Integrated hydraulic rotary main shaft with sealing structure and sealing method

Abstract

The invention discloses an integrated hydraulic rotary spindle with a sealing structure, which belongs to the technical field of spindles, and is characterized in that the integrated hydraulic rotary spindle comprises a spindle sleeve, an inner shaft, an end cover and a dust sealing flange, the inner shaft is rotatably arranged in the spindle sleeve, the dust sealing flange and the end cover are respectively mounted at two ends of the spindle sleeve, and two ends of the inner shaft respectively penetrate through the dust sealing flange and the end cover; a plurality of first hydraulic channels are formed in the main shaft sleeve, a plurality of second hydraulic channels with different lengths are formed in the inner shaft, and a plurality of annular communicating grooves used for communicating the first hydraulic channels with the second hydraulic channels are formed in the inner side wall of the main shaft sleeve. Two sealing assemblies distributed in a spaced mode are arranged in the main shaft sleeve, the two sealing assemblies are both used for sealing a gap between the main shaft sleeve and the inner shaft, the two sealing assemblies are matched between the main shaft sleeve and the inner shaft to form a sealing interval, the multiple annular communicating grooves are all located in the sealing interval, and the sealing structure of the main shaft can prevent hydraulic oil from leaking; the invention further discloses a sealing method.

Description

Technical Field

[0001] The present invention belongs to the technical field of spindles, and particularly relates to an integrated hydraulic rotary spindle with a sealing structure. Background Art

[0002] As an important functional component in a numerically controlled machine tool, the spindle plays a key role in workpiece machining. The spindle transmits power to the tool through a motor or a transmission device to ensure synchronous operation with the spindle. The tool includes a fixture, a cutting tool, etc.

[0003] The basic principle of hydraulic transmission is to convert the mechanical energy of a prime mover (such as an electric motor or an internal combustion engine) into the pressure energy of a liquid by using a hydraulic pump, and then through pipelines, hydraulic control and regulating devices, etc., and with the help of an actuator (such as a hydraulic cylinder or a hydraulic motor), convert the pressure energy of the liquid back into mechanical energy, so as to drive the load to achieve linear or rotary motion.

[0004] In modern numerically controlled machine tools, in order to meet the machining requirements of complex parts, it is necessary to combine hydraulic transmission with a rotary spindle, so as to improve the machining accuracy and efficiency of the machine tool and adapt to complex machining requirements. However, since the spindle needs to rotate continuously during machining, and the hydraulic transmission system usually transmits hydraulic oil through the hydraulic channels inside the spindle, how to ensure the sealing performance and prevent hydraulic oil leakage is a crucial issue. Summary of the Invention

[0005] The purpose of the present invention is to propose an integrated hydraulic rotary spindle with a sealing structure for the above problems existing in the prior art. The technical problem to be solved by the present invention is: how to ensure the sealing performance and prevent hydraulic oil leakage.

[0006] The above technical object of the present invention can be achieved by the following technical solutions: an integrated hydraulic rotary spindle with a sealing structure, including a spindle sleeve, an inner shaft, an end cover, and a dust-proof flange. The inner shaft is rotatably arranged in the spindle sleeve. The dust-proof flange is installed at one end of the spindle sleeve, and the end cover is installed at the other end of the spindle sleeve. Both ends of the inner shaft pass through the dust-proof flange and the end cover respectively. A plurality of first hydraulic channels are provided on the spindle sleeve, and a plurality of second hydraulic channels with different lengths are provided on the inner shaft. A plurality of annular communication grooves for communicating the corresponding first hydraulic channels with the second hydraulic channels are provided on the inner side wall of the spindle sleeve. Two spaced-apart sealing components are arranged in the spindle sleeve. Both of the sealing components are used to seal the gap between the spindle sleeve and the inner shaft, and the two sealing components cooperate to form a sealing interval between the spindle sleeve and the inner shaft. All of the plurality of annular communication grooves are located in the sealing interval.

[0007] In the above-mentioned integrated hydraulic rotary spindle with a sealing structure, the sealing assembly includes an oil seal sleeve and a skeleton oil seal. The oil seal sleeve is detachably connected to the spindle sleeve, and the skeleton oil seal is arranged between the oil seal sleeve and the inner shaft.

