High-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable

Abstract

The present invention belongs to the technical field of precision machine tools, and discloses a high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable, comprising a base, a rotating body, a cover plate covering the base, a turntable table fixedly connected to the rotating body, and a permanent magnet torque motor driving the rotating body; the base has an annular cavity, and an isolation cylinder is arranged in the annular cavity; the permanent magnet torque motor is located in the outer annular cavity and is arranged around the outer peripheral side of the rotating body, the isolation cylinder is fixed on the outer peripheral side of the rotating body, and the motor mover is fixed on the outer peripheral side of the isolation cylinder, so that the driving force arm of the permanent magnet torque motor on the rotating body is greater than the radius of the rotating body to increase the driving torque on the rotating body. The present invention meets the requirements of high-speed and high-precision rotary motion of heavy-duty turntables by reducing the axial height of the turntable and increasing the driving torque on the rotating body.

Description

Technical Field

[0001] The invention relates to the technical field of precision machine tools, and in particular to a high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable. Background Art

[0002] For a heavy-duty turntable with a large diameter-to-height ratio, the diameter of the turntable table can exceed 1m, and the mass of the workpiece that needs to be processed and rotated can reach several tons, which places higher requirements on the turntable's driving torque, rotation accuracy and other characteristics.

[0003] Chinese patent CN103111855B discloses an ultra-precision liquid hydrostatic turntable with a large diameter-to-height ratio, in which the lower end of the main shaft is fixedly connected to the rotor of the torque motor through a connecting plate, and the rotor of the torque motor is fixedly connected to the lower plane of the turntable base through a motor seat, that is, the torque motor is installed at the bottom of the turntable, which brings at least the following defects: First, because the torque motor is installed at the bottom of the turntable, the overall height of the turntable is relatively large, which increases the risk of overturning of the turntable surface and is not conducive to improving the end face runout accuracy of the turntable surface; second, the torque motor has a small force arm on the main shaft, and the driving torque generated is small, which is difficult to meet the actual needs of high-speed and high-precision rotary motion of heavy-duty turntables. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a high-speed, high-precision, heavy-loaded permanent magnet torque motor liquid hydrostatic turntable, in which the permanent magnet torque motor is arranged on the outer peripheral side of the rotating body, and the requirements for high-speed and high-precision rotational motion of the heavy-loaded turntable are met by reducing the axial height of the turntable and increasing the driving torque of the rotating body.

[0005] The present invention proposes a high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable, comprising a base, a rotating body, a cover plate covering the base, a turntable table top located above the cover plate and fixedly connected to the rotating body, and a permanent magnet torque motor for driving the rotating body; the base has an annular cavity, a mounting shaft is provided in the middle of the annular cavity; an isolating cylinder coaxial with the mounting shaft is provided in the annular cavity, the axial height of the isolating cylinder is greater than that of the rotating body, and the annular cavity is divided by the isolating cylinder into an inner annular cavity located between the isolating cylinder and the mounting shaft and an inner annular cavity located between the isolating cylinder and the annular cavity An outer ring cavity between the inner and outer walls; the rotating body is located in the inner ring cavity, and is sleeved on the mounting shaft through the axial hole in the middle, and a liquid static pressure support structure is provided between the rotating body and the inner ring cavity; the permanent magnet torque motor is located in the outer ring cavity and is arranged in an annular manner on the outer circumference of the rotating body, including a circular motor stator and a circular motor mover, and the motor stator is fixed on the inner wall of the annular cavity; the isolation cylinder is fixed on the outer circumference of the rotating body, and the motor mover is fixed on the outer circumference of the isolation cylinder, so that the driving force arm of the permanent magnet torque motor on the rotating body is greater than the radius of the rotating body to increase the driving torque on the rotating body.

[0006] Preferably, a plurality of first static pressure components are evenly spaced in a ring on the mounting shaft, and a radial gap for forming a radial static pressure thrust oil film is provided between the first static pressure component and the inner wall of the shaft hole; a plurality of second static pressure components are arranged in a circular ring shape on the lower side surface of the cover plate, and an upper axial gap for forming a downward static pressure thrust oil film is provided between the second static pressure component and the upper end surface of the rotating body; a plurality of third static pressure components are evenly spaced in a circular ring shape on the bottom of the annular cavity, and a lower axial gap for forming an upward static pressure thrust oil film is provided between the third static pressure component and the upper end surface of the rotating body; wherein the radial gap, the upper axial gap and the lower axial gap are all 0.1mm-0.05mm.

