An adaptive eccentric adjustment electric spindle

Abstract

The present invention relates to an electric spindle with adaptive eccentricity adjustment, comprising: a motor, a spindle connected to a motor rotor, a bearing mechanism, and an adaptive eccentricity adjustment mechanism, three in number, symmetrically arranged on the spindle, for compensating for the eccentricity of the spindle rotation; a vibration sensor, arranged outside the bearing mechanism, for obtaining vibration parameters of the eccentric rotation of the spindle; the adaptive eccentricity adjustment mechanism comprises a folding counterweight mechanism, a screw mechanism for driving the counterweight mechanism to fold, and a small electric spindle for driving the screw mechanism to rotate the screw. The adaptive eccentricity adjustment mechanism is adopted, so that the electric spindle of the present invention can be adjusted in real time, and is always in a state of dynamically balancing the vibration of the spindle, especially as the eccentricity generated gradually changes with the processing of the workpiece, the adaptive eccentricity adjustment mechanism of the present invention can be adaptively balanced according to the actual situation, with better adjustment efficiency and accuracy, thus improving the processing efficiency and processing accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of electric spindles, and in particular relates to an electric spindle with self-adaptive eccentricity adjustment. Background Art

[0002] The electric spindle is a new technology that integrates the machine tool spindle and the spindle motor. Its application in the field of CNC machine tools has promoted the development of high-speed processing technology. Electric spindles are widely used in precision processing equipment such as CNC machine tools, lathes, milling machines, grinders, etc., especially in the automotive manufacturing, aerospace, mold manufacturing and other industries. The advantages of electric spindles include high speed, high precision, low noise, low vibration, and the ability to achieve stepless speed regulation and fast start and stop.

[0003] In the prior art, the spindle of the electric spindle rotates, the spindle drives the chuck to rotate, and the workpiece is clamped on the chuck. If the workpiece is irregular in shape, its center of gravity is difficult to determine. In order to avoid vibration caused by the offset between the center of gravity of the workpiece and the rotation axis of the spindle, the worker needs to adjust the workpiece multiple times when clamping, and needs to start the machine to determine whether there is an offset by observation, and then re-clamp it based on experience. This adjustment efficiency is relatively low.

[0004] Sometimes, the workpiece needs to be processed eccentrically, so eccentric clamping should be considered when clamping. At this time, the spindle will be affected by the eccentricity when rotating and produce vibration, which is not good for the spindle. It will not only affect the working accuracy of the electric spindle, but also affect the service life of the electric spindle. Summary of the invention

[0005] The present invention solves the problem that the coincidence between the center of gravity of the workpiece and the axis of rotation cannot be ensured when the workpiece is clamped in the prior art, and multiple adjustments are required, the adjustment efficiency is relatively low, and the adjustment cannot completely overcome the eccentricity, which easily causes the electric spindle to vibrate, affecting the working accuracy and service life of the electric spindle. An electric spindle with adaptive eccentricity adjustment is provided. An adaptive adjustment mechanism is provided on the electric spindle, which can actively generate eccentricity, thereby balancing the eccentricity generated after the workpiece is clamped, so as to eliminate the vibration of the electric spindle, ensure processing accuracy, and extend the service life of the electric spindle.

[0006] The present invention also solves the problem in the prior art that when the workpiece needs eccentric machining, the electric spindle needs to withstand adverse factors such as vibration caused by eccentricity, which affects the working accuracy and service life of the electric spindle. An electric spindle with adaptive eccentricity adjustment is provided. By arranging an adaptive adjustment mechanism on the electric spindle, eccentricity can be actively generated, thereby balancing the vibration of the electric spindle rotation, ensuring machining accuracy and extending the service life of the electric spindle.

