Internal feedback rotating table for machine tool
By adopting a built-in feedback structure in the grinder rotary workbench and using the grooves and boss design of the static press bearing, the axial and radial oil film feedback is achieved, which solves the problems of uncompact structure and low rotation accuracy in the prior art, and improves the load-bearing capacity and service life of the workbench.
Patent Information
- Application Number
- CN202422362683.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2034-09-27
AI Technical Summary
The existing grinder rotary table is not compact in structure, and the external feedback device leads to low rotation accuracy, easy wear, short life, and lacks radial oil cavity feedback function between the static bearing and the rotating shaft.
The built-in feedback structure is adopted, by forming upper grooves, lower grooves and side grooves on the end surface and inner side of the static press bearing, and forming a boss in the groove, the annular oil inlet groove and throttling oil passage forms an oil cavity, lower oil cavity and side oil cavity, so as to achieve axial and radial oil film feedback, and self-regulate the oil pressure to adapt to load changes.
It improves the structural compactness of the rotary table, enhances the load-bearing capacity, improves the rotation accuracy and service life, and avoids eccentric wear of the rotary shaft.
Smart Images
Figure CN223114866U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of machine tools, in particular to an internal feedback rotary table for machine tools. Background Art
[0002] For the existing rotary table of a grinding machine, in order to bear the axial load generated by the weight of the table top and the workpiece, and enable the rotating shaft to have a certain self - adapting ability along the axial direction, an external film feedback device is arranged in the upper and lower oil cavities formed between the rotating shaft, the thrust ring and the end face of the hydrostatic bearing.
[0003] However, the thickness of such a feedback device needs to be continuously adjusted according to the actual working conditions, with high design difficulty and cost. Moreover, due to the existence of the external feedback device, the whole rotary table is large in volume and not compact in structure. Secondly, there is no feedback function for the radial oil cavities on the opposite sides between the hydrostatic bearing and the rotating shaft. When the table rotates, the pressures in the radial oil cavities are inconsistent, which easily causes the rotating shaft to be eccentric, resulting in low rotary accuracy, easy wear and short service life of the rotary table. Summary of the Utility Model
[0004] To solve the above - mentioned deficiencies of the prior art, the utility model provides an internal feedback rotary table for machine tools, which has the advantages of compact structure, strong load - bearing capacity, high rotary accuracy and long service life.
[0005] The technical solution of the present utility model is: an internal feedback rotary table for a machine tool, including a turntable base, a hydrostatic bearing fixed inside the turntable base, a lower seal cover fixed at the bottom of the turntable base, and a rotating shaft rotatably connected inside the hydrostatic bearing and penetrating downward through the lower seal cover. Upper and lower stepped portions are formed on the rotating shaft at both ends of the hydrostatic bearing. A thrust ring for axially supporting the hydrostatic bearing together with the upper stepped portion is fixed on the lower stepped portion. An annular oil inlet groove communicating with the oil inlet on the turntable base is provided outside the hydrostatic bearing. An oil return cavity communicating with the oil return port on the turntable base is formed between the outer side of the thrust ring and the inner side of the turntable base. A plurality of upper grooves and lower grooves are evenly arranged along the circumferences of the upper and lower end faces of the hydrostatic bearing respectively and are distributed in a vertically staggered manner. Upper and lower bosses are formed in the upper and lower grooves respectively. First throttle oil channels communicating with the corresponding lower and upper grooves and first oil inlet channels communicating with the annular oil inlet groove are formed on the upper and lower bosses respectively. A plurality of side grooves are arranged along the circumference inside the hydrostatic bearing. Side bosses are formed in the side grooves. Second throttle oil channels communicating with adjacent / alternate side grooves and second oil inlet channels communicating with the annular oil inlet groove are formed on the side bosses. Upper oil cavities, lower oil cavities and side oil cavities are respectively formed between the upper grooves and the upper stepped portion, between the lower grooves and the thrust ring, and between the side grooves and the rotating shaft. Oil return channels for communicating the upper oil cavity, the lower oil cavity and the side oil cavity with the oil return cavity are provided on the hydrostatic bearing. By forming upper grooves, lower grooves and side grooves on the end face and inside of the hydrostatic bearing respectively, and forming upper bosses, lower bosses and side bosses in the corresponding grooves, oil is fed into the oil inlet channels of each boss through the annular oil inlet groove outside the hydrostatic bearing, and the oil reaching the surface of the boss is then fed back into the corresponding different grooves through the throttle oil channels, so that upper oil cavities and lower oil cavities with feedback functions are formed between the upper grooves of the hydrostatic bearing and the upper stepped portion of the rotating shaft and between the lower grooves of the hydrostatic bearing and the thrust ring, and a side oil cavity with a feedback function is formed between the side grooves of the hydrostatic bearing and the rotating shaft. Oil films are formed in each oil cavity and can perform self-adjusting feedback of oil pressure according to the pressure received. The setting of this built-in feedback structure ensures the compactness of the entire rotary table. At the same time, the two-way feedback in the radial and axial directions effectively avoids eccentric wear of the rotating shaft and improves the rotary accuracy and service life.