[0007] Preferably, the orthographic projections of the motor stator and the motor mover in the longitudinal section at least partially overlap with the rotating body, and the top of the permanent magnet torque motor is not higher than the top of the rotating body.

[0008] Preferably, the center of mass of the permanent magnet torque motor is arranged to coincide with the center of mass of the rotating body or to be located below the center of mass of the rotating body.

[0009] Preferably, at least 4 / 5 of the orthographic projection of the motor stator and the motor mover in the longitudinal section overlap with the rotating body, and the bottom ends of the motor stator and the motor mover extend downward out of the bottom end of the rotating body.

[0010] Preferably, the lower end of the mounting shaft is provided with an inner support platform whose outer diameter is larger than the inner diameter of the shaft hole, a support ring is provided at the bottom of the annular cavity, a first oil accumulation ring groove is formed between the inner support platform and the support ring, and a plurality of first oil drain ports are provided at the bottom of the first oil accumulation ring groove.

[0011] Preferably, the top surface of the support ring is lower than the inner support platform, and a plurality of third static pressure components are evenly spaced and arranged on the top surface of the support ring, and the third static pressure components are arranged close to the outer circumference of the rotating body.

[0012] Preferably, a second oil accumulation ring groove is formed between the lower end of the isolation cylinder and the support ring, and a plurality of second oil drain ports are provided at the bottom of the second oil accumulation ring groove; a plurality of oil-passing vertical grooves are evenly spaced on the outer peripheral side of the rotating body, and the lower ends of the oil-passing vertical grooves are connected to the second oil accumulation ring groove.

[0013] Preferably, there is a first oil-blocking structure between the bottom end of the isolation tube and the bottom of the annular cavity, and the first oil-blocking structure includes: a first oil-blocking ring portion with an inverted L-shaped longitudinal cross-section is provided at the bottom of the annular cavity relative to the support ring, and a raised ring extending outward from the bottom end of the isolation tube, and the end of the raised ring extends to below the first oil-blocking ring portion.

[0014] Preferably, there is a second oil-blocking structure between the top of the isolation tube and the cover plate, and the second oil-blocking structure includes: a second oil-blocking ring portion extending upward from the top of the isolation tube and having an inverted L-shaped longitudinal cross-section, and an oil-blocking groove arranged on the lower side of the cover plate, and the second oil-blocking ring portion extends into the oil-blocking groove.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] Compared with the prior art in which the torque motor is installed at the bottom of the rotating body, the present invention coaxially arranges the permanent magnet torque motor on the outer peripheral side of the rotating body, and the motor rotor of the permanent magnet torque motor is fixedly connected to the outer peripheral side of the rotating body through an isolation tube. Not only does the permanent magnet torque motor not increase the overall height of the turntable, but the isolation tube is also used to increase the driving torque of the permanent magnet torque motor to drive the rotating body, which can meet the driving requirements of high-speed and high-precision rotational motion of heavy-loaded turntables with a large diameter-to-height ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional structural schematic diagram of the turntable of the present invention.

[0018] Figure 2 It is a schematic diagram of the exploded structure of the turntable of the present invention.

[0019] Figure 3 It is a schematic diagram of the three-dimensional structure of the base.

[0020] Figure 4 It is a schematic diagram of the assembly structure of the isolation cylinder and the rotating body.

[0021] Figure 5 It is a schematic diagram of the cross-sectional structure of the isolation tube.

[0022] Figure 6 It is a structural schematic diagram of the fixed assembly of the rotating body and the turntable table.

[0023] Figure 7 It is a structural schematic diagram of the second static pressure assembly installed on the lower side of the cover plate.

[0024] Figure 8 A schematic cross-sectional view of the stereoscopic structure of the turntable of the present invention.

[0025] Fig. 9 A schematic cross-sectional structure diagram of a turntable of the present invention.

