Gap eliminating mechanism for large-span gear and rack transmission of machine tool

Abstract

The utility model relates to a clearance eliminating mechanism for large-span gear and rack transmission of a machine tool, and belongs to the technical field of machine tools. According to the utility model, the meshing clearance between the gear and the rack is eliminated, the contact between the gear and the rack is tighter, so that the purpose of gapless transmission is achieved, error accumulation caused by the clearance is effectively reduced, and meanwhile, the clearance eliminating assembly can be adaptively adjusted to adapt to the clearance change of the gear and the rack caused by abrasion or temperature change; dynamic compensation of the gap between the gear and the rack is achieved, maintenance cost is reduced, accuracy and stability of transmission of a machine tool are improved, and vibration and noise are effectively reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of machine tools, and particularly relates to a clearance elimination mechanism for large-span gear-rack transmission of a machine tool. Background Technique

[0002] In the field of machining, the ball screw drive has its significant advantages as a drive for short-span machine tools. However, during horizontal transmission, for some machine tools with long-distance transmission, the screw is relatively long, and natural sagging and bending will occur to varying degrees in the middle of the screw. Due to the advantages of simple structure and high transmission efficiency of the gear-rack transmission mechanism, therefore, the large-span transmission structure of some machine tools adopts the gear-rack structure for transmission.

[0003] However, during the long-term use of the gear-rack, wear will occur due to the relative sliding and impact between the gear and the rack. As the wear intensifies, the clearance at the meshing part of the gear-rack gradually increases, which will lead to a decrease in transmission accuracy and affect the machining quality of workpieces. At the same time, the clearance will cause impact and vibration during the transmission of the gear-rack, thereby causing noise problems. In addition, workers need to regularly maintain and replace the gear-rack, increasing the maintenance cost. Content of the Utility Model

[0004] In order to overcome the problem that the clearance at the meshing part of the gear-rack gradually increases during the long-term use in the background technique, which will lead to a decrease in transmission accuracy and affect the machining quality of workpieces. At the same time, the clearance will cause impact and vibration during the transmission of the gear-rack, thereby causing noise problems. In addition, workers need to regularly maintain and replace the gear-rack, increasing the maintenance cost, the utility model provides a clearance elimination mechanism for large-span gear-rack transmission of a machine tool; it can eliminate the clearance of the gear-rack meshing, make the contact between the gear and the rack closer, so as to achieve the purpose of gapless transmission, effectively reduce the error accumulation caused by the clearance. At the same time, the clearance elimination component can be adaptively adjusted to adapt to the clearance change of the gear-rack caused by wear or temperature change, realizing the dynamic compensation of the gear-rack clearance, reducing the maintenance cost, improving the accuracy and stability of the machine tool transmission, and effectively reducing vibration and noise.

[0005] To achieve the above object, the utility model is realized through the following technical solutions: A clearance elimination mechanism for large-span gear-rack transmission of a machine tool mainly includes a rack, a gear, a speed reducer, a motor, a clearance elimination component, and a carriage. The rack is installed on the side wall of the machine tool. At the four corners of the top of the carriage, first guide rods are provided. The carriage is slidably installed at the bottom of the carriage of the machine tool through the first guide rods. The top of the first guide rod is threadedly connected with a limit nut. A speed reducer is installed in the carriage. The motor is installed on the speed reducer, and the motor is in transmission connection with the speed reducer. A gear meshing with the rack is installed on the output shaft of the speed reducer, and the gear is located directly above the rack. A clearance elimination component for eliminating the meshing clearance between the rack and the gear is installed at the bottom end of the carriage.

[0006] The clearance elimination component includes a connecting block, a wedge-shaped cushion block, a second guide rod, and a top spring. Connecting blocks are installed on the left and right side walls of the machine tool carriage. Through holes for fixing and guiding the longitudinal movement of the wedge-shaped cushion block are provided on the connecting blocks. A second guide rod is provided at the end of the wedge-shaped cushion block. The wedge-shaped cushion block is slidably installed on the connecting block through the second guide rod. The top surface of the wedge-shaped cushion block contacts the bottom surface of the machine tool carriage, and the bottom surface contacts the top surface of the carriage. One end of the second guide rod penetrates through the through hole of the wedge-shaped cushion block and is threadedly connected with a limit nut. A top spring is sleeved on the second guide rod. One end of the top spring abuts against the end of the wedge-shaped cushion block, and the other end abuts against the end of the connecting block.

