A linear motor direct drive worktable with safety protection device

Abstract

This utility model relates to a linear motor direct drive worktable with a safety protection device. The utility model includes a linear guide rail mounted on the machine tool bed; a worktable body with a slider slidably connected to the linear guide rail at its bottom; a linear motor including a primary and a secondary component, the primary component mounted at the bottom of the worktable body and the secondary component mounted on the machine tool bed; a linear encoder ruler mounted on the machine tool bed and extending along the sliding direction of the worktable body; an encoder ruler reading head mounted on the worktable body corresponding to the linear encoder ruler; a first and a second limit buffer device, respectively mounted on the machine tool bed and located on opposite sides of the worktable body's moving direction; and a braking device mounted on the slider. This utility model achieves high-speed, stable, and safe linear motion of the worktable.

Description

Technical Field

[0001] This utility model relates to the field of workbench technology, and in particular to a workbench with a linear motor direct drive and a safety protection device. Background Technology

[0002] Currently, large surface grinders, guideway grinders, and gantry machining centers often have long worktables, requiring high table movement speeds, generally exceeding 15-20 meters per minute, to ensure good machining quality and efficiency. Traditional structures use long hydraulic cylinders or servo motors to drive long ball screw transmissions.

[0003] The disadvantages of this structure are as follows: With a long cylinder, the piston rod is difficult to machine due to its length, making it hard to guarantee straightness. Long-term operation leads to wear and oil leakage, resulting in decreased accuracy. Furthermore, the cylinder cannot be stopped mid-operation or precisely positioned, limiting its application. Conversely, using a servo motor to drive a long ball screw requires a higher rotational speed due to its length. This results in significant screw sag due to gravity and large runout at high speeds, making the screw prone to damage and resulting in poor accuracy retention. Summary of the Invention

[0004] Therefore, this utility model provides a linear motor direct drive worktable with a safety protection device. The primary component of the linear motor is installed at the bottom of the worktable body, and the secondary component is installed on the machine tool bed, realizing high-speed linear motion of the worktable. Compared with the traditional hydraulic cylinder drive or servo motor drive ball screw structure, it avoids the defects of long hydraulic cylinders such as difficult manufacturing of piston rods, difficulty in ensuring accuracy, easy wear and oil leakage, inability to stop midway and precise positioning, etc. At the same time, it overcomes the problems of long screws such as sag due to gravity, easy damage at high speed, and poor accuracy retention.

[0005] To solve the above-mentioned technical problems, this utility model provides a worktable with a linear motor direct drive and a safety protection device, comprising:

[0006] Linear guide rails are mounted on the machine tool bed;

[0007] The workbench body has a slider that is slidably connected to the linear guide rail at its bottom;

[0008] A linear motor includes a corresponding primary component and a secondary component. The primary component is mounted on the bottom of the worktable body, and the secondary component is mounted on the machine tool bed.

[0009] A linear grating ruler is disposed on the machine tool bed and extends along the sliding direction of the worktable body; a grating ruler reading head is installed on the worktable body corresponding to the linear grating ruler;

[0010] The first limiting buffer device and the second limiting buffer device are respectively disposed on the machine tool bed and located on both sides of the moving direction of the worktable body;

[0011] A braking device, mounted on the slider, is used to cooperate with the linear guide rail to generate braking force.

[0012] In one embodiment of this utility model, the secondary component of the linear motor is a multi-plate structure.

[0013] In one embodiment of this utility model, the linear guide rails are provided with two parallel rails, and the secondary component of the linear motor is disposed between the two linear guide rails.

[0014] In one embodiment of this utility model, the slider interval is provided in multiple sets.

[0015] In one embodiment of the present invention, the first limiting buffer device includes a first bracket and a first hydraulic limiting buffer threadedly connected to the first bracket.

[0016] In one embodiment of the present invention, the second limiting buffer device includes a second bracket and a second hydraulic limiting buffer threadedly connected to the second bracket.

[0017] In one embodiment of this utility model, the braking device is a guide rail clamp.

[0018] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art:

[0019] This utility model discloses a linear motor-driven worktable with a safety protection device. A linear motor is installed between the bed and the worktable to drive the worktable at high speed, avoiding wear. A linear encoder is installed between the bed and the worktable to control the motion accuracy of the worktable. The linear motor achieves contactless drive of the worktable, eliminating mechanical friction between primary and secondary components, enabling high-speed, fast-response, and wear-free linear motion. Combined with the linear encoder and reading head, real-time precise detection and feedback of position achieve fully closed-loop control of the motion process, ensuring high precision and high dynamic performance.