[0008] In the above-mentioned integrated hydraulic rotary spindle with a sealing structure, the oil seal sleeve is provided with an annular limiting groove. The cross-section of the annular limiting groove is in an "L" shape. The skeleton oil seal is arranged in the annular limiting groove and is adapted to the annular limiting groove.

[0009] In the above-mentioned integrated hydraulic rotary spindle with a sealing structure, two annular recovery grooves are arranged on the inner side wall of the spindle sleeve at intervals, and several annular communication grooves are located between the two annular recovery grooves. A liquid return channel communicating with the two annular recovery grooves is formed on the spindle sleeve.

[0010] In the above-mentioned integrated hydraulic rotary spindle with a sealing structure, the skeleton oil seal is provided with an annular groove. The cross-section of the annular groove is in a "U" shape, and the opening of the annular groove faces the annular recovery groove.

[0011] In the above-mentioned integrated hydraulic rotary spindle with a sealing structure, several hydraulic channels one penetrate from the outer side wall of the spindle sleeve to the bottom surface of the annular communication groove, and several hydraulic channels two penetrate from the outer side wall of the inner shaft to the end face of the inner shaft.

[0012] In the above-mentioned integrated hydraulic rotary spindle with a sealing structure, the outer side wall of the inner shaft has a first threaded portion. A first limit nut is threadedly connected to the first threaded portion, and the first limit nut is used to limit the flange.

[0013] In the above-mentioned integrated hydraulic rotary spindle with a sealing structure, a baffle and a synchronous pulley are circumferentially fixed on the outer side wall of the inner shaft. The end face of the baffle abuts against the end of the first threaded portion, and the end face of the synchronous pulley abuts against the end face of the baffle. The outer side wall of the inner shaft has a second threaded portion. A second limit nut is threadedly connected to the second threaded portion, and the second limit nut is used to limit the synchronous pulley.

[0014] In the above-mentioned integrated hydraulic rotary spindle with a sealing structure, a first bearing is arranged between one end of the inner shaft and one end of the spindle sleeve, and a second bearing is arranged between the other end of the inner shaft and the other end of the spindle sleeve.

[0015] A sealing method, applied to the above integrated hydraulic rotary spindle, includes the following steps: S1, making the opening of the annular groove face away from the annular limiting groove, and then installing the skeleton oil seal into the annular limiting groove; S2, connecting the oil seal sleeve to the spindle sleeve; S3, applying an appropriate amount of lubricating grease to the inner ring of the skeleton oil seal; S4, passing the inner shaft through the skeleton oil seal.

[0016] In summary, the beneficial effects of the present invention compared with the prior art are as follows: By providing two sealing components spaced apart in the spindle sleeve, both of the two sealing components are used to seal the gap between the spindle sleeve and the inner shaft, and the two sealing components cooperate to form a sealing interval between the spindle sleeve and the inner shaft. A plurality of annular communication grooves are all located within the sealing interval. In this way, the sealing performance is ensured, preventing the hydraulic oil from leaking out through the gap between the two, and ensuring the stable transmission of the hydraulic oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the embodiment; Figure 2 is a cross-sectional view of the embodiment; Figure 3 is Figure 2 an enlarged view of part A of Figure 4 is another cross-sectional view of the embodiment; Figure 5 is Figure 4 an enlarged view of part B of Figure 6 is a schematic structural diagram of the inner shaft of the embodiment.

[0018] Reference numerals: 1, spindle sleeve; 2, inner shaft; 3, end cover; 4, dust-proof flange; 5, hydraulic passage one; 6, hydraulic passage two; 7, annular communication groove; 8, sealing component; 81, oil seal sleeve; 82, skeleton oil seal; 9, sealing interval; 10, annular limiting groove; 11, annular recovery groove; 12, liquid return passage; 13, annular groove; 14, thread part one; 15, thread part two; 16, limiting nut one; 17, limiting nut two; 18, baffle; 19, synchronous pulley; 20, bearing one; 21, bearing two. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following are specific embodiments of the present invention in combination with the drawings, and the technical solutions of the present invention will be further described, but the present invention is not limited to these embodiments.