[0026] Among them, the meanings of the numbers in the figure are as follows: base 1, annular cavity 11, mounting shaft 12, inner bearing 121, support ring 13, first oil accumulation ring groove 14, first oil drain port 15, second oil accumulation ring groove 16, first oil retaining ring part 17, rotating body 2, shaft hole 21, oil vertical groove 22, cover plate 3, turntable table 4, motor stator 51, motor rotor 52, isolation tube 6, raised ring 61, second oil retaining ring part 62, first static pressure assembly 71, second static pressure assembly 72, third static pressure assembly 73. DETAILED DESCRIPTION

[0027] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined purpose, the specific implementation methods, structures, features and effects of the present application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0028] The present invention discloses a high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable (referred to as "liquid hydrostatic turntable" or "turntable"), which mainly reduces the axial height of the turntable and increases the driving torque of the permanent magnet torque motor on the rotating body by improving the assembly structure of the permanent magnet torque motor and the rotating body, so as to meet the requirements of high-speed, high-precision rotational motion of a heavy-load turntable with a large diameter-to-height ratio (generally referring to the ratio of the diameter to the height of the rotating body being not less than 3) and capable of carrying heavier workpieces.

[0029] Combination Figure 1-9 As shown, the turntable disclosed in the present invention specifically comprises a base 1, a rotating body 2, a cover plate 3 covering the base 1, a turntable table 4 located above the cover plate 3 and fixedly connected to the rotating body 2, and a permanent magnet torque motor for driving the rotating body 2. The permanent magnet torque motor generates a driving torque on the rotating body 2, driving the rotating body 2 to drive the turntable table 4 to perform a rotational motion, so as to meet the need for high-precision and rapid rotational motion of the workpiece mounted on the turntable table 4 during the processing process.

[0030] The base 1 has an annular cavity 11, and a mounting shaft 12 is provided in the middle of the annular cavity 11. The rotating body 2 and the permanent magnet torque motor are coaxially arranged in the annular cavity 11. The cover plate 3 covers the annular cavity 11, and the main shaft of the turntable table 4 is fixed to the rotating body 2 by screws.

[0031] Specifically, an isolation cylinder 6 coaxial with the installation shaft 12 is provided in the annular cavity 11, and the axial height of the isolation cylinder 6 is greater than the rotating body 2; the top and bottom ends of the isolation cylinder 6 are respectively arranged non-contactly relative to the cover plate 3 and the bottom of the annular cavity 11, and the annular cavity 11 is divided by the isolation cylinder 6 into an inner annular cavity between the isolation cylinder 6 and the installation shaft 12 and an outer annular cavity between the isolation cylinder 6 and the inner wall of the annular cavity 11.

[0032] The rotating body 2 is a circular ring structure, and a shaft hole 21 with a hole diameter larger than the outer diameter of the installation shaft 12 is provided in the middle thereof; the rotating body 2 is located in the inner ring cavity, and is sleeved on the installation shaft 12 through the shaft hole 21 in the middle thereof.

[0033] The support form of the rotating body 2 in the inner ring cavity adopts liquid hydrostatic pressure, that is, there is a liquid hydrostatic support structure between the rotating body 2 and the inner ring cavity. Specifically, the liquid hydrostatic support structure includes: a plurality of first hydrostatic components 71 are evenly spaced in a ring on the mounting shaft 12, a radial gap is formed between the first hydrostatic component 71 and the inner wall of the shaft hole 21, the first hydrostatic component 71 is connected to the oil supply pipeline to inject hydraulic oil into the radial gap as needed, and the hydraulic oil forms a radial hydrostatic thrust oil film for the rotating body 2 in the radial gap; a plurality of second hydrostatic components 72 are evenly spaced in a circular ring shape on the lower side of the cover plate 3, and the second hydrostatic component 72 has an upper axial gap between the upper end face of the rotating body 2 and the lower end face of the cover plate 3. The second static pressure component 72 is connected to the oil supply pipeline to inject hydraulic oil into the upper axial gap as needed, and the hydraulic oil forms a downward static pressure thrust oil film on the rotating body 2 in the upper axial gap; a plurality of third static pressure components 73 are arranged in a circular ring shape and evenly spaced at the bottom of the annular cavity 11, and a lower axial gap is provided between the third static pressure component 73 and the upper end surface of the rotating body 2. The oil supply pipeline injects hydraulic oil into the lower axial gap through the third static pressure component 73 as needed, and the hydraulic oil forms an upward static pressure thrust oil film on the rotating body 2 in the lower axial gap.