[0007] The length of the wedge-shaped cushion block is greater than the length of the carriage.

[0008] The rack is a helical rack, and the gear is a helical gear. The helical gear meshes with the helical rack.

[0009] The beneficial effects of the utility model:

[0010] The utility model eliminates the meshing clearance between the gear and the rack, making the contact between the gear and the rack closer, thereby achieving the purpose of backlash-free transmission, effectively reducing the error accumulation caused by the clearance. At the same time, the clearance elimination component can be adjusted adaptively to adapt to the clearance change of the gear and the rack due to wear or temperature change, realizing the dynamic compensation of the gear and rack clearance, reducing the maintenance cost, improving the accuracy and stability of the machine tool transmission, and effectively reducing vibration and noise. Description of the Drawings

[0011] Figure 1 It is an isometric view of the utility model.

[0012] Figure 2 It is a three-dimensional schematic diagram of the installation state of the utility model.

[0013] Figure 3 It is a planar schematic diagram of the installation state of the clearance elimination component.

[0014] Figure 4 This is the exploded view of the utility model. Detailed implementation manners

[0015] In order to make the purpose, technical solutions and beneficial effects of the utility model clearer, the preferred embodiments of the utility model will be described in detail below with reference to the accompanying drawings for the convenience of technicians to understand.

[0016] The utility model discloses a clearance elimination mechanism for a large-span gear-rack transmission of a machine tool. The clearance elimination mechanism for a large-span gear-rack transmission of a machine tool mainly includes a rack 1, a gear 2, a speed reducer 3, a motor 4, a clearance elimination component 5, and a carriage 6. The rack 1 is installed on the side wall of the machine tool. First guide rods 601 are provided at the four corners of the top end of the carriage 6. The carriage 6 is slidably installed at the bottom of the carriage of the machine tool through the first guide rods 601. The top ends of the first guide rods 601 are threadedly connected with limit nuts. A speed reducer 3 is installed in the carriage 6. The motor 4 is installed on the speed reducer 3. The motor 4 is in transmission connection with the speed reducer 3. A gear 2 meshing with the rack 1 is installed on the output shaft of the speed reducer 3. The gear 2 is located directly above the rack 1. A clearance elimination component 5 for eliminating the meshing clearance between the rack 1 and the gear 2 is installed at the bottom end of the carriage. The clearance elimination component 5 includes a connection block 501, a wedge-shaped pad 502, a second guide rod 503, and a top spring 504. Connection blocks 501 are installed on the left and right side walls of the machine tool carriage. Through holes for fixing and guiding the longitudinal movement of the wedge-shaped pad 502 are provided on the connection blocks 501. A second guide rod 503 is provided at the end of the wedge-shaped pad 502. The wedge-shaped pad 502 is slidably installed on the connection block 501 through the second guide rod 503. The top surface of the wedge-shaped pad 502 contacts the bottom surface of the machine tool carriage, and the bottom surface contacts the top surface of the carriage 6. One end of the second guide rod 503 penetrates through the through hole of the wedge-shaped pad 502 and is threadedly connected with a limit nut. A top spring 504 is sleeved on the second guide rod 503. One end of the top spring 504 abuts against the end of the wedge-shaped pad 502, and the other end abuts against the end of the connection block 501.

[0017] During the working process of the machine tool, the motor 4 drives the gear 2 to rotate through the speed reducer 3, further driving the apron 6 to move linearly along the rack 1, thereby driving the apron and the tool post to move and machining the workpiece. When the gap is generated between the gear 2 and the rack 1 due to wear, the wedge-shaped cushion block 502 can axially move along the second guide rod 503 under the elastic force of the tightening spring 504, further tightening the apron 6, so that the speed reducer 3 inside the apron 6 moves downward, thereby filling the gap between the gear 2 and the rack 1. The pre-tightening force of the tightening spring 504 enables the wedge-shaped cushion block 502 to always maintain the pressing state on the gear 2 and the rack 1. When new gaps appear between the gear 2 and the rack 1 due to wear or temperature change, the wedge-shaped cushion block 502 can also automatically adjust its position through the pressure of the tightening spring 504 to maintain the pressing force to adapt to the change of the gap, thereby maintaining the close contact between the gear 2 and the rack 1, realizing the dynamic compensation of the gap between the gear 2 and the rack 1, ensuring the transmission accuracy, and avoiding the error accumulation caused by the gap. Since the gap is effectively eliminated, the relative sliding between the gear 2 and the rack 1 during the transmission process is reduced, so the impact and vibration are also reduced, thereby reducing the noise.