[0006] The number of the first oil inlet channels on each of the upper bosses and each of the lower bosses is two, symmetrically distributed on both sides of the first throttle oil channel. The number of the second oil inlet channels on each of the side bosses is two, respectively symmetrically distributed on both sides of the second throttle oil channel. Arranging the oil inlet channels on both sides of the throttle oil channel can ensure the stability of the oil film formed in each oil cavity.
[0007] A plurality of arc-shaped feedback oil channels are arranged outside the hydrostatic bearing. One end of each arc-shaped feedback oil channel is communicated with the second throttle oil channel of any one of the side bosses, and the other end is communicated with the side groove at the adjacent / alternate position of the side boss. An arc-shaped feedback oil channel for communicating the second throttle oil channel and the side groove is arranged outside the hydrostatic bearing, which reduces the processing difficulty of the communication between the oil channels at this place.
[0008] The oil return channel is arranged radially on the end face of the hydrostatic bearing between the adjacent upper groove / lower groove. The two ends of the oil return channel are respectively communicated with the inner and outer sides of the hydrostatic bearing. The oil return channels on the upper and lower end faces of the hydrostatic bearing are communicated through oil return holes.
[0009] An adjusting gasket is arranged between the thrust ring and the lower step of the rotating shaft. By selecting adjusting gaskets with different widths, the floating amount of the turntable axially relative to the rotating shaft can be controlled, so as to adapt to the strong load-bearing capacity of the rotary table itself.
[0010] The surface of the lower seal cover is in sealed contact with the turntable base through an O-ring, and the inner end of the lower seal cover is rotationally sealed with the rotating shaft through a sealing ring. The arrangement of the O-ring and the sealing ring can prevent the oil in the inner cavity of the turntable base from overflowing.
[0011] An annular baffle is fixed on the top of the turntable base, and an annular groove in clearance fit with the annular baffle is opened on the upper step of the rotating shaft. The annular baffle is arranged on the top of the turntable base, which can prevent the cutting fluid from entering the inside of the hydrostatic bearing and ensure the normal operation of the rotary table.
[0012] A motor rotor and a motor stator are arranged outside one end of the rotating shaft that penetrates downward through the lower seal cover. The motor rotor is connected to the rotating shaft as a whole through a rotor gland, and the motor stator is embedded in the stator outer sleeve and fixed to the lower seal cover together with the stator outer sleeve.
[0013] It includes an encoder, and the encoder is locked at the end of the rotating shaft through a locking nut to realize the fixed-angle rotation of the rotating shaft.
[0014] The beneficial effects of the present utility model are as follows: In this solution, an upper groove, a lower groove, and a side groove are respectively formed on the end face and the inner side of the hydrostatic bearing, and an upper boss, a lower boss, and a side boss are formed in the corresponding grooves. Oil is fed into the oil inlet channels of each boss through the annular oil inlet groove on the outer side of the hydrostatic bearing, and the oil reaching the surface of the boss is fed back into the corresponding different grooves through the throttle oil channels. Thus, an upper oil cavity with an axial feedback function is formed between the upper groove of the hydrostatic bearing and the upper step of the rotating shaft, and a lower oil cavity with an axial feedback function is formed between the lower groove of the hydrostatic bearing and the thrust ring. A side oil cavity with a radial feedback function is formed between the side groove of the hydrostatic bearing and the rotating shaft. Oil films are formed in each oil cavity and can perform self-adjusting feedback of the oil pressure according to the pressure received. The setting of this built-in feedback structure ensures the compactness of the entire rotary worktable. At the same time, the two-way feedback in the radial and axial directions effectively avoids eccentric wear of the rotating shaft and improves the rotary accuracy and service life. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 is a schematic structural diagram of the present utility model;
[0016] Figure 2 is a schematic structural diagram of the hydrostatic bearing in the present utility model;
[0017] Figure 3 is a schematic structural diagram of the hydrostatic bearing from another angle in the present utility model;
[0018] Figure 4 is a schematic structural diagram of the turntable base in the present utility model;
[0019] Figure 5 is a schematic diagram of the oil inlet and oil return paths in the present utility model.