[0034] The radial static pressure thrust oil film, the downward static pressure thrust oil film and the upward static pressure thrust oil film are used to respectively perform thrust limiting on the rotating body 2 in the radial and upper and lower axial directions, thereby meeting the requirements of the rotation accuracy and positioning accuracy of the turntable, which is beneficial to improving the load-bearing capacity of the turntable and ensuring the rotation accuracy, while ensuring reliable holding performance during the use of the turntable to improve stability and reliability.

[0035] Among them, the radial clearance, the upper axial clearance and the lower axial clearance are all 0.1mm-0.05mm, so that the radial static pressure thrust oil film, the downward static pressure thrust oil film and the upward static pressure thrust oil film are all within the range of 0.1mm-0.05mm. The moderate thickness of the oil film can not only ensure that the oil film has sufficient strength to meet the heavy load requirements of the turntable, but also reduce the friction resistance between the rotating body 2 and the annular cavity 11 by using the oil film, which is beneficial to reduce the power loss of the permanent magnet torque motor to improve the static performance and dynamic performance of the turntable.

[0036] In a specific practical application, the radial clearance, upper axial clearance and lower axial clearance are all between 0.08mm and 0.05mm. The maximum rotation diameter of the turntable implemented according to this solution reaches 1.8m, the turntable table diameter reaches 1.6m, the maximum mass of the workpiece that can be carried reaches 8T, and the maximum torque of the turntable reaches 24KN*m, which can meet the rotation requirements for processing large mass workpieces. The entire turntable runs smoothly and with high precision.

[0037] The present invention accommodates the permanent magnet torque motor in the outer ring cavity and is arranged on the outer peripheral side of the rotating body 2. Specifically, the permanent magnet torque motor includes a circular ring-shaped motor stator 51 and a circular ring-shaped motor mover 52, the motor stator 51 is fixed to the inner wall of the annular cavity 11; the motor mover 52 is fixed to the outer peripheral side of the isolation cylinder 6, and the isolation cylinder 6 is fixed to the outer peripheral side of the rotating body 2.

[0038] like Figure 6 As shown, OO is the center axis of the rotating body 2 or the mounting shaft 12, and the radius R of the rotating body 2. Since the motor stator 51 is fixed to the outer peripheral side of the rotating body 2 by the isolating tube 6, the isolating tube 6 is located between the rotating body 2 and the motor stator 51. The isolating tube 6 is used to increase the driving force arm L of the motor mover 52 on the rotating body 2, so that the driving force arm L of the permanent magnet torque motor on the rotating body 2 is greater than the radius R of the rotating body 2. When the output power of the permanent magnet torque motor remains unchanged, the driving torque on the rotating body 2 can be correspondingly increased by increasing the driving force arm L, so as to meet the driving requirements of the turntable for heavy load and high-speed rotation.

[0039] The orthographic projections of the motor stator 51 and the motor mover 52 in the longitudinal section at least partially overlap with the rotating body 2 , so that the overall height of the rotating body 2 will not be significantly increased when the motor mover 52 is fixed to the outer peripheral side of the rotating body 2 .

[0040] Moreover, the top of the permanent magnet torque motor is set no higher than the top of the rotating body 2. This is because: when the workpiece fixed on the turntable table 4 is subjected to a large impact load during processing, resulting in serious circumferential or / and axial eccentric loads on the turntable table 4, the turntable table 4 will deform or vibrate due to uneven force when subjected to uneven loads, forming an end diameter jump error; when the top of the permanent magnet torque motor is higher than the top of the rotating body 2, the driving torque applied by the permanent magnet torque motor to the rotating body 2 is mainly located in the middle and upper part of the rotating body 2, and the driving torque may aggravate the end diameter jump error generated by the turntable table 4 under uneven loads, resulting in low precision of the turntable. For this reason, the present invention sets the top of the permanent magnet torque motor no higher than the top of the rotating body 2, so that the driving torque applied by the permanent magnet torque motor to the rotating body 2 is mainly located in the middle and lower part of the rotating body 2, so that the turntable runs more smoothly and has a smaller end diameter jump error, which is beneficial to improving the rotation accuracy and positioning accuracy of the turntable.