[0020] This invention addresses the lack of self-feedback safety protection in linear motors, which pose a risk of "runaway" if the control unit fails or loses power. The invention incorporates a braking device (rail clamp) on the slider that engages with the linear guide rail. Under normal conditions, this device is in a released state; in the event of a malfunction, it immediately clamps the guide rail, providing a mechanical emergency brake and ensuring forced safety braking to prevent the worktable from flying off due to inertia and causing damage to equipment and personnel. Furthermore, by installing a first limiting buffer device and a second limiting buffer device (hydraulic limiting buffer) on both sides of the worktable body, end-point buffering protection is achieved under extreme operating conditions, effectively absorbing the inertial impact of the worktable and further enhancing safety performance. Attached Figure Description

[0021] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0022] Figure 1 This is a front view of the linear motor direct drive and the worktable with safety protection device of this utility model.

[0023] Figure 2 This is a side view of the linear motor direct drive and the worktable with safety protection device of this utility model.

[0024] Figure 3 This is a top view of the linear motor direct drive and the worktable with safety protection device of this utility model.

[0025] Explanation of reference numerals on the accompanying drawings:

[0026] 1. Machine tool bed; 30a. First limit buffer device; 30b. Second limit buffer device; 2. First support; 3. First hydraulic limit buffer; 4. Worktable body; 5. Second support; 6. Second hydraulic limit buffer; 7. Linear motor secondary component; 8. Linear motor primary component; 9. Linear grating ruler; 10. Linear guide rail; 11. Slider; 12. Braking device. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0028] In this utility model, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this utility model, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.

[0029] In this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number; "above," "below," "within," etc. are understood to include the stated number. In the description of this utility model, if "first" or "second" is used, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0030] In this utility model, unless otherwise explicitly defined, terms such as "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model based on the specific content of the technical solution.

[0031] Reference Figures 1 to 3 As shown, the present invention relates to a linear motor direct drive and a worktable with a safety protection device, comprising:

[0032] Linear guide 10 is mounted on the machine tool bed 1;

[0033] The workbench body 4 has a slider 11 that is slidably connected to the linear guide rail 10 at its bottom;

[0034] The linear motor includes a corresponding primary component 8 and a secondary component 7. The primary component 8 is mounted on the bottom end of the worktable body 4, and the secondary component 7 is mounted on the machine tool bed 1. The primary component 8 can generate a changing magnetic field to drive the secondary component to perform linear motion.

[0035] A linear grating ruler 9 is disposed on the machine tool bed 1 and extends along the sliding direction of the worktable body 4; a grating ruler reading head is installed on the worktable body 4 corresponding to the linear grating ruler 9.

[0036] The first limiting buffer device 30a and the second limiting buffer device 30b are respectively disposed on the machine tool bed 1 and located on both sides of the moving direction of the worktable body 4;

[0037] Braking device 12, mounted on slider 11, is used to cooperate with linear guide rail 10 to generate braking force.

[0038] It should be noted that existing linear motors have the disadvantage of not being able to self-feedback control their motion state and must be used in conjunction with an external control unit. If the external control unit fails or the equipment suddenly loses power, it can easily cause a "runaway" phenomenon, often with serious consequences. This restricts the safe use of linear motors at high speeds. With the above setup, when the worktable body 4 needs to move, the CNC system continuously supplies current and voltage to the primary component 8 of the linear motor, generating magnetic levitation thrust. The primary component 8 and the secondary component 7 of the linear motor do not contact each other, preventing wear, thus enabling high-speed response motion. A precision linear encoder 9 transmits the precise position and movement process of the worktable to the system in real time, achieving high-speed, high-precision, and backlash-free movement. When the linear encoder 9 suddenly malfunctions, the CNC system immediately applies an emergency brake upon failing to acquire the position signal from the linear encoder 9. Simultaneously, the braking device 12 mechanically clamps the guide rail to ensure the emergency safety braking of the worktable body 4, preventing a "runaway" phenomenon. Limit buffering is also provided by the first limit buffer device 30a and the second limit buffer device 30b installed on both sides of the worktable body 4.

[0039] In one embodiment, the secondary component 7 of the linear motor is a multi-plate structure, bolted to the lathe bed. The number can be selected according to the thrust and effective stroke. Furthermore, the gap between the primary component 8 and the secondary component 7 of the linear motor is adjusted by adjusting the shims to ensure that the linear motor generates a stable and continuous thrust after being energized.