[0020] Reference numerals: 1, turntable base; 101, oil inlet; 102, oil return port; 103, oil return cavity; 2, hydrostatic bearing; 201, annular oil inlet groove; 202, upper groove; 203, lower groove; 204, side groove; 205, oil return channel; 206, arc-shaped feedback oil channel; 207, oil return hole; 3, rotating shaft; 301, annular groove; 4, thrust ring; 5, lower seal cover; 6, upper boss; 601, first oil inlet channel; 602, first throttle oil channel; 7, lower boss; 8, side boss; 801, second oil inlet channel; 802, second throttle oil channel; 9, upper oil cavity; 10, lower oil cavity; 11, side oil cavity; 12, adjusting gasket; 13, sealing ring; 14, O-ring; 15, annular baffle; 16, motor rotor; 17, rotor gland; 18, motor stator; 19, stator outer sleeve; 20, locking nut; 21, encoder. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] To enable those skilled in the art to better understand the technical solutions in the present utility model, the following will clearly and completely describe the technical solutions in the present utility model with reference to the accompanying drawings. Other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present utility model.
[0022] As Figure 1 shown, the present utility model provides an internal feedback rotary table for a machine tool, including a turntable base 1, a hydrostatic bearing 2 fixed in the inner cavity of the turntable base 1, a lower seal cover 5 fixed at the bottom of the turntable base 1, and a rotating shaft 3 rotatably connected in the hydrostatic bearing 2 and penetrating downward through the lower seal cover 5. Among them, upper and lower stepped portions are formed on the rotating shaft 3 at both ends of the hydrostatic bearing 2, and a thrust ring 4 that axially supports the hydrostatic bearing 2 together with the upper stepped portion is fixed on the lower stepped portion. In this embodiment, the upper end of the rotating shaft 3 is fixedly connected to the worktable. To realize the rotation of the rotating shaft 3, a motor rotor 16 and a motor stator 18 are provided outside one end of the rotating shaft 3 that penetrates downward through the lower seal cover 5. The motor rotor 16 is connected to the rotating shaft 3 as a whole through a rotor gland 17. The motor stator 18 is embedded in a stator outer sleeve 19 and is fixed to the lower seal cover 5 together with the stator outer sleeve 19. Preferably, an encoder 21 is further provided at the end position of the rotating shaft 3. The encoder 21 is locked and fixed to the rotating shaft 3 through a lock nut 20, thereby realizing the fixed-angle rotation of the rotating shaft 3.
