Gear and rack meshing mechanism for eliminating transmission clearance

Abstract

The invention provides a gear and rack meshing mechanism capable of eliminating a transmission gap. The gear and rack meshing mechanism comprises a machine tool, a helical rack fixedly installed on the machine tool, a sliding base connected to the upper portion of the machine tool in a sliding mode, a reduction gearbox fixedly installed at the bottom of the sliding base and a motor fixedly installed on the reduction gearbox. According to the gear and rack meshing mechanism for eliminating the transmission clearance, a first jacking screw or a second jacking screw is rotated, so that a clearance eliminating shaft can be driven to move in the axial direction of the clearance eliminating shaft, and meanwhile a first transmission gear and a second transmission gear are driven to move synchronously; then, the meshing clearance between the first bevel gear and the first transmission gear and the meshing clearance between the second bevel gear and the second transmission gear are adjusted, and at the moment, a first bevel gear shaft or a second bevel gear shaft can be driven to deflect in the axial direction of the first bevel gear shaft or the second bevel gear shaft through contact transmission between bevel teeth; and the tooth surfaces of the meshing parts between the first bevel gear shaft or the second bevel gear shaft and the helical rack can be attached, so that the transmission clearance of the meshing mechanism is easy to eliminate.

Description

Technical Field

[0001] The invention relates to the technical field of gear-rack meshing transmission, and in particular discloses a gear-rack meshing mechanism for eliminating transmission clearance. Background Art

[0002] The longitudinal feed of CNC machine tools generally adopts screw drive and gear rack drive. At present, screw drive is suitable for transmission with a stroke of less than 6 meters, and gear rack drive is used for strokes above 6 meters. However, for high-precision CNC machine tools, since the existing anti-backlash shaft and the transmission gear used to eliminate the transmission gap are connected by splines, the transmission gears cannot be directly transmitted to each other, which makes it easy for the transmission gears to deflect in the radial direction of the anti-backlash shaft, thereby making the transmission accuracy of the gear rack meshing mechanism low and the gap large, which has a great impact on the performance of the machine tool. Therefore, a reasonable structure must be adopted to eliminate the transmission gap in order to improve the accuracy. Summary of the invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, the present application aims to provide a gear rack meshing mechanism for eliminating transmission clearance, including a machine tool, a helical rack fixedly mounted on the machine tool, a slide seat slidably connected above the machine tool, a reduction box fixedly mounted at the bottom of the slide seat, and a motor fixedly mounted on the reduction box, wherein the reduction box is internally rotatably connected with a first helical gear shaft, a second helical gear shaft, an I axis, an II axis, an III axis, an IV axis, and a V axis, the first helical gear shaft and the second helical gear shaft are symmetrically distributed and have the same rotation direction, and the outer edges of the first helical gear shaft and the second helical gear shaft are both aligned with the helical gear shaft. The racks are meshed with each other for transmission, the upper end cover and the lower end cover are respectively fixedly installed on the inner sides of the top and bottom of the reduction box, the outer side of the bottom end of the first helical gear shaft is fixedly sleeved with the first gear for meshing transmission between the I shaft, the outer side of the bottom end of the second helical gear shaft is fixedly sleeved with the second gear for meshing transmission with the II shaft, the outer side of the top end of the I shaft is fixedly sleeved with the first helical gear, the outer side of the bottom end of the II shaft is fixedly sleeved with the second helical gear, the internal thread sleeve of the top of the upper end cover is sleeved with the first jacking screw, and the internal thread sleeve of the bottom of the lower end cover is sleeved with the second jacking screw; The interiors of the upper end cover and the lower end cover are both movably fitted with symmetrically distributed piston shafts, the inner side of one end of the piston shaft is fitted with a thrust bearing, and an anti-backlash shaft is commonly fitted between the thrust bearings, and the outer side of the anti-backlash shaft is movably fitted with a first transmission gear, a second transmission gear and a third transmission gear that respectively mesh with the first bevel gear, the second bevel gear and the V-axis for transmission, the first transmission gear and the second transmission gear have opposite rotation directions, end faces on both sides of the second transmission gear are both provided with end teeth, and end faces on one side of the first transmission gear and the third transmission gear are both provided with end teeth that mesh with the end face of the second transmission gear, and the outer side of the top end of the anti-backlash shaft extending out of the outside of the first transmission gear is threadedly fitted with a locking nut and a limiting sleeve located between the first transmission gear and the locking nut.