[0041] like Figure 6As shown, the present invention sets the center of mass n of the permanent magnet torque motor to coincide with the center of mass m of the rotating body 2, or the center of mass n of the permanent magnet torque motor is located below the center of mass m of the rotating body 2. For ease of understanding, assuming that the permanent magnet torque motor and the rotating body 2 are components with regular shapes and uniform mass, then the center of mass m of the rotating body 2 is located at the intersection of the two axial bisectors AA of the rotating body 2 and the central axis OO, and the center of mass n of the permanent magnet torque motor is located at the intersection of the two axial bisectors BB of the permanent magnet torque motor and the central axis OO. Such a structure ensures that the position where the permanent magnet torque motor applies the driving torque to the rotating body 2 is mainly concentrated in the middle or lower middle part of the rotating body 2, which is conducive to making the turntable run more smoothly, with smaller errors and higher precision.

[0042] In one embodiment, the orthographic projections of the motor stator 51 and the motor mover 52 in the longitudinal section overlap with the rotating body 2 by a height h1, and the bottom ends of the motor stator 51 and the motor mover 52 extend downward by a height h2 of the bottom end of the rotating body 2, then, the actual height of the motor stator 51 and the motor mover 52 is h1+h2, and h1 accounts for at least 4 / 5 of the actual height. Such an arrangement can basically ensure that the mass center n of the permanent magnet torque motor coincides with the mass center m of the rotating body 2 or is located below the mass center m of the rotating body 2.

[0043] The role of the isolation tube 6 in the entire technical solution of the present invention includes at least the following aspects: first, the isolation tube 6 serves as a connecting medium between the motor mover 52 and the rotating body 2, so that the motor mover 52 can be fixed on the outer peripheral side of the rotating body 2 through the isolation tube 6; second, the isolation tube 6 is used to increase the driving force arm of the motor mover 52 on the rotating body 2, thereby increasing the driving torque of the permanent magnet torque motor on the rotating body 2; third, the annular cavity 11 of the base 1 is separated, so that the hydraulic oil in the inner ring cavity is isolated from the outer ring cavity, so that the oil film formed by the hydraulic oil in the inner ring cavity can achieve hydrostatic support for the rotating body 2.

[0044] Of course, part or all of the hydraulic oil that enters the inner ring cavity needs to be discharged in time according to the actual static pressure conditions. For this purpose, an oil discharge channel is provided below the rotating body 2.

[0045] Specifically, the lower end of the mounting shaft 12 is provided with an inner support 121 whose outer diameter is larger than the inner diameter of the shaft hole 21, a support ring 13 is provided at the bottom of the annular cavity 11, a first oil accumulation annular groove 14 is formed between the inner support 121 and the support ring 13, and a plurality of first oil drain ports 15 are provided at the bottom of the first oil accumulation annular groove 14. The hydraulic oil sprayed from the first static pressure assembly 71 and the third static pressure assembly 73 partially flows downward into the first oil accumulation annular groove 14, and when it is necessary to partially or completely drain it, it flows out through the first oil drain ports 15 to the oil return chamber at the bottom of the base 1 or is drained in time through the return pipeline.

[0046] The top surface of the support ring 13 is lower than the inner support platform 121, and a plurality of third static pressure components 73 are evenly spaced and arranged on the top surface of the support ring 13, and the third static pressure components are arranged close to the outer circumference of the rotating body 2. In addition, the top surface of the third static pressure component 73 is also lower than the top surface of the inner support platform 121.

[0047] Furthermore, a second oil-accumulating annular groove 16 is formed between the lower end of the isolation cylinder 6 and the support ring 13, and a plurality of second oil drain ports are provided at the bottom of the second oil-accumulating annular groove 16; a plurality of oil-passing vertical grooves 22 are evenly spaced on the outer peripheral side of the rotating body 2, and the lower ends of the oil-passing vertical grooves 22 are connected to the second oil-accumulating annular groove 16. When the hydraulic oil sprayed from the second static pressure component 72 forms a downward static pressure thrust oil film between the second static pressure component 72 and the upper end surface of the rotating body 2, part of the hydraulic oil flows downward into the second oil-accumulating annular groove 16 through the plurality of oil-passing vertical grooves 22. When the hydraulic oil in the second oil-accumulating annular groove 16 needs to be drained, it flows out through the second oil drain port to the oil return chamber at the bottom of the base 1 or is promptly drained through the return pipeline.