[0023] As Figure 4 shown, an oil inlet 101 and an oil return port 102 penetrating through to the inner cavity are provided on the turntable base 1. As Figure 2 shown, an annular oil inlet groove 201 communicating with the oil inlet 101 on the turntable base 1 is provided outside the hydrostatic bearing 2. As Figure 1 shown, an oil return cavity 103 communicating with the oil return port 102 on the turntable base 1 is formed between the outside of the thrust ring 4 and the inner side of the turntable base 1. As Figure 2 and Figure 3As shown, a number of upper grooves 202 and lower grooves 203 which are distributed in a vertically staggered manner are evenly arranged along the circumferences of the upper and lower end faces of the hydrostatic bearing 2. In this embodiment, the upper grooves 202 and the lower grooves 203 are sector-shaped grooves, and the number of each is 4, and they are arranged at equal intervals on the end faces of the hydrostatic bearing 2; upper bosses 6 and lower bosses 7 are formed in the upper grooves 202 and the lower grooves 203 respectively, and first throttle oil channels 602 communicating with the lower grooves 203 and the upper grooves 202 at corresponding positions and first oil inlet channels 601 communicating with the annular oil inlet groove 201 are respectively formed on the upper bosses 6 and the lower bosses 7. Specifically, the first throttle oil channels 602 and the lower grooves 203 / upper grooves 202 are communicated in an axial channel manner, and the first oil inlet channels 601 and the annular oil inlet groove 201 are communicated in a manner that a radial channel intersects with an axial channel; a number of side grooves 204 are arranged along the circumference on the inner side of the hydrostatic bearing 2. In this embodiment, the number of the side grooves 204 is 4, and they are arranged in a centrosymmetric manner on the inner side of the hydrostatic bearing 2, and are respectively denoted as a first side groove, a second side groove, a third side groove, and a fourth side groove in the clockwise direction; side bosses 8 are formed in the side grooves 204, and second throttle oil channels 802 communicating with the side grooves 204 at adjacent / alternate positions and second oil inlet channels 801 communicating with the annular oil inlet groove 201 are formed on the side bosses 8; specifically, in order to reduce the processing difficulty of the connection of the lateral oil channels, a number of arc-shaped feedback oil channels 206 are provided on the outer side of the hydrostatic bearing 2. One end of each of the arc-shaped feedback oil channels 206 is communicated with the second throttle oil channel 802 of any one of the side bosses 8, and the other end is communicated with the side groove 204 at the adjacent / alternate position of the side boss 8. The above connections are all in a radial channel manner. Preferably, in order to ensure the stability of the oil film force in the lateral feedback unit, the arc-shaped feedback oil channels 206 are semi-ring-shaped feedback oil channels, and they communicate the side grooves 204 and the second throttle oil channels 802 at the alternate positions (i.e., the opposite positions).
[0024] An upper oil cavity 9, a lower oil cavity 10 and a side oil cavity 11 are respectively formed between the upper groove 202 and the upper step portion of the rotating shaft 3, between the lower groove 203 and the thrust ring 4, and between the side groove 204 and the rotating shaft 3. The hydrostatic bearing 2 is provided with an oil return channel 205 for communicating the upper oil cavity 9, the lower oil cavity 10 and the side oil cavity 11 with the oil return cavity 103.
[0025] By forming an upper groove 202, a lower groove 203 and a side groove 204 on the end face and the inner side of the hydrostatic bearing 2 respectively, and forming an upper boss 6, a lower boss 7 and a side boss 8 in the corresponding grooves, oil is fed into the oil inlet channels of each boss through the annular oil inlet groove 201 on the outer side of the hydrostatic bearing 2, and the oil reaching the surface of the boss is fed back to the corresponding different grooves through the throttle oil channels. Thus, an upper oil cavity 9 with an axial feedback function is formed between the upper groove 202 of the hydrostatic bearing 2 and the upper stepped portion of the rotating shaft 3, and a lower oil cavity 10 with an axial feedback function is formed between the lower groove 203 of the hydrostatic bearing 2 and the thrust ring 4. A side oil cavity 11 with a radial feedback function is formed between the side groove 204 of the hydrostatic bearing 2 and the rotating shaft 3. Oil films are formed in each oil cavity and can perform self-adjusting feedback of oil pressure according to the pressure received. The setting of this built-in feedback structure ensures the compactness of the entire rotary table. At the same time, the two-way feedback in the radial and axial directions effectively avoids eccentric wear of the rotating shaft 3 and improves the rotary accuracy and service life.
[0026] In order to further improve the stability of the oil film formed in each oil cavity, the number of the first oil inlet channels 601 on each of the upper bosses 6 and each of the lower bosses 7 is two, symmetrically distributed on both sides of the first throttle oil channel 602, and the number of the second oil inlet channels 801 on each of the side bosses 8 is two, symmetrically distributed on both sides of the second throttle oil channel 802 respectively.
[0027] As Figure 2 and Figure 3 shown, the oil return channel 205 is arranged radially on the end face of the hydrostatic bearing 2 between the adjacent upper grooves 202 / lower grooves 203. Both ends of the oil return channel 205 are communicated with the inner and outer sides of the hydrostatic bearing 2 respectively. The oil return channels 205 on the upper and lower end faces of the hydrostatic bearing 2 are communicated through the oil return holes 207. Thus, the oil return in the upper oil cavity 9 passes through the oil return hole 207 and returns to the oil return cavity 103 together with the oil return in the side oil cavity 11 and the lower oil cavity 10 through the oil return channel 205 on the lower end face of the hydrostatic bearing 2, and then is discharged through the oil return port 102 to realize the recovery of the oil fluid.