[0007] The specific technical solution of the present invention is: an electric spindle with adaptive eccentricity adjustment, comprising:

[0008] A motor, used to provide power for rotation;

[0009] The main shaft is connected to the motor rotor and is used to transmit torque and rotational motion;

[0010] A bearing mechanism, connected to the main shaft, used to support the rotation of the main shaft;

[0011] Adaptive eccentricity adjustment mechanisms, three in number, symmetrically arranged on the main shaft, used to compensate for the eccentricity of the main shaft rotation;

[0012] A vibration sensor is arranged outside the bearing mechanism to obtain vibration parameters of the eccentric rotation of the main shaft;

[0013] The self-adaptive eccentricity adjustment mechanism comprises a foldable counterweight mechanism, a screw mechanism for driving the counterweight mechanism to fold, and a small electric spindle for driving the screw of the screw mechanism to rotate.

[0014] Three adaptive eccentricity adjustment mechanisms are symmetrically arranged on the spindle. Once the vibration sensor detects the vibration caused by the eccentric rotation of the spindle, it can automatically adjust to form an eccentric counterweight on the spindle, thereby compensating for the eccentricity of the spindle, balancing the vibration of the spindle, ensuring the processing accuracy, and extending the service life of the electric spindle; adaptive means that the eccentricity adjustment mechanism of the present invention is a real-time adjustment, which is always balancing the vibration of the spindle. In particular, as the eccentricity generated gradually changes with the processing of the workpiece, the adaptive eccentricity adjustment mechanism of the present invention can be balanced according to the actual situation, with better adjustment efficiency and accuracy, thereby improving the processing efficiency and the processing accuracy; the adaptive eccentricity adjustment mechanism adopts three, which can basically cover the eccentricity of the spindle and balance the vibrations generated by different phase angles; the adaptive eccentricity adjustment mechanism of the present invention mainly adopts the method of changing the distance between the center of gravity of the counterweight and the spindle Therefore, a foldable counterweight mechanism is adopted. The overall weight of the counterweight does not change, but the radius of the combined center of gravity relative to the axis of rotation of the spindle can be changed by folding at different angles. The folding of the counterweight mechanism is driven by a screw mechanism, and the rotation of the screw of the screw mechanism is driven by a small electric spindle. The small electric spindle is a miniature electric spindle, and it is also an electric spindle itself. Therefore, the advantages of the electric spindle make it very suitable for driving the rotation of the screw of the screw mechanism; the power supply of the small electric spindle can be obtained by means of brushes, and the control signal of the small electric spindle can be transmitted in a variety of ways. In particular, the small electric spindle itself has an encoder, so the control will be simpler and the adjustment accuracy can be guaranteed; the screw mechanism, as the folding drive of the counterweight mechanism, can achieve high-precision adjustment, and at the same time, a self-locking is formed after adjustment to avoid changes in the combined center of gravity of the counterweight mechanism outside the adjustment during the rotation of the spindle.

[0015] Preferably, the counterweight mechanism includes a counterweight plate and a support plate, the first end of the counterweight plate is hinged to the main shaft, the first end of the support plate is hinged to the screw mechanism, the second end of the counterweight plate is hinged to the second end of the support plate, and the connecting line of the hinge points at both ends of the counterweight plate intersects with the connecting line of the hinge points at both ends of the support plate. The connecting line of the hinge points at both ends of the counterweight plate and the connecting line of the hinge points at both ends of the support plate are not on the same straight line, so as to avoid the folding force from being unable to drive the counterweight mechanism to fold, and ensure smooth adjustment.

[0016] Preferably, the center of gravity of the counterweight plate and the center of gravity of the support plate are symmetrical relative to the hinged portion of the two. After the counterweight plate and the support plate are hinged, the combined center of gravity of the two is located on the radial surface of the main shaft corresponding to the hinged portion of the two. The center of gravity of the counterweight plate and the support plate is symmetrical, so that the combined center of gravity of the two is located on the radial surface of the hinged portion of the two on the main shaft, which is convenient for controlling the small electric spindle.

[0017] Preferably, a groove is provided in the middle of the counterweight plate, the groove is open toward the second end of the hinged support plate, hinge holes are provided on both sides of the groove at the second end, a rotating shaft is provided at the second end of the support plate, and the end of the rotating shaft matches the hinge hole. The groove is used to reduce the weight of the counterweight plate and is also convenient for hinge connection with the end of the support plate.