[0048] The isolation cylinder 6 is used to isolate the hydraulic oil in the inner ring cavity relative to the outer ring cavity. The axial height of the isolation cylinder 6 is set to be greater than the rotating body 2, and the bottom and top ends of the isolation cylinder 6 are respectively provided with a first oil-blocking structure and a second oil-blocking structure between the cover plate 3 and the bottom of the annular cavity 11. The first oil-blocking structure and the second oil-blocking structure are used to improve the blocking ability of the isolation cylinder 6 to the hydraulic oil in the inner ring cavity, so as to prevent the hydraulic oil in the inner ring cavity from overflowing from the bottom and top ends of the isolation cylinder 6.

[0049] The first oil retaining structure specifically includes: a first oil retaining ring portion 17 with an inverted L-shaped longitudinal section is provided at the bottom of the annular cavity 11 relative to the support ring 13; the bottom end of the isolation tube 6 has a raised ring 61 extending outward, and the end of the raised ring 61 extends to the bottom of the first oil retaining ring portion 17. During the rotation of the rotating body 2, part of the hydraulic oil sprayed from the second static pressure component 72 and the third static pressure component 73 will be thrown into the second oil accumulation ring groove 16, and extend to the bottom of the first oil retaining ring portion 17 through the end of the raised ring 61 at the bottom end of the isolation tube 6. The raised ring 61 blocks and guides the hydraulic oil, so that the hydraulic oil in the second oil accumulation ring groove 16 will not leak from between the raised ring 61 and the first oil retaining ring portion 17.

[0050] The second oil-blocking structure specifically includes: a second oil-blocking ring portion 62 with an inverted L-shaped longitudinal section extending upward from the top of the isolation cylinder 6, an oil-blocking groove is provided on the lower side of the cover plate 3, and the second oil-blocking ring portion 62 extends into the oil-blocking groove. When part of the hydraulic oil sprayed out by the second static pressure component 72 moves to the inner wall of the isolation cylinder 6, part of the hydraulic oil moves upward along the inner wall of the isolation cylinder 6 under the action of the centrifugal force generated during the rotation of the rotating body 2, and the oil-blocking groove on the lower side of the cover plate 3 and the second oil-blocking ring portion 62 on the top of the isolation cylinder 6 cooperate to block the hydraulic oil, allowing the hydraulic oil to fall back and fall into the second oil-accumulating ring groove 16 through the oil-passing vertical groove 22 on the side of the rotating body 2, thereby preventing the hydraulic oil from leaking through the junction between the top of the isolation cylinder 6 and the lower side of the cover plate 3.

[0051] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable, characterized in that: It comprises a base (1), a rotating body (2), a cover plate (3) covering the base (1), a turntable surface (4) located above the cover plate (3) and fixedly connected to the rotating body (2), and a permanent magnet torque motor for driving the rotating body (2); The base (1) has an annular cavity (11), and a mounting shaft (12) is provided in the middle of the annular cavity (11); An isolating cylinder (6) coaxial with the mounting shaft (12) is provided in the annular cavity (11); the axial height of the isolating cylinder (6) is greater than that of the rotating body (2); the isolating cylinder (6) divides the annular cavity (11) into an inner annular cavity located between the isolating cylinder (6) and the mounting shaft (12), and an outer annular cavity located between the isolating cylinder (6) and the inner side wall of the annular cavity (11); The rotating body (2) is located in the inner annular cavity and is sleeved on the mounting shaft (12) through a shaft hole (21) in the middle, and a liquid static pressure support structure is provided between the rotating body (2) and the inner annular cavity; The permanent magnet torque motor is located in the outer annular cavity and is arranged in an annular shape on the outer circumference of the rotating body (2), and comprises an annular motor stator (51) and an annular motor mover (52); the motor stator (51) is fixed to the inner wall of the annular cavity (11); The isolation cylinder (6) is fixed to the outer peripheral side of the rotating body (2), and the motor mover (52) is fixed to the outer peripheral side of the isolation cylinder (6), so that the driving force arm of the permanent magnet torque motor on the rotating body (2) is greater than the radius of the rotating body (2) to increase the driving torque on the rotating body (2); The liquid hydrostatic bearing structure specifically comprises: a plurality of first hydrostatic components (71) are evenly spaced in a ring on the mounting shaft (12), and a radial gap is provided between the first hydrostatic components (71) and the inner wall of the shaft hole (21) to form a radial hydrostatic thrust oil film; a plurality of second hydrostatic components (72) are arranged in a circular ring shape on the lower side surface of the cover plate (3), and an upper axial gap is provided between the second hydrostatic components (72) and the upper end surface of the rotating body (2) to form a downward hydrostatic thrust oil film; a plurality of third hydrostatic components (73) are evenly spaced in a circular ring shape on the bottom of the annular cavity (11), and a lower axial gap is provided between the third hydrostatic components (73) and the upper end surface of the rotating body (2) to form an upward hydrostatic thrust oil film; wherein the radial gap, the upper axial gap and the lower axial gap are all 0.1 mm to 0.05 mm.