[0028] Further preferably, as Figure 1 shown, an adjusting gasket 12 is provided between the thrust ring 4 and the lower stepped portion of the rotating shaft 3. By selecting adjusting gaskets 12 with different widths, the floating amount of the turntable axially relative to the rotating shaft 3 is controlled to adapt to the strong load-bearing capacity of the rotary table itself.
[0029] In order to prevent the oil fluid in the oil return cavity 103 from overflowing outside the lower sealing cover 5, the surface of the lower sealing cover 5 is in sealed contact with the turntable base 1 through an O-ring 14. At the same time, in order to prevent the oil fluid from overflowing along the rotating shaft 3, the inner end of the lower sealing cover 5 is rotationally sealed with the rotating shaft 3 through a sealing ring 13.
[0030] Further preferably, asFigure 1 As shown, a ring-shaped baffle 15 is fixed to the top of the turntable base 1, and a ring-shaped groove 301 which is in clearance fit with the ring-shaped baffle 15 is formed on the upper step portion of the rotating shaft 3. By arranging the ring-shaped baffle 15 on the top of the turntable base 1, cutting fluid can be prevented from entering the interior of the hydrostatic bearing 2, ensuring the normal operation of the rotary table.
[0031] When implementing the above technical solution, as Figure 5As shown in the figure, the internal feedback principle of the entire rotary table is as follows: A path of hydraulic oil enters the upper boss 6 inside the upper oil cavity 9 along path A through the annular oil inlet groove 201, and after throttling through the first throttling oil passage 602 on the upper boss 6, it enters the lower oil cavity 10 corresponding to the lower groove 203. Another path of hydraulic oil enters the lower boss 7 inside the lower oil cavity 10 along path B, and after throttling through the first throttling oil passage 602 on the lower boss 7, it enters the upper oil cavity 9 corresponding to the upper groove 202, forming an axial closed static pressure structure. According to the actual load capacity required by the worktable, a regulating gasket 12 with a corresponding thickness is selected. At this time, the heights of both the upper oil cavity 9 and the lower oil cavity 10 are h0. When a workpiece is placed on the worktable and under the action of gravity G, a gap change value of △h0 is generated. At this time, the pressure in the upper oil cavity 9 increases due to the decrease in the gap value (decreasing to h0 - △h0). At the same time, the pressure loss on the first throttling oil passage 602 at the lower boss 7 inside the lower oil cavity 10 decreases due to the increase in the gap value, making the pressure entering the upper oil cavity 9 greater; similarly, the pressure in the lower oil cavity 10 decreases due to the increase in the gap value (increasing to h0 + △h0). At the same time, the pressure loss on the first throttling oil passage 602 at the upper boss 6 inside the upper oil cavity 9 increases due to the decrease in the gap value, making the pressure entering the lower oil cavity 10 smaller, realizing the axial feedback self-regulation effect and enabling the rotating shaft 3 to reach a stable working state axially. A path of hydraulic oil enters the first side boss inside the side oil cavity 11 along path C through the annular oil inlet groove 201 and enters the opposite third side groove through the second throttling oil passage 802. Another path of hydraulic oil enters the third side boss along path D and enters the first side groove through the second throttling oil passage 802, forming a radial closed static pressure structure. In the state without lateral force, there is a gap h1 between the static pressure bearing 2 and the rotating shaft 3. When the rotating shaft 3 is subjected to a leftward pulling force F, a gap change value of △h1 is generated. At this time, the gap value between the first side groove and the rotating shaft 3 decreases (decreasing to h1 - △h1), resulting in an increase in the pressure in the oil cavity at that place. At the same time, the pressure loss on the second throttling oil passage 802 at the third side boss decreases due to the increase in the gap value, making the pressure entering the first side groove greater; similarly, the gap value between the third side groove and the rotating shaft 3 increases (increasing to h1 + △h1), resulting in a decrease in the pressure in the oil cavity at that place. At the same time, the pressure loss on the second throttling oil passage 802 at the first side boss increases due to the decrease in the gap value, making the pressure entering the third side groove smaller, realizing the radial feedback self-regulation effect and enabling the rotating shaft 3 to reach a stable working state radially. The entire machine tool rotary table has the advantages of compact structure, strong load-bearing capacity, high rotary accuracy, and long service life under the action of the internal feedback structure.
