can enter the first annular groove 303 through the oil supply port 207, thus providing high-pressure oil to the chamber 301. Of course, in other embodiments, an external hydraulic cylinder can be used directly to supply high-pressure oil to the oil supply port 207.

[0028] Reference Figures 1-3 An end cover 4 is fitted onto the main shaft 1. The inner wall of the end cover 4 is disassembled and connected to the end face of the stepped hole 205. Bolts are preferably used for disassembly and connection. During use, the bearing bush 3 can be easily replaced or maintained by disassembling the end cover 4 on the sleeve 2, thus improving the flexibility of use.

[0029] Reference Figure 2A retaining ring is fixedly connected to the inner wall of the end cover 4. One end of the bearing shell 3, away from the piston block 101, abuts against the retaining ring, and the other end of the bearing shell 3 abuts against the inner wall of the mounting cavity 202, thus limiting the movement of the bearing shell 3. During use, by fixing the retaining ring to the inner wall of the end cover 4, the bearing shell 3 can be limited, reducing its axial displacement and helping to extend the service life of the sealing ring on the outer wall of the bearing shell 3. However, this method is more difficult to manufacture. In other embodiments, a space is left between the inner wall of the retaining ring and the bearing shell 3, allowing the bearing shell 3 to move axially. This not only provides a certain buffering effect but also reduces the manufacturing difficulty of the retaining ring.

[0030] Components not described in detail in this article are existing technologies.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A high frequency static pressure support actuator comprising a sleeve (2), characterized in that, Also includes: A main shaft (1) is slidably connected inside a sleeve (2). A piston chamber (201) is provided inside the sleeve (2). A piston block (101) is slidably connected inside the piston chamber (201). The piston block (101) is fixedly connected to the main shaft (1). A first annular sealing tooth is fixedly connected on the circumference of the piston block (101). The first annular sealing tooth is used to seal the circumference of the piston block (101) and the inner wall of the piston chamber (201). A drive unit for driving the piston block (101) to slide is connected on the sleeve (2). The bearing (3) is sleeved on the main shaft (1). The bearing (3) is located inside the sleeve (2), and the inner wall of the bearing (3) is provided with a plurality of evenly distributed chambers (301). An oil film support is formed between the chambers (301) and the outer wall of the main shaft (1).

2. A high frequency static pressure support actuator according to claim 1, wherein, The outer wall of the bearing bush (3) is provided with a first annular groove (303), and the multiple chambers (301) are connected to the first annular groove (303) through a first hole. The sleeve (2) is provided with an oil supply hole (207), which is connected to the first annular groove (303) and is used to supply hydraulic oil to the chambers (301).

3. A high frequency static pressure support actuator according to claim 2, wherein, The inner wall of the bearing bush (3) is provided with an annular oil passage (302), and the outer wall of the bearing bush (3) is provided with a second annular groove (304). The second annular groove (304) is connected to the annular oil passage (302) through a second small hole. The sleeve (2) is provided with an oil outlet hole (204), which is connected to the second annular groove (304). The oil film flows from the chamber (301) to the annular oil passage (302).

4. The high frequency static pressure support actuator of claim 1, wherein, The inner wall of the bearing bush (3) away from the piston block (101) has a second annular sealing tooth (305), which is used to seal the inner wall of the bearing bush (3) and the outer wall of the main shaft (1).

5. A high-frequency hydrostatic support actuator according to claim 4, characterized in that, The sleeve (2) has an installation cavity (202) inside, the bearing (3) is connected to the installation cavity (202), and the outer wall of the bearing (3) has a sealing groove, and a sealing ring is fitted in the sealing groove, and the sealing ring abuts against the inner wall of the installation cavity (202).

6. A high-frequency hydrostatic support actuator according to claim 2, characterized in that, The drive unit includes at least two sets of oil pipes (203) opened in the sleeve (2). The piston chamber (201) is divided into a first chamber and a second chamber by a piston block (101). The two sets of oil pipes (203) are respectively connected to the first chamber and the second chamber. A two-stage electro-hydraulic flow servo valve (5) is fixedly connected to the outer wall of the sleeve (2). The two-stage electro-hydraulic flow servo valve (5) is used to change the movement state of the piston block (101).

7. A high-frequency hydrostatic support actuator according to claim 6, characterized in that, Both ends of the sleeve (2) are provided with stepped holes (205), and a channel (206) is provided in the stepped holes (205). One end of the channel (206) is connected to the first cavity and the second cavity respectively, and the oil pipe (203) is connected to the other end of the channel (206) through the stepped holes (205).

8. A high-frequency hydrostatic support actuator according to claim 6, characterized in that, The end of the oil supply hole (207) away from the first annular groove (303) is connected to the oil pipe (203).

9. A high-frequency hydrostatic support actuator according to claim 7, characterized in that, An end cap (4) is fitted onto the main shaft (1), and the inner wall of the end cap (4) is detachably connected to the end face of the stepped hole (205).

10. A high-frequency hydrostatic support actuator according to claim 9, characterized in that, A retaining ring is fixedly connected to the inner wall of the end cap (4), and the end of the bearing (3) away from the piston block (101) abuts against the retaining ring.

Images