[0018] Preferably, the screw mechanism includes a screw and a moving block, the axis of the screw is parallel to the axis of the spindle, one end of the screw is connected to the rotor of the small electric spindle, the moving block has a threaded hole, and the moving block is screwed on the screw.

[0019] Preferably, the outer surface of the main shaft is provided with three symmetrical installation grooves, the installation grooves are arranged axially relative to the main shaft, and the adaptive eccentricity adjustment mechanism is arranged in the installation grooves.

[0020] Preferably, the cross-sectional shape of the bottom of the mounting groove is an arc shape, and the bottom of the movable block is an arc shape; a small electric spindle mounting hole is provided at one end of the mounting groove, and a screw bearing mounting hole is provided at the other end of the mounting groove, a screw bearing is provided in the screw bearing mounting hole, and the end of the screw is supported by the screw bearing.

[0021] Preferably, a sliding groove is provided near the groove opening on the two groove walls of the installation groove, the length of the sliding groove is arranged along the axial direction of the main shaft, and sliding columns adapted to the sliding groove are arranged on both sides of the moving block. The sliding groove guides the movement of the moving block and limits the movement of the moving block to ensure the moving direction and position of the moving block.

[0022] Preferably, the upper wall of the slide groove is evenly distributed with a plurality of locking grooves, the shape of the locking grooves matches the outer shape of the slide column, and the depth of the locking grooves is less than 0.8 mm. The locking grooves can limit and lock the moving block to prevent the moving block from moving during the rotation of the main shaft.

[0023] Preferably, the moving block includes a moving block body and a U-shaped seat arranged on the moving block body. The moving block body is provided with a plug-in slot with a lock, a spring is arranged in the plug-in slot, a connecting column is arranged at the bottom of the U-shaped seat, the connecting column is inserted into the plug-in slot, and a sliding column is arranged on both sides of the U-shaped seat. The U-shaped seat and the moving block body are elastically connected through the spring, and the sliding column can cooperate with the locking slot, while the locking slot will not hinder the movement of the moving block.

[0024] The beneficial effects of the present invention are as follows: 1. Three adaptive eccentricity adjustment mechanisms are symmetrically arranged on the spindle. Once the vibration sensor detects the vibration caused by the eccentric rotation of the spindle, it can automatically adjust to form an eccentric counterweight on the spindle, thereby compensating for the eccentricity of the spindle, balancing the vibration of the spindle, ensuring the processing accuracy, and extending the service life of the electric spindle;

[0025] 2. The adaptive eccentricity adjustment mechanism is adopted, so that the electric spindle of the present invention can be adjusted in real time and is always in a state of dynamically balancing the spindle vibration. In particular, as the workpiece is processed, the eccentricity generated gradually changes. The adaptive eccentricity adjustment mechanism of the present invention can perform adaptive balancing according to actual conditions, with better adjustment efficiency and accuracy, thus improving processing efficiency and processing accuracy.

[0026] 3. The present invention adopts three symmetrical adaptive eccentricity adjustment mechanisms, which can basically cover the eccentricity of the main shaft and balance the vibrations generated by different phase angles;

[0027] 4. The adaptive eccentricity adjustment mechanism of the present invention adopts a foldable counterweight mechanism. The overall weight of the counterweight does not change, but the radius of the combined center of gravity relative to the main shaft rotation axis can be changed by different folding angles, making the adjustment more convenient;

[0028] 5. The folding of the counterweight mechanism is driven by a screw mechanism, and the screw rotation of the screw mechanism is driven by a small electric spindle, which makes full use of the advantages of the electric spindle, making the control simpler and ensuring the accuracy of adjustment;

[0029] 6. The screw mechanism, as the folding drive of the counterweight mechanism, can achieve high-precision adjustment. At the same time, it forms a self-locking after adjustment to avoid the combined center of gravity of the counterweight mechanism from changing beyond the adjustment during the rotation of the spindle;