[0004] Preferably, a positioning hole matched with the first tightening screw and the second tightening screw is formed on the end surface of one side of the piston shaft.

[0005] Preferably, the inner side of the limiting sleeve is provided with symmetrically distributed limiting bosses, the outer side of one end of the anti-backlash shaft is provided with a limiting groove matched with the limiting boss, and the length of the limiting groove is greater than the length of the limiting boss. Beneficial Effects

[0006] 1. The gear-rack meshing mechanism for eliminating transmission clearance, by arranging end teeth on the end faces of the first transmission gear, the second transmission gear and the third transmission gear, makes it possible for the meshing mechanism to adapt to the adjustment of the meshing clearance between the first helical gear shaft, the second helical gear shaft and the helical rack when the reduction box is in any position by changing the circumferential position of the meshing of the end teeth compared to the key shaft matching, and is easy to assemble. After the end teeth are meshed, the first transmission gear, the second transmission gear and the third transmission gear can be pressed and fixed by tightening the locking nut, so that the transmission gears can be directly transmitted to each other, ensuring that the transmission gears are not easy to deflect in the radial direction of the anti-backlash shaft, thereby improving the transmission accuracy of the gear-rack meshing mechanism.

[0007] 2. The gear rack meshing mechanism for eliminating transmission clearance can drive the anti-backlash shaft to move along its own axial direction and drive the first transmission gear and the second transmission gear to move synchronously by rotating the first tightening screw or the second tightening screw, thereby adjusting the meshing clearance between the first bevel gear and the first transmission gear and the second bevel gear and the second transmission gear. At this time, the contact transmission between the bevel teeth can drive the first bevel gear shaft or the second bevel gear shaft to deflect around its own axial direction, so that the tooth surfaces of the meshing part between the first bevel gear shaft or the second bevel gear shaft and the bevel rack can fit together, thereby easily realizing the elimination of the transmission clearance of the meshing mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 It is a partial schematic diagram of the structure of the present invention; Figure 2 It is a schematic diagram of the structure of the present invention; Figure 3 It is a schematic diagram of the back side of the structure of the present invention; Figure 4 is a side sectional view of the structure of the present invention; Figure 5 It is a schematic diagram of the meshing of the transmission gears of the structure of the present invention; Figure 6 for Figure 4 A magnified schematic diagram of the structure at center A; Figure 7 It is a schematic diagram of the limiting sleeve of the present invention; Figure 8 It is a schematic diagram of the anti-backlash shaft of the present invention; Fig. 9 It is a schematic diagram of the transmission gear of the structure of the present invention; Fig.10 It is a schematic diagram of the installation of the structure of the present invention.

[0009] In the figure: 1. machine tool; 2. bevel rack; 3. slide; 4. reduction box; 5. motor; 6. first bevel gear shaft; 7. second bevel gear shaft; 8. I shaft; 9. II shaft; 10. III shaft; 11. IV shaft; 12. V shaft; 13. upper end cover; 14. lower end cover; 15. first gear; 16. second gear; 17. first bevel gear; 18. second bevel gear; 19. first jacking screw; 20. second jacking screw; 21. piston shaft; 22. thrust bearing; 23. anti-backlash shaft; 24. first transmission gear; 25. second transmission gear; 26. third transmission gear; 27. locking nut; 28. limiting sleeve; 29. ​​positioning hole; 30. limiting boss; 31. limiting groove. DETAILED DESCRIPTION

[0010] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0011] The accompanying drawings in the embodiments of the present invention: different types of section lines in the drawings are not marked according to national standards, nor do they impose requirements on the materials of the components. Instead, they are used to distinguish the cross-sectional views of the components in the drawings.

