Self-anti-backlash gear rotary table

Abstract

The utility model discloses a self-anti-backlash gear rotary table, which belongs to the technical field of numerical control machine tools and comprises a body base, a working table is arranged above the body base, an anti-backlash gear box is fixedly mounted on the side surface of the working table, two combined bearings are clamped in the anti-backlash gear box, gears are rotatably mounted in the combined bearings, and the gears are rotatably mounted on the body base. A crossed roller bearing is fixedly installed on the workbench, a gear ring is fixedly installed on the outer surface of the crossed roller bearing, and the gear ring is used in cooperation with a gear. By arranging the crossed roller bearing, the gear, the main worm, the main worm gear, the auxiliary worm and the auxiliary worm gear to be matched with the disc spring for use, the crossed roller bearing has extremely high rotation precision and rigidity, and meanwhile, the gear ring with the high precision grade is integrated on the outer ring of the bearing, so that the rotary table is more compact in structure and very convenient to install and maintain; the main worm and the auxiliary worm are connected through a sliding key and are used in cooperation with a disc spring, so that a transmission gap is eliminated, and the workbench is accurately divided.

Description

Technical Field

[0001] The utility model belongs to the technical field of numerically controlled machine tools, and particularly relates to a self-backlash eliminating gear turntable. Background Art

[0002] The CNC rotary table is a common component of CNC milling machines, often serving as a servo axis, namely the C-axis of vertical CNC milling machines and the B-axis of horizontal CNC milling machines. As the B-axis, the CNC rotary table is a key functional component of CNC horizontal machining centers and CNC boring and milling machines. Through the rotation and indexing of the CNC rotary table, the machine tool can complete the machining of complex workpieces with holes, curved surfaces, and curves at various angles. CNC rotary tables generally use a dual-lead worm gear for indexing. Dual-lead worm gears can eliminate backlash by varying the worm tooth thickness, and are widely used in indexing mechanisms.

[0003] The worm gears used in large CNC rotary tables are difficult to manufacture, requiring expensive copper alloys for the worm gears, and increasing the table's rotational speed is difficult. Using a small gear ring indexing system for large-scale rotary tables can reduce costs and increase table lifespan and rotational speed, but this requires eliminating gear transmission backlash to meet the requirements of CNC rotary tables. Previous developments of gear rotary tables suffered from numerous drawbacks, including difficult ring gear machining, complex structures, high production costs, and inconvenient backlash adjustment. Therefore, a self-backlash-eliminating gear rotary table was urgently needed to address these issues. Utility Model Content

[0004] The purpose of the present utility model is to provide a self-clearing gear turntable to solve the difficulties in manufacturing the worm gear of the large CNC rotary table mentioned in the above background technology. The worm gear requires expensive copper alloy and the turntable speed is difficult to increase. The large-scale turntable adopts a small gear ring indexing to reduce costs and increase the turntable life and speed, but the clearance of the gear transmission must be eliminated to meet the use requirements of the CNC turntable. The early development of gear turntable products has many shortcomings such as difficulty in processing the gear ring, complex structure, high production cost, and inconvenient gap adjustment.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a self-eliminating gear turntable, comprising a main body base, a workbench is arranged above the main body base, an anti-backlash gear box is fixedly installed on the side of the workbench, two combined bearings are clamped in the anti-backlash gear box, a gear is rotatably installed in the combined bearing, a cross-roller bearing is fixedly installed on the workbench, a gear ring is fixedly installed on the outer surface of the cross-roller bearing, the gear ring is used in conjunction with the gear, a servo motor is fixedly installed on the side of the anti-backlash gear box, a main worm and a secondary worm are rotatably installed inside the anti-backlash gear box, the main worm and the secondary worm are used in conjunction with each other, the output shaft of the servo motor is fixedly connected to the main worm, and the outer surfaces of the wheel axles of the two gears are respectively fixedly installed with a main worm wheel and a secondary worm wheel, a braking mechanism is provided on the main body base, and an anti-backlash element is provided on the secondary worm.