[0020] An integrated hydraulic rotary spindle with a sealing structure, as shown in Figures 1 to 6As shown in the figure, it includes a main shaft sleeve 1, an inner shaft 2, an end cover 3, and a dust-proof flange 4. The inner shaft 2 is rotatably arranged inside the main shaft sleeve 1. There is a first bearing 20 between one end of the inner shaft 2 and one end of the main shaft sleeve 1, and a second bearing 21 between the other end of the inner shaft 2 and the other end of the main shaft sleeve 1. In this embodiment, there are at least two first bearings 20 arranged along the axial direction of the inner shaft 2, and several second bearings 21 arranged along the axial direction of the inner shaft 2. Through the action of the first bearing 20 and the second bearing 21, the coaxiality of the inner shaft 2 can be effectively guaranteed during rotation, and the rotation stability of the inner shaft 2 is improved.

[0021] The dust-proof flange 4 is installed at one end of the main shaft sleeve 1, and the end cover 3 is installed at the other end of the main shaft sleeve 1. Both ends of the inner shaft 2 pass through the dust-proof flange 4 and the end cover 3 respectively. It should be noted that the dust-proof flange 4 is located outside the first bearing 20, and the end cover 3 is located outside the second bearing 21. By blocking the dust and impurities outside through the dust-proof flange 4 and the end cover 3 from entering the inside of the main shaft sleeve 1 and contacting the first bearing 20 and the second bearing 21, the cleanliness inside the main shaft sleeve 1 is maintained, and the failure rate of the first bearing 20 and the second bearing 21 caused by wear or pollution is reduced, improving the reliability and stability of the overall structure.

[0022] The outer side wall of the inner shaft 2 has a first threaded portion 14, and a first limit nut 16 is threadedly connected to the first threaded portion 14. The first limit nut 16 is used to limit the flange. Specifically, the end face of the first limit nut 16 abuts against the end face of the flange, thereby restricting the position of the flange and ensuring its stability.

[0023] Furthermore, a baffle 18 and a synchronous pulley 19 are circumferentially fixed on the outer side wall of the inner shaft 2. The end face of the baffle 18 abuts against the end of the first threaded portion 14, and the end face of the synchronous pulley 19 abuts against the end face of the baffle 18. The outer side wall of the inner shaft 2 has a second threaded portion 15, and a second limit nut 17 is threadedly connected to the second threaded portion 15. The second limit nut 17 is used to limit the synchronous pulley 19. Specifically, the end face of the second limit nut 17 abuts against the end face of the synchronous pulley 19. By cooperating the second limit nut 17 with the first threaded portion 14, the positions of the baffle 18 and the synchronous pulley 19 are restricted, ensuring their stability.

[0024] Several first hydraulic channels 5 are provided on the main shaft sleeve 1, several second hydraulic channels 6 with different lengths are provided on the inner shaft 2, and several annular communication grooves 7 for communicating the corresponding first hydraulic channels 5 and second hydraulic channels 6 are provided on the inner side wall of the main shaft sleeve 1. In this embodiment, several first hydraulic channels 5 penetrate from the outer side wall of the main shaft sleeve 1 to the bottom surface of the annular communication groove 7, and several first hydraulic channels 5 are arranged radially along the main shaft sleeve 1. Several second hydraulic channels 6 penetrate from the outer side wall of the inner shaft 2 to the end face of the inner shaft 2.

[0025] The hydraulic oil can enter the corresponding second hydraulic passage 6 from any one of the first hydraulic passages 5 through the corresponding annular communication grooves 7, so as to selectively flow to different actuators or components as needed, realize various control functions, and meet complex processing requirements.

[0026] Two annular recovery grooves 11 are arranged on the inner side wall of the spindle sleeve 1 at intervals, and several annular communication grooves 7 are all located between the two annular recovery grooves 11. A liquid return passage 12 communicating with the two annular recovery grooves 11 is opened on the spindle sleeve 1. The hydraulic oil in the several annular communication grooves 7 seeps into the gap between the spindle sleeve 1 and the inner shaft 2 and then flows into the annular recovery grooves 11 for concentration, and then is recovered through the liquid return passage 12, so as to realize the recycling of the hydraulic oil.