[0012] See also Figure 1-10, a gear rack meshing mechanism for eliminating transmission clearance comprises a machine tool 1, a helical rack 2 fixedly mounted on the machine tool 1, a slide 3 slidably connected above the machine tool 1, a reduction box 4 fixedly mounted at the bottom of the slide 3 and a motor 5 fixedly mounted on the reduction box 4, wherein the reduction box 4 is internally rotatably connected with a first helical gear shaft 6, a second helical gear shaft 7, an I shaft 8, an II shaft 9, a III shaft 10, an IV shaft 11 and a V shaft 12, the outer sides of the III shaft 10, the IV shaft 11 and the V shaft 12 are fixedly sleeved with spur gears, and the three are meshed and transmitted by spur gears while being able to reduce the speed of the drive of the motor 5, the outer side of the top end of the III shaft 10 is fixedly sleeved with the output shaft of the motor 5 through a sleeve, and the drive of the motor 5 can drive the III shaft 10 to rotate while being able to transmit the driving force to the first helical gear shaft 6 and the second helical gear shaft 7 through the step-by-step transmission between the shafts, and then through the drive of the first helical gear shaft 6 and the second helical gear shaft 7 The reducer 4 is driven to move along the outer side of the helical rack 2, and the slide 3 is driven to move synchronously along the outer side of the machine tool 1, so as to control the longitudinal feed amount of the slide 3. The first helical gear shaft 6 and the second helical gear shaft 7 are symmetrically distributed and have the same rotation direction. The outer edges of the first helical gear shaft 6 and the second helical gear shaft 7 are meshed with the helical rack 2 for transmission. The inner sides of the top and bottom of the reducer 4 are respectively fixedly installed with an upper end cover 13 and a lower end cover 14. The outer side of the bottom end of the first helical gear shaft 6 is fixedly sleeved with a first gear 15 for meshing transmission between the I shaft 8, and the outer side of the bottom end of the second helical gear shaft 7 is fixedly sleeved with a second gear 16 for meshing transmission with the II shaft 9. The outer side of the top end of the I shaft 8 is fixedly sleeved with a first helical gear 17, and the outer side of the bottom end of the II shaft 9 is fixedly sleeved with a second helical gear 18. The internal thread on the top of the upper end cover 13 is sleeved with a first tightening screw 19, and the internal thread on the bottom of the lower end cover 14 is sleeved with a second tightening screw 20. The interiors of the upper end cover 13 and the lower end cover 14 are both movably sleeved with symmetrically distributed piston shafts 21, and the inner side of one end of the piston shaft 21 is sleeved with a thrust bearing 22, and an anti-backlash shaft 23 is sleeved between the thrust bearings 22. The thrust bearing 22 allows the axial thrust generated when the first tightening screw 19 and the second tightening screw 20 are tightened to be unloaded through the thrust bearing 22, thereby reducing the resistance that needs to be overcome for the anti-backlash shaft 23 to rotate, so that the anti-backlash shaft 23 is driven to move along its own axial direction through the rotation of the first tightening screw 19 and the second tightening screw 20. The outer side of the anti-backlash shaft 23 is movably sleeved with a first transmission gear 24, a second transmission gear 25 and a third transmission gear 26 that are respectively meshed with the first bevel gear 17, the second bevel gear 18 and the V-shaft 12. The first transmission gear 24 and the second transmission gear 25 have opposite rotation directions. By setting the rotation directions of the first transmission gear 24 and the second transmission gear 25 opposite, the first transmission gear 24 and the second transmission gear 25 can be driven by the meshing transmission between the gears while the first transmission gear 24 and the second transmission gear 25 rotate. The first bevel gear shaft 6 and the second bevel gear shaft 7 rotate in the same direction around their own axial directions. The end faces on both sides of the second transmission gear 25 are provided with end teeth, and the end faces on one side of the first transmission gear 24 and the third transmission gear 26 are provided with end teeth meshing with the end faces of the second transmission gear 25. The provided end teeth enable the first transmission gear 24 and the second transmission gear 25 to be able to rotate and adjust around the axial direction of the anti-backlash shaft 23 according to the positions of the first bevel gear 17 and the second bevel gear 18 during installation, thereby facilitating the adjustment of the meshing clearance between the gears. The top end of the anti-backlash shaft 23 extending out of the outside of the first transmission gear 24 is respectively threadedly fitted with a locking nut 27 and a limiting sleeve 28 located between the first transmission gear 24 and the locking nut 27. By tightening the locking nut 27, the first transmission gear 24 can be compressed through the limiting sleeve 28, while the end teeth between the first transmission gear 24, the second transmission gear 25 and the third transmission gear 26 can be fully meshed, ensuring that the three can rotate synchronously around the axial direction of the anti-backlash shaft 23.