[0006] By adopting the above scheme, through setting up crossed roller bearings, gears, main worm, main worm wheel, auxiliary worm, and auxiliary worm wheel in conjunction with disc springs, the crossed roller bearings have extremely high rotation accuracy and rigidity. At the same time, the outer ring of the bearing is integrated with a gear ring with a high precision grade, making the turntable structure more compact and very convenient for installation and maintenance. The main worm and auxiliary worm are connected by a sliding key and used in conjunction with disc springs to eliminate transmission clearance and enable accurate indexing of the workbench.

[0007] As a preferred embodiment, an encoder is fixedly mounted on the body base, and the encoder is specifically a high-precision angle encoder.

[0008] The above solution has high production requirements because the indexing accuracy of the gear turntable is limited by the accuracy of the gear ring. In order to ensure the economy of the product, an absolute encoder is used for closed-loop control, and a high-precision angle encoder is matched inside the turntable to make the overall indexing accuracy of the turntable reach the advanced level at home and abroad.

[0009] As a preferred embodiment, a sliding key is provided at one end of the main worm and the auxiliary worm that are close to each other, and the main worm and the auxiliary worm are connected via the sliding key.

[0010] With the above solution, the setting of the sliding key can ensure the effective connection between the main worm and the auxiliary worm, so that the main worm and the auxiliary worm can rotate synchronously, and the movement stability effect is good.

[0011] As a preferred embodiment, the braking mechanism includes a plurality of hydraulic clamping cylinders, and the hydraulic clamping cylinders are connected and controlled by external pressure oil delivery pipelines.

[0012] The above solution uses multiple hydraulic clamping cylinders to form a braking mechanism, which can achieve heavy-load cutting. It is driven by external pressure oil, and a reversing valve is configured in the hydraulic system to control the conversion of the oil direction. The hydraulic station ensures zero back pressure and generally uses a two-position three-way reversing valve.

[0013] As a preferred embodiment, the anti-backlash element is specifically a disc spring, and both ends of the disc spring respectively conflict with the inner wall of the anti-backlash gear box and one end of the auxiliary worm.

[0014] The above scheme is adopted, and the disc spring is used as the anti-backlash element. The force generated by the disc spring always acts on the auxiliary worm, so that the auxiliary worm is always in close contact with the auxiliary worm wheel at the same side, and the force is transmitted to the gear at the same side. The gear at the same side applies a counterclockwise thrust to the ring gear at the same side, so that the ring gear at the other side applies a counterclockwise thrust to the gear at the other side, and then the force of the gear at the other side is transmitted to the main worm wheel at the other side, ensuring that the main worm wheel at the other side is also in single-sided contact with the main worm at the other side. The force of the disc spring is used to eliminate the transmission gap and make the workbench accurately indexed.

[0015] As a preferred embodiment, the module of the ring gear on the cross roller bearing is the same as the module of the gear.

[0016] By adopting the above solution, by setting the module of the ring gear to be the same as the module of the gear, stable rotation and good rotation effect are achieved.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] The self-eliminating gear turntable is equipped with crossed roller bearings, gears, main worm, main worm wheel, auxiliary worm, and auxiliary worm wheel in conjunction with disc springs. The crossed roller bearings have extremely high rotation accuracy and rigidity. At the same time, the outer ring of the bearing is integrated with a gear ring with a high precision grade, making the turntable structure more compact and very convenient to install and maintain. The main worm and auxiliary worm are connected by a sliding key and used in conjunction with disc springs to eliminate transmission clearance and enable accurate indexing of the worktable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the utility model;

[0020] Figure 2 This is a schematic diagram of the structure of the side cross-section of the utility model;

[0021] Figure 3 It is a schematic diagram of the structure of the utility model in a top view.