[0030] 7. Regardless of whether the workpiece is clamped eccentrically or needs to be processed eccentrically, the use of the electric spindle of the present invention can balance the vibration caused by the eccentricity, ensure the processing accuracy, and extend the service life of the processing equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the present invention;

[0032] Figure 2 It is a structural schematic diagram of an adaptive eccentricity adjustment mechanism of the present invention;

[0033] Figure 3 It is a structural schematic diagram of a support plate of the present invention;

[0034] Figure 4 It is a structural schematic diagram of a counterweight plate of the present invention;

[0035] Figure 5 It is a structural schematic diagram of a mounting groove on a main shaft of the present invention;

[0036] Figure 6 It is a schematic diagram of an adjustment state of the present invention;

[0037] Figure 7 is a schematic structural diagram of a second moving block of the present invention;

[0038] Figure 8 It is a schematic diagram of the structure of the second type of mounting groove on the main shaft of the present invention;

[0039] In the figure: 1. motor, 2. bearing mechanism, 3. spindle, 4. mounting groove, 5. adaptive eccentric adjustment mechanism, 6. chuck, 7. vibration sensor, 401. sliding groove, 402. locking groove, 501. small electric spindle, 502. sliding column, 503. hinge groove, 504. support plate, 505. counterweight plate, 506. rotating shaft, 507. screw bearing, 508. screw, 509. moving block, 510. rotating shaft, 511. groove, 512. hinge hole, 513. U-shaped seat, 514. lock mouth, 515. limit plate, 516. spring, 517. moving block body, 518. connecting column. DETAILED DESCRIPTION

[0040] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings. Example

[0041] like Figure 1 As shown, an electric spindle with adaptive eccentric adjustment includes: a motor 1 for providing rotational power, a spindle 3 connected to the motor rotor, and a bearing mechanism 2 connected to the spindle for supporting the spindle rotation. Three adaptive eccentric adjustment mechanisms 5 are symmetrically arranged on the spindle. A vibration sensor 7 for obtaining vibration parameters of the eccentric rotation of the spindle is arranged outside the bearing mechanism, and a chuck 6 for clamping a workpiece is arranged at the end of the spindle.

[0042] like Figure 5As shown, the outer surface of the main shaft is provided with three symmetrical mounting grooves 4, which are spaced 120° apart from each other, and are arranged axially relative to the main shaft, and the adaptive eccentric adjustment mechanism is arranged in the mounting groove. The bottom of the mounting groove is in an arc shape, and a small electric spindle mounting hole is arranged at one end of the mounting groove, and a screw bearing mounting hole is arranged at the other end of the mounting groove, and a screw bearing 507 is arranged in the screw bearing mounting hole. Sliding grooves 401 are arranged near the notch on the two groove walls of the mounting groove, and the length of the sliding groove is arranged along the axial direction of the main shaft, and the notches of the two sliding grooves are opposite.

[0043] like Figure 2 Figure 3 Figure 4 As shown, the adaptive eccentric adjustment mechanism 5 includes a foldable counterweight mechanism, a screw mechanism for driving the counterweight mechanism to fold, and a small electric spindle 501 for driving the screw of the screw mechanism to rotate.

[0044] The counterweight mechanism includes a counterweight plate 505 and a support plate 504. The counterweight plate and the support plate are hinged, and the center of gravity of the counterweight plate and the center of gravity of the support plate are symmetrical relative to the hinged position of the two. After the counterweight plate and the support plate are hinged, the combined center of gravity of the two is located on the radial plane of the main axis corresponding to the hinged position of the two. Alternatively, the counterweight plate and the support plate adopt the same structure, and the counterweight plate and the support plate form a symmetrical structure.