[0013] Among them, a positioning hole 29 compatible with the first tightening screw 19 and the second tightening screw 20 is opened on the end surface of one side of the piston shaft 21. The first tightening screw 19 and the second tightening screw 20 can be positioned through the positioning hole 29, so that the first tightening screw 19 and the second tightening screw 20 are not easy to bend during the tightening process, so that the rotation of the first tightening screw 19 and the second tightening screw 20 can drive the anti-backlash shaft 23 to move along its own axial direction while eliminating the gear meshing clearance.

[0014] Among them, the inner side of the limiting sleeve 28 is provided with symmetrically distributed limiting bosses 30, and the outer side of one end of the anti-backlash shaft 23 is provided with a limiting groove 31 matched with the limiting boss 30, and the length of the limiting groove 31 is greater than the length of the limiting boss 30. The limiting sleeve 28 can be limited by the cooperation of the limiting boss 30 and the limiting groove 31, so that the limiting sleeve 28 will not rotate around the axial direction of the anti-backlash shaft 23, ensuring that the locking nut 27 is not easy to loosen after tightening, so that the first transmission gear 24, the second transmission gear 25 and the third transmission gear 26 can be stably fixed on the outer side of the anti-backlash shaft 23 through the cooperation of the locking nut 27 and the limiting sleeve 28.

[0015] When installing the reduction gear box 4, the locking nut 27, the limiting sleeve 28 and the thrust bearing 22 on the top of the anti-backlash shaft 23, as well as the upper end cover 13 and the piston shaft 21 are not installed first. At this time, the first transmission gear 24, the second transmission gear 25 and the third transmission gear 26 are in a free state. After the first helical gear shaft 6 and the second helical gear shaft 7 are meshed with the helical rack 2, the reduction gear box 4 is fixedly installed on the bottom of the slide 3, and the limiting sleeve 28 is fitted on the outer side of the anti-backlash shaft 23 through the matching sleeve of the limiting boss 30 and the limiting groove 31, and then the locking nut 27 is locked. The first transmission gear 24, the second transmission gear 25 and the third transmission gear 26 are pressed and fixed on the outer side of the anti-backlash shaft 23 through the locking nut 27. In this way, the initial installation is in place, and then the thrust bearing 22, the piston shaft 21 and the upper end cover 13 are installed one by one. By tightening the first tightening screw 19 and the second tightening screw 20 The rotation drives the anti-backlash shaft 23 to move up and down, driving the first transmission gear 24, the second transmission gear 25 and the third transmission gear 26 to move up and down synchronously. In this process, the first transmission gear 24 contacts the tooth surface of the first bevel gear 17 or the second transmission gear 25 contacts the tooth surface of the second bevel gear 18, and at this time, the first bevel gear 17 is pushed to deflect around the axial direction of the I axis 8 or the second bevel gear 18 is pushed to deflect around the axial direction of the II axis 9, and then the first bevel gear shaft 6 is driven to deflect through the meshing transmission between the I axis 8 and the first gear 15, or the second bevel gear shaft 7 is driven to deflect through the meshing transmission between the II axis 9 and the second gear 16, and the meshing transmission clearance between the first bevel gear shaft 6 or the second bevel gear shaft 7 and the bevel rack 2 is gradually reduced until it is eliminated. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0016] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0017] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A gear rack meshing mechanism for eliminating transmission clearance, comprising a machine tool (1), a helical rack (2) fixedly mounted on the machine tool (1), a slide (3) slidably connected above the machine tool (1), a reduction box (4) fixedly mounted on the bottom of the slide (3), and a motor (5) fixedly mounted on the reduction box (4), characterized in that: The reduction box (4) is internally rotatably connected with a first helical gear shaft (6), a second helical gear shaft (7), an I shaft (8), an II shaft (9), an III shaft (10), an IV shaft (11) and