2. According to the high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable of claim 1, it is characterized in that: The orthographic projections of the motor stator (51) and the motor mover (52) in the longitudinal section at least partially overlap with the rotating body (2), and the top of the permanent magnet torque motor is not higher than the top of the rotating body (2).

3. According to the high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable of claim 2, it is characterized in that: The center of mass of the permanent magnet torque motor is arranged to coincide with the center of mass of the rotating body (2) or to be located below the center of mass of the rotating body (2).

4. According to the high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable of claim 2, it is characterized in that: At least 4 / 5 of the orthographic projection of the motor stator (51) and the motor mover (52) in the longitudinal section overlaps with the rotating body (2), and the bottom ends of the motor stator (51) and the motor mover (52) extend downwards beyond the bottom end of the rotating body (2).

5. According to the high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable of claim 1, it is characterized in that: An inner support platform (121) having an outer diameter greater than the inner diameter of the shaft hole (21) is provided at the lower end of the mounting shaft (12); a support ring (13) is provided at the bottom of the annular cavity (11); a first oil accumulation ring groove (14) is formed between the inner support platform (121) and the support ring (13); and a plurality of first oil drain ports (15) are provided at the bottom of the first oil accumulation ring groove (14).

6. The high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable according to claim 5 is characterized in that: The top end surface of the support ring (13) is lower than the inner support platform (121), and a plurality of third static pressure components are evenly spaced and arranged on the top end surface of the support ring (13), and the third static pressure components are arranged close to the outer circumference of the rotating body (2).

7. The high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable according to claim 5 is characterized in that: A second oil accumulation annular groove (16) is formed between the lower end of the isolation cylinder (6) and the support ring (13), and a plurality of second oil drain ports are provided at the bottom of the second oil accumulation annular groove (16); a plurality of oil passing vertical grooves (22) are evenly spaced apart on the outer peripheral side of the rotating body (2), and the lower ends of the oil passing vertical grooves (22) are connected to the second oil accumulation annular groove (16).

8. The high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable according to claim 7 is characterized in that: A first oil-blocking structure is provided between the bottom end of the isolating cylinder (6) and the bottom of the annular cavity (11), the first oil-blocking structure comprising: a first oil-blocking ring portion (17) having an inverted L-shaped longitudinal cross section provided at the bottom of the annular cavity (11) relative to the support ring (13), and a raised ring (61) extending outward from the bottom end of the isolating cylinder (6), the distal end of the raised ring (61) extending below the first oil-blocking ring portion (17).

9. The high-speed, high-precision, heavy-load permanent magnet torque motor liquid hydrostatic turntable according to any one of claims 1 to 8, characterized in that: A second oil-blocking structure is provided between the top end of the isolation tube (6) and the cover plate (3), the second oil-blocking structure comprising: a second oil-blocking ring portion (62) extending upward from the top end of the isolation tube (6) and having an inverted L-shaped longitudinal cross section, and an oil-blocking groove provided on the lower side of the cover plate (3), the second oil-blocking ring portion (62) extending into the oil-blocking groove.

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