[0027] Two sealing components 8 are arranged in the spindle sleeve 1 at intervals. Both of the two sealing components 8 are used to seal the gap between the spindle sleeve 1 and the inner shaft 2, and the two sealing components 8 cooperate to form a sealing interval 9 between the spindle sleeve 1 and the inner shaft 2. Several annular communication grooves 7 are all located in the sealing interval 9.

[0028] Specifically, the sealing component 8 includes an oil seal sleeve 81 and a skeleton oil seal 82. The oil seal sleeve 81 is detachably connected to the spindle sleeve 1. In this embodiment, the oil seal sleeve 81 and the spindle sleeve 1 are connected by screws. The screws pass through the oil seal sleeve 81 and are threadedly connected to the spindle sleeve 1. The skeleton oil seal 82 is arranged between the oil seal sleeve 81 and the inner shaft 2. An annular limiting groove 10 is arranged on the oil seal sleeve 81. The cross section of the annular limiting groove 10 is in an "L" shape. The skeleton oil seal 82 is arranged in the annular limiting groove 10, and the skeleton oil seal 82 is adapted to the annular limiting groove 10. Through the limitation and support of the annular limiting groove 10 on the skeleton oil seal 82, the position of the skeleton oil seal 82 is ensured to be stable, so as to ensure the effective sealing of the gap between the spindle sleeve 1 and the inner shaft 2, improve the reliability of the sealing, and facilitate the installation of the skeleton oil seal 82.

[0029] Therefore, during disassembly, only need to remove the screws to release the connection between the oil seal sleeve 81 and the spindle sleeve 1, and then the oil seal sleeve 81 and the skeleton oil seal 82 can be removed. The operation is simple and the disassembly is convenient.

[0030] The two sealing components 8 seal the gap between the spindle sleeve 1 and the inner shaft 2 at two positions, so as to form a sealing interval 9 between the spindle sleeve 1 and the inner shaft 2. Several annular communication grooves 7 are all located in the sealing interval 9, so as to ensure the sealing performance, prevent the hydraulic oil from leaking out from the gap between the spindle sleeve 1 and the inner shaft 2, and ensure the stable transmission of the hydraulic oil.

[0031] An annular groove 13 is provided on the skeleton oil seal 82. The cross-section of the annular groove 13 is in a "U" shape, and the opening of the annular groove 13 faces the annular recovery groove 11. The "U" shape can centrally collect hydraulic oil, preventing the hydraulic oil from continuing to flow along the surface of the inner shaft 2 or the skeleton oil seal 82, reducing the risk of further leakage of the hydraulic oil through the tiny gap.

[0032] A sealing method, applied to the above integrated hydraulic rotary spindle, includes the following steps: S1, make the opening of the annular groove 13 face away from the annular limit groove 10, and then install the skeleton oil seal 82 into the annular limit groove 10; S2, connect the oil seal sleeve 81 with the spindle sleeve 1; S3, apply an appropriate amount of grease to the inner ring of the skeleton oil seal 82; S4, pass the inner shaft 2 through the skeleton oil seal 82.

[0033] It should be noted that the grease can effectively reduce the friction between the skeleton oil seal 82 and the inner shaft 2, which is more conducive to the assembly of the skeleton oil seal 82 and the inner shaft 2, and can effectively extend the service life of the skeleton oil seal 82.

[0034] The specific embodiments described herein are merely illustrative of the spirit of the present invention; those skilled in the art of the present invention can make various modifications or supplements or use similar methods to replace the specific embodiments described, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. An integrated hydraulic rotary spindle with a sealing structure, comprising a spindle sleeve (1), an inner shaft (2), an end cover (3) and a dust sealing flange (4), characterized in that: The inner shaft (2) is rotatably arranged in the main shaft sleeve (1); the dust seal flange (4) is installed at one end of the main shaft sleeve (1); the end cover (3) is installed at the other end of the main shaft sleeve (1); the two ends of the inner shaft (2) are respectively passed through the dust seal flange (4) and the end cover (3); the main shaft sleeve (1) is provided with a plurality of hydraulic channels (5); the inner shaft (2) is provided with a plurality of hydraulic channels (6) of different lengths; the inner side wall of the main shaft sleeve (1) is provided with a plurality of hydraulic channels (7) for connecting the main shaft sleeve (1) and the inner side wall of the main shaft sleeve (1). A plurality of annular connecting grooves (7) corresponding to the hydraulic channel 1 (5) and the hydraulic channel 2 (6); two sealing assemblies (8) are arranged in the main shaft sleeve (1) and are spaced apart from each other. The two sealing assemblies (8) are used to seal the gap between the main shaft sleeve (1) and the inner shaft (2), and the two sealing assemblies (8) cooperate to form a sealing zone (9) between the main shaft sleeve (1) and the inner shaft (2), and the plurality of annular connecting grooves (7) are all located in the sealing zone (9).