[0045] A rotating shaft 506 is provided on both sides of the first end of the counterweight plate, a rotating hole is provided on the groove wall corresponding to the rotating shaft in the installation groove of the main shaft, the rotating shaft is inserted into the rotating hole and hinged with the main shaft, a groove 511 is provided in the middle part of the counterweight plate, the groove is open toward the second end of the hinged support plate, and hinge holes 512 are provided on both sides of the groove at the second end. A rotating shaft 510 is provided on the first and second ends of the support plate, the first end of the support plate is hinged to the screw mechanism through the rotating shaft, the second end of the counterweight plate is hinged to the second end of the support plate, the two ends of the rotating shaft at the second end of the support plate are hinged to the hinge holes on both sides of the groove at the second end of the counterweight plate, and the connecting line of the hinge points at both ends of the counterweight plate intersects with the connecting line of the hinge points at both ends of the support plate.

[0046] The screw mechanism includes a screw 508 and a moving block 509. The axis of the screw is parallel to the axis of the main shaft. One end of the screw is connected to the rotor of the small electric main shaft 501, and the other end of the screw is connected to the screw bearing 507. The moving block has a threaded hole, and the moving block is screwed on the screw. The bottom of the moving block is an arc shape that matches the arc bottom of the installation groove. The upper part of the moving block is provided with a hinge groove 503, and the two sides of the hinge groove are provided with axial holes that match the two ends of the rotating shaft of the first end of the support plate. The upper two sides of the moving block are provided with protruding sliding columns 502. After the moving block and the screw thread are matched, the sliding columns are inserted into the sliding grooves on both sides of the installation groove.

[0047] like Figure 6As shown, after the workpiece is initially observed and judged, it is clamped on the chuck, and the motor 1 drives the spindle 3 to rotate. When the spindle rotates, the spindle vibrates due to the eccentricity. The vibration sensor monitors the vibration parameters of the spindle, the amplitude and limit angle of the spindle, and the angular frequency of the spindle rotation. At this time, the eccentricity of the spindle center can be obtained. The three adaptive eccentricity adjustment mechanisms on the spindle are spaced 120° apart from each other. The three positions are set to 0°, 120° and 240° respectively. In this way, the eccentricity of each of the three positions on the spindle can be calculated, and the respective eccentricities are transmitted to the corresponding small electric spindle 501. The small electric spindle starts and drives the screw 508 to rotate. After the screw rotates, it drives the moving block 509 to move, and the support plate and the counterweight plate are folded with each other, so that the center of gravity of the combination moves to the required eccentric position to ensure smooth rotation of the electric spindle. Example

[0048] An electric spindle with adaptive eccentricity adjustment is different from the embodiment 1 in that Figure 7 Figure 8 As shown, the adaptive eccentric adjustment mechanism is equipped with a locking structure.

[0049] The upper wall of the sliding groove is continuously and evenly distributed with a plurality of locking grooves 402, the shape of the locking grooves is adapted to the outer shape of the sliding column, and the depth of the locking grooves is 0.5 mm. The moving block includes a moving block body 517, a U-shaped seat 513 arranged on the moving block body, a plug-in slot with a lock 514 is arranged on the moving block body, a spring 516 is arranged in the plug-in slot, a connecting column 518 is arranged at the bottom of the U-shaped seat, and a limiting plate 515 is arranged at the end of the connecting column, the size of the limiting plate is adapted to the size of the plug-in slot, and the limiting plate is used to prevent the U-shaped seat from separating from the moving block body, the connecting column is inserted into the plug-in slot, and the sliding column is arranged on both sides of the U-shaped seat. The threaded hole matching the screw rod is arranged on the moving block body.

[0050] The small electric spindle drives the screw to rotate. When the screw drives the moving block to move, the slide column slides in the slide groove. After reaching the required position, the U-shaped seat is raised under the action of the spring, and the slide column cooperates with the corresponding locking groove. Due to the arbitrariness of the moving position of the moving block, the position of the slide column relative to the locking groove exists in multiple states, and sometimes it is not completely matched. Under the centrifugal force of the spindle rotation, the moving block can be locked through the cooperation of the locking groove and the slide column to ensure the stable position of the moving block. The rest of the structure refers to Example 1.