[0018] The length of the wedge-shaped cushion block 502 is greater than the length of the apron 6; a longer contact surface can be provided, and a larger supporting area can be provided when contacting with the apron 6, reducing the local pressure, thereby enhancing the stability of the whole structure.

[0019] The rack 1 is a helical rack, and the gear 2 is a helical gear, and the helical gear meshes with the helical rack; the helical gear and the helical rack help to reduce the axial clearance and improve the rigidity and accuracy of the transmission.

[0020] Working process:

[0021] During the working process of the machine tool, the motor 4 drives the gear 2 to rotate through the speed reducer 3, further driving the apron 6 to move linearly along the rack 1, thereby driving the apron and the tool post to move and machining the workpiece. When the gap is generated between the gear 2 and the rack 1 due to wear, the wedge-shaped cushion block 502 can axially move along the second guide rod 503 under the elastic force of the tightening spring 504, further tightening the apron 6, so that the speed reducer 3 inside the apron 6 moves downward, thereby filling the gap between the gear 2 and the rack 1. The pre-tightening force of the tightening spring 504 enables the wedge-shaped cushion block 502 to always maintain the pressing state on the gear 2 and the rack 1. When new gaps appear between the gear 2 and the rack 1 due to wear or temperature change, the wedge-shaped cushion block 502 can also automatically adjust its position through the pressure of the tightening spring 504 to maintain the pressing force to adapt to the change of the gap, thereby maintaining the close contact between the gear 2 and the rack 1, realizing the dynamic compensation of the gap between the gear 2 and the rack 1, ensuring the transmission accuracy, and avoiding the error accumulation caused by the gap. Since the gap is effectively eliminated, the relative sliding between the gear 2 and the rack 1 during the transmission process is reduced, so the impact and vibration are also reduced, thereby reducing the noise.

[0022] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A clearance elimination mechanism for a large-span gear rack transmission of a machine tool, characterized in that: The clearance elimination mechanism of a large-span rack and pinion transmission of a machine tool comprises a rack (1), a gear (2), a reducer (3), a motor (4), a clearance elimination component (5), and a slide box (6). The rack (1) is mounted on the side wall of the machine tool. First guide rods (601) are arranged at the four corners of the top of the reducer slide box (6). The slide box (6) is slidably mounted on the bottom of the slide of the machine tool through the first guide rods (601). The top of the first guide rod (601) is threadedly connected to a limit nut. The reducer (3) is installed in the slide box (6). The motor (4) is installed on the reducer (3). The motor (4) is connected to the reducer (3) in a transmission manner. A gear (2) meshing with the rack (1) is installed on the output shaft of the reducer (3). The gear (2) is located directly above the rack (1). The bottom of the slide is equipped with a clearance elimination component (5) for eliminating the meshing clearance between the rack (1) and the gear (2).

2. A clearance elimination mechanism for a large-span gear rack transmission of a machine tool as claimed in claim 1, characterized in that: The gap elimination assembly (5) comprises a connecting block (501), a wedge-shaped pad (502), a second guide rod (503), and a tightening spring (504). The connecting blocks (501) are installed on the left and right side walls of the machine tool slide. The connecting blocks (501) are provided with through holes for fixing and guiding the longitudinal movement of the wedge-shaped pad (502). The end of the wedge-shaped pad (502) is provided with a second guide rod (503). The wedge-shaped pad (502) is connected to the second guide rod (503) by the second guide rod (504). 3) Slidingly mounted on the connecting block (501), the top surface of the wedge-shaped pad (502) contacts the bottom surface of the machine tool slide, and the bottom surface contacts the top surface of the slide box (6), one end of the second guide rod (503) passes through the through hole of the wedge-shaped pad (502) and is threadedly connected to the limit nut, and a tightening spring (504) is sleeved on the second guide rod (503), one end of the tightening spring (504) is tightly pressed against the end of the wedge-shaped pad (502), and the other end is tightly pressed against the end of the connecting block (501).

3. A clearance elimination mechanism for a large-span rack and pinion transmission of a machine tool as claimed in claim 2, characterized in that: The length of the wedge-shaped pad (502) is greater than the length of the slide box (6).

4. A clearance elimination mechanism for a large-span gear rack transmission of a machine tool as claimed in claim 1, characterized in that: The rack (1) is a helical rack, the gear (2) is a helical gear, and the helical gear and the helical rack are meshed with each other.

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