2. The integrated hydraulic rotary spindle with a sealing structure according to claim 1, characterized in that: The sealing assembly (8) comprises an oil seal sleeve (81) and a skeleton oil seal (82); the oil seal sleeve (81) is detachably connected to the main shaft sleeve (1); and the skeleton oil seal (82) is arranged between the oil seal sleeve (81) and the inner shaft (2).

3. The integrated hydraulic rotary spindle with a sealing structure according to claim 2, characterized in that: The oil seal sleeve (81) is provided with an annular limiting groove (10), the cross section of which is in an "L" shape, and the skeleton oil seal (82) is arranged in the annular limiting groove (10), and the skeleton oil seal (82) is adapted to the annular limiting groove (10).

4. The integrated hydraulic rotary spindle with a sealing structure according to claim 3, characterized in that: The inner side wall of the main shaft sleeve (1) is provided with two annular recovery grooves (11) distributed at intervals, and the plurality of annular connecting grooves (7) are located between the two annular recovery grooves (11). The main shaft sleeve (1) is provided with a liquid return channel (12) connected to the two annular recovery grooves (11).

5. The integrated hydraulic rotary spindle with a sealing structure according to claim 4, characterized in that: The skeleton oil seal (82) is provided with an annular groove (13), the cross section of the annular groove (13) is in a "U" shape, and the opening of the annular groove (13) faces the annular recovery groove (11).

6. The integrated hydraulic rotary spindle with a sealing structure according to claim 1, characterized in that: A plurality of the hydraulic channels 1 (5) are penetrated from the outer wall of the main shaft sleeve (1) to the bottom surface of the annular connecting groove (7), and a plurality of the hydraulic channels 2 (6) are penetrated from the outer wall of the inner shaft (2) to the end surface of the inner shaft (2).

7. The integrated hydraulic rotary spindle with a sealing structure according to claim 1, characterized in that: The outer wall of the inner shaft (2) has a threaded portion (14), and a limiting nut (16) is threadedly connected to the threaded portion (14), and the limiting nut (16) is used to limit the flange.

8. The integrated hydraulic rotary spindle with a sealing structure according to claim 7, characterized in that: A baffle (18) and a synchronous wheel (19) are fixed circumferentially to the outer wall of the inner shaft (2); the end face of the baffle (18) abuts against the end of the first threaded portion (14); the end face of the synchronous wheel (19) abuts against the end face of the baffle (18); the outer wall of the inner shaft (2) has a second threaded portion (15); a second limiting nut (17) is threadedly connected to the second threaded portion (15); the second limiting nut (17) is used to limit the synchronous wheel (19).

9. The integrated hydraulic rotary spindle with a sealing structure according to claim 1, characterized in that: A bearing 1 (20) is arranged between one end of the inner shaft (2) and one end of the main shaft sleeve (1), and a bearing 2 (21) is arranged between the other end of the inner shaft (2) and the other end of the main shaft sleeve (1).

10. A sealing method, applied to the integrated hydraulic rotary spindle according to claim 5, characterized in that: The following steps are involved: S1, make the opening of the annular groove (13) face away from the annular limiting groove (10), and then install the skeleton oil seal (82) into the annular limiting groove (10); S2, connect the oil seal sleeve (81) with the main shaft sleeve (1); S3, apply a proper amount of grease to the inner ring of the skeleton oil seal (82); S4, pass the inner shaft (2) through the skeleton oil seal (82).

Images