[0032] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims
1. Inner feedback rotary worktable for machine tool, comprising a turntable base, a hydrostatic bearing fixed inside the turntable base, a lower seal cover fixed at the bottom of the turntable base, and a rotating shaft rotatably connected inside the hydrostatic bearing and extending downward through the lower seal cover. Upper and lower stepped portions are formed on the rotating shaft at both ends of the hydrostatic bearing. A thrust ring is fixed on the lower stepped portion and axially supports the hydrostatic bearing together with the upper stepped portion. It is characterized in that, An annular oil inlet groove communicating with the oil inlet on the turntable base is provided on the outer side of the hydrostatic bearing. An oil return cavity communicating with the oil return port on the turntable base is formed between the outer side of the thrust ring and the inner side of the turntable base. A plurality of upper grooves and lower grooves are uniformly arranged along the circumferences of the upper and lower end faces of the hydrostatic bearing in a vertically staggered distribution. Upper bosses and lower bosses are formed in the upper grooves and the lower grooves respectively. First throttle oil channels communicating with the lower grooves and the upper grooves at corresponding positions, and first oil inlet channels communicating with the annular oil inlet groove are formed on the upper bosses and the lower bosses respectively. A plurality of side grooves are arranged along the circumference on the inner side of the hydrostatic bearing. Side bosses are formed in the side grooves. Second throttle oil channels communicating with the side grooves at adjacent / alternate positions, and second oil inlet channels communicating with the annular oil inlet groove are formed on the side bosses. Upper oil cavities, lower oil cavities and side oil cavities are respectively formed between the upper grooves and the upper step portions, between the lower grooves and the thrust ring, and between the side grooves and the rotating shaft. An oil return channel for communicating the upper oil cavity, the lower oil cavity and the side oil cavity with the oil return cavity is provided on the hydrostatic bearing.
2. The internal feedback rotary table for machine tools according to claim 1, characterized in that, The number of the first oil inlet channels on each of the upper bosses and the lower bosses is two, symmetrically distributed on both sides of the first throttle oil channel. The number of the second oil inlet channels on each of the side bosses is two, respectively symmetrically distributed on both sides of the second throttle oil channel.
3. The internal feedback rotary table for machine tools according to claim 1, characterized in that, A plurality of arc-shaped feedback oil channels are provided on the outer side of the hydrostatic bearing. One end of each of the arc-shaped feedback oil channels communicates with the second throttle oil channel of any one of the side bosses, and the other end communicates with the side groove at the adjacent / alternate position of the side boss.
4. The internal feedback rotary table for machine tools according to claim 1, characterized in that, The oil return channel is arranged radially on the end face of the hydrostatic bearing between the adjacent upper grooves / lower grooves. Both ends of the oil return channel communicate with the inner and outer sides of the hydrostatic bearing respectively. The oil return channels on the upper and lower end faces of the hydrostatic bearing are communicated through oil return holes.
5. The internal feedback rotary table for machine tools according to any one of claims 1-4, characterized in that, An adjusting gasket is provided between the thrust ring and the lower step portion of the rotating shaft.
6. The internal feedback rotary table for machine tools according to any one of claims 1-4, characterized in that, The surface of the lower sealing cover is in sealed contact with the turntable base through an O-ring, and the inner end of the lower sealing cover is in rotational sealing with the rotating shaft through a sealing ring.
7. The internal feedback rotary table for machine tools according to any one of claims 1-4, characterized in that An annular baffle is fixed on the top of the turntable base. An annular groove in clearance fit with the annular baffle is formed on the upper step portion of the rotating shaft.
8. The internal feedback rotary table for machine tools according to any one of claims 1-4, characterized in that, A motor rotor and a motor stator are provided on the outer side of one end of the rotating shaft penetrating out of the lower sealing cover. The motor rotor is connected to the rotating shaft as a whole through a rotor gland. The motor stator is embedded in a stator outer sleeve and is fixed on the lower sealing cover together with the stator outer sleeve.
9. The internal feedback rotary table for machine tools according to claim 8, characterized in that, It includes an encoder. The encoder is locked on the end of the rotating shaft through a lock nut to realize the fixed-angle rotation of the rotating shaft.