[0051] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. An electric spindle with adaptive eccentricity adjustment, characterized in that: include: A motor (1) for providing rotational power; A main shaft (3) connected to the motor rotor for transmitting torque and rotational motion; A bearing mechanism (2) connected to the main shaft and used to support the rotation of the main shaft; Three adaptive eccentricity adjustment mechanisms (5) are symmetrically arranged on the main shaft and are used to compensate for the eccentricity of the main shaft rotation; A vibration sensor (7) is arranged outside the bearing mechanism and is used to obtain vibration parameters of the eccentric rotation of the main shaft; The adaptive eccentric adjustment mechanism comprises a foldable counterweight mechanism, a screw mechanism for driving the counterweight mechanism to fold, and a small electric spindle (501) for driving the screw mechanism to rotate. The counterweight mechanism comprises a counterweight plate (505) and a support plate (504); the first end of the counterweight plate is hinged to the main shaft, the first end of the support plate is hinged to the screw mechanism, the second end of the counterweight plate is hinged to the second end of the support plate, and the connecting line of the hinge points at both ends of the counterweight plate intersects with the connecting line of the hinge points at both ends of the support plate; the center of gravity of the counterweight plate and the center of gravity of the support plate are symmetrical relative to the hinged position of the two, and after the counterweight plate and the support plate are hinged, the combined center of gravity of the two is located on the radial surface of the main shaft corresponding to the hinged surface of the two.

2. The electric spindle with adaptive eccentricity adjustment according to claim 1, characterized in that: A groove (511) is provided in the middle of the counterweight plate, the groove is open toward the second end of the hinged support plate, hinge holes (512) are provided on both sides of the groove at the second end, a rotating shaft is provided at the second end of the support plate, and the ends of the rotating shaft are matched with the hinge holes.

3. The electric spindle with adaptive eccentricity adjustment according to claim 1, characterized in that: The screw mechanism comprises a screw (508) and a moving block (509), the axis of the screw is parallel to the axis of the main shaft, one end of the screw is connected to the rotor of the small electric main shaft, the moving block has a threaded hole, and the moving block is screwed on the screw.

4. An electric spindle with adaptive eccentricity adjustment according to claim 1 or 2, characterized in that: The outer surface of the main shaft is provided with three symmetrical installation grooves (4), the installation grooves are arranged axially relative to the main shaft, and the self-adaptive eccentricity adjustment mechanism is arranged in the installation grooves.

5. The electric spindle with adaptive eccentricity adjustment according to claim 4, characterized in that: The cross-sectional shape of the bottom of the mounting groove is an arc shape, and the bottom of the moving block is an arc shape; a small electric spindle mounting hole is arranged at one end of the mounting groove, and a screw bearing mounting hole is arranged at the other end of the mounting groove. A screw bearing is arranged in the screw bearing mounting hole, and the end of the screw is supported by the screw bearing.

6. The electric spindle with adaptive eccentricity adjustment according to claim 5, characterized in that: Sliding grooves (401) are arranged on the two groove walls of the installation groove near the groove opening, the length of the sliding groove is arranged along the axial direction of the main shaft, and sliding columns (502) adapted to the sliding grooves are arranged on both sides of the moving block.

7. The electric spindle with adaptive eccentricity adjustment according to claim 6, characterized in that: The upper wall of the sliding groove is evenly distributed with a plurality of locking grooves (402), the shape of the locking grooves is adapted to the outer shape of the sliding column, and the depth of the locking grooves is less than 0.8 mm.

8. The electric spindle with adaptive eccentricity adjustment according to claim 7, characterized in that: The moving block comprises a moving block body (517) and a U-shaped seat (513) arranged on the moving block body. The moving block body is provided with a plug-in slot with a lock (514), a spring (516) is arranged in the plug-in slot, a connecting column (518) is arranged at the bottom of the U-shaped seat, the connecting column is inserted into the plug-in slot, and sliding columns are arranged on both sides of the U-shaped seat.

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