[0040] Understandably, the primary component 8 of the linear motor is the stator, i.e., the coil assembly, while the secondary component 7 is the mover, i.e., the magnetic pole plate. The permanent magnet is supported and fixed by a supporting base, ensuring uniform magnetic field distribution and structural rigidity. The secondary component 7 is designed as several independent flat plate structures, each of which can function as a separate secondary component and can be combined with others. By increasing the number of flat plate structures, each can provide a certain driving force; the overall thrust increases exponentially after multiple sets are stacked, thus flexibly adapting to different load levels.

[0041] In addition, the linear grating ruler 9 is installed inside the linear guide rail 10, and the grating ruler reading head is installed inside the workbench via a mounting bracket.

[0042] In one embodiment, the linear guide rail 10 has two parallel rails, and the linear motor secondary component 7 is disposed between the two linear guide rails 10.

[0043] In one embodiment, multiple sets (specifically 8-12 sets) of sliders 11 are spaced apart. A set of braking devices 12 corresponding to the linear guide rail 10 is installed inside the rightmost set of sliders 11. The braking device 12 is a guide rail clamp. This structural design fully considers the needs of large surface grinders, guide rail grinders, gantry machining centers, and other applications requiring large strokes and high speeds.

[0044] In one embodiment, the first limiting buffer device 30a includes a first bracket 2 and a first hydraulic limiting buffer 3 threadedly connected to the first bracket 2; the second limiting buffer device 30b includes a second bracket 5 and a second hydraulic limiting buffer 6 threadedly connected to the second bracket 5.

[0045] During operation, the primary component 8 and secondary component 7 of the linear motor, installed between the machine tool bed 1 and the worktable body 4, generate a continuous and stable thrust. The worktable body 4 slides along the linear guide rail 10, and the movement is controlled by a linear grating ruler 9 that measures accuracy. When the machine tool is working normally, the worktable body 4 often needs to move at high speed. The CNC system controls the linear motor to generate a continuous thrust, propelling the worktable body 4 to move at high speed. Its speed and position are detected and fed back in real time by the linear grating ruler 9, and precise random feedback adjustments are made. When the linear grating ruler 9 malfunctions and cannot function properly, and the system cannot collect the signal from the linear grating ruler 9, the CNC system assumes a machine tool malfunction and must immediately stop at the current position. Since the worktable body 4 may experience this malfunction during high-speed movement, and the worktable body 4 has significant inertia, the CNC system needs to perform emergency braking on the linear motor and use a guide rail clamp to clamp the guide rail to prevent runaway. Multiple protections are provided by the first limit buffer device 30a and the second limit buffer device 30b (hydraulic limit buffer) installed on both sides of the worktable body 4. This workbench features a simple and reliable structure, low processing and manufacturing costs, easy implementation, stable performance, high precision, and long service life. It ensures both high rigidity and high precision, as well as flexible adjustment convenience.

[0046] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although this utility model has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A worktable with a linear motor direct drive and a safety protection device, characterized in that, include: Linear guide (10) is mounted on the machine tool bed (1); The workbench body (4) has a slider (11) that is slidably connected to the linear guide rail (10) at its bottom. The linear motor includes a corresponding primary component (8) and a secondary component (7). The primary component (8) is installed at the bottom of the worktable body (4), and the secondary component (7) is installed on the machine tool bed (1). A linear grating ruler (9) is disposed on the machine tool bed (1) and extends along the sliding direction of the worktable body (4); a grating ruler reading head is installed on the worktable body (4) corresponding to the linear grating ruler (9); The first limiting buffer device (30a) and the second limiting buffer device (30b) are respectively disposed on the machine tool bed (1) and located on both sides of the moving direction of the worktable body (4); A braking device (12) is mounted on the slider (11) and is used to cooperate with the linear guide (10) to generate braking force.

2. A linear motor direct drive workbench with a safety protection device according to claim 1, characterized in that, The linear motor secondary component (7) has multiple flat plate structures.

3. A workbench with a linear motor direct drive and a safety protection device according to claim 1, characterized in that, The linear guide (10) has two parallel rails, and the linear motor secondary component (7) is located between the two linear guides (10).

4. A linear motor direct drive workbench with a safety protection device according to claim 1, characterized in that, The slider (11) is provided in multiple sets at intervals.

5. A linear motor direct drive workbench with a safety protection device according to claim 1, characterized in that, The first limiting buffer device (30a) includes a first bracket (2) and a first hydraulic limiting buffer (3) threadedly connected to the first bracket (2).

6. A linear motor direct drive workbench with a safety protection device according to claim 1, characterized in that, The second limiting buffer device (30b) includes a second bracket (5) and a second hydraulic limiting buffer (6) threaded onto the second bracket (5).

7. A linear motor direct drive workbench with a safety protection device according to claim 1, characterized in that, The braking device (12) is a guide rail clamp.

Images