[0022] In the figure: 1. Main body base; 2. Cross roller bearing; 3. Workbench; 4. Encoder; 5. Gear; 6. Combined bearing; 7. Braking mechanism; 8. Servo motor; 9. Main worm; 10. Main worm gear; 11. Slide key; 12. Auxiliary worm; 13. Disc spring; 14. Auxiliary worm gear. DETAILED DESCRIPTION

[0023] See also Figure 1-3 The utility model provides a self-eliminating gear turntable, including a main body base 1, a workbench 3 is provided above the main body base 1, an anti-backlash gear box 5 is fixedly installed on the side of the workbench 3, two combined bearings 6 are clamped in the anti-backlash gear box 5, and a gear 5 is rotatably installed in the combined bearing 6, a cross roller bearing 2 is fixedly installed on the workbench 3, a gear ring is fixedly installed on the outer surface of the cross roller bearing 2, and the gear ring is used in conjunction with the gear 5, a servo motor 8 is fixedly installed on the side of the anti-backlash gear box 5, a main worm 9 and a sub-worm 12 are rotatably installed inside the anti-backlash gear box 5, the main worm 9 and the sub-worm 12 are used in conjunction with each other, the output shaft of the servo motor 8 is fixedly connected to the main worm 9, and a main worm gear 10 and a sub-worm gear 14 are respectively fixedly installed on the outer surfaces of the wheel axles of the two gears 5, a braking mechanism 7 is provided on the main body base 1, and an anti-backlash element is provided on the sub-worm 12.

[0024] By arranging the crossed roller bearing 2, gear 5, main worm 9, main worm wheel 10, auxiliary worm 12, auxiliary worm wheel 14 in conjunction with the disc spring 13, the crossed roller bearing 2 has extremely high rotation accuracy and rigidity. At the same time, the outer ring of the bearing is integrated with a gear ring with a high precision grade, making the turntable structure more compact and very convenient to install and maintain. The main worm 9 and auxiliary worm 12 are connected by a sliding key 11 and used in conjunction with the disc spring 13, thereby eliminating the transmission gap and making the workbench 3 accurately indexed.

[0025] An encoder 4 is fixedly installed on the base of the main body. The encoder 4 is specifically a high-precision angle encoder 4. Since the indexing accuracy of the gear turntable is limited by the accuracy of the gear ring, the production requirements are relatively high. For the economy of the product, closed-loop control is performed in conjunction with the absolute value encoder 4. The high-precision angle encoder 4 is matched inside the turntable to make the overall indexing accuracy of the turntable reach the advanced level at home and abroad.

[0026] A sliding key 11 is provided at one end of the main worm 9 and the auxiliary worm 12 that are close to each other. The main worm 9 and the auxiliary worm 12 are connected by the sliding key 11. The setting of the sliding key 11 can ensure the effective connection between the main worm 9 and the auxiliary worm 12, so that the main worm 9 and the auxiliary worm 12 can rotate synchronously, and the movement stability effect is good.

[0027] The braking mechanism 7 includes several hydraulic clamping cylinders, which are connected and controlled by external pressure oil delivery pipelines. The braking mechanism 7 is composed of multiple hydraulic clamping cylinders, which can achieve heavy-load cutting and is driven by external pressure oil. A reversing valve is configured in the hydraulic system to control the conversion of the oil direction. The hydraulic station ensures zero back pressure and generally adopts a two-position three-way reversing valve.

[0028] The anti-backlash element is specifically a disc spring 13, and the two ends of the disc spring 13 respectively conflict with the inner wall of the anti-backlash gear box 5 and one end of the auxiliary worm 12. The disc spring 13 is used as an anti-backlash element. The force generated by the disc spring 13 always acts on the auxiliary worm 12, so that the auxiliary worm 12 is always in close contact with the auxiliary worm wheel 14 at the same side position, and the force is transmitted to the gear 5 at the same side position. The gear 5 at the same side position applies a counterclockwise thrust to the ring gear at the same side position, so that the ring gear at the other side position applies a counterclockwise thrust to the gear 5 at the other side position, and then the gear 5 at the other side position is subjected to force and transmitted to the main worm wheel 10 at the other side position, ensuring that the main worm wheel 10 at the other side position is also in unilateral contact with the main worm 9 at the other side position. Through the force of the disc spring 13, the transmission gap is eliminated, and the workbench 3 is accurately indexed.

[0029] The module of the ring gear on the cross roller bearing 2 is the same as the module of the gear 5. By setting the module of the ring gear to be the same as the module of the gear 5, stable rotation is achieved with good rotation effect.

[0030] When in use, the servo motor 8 drives the main worm 9, and the main worm 9 and the auxiliary worm 12 are connected by the sliding key 11 to realize synchronous rotation. The main worm 9 and the auxiliary worm 12 are respectively engaged with the main worm wheel 10 and the auxiliary worm wheel 14. The main worm wheel 10 and the auxiliary worm wheel 14 are both coaxially connected to the gear 5. The gear 5 is engaged with the gear ring on the surface of the cross roller bearing 2 to drive the workbench 3 to rotate, and during the working process, the force generated by the disc spring 13 always acts on the auxiliary worm 12, so that the auxiliary worm 12 is always in contact with the auxiliary worm wheel 14 at the same side. The gear 5 at the same side applies a counterclockwise thrust to the ring gear at the same side, so that the ring gear at the other side applies a counterclockwise thrust to the gear 5 at the other side, and the force of the gear 5 at the other side is transmitted to the main worm gear 10 at the other side, ensuring that the main worm gear 10 at the other side is also in single-sided contact with the main worm 9 at the other side. The transmission gap is eliminated through the force of the disc spring 13, so that the workbench 3 can be accurately indexed.

Claims

1. Self-backlash-eliminating gear turntable, characterized by: The invention comprises a main body base (1), a workbench (3) is arranged above the main body base (1), a backlash elimination gear (5) box is fixedly installed on the side of the workbench (3), two combined bearings (6) are clamped in the backlash elimination gear (5) box, a gear (5) is rotatably installed in the combined bearing (6), a cross roller bearing (2) is fixedly installed on the workbench (3), a gear ring is fixedly installed on the outer surface of the cross roller bearing (2), the gear ring is used in conjunction with the gear (5), a servo motor (8) is fixedly installed on the side of the backlash elimination gear (5) box, and the backlash elimination gear (5) is fixedly installed on the side of the workbench (3). A main worm (9) and a secondary worm (12) are rotatably mounted inside the wheel (5) box. The main worm (9) and the secondary worm (12) are used in conjunction with each other. The output shaft of the servo motor (8) is fixedly connected to the main worm (9). The outer surfaces of the wheel shafts of the two gears (5) are respectively fixedly mounted with a main worm gear (10) and a secondary worm gear (14). A braking mechanism (7) is provided on the main body base (1), and an anti-backlash element is provided on the secondary worm gear (12). An encoder (4) is fixedly mounted on the main body base, and the encoder (4) is specifically a high-precision angle encoder (4).

2. The self-backlash eliminating gear turntable according to claim 1, characterized in that: A sliding key (11) is provided at one end of the main worm (9) and the auxiliary worm (12) that are close to each other, and the main worm (9) and the auxiliary worm (12) are connected via the sliding key (11).

3. The self-backlash eliminating gear turntable according to claim 1, characterized in that: The braking mechanism (7) comprises a plurality of hydraulic clamping oil cylinders, and the hydraulic clamping oil cylinders are connected and controlled by external pressure oil delivery pipelines.

4. The self-backlash eliminating gear turntable according to claim 1, characterized in that: The anti-backlash element is specifically a disc spring (13), and the two ends of the disc spring (13) respectively conflict with the inner wall of the anti-backlash gear (5) box and one end of the auxiliary worm (12).

5. The self-backlash eliminating gear turntable according to claim 1, characterized in that: The gear ring on the cross roller bearing (2) has a module that is the same as the module of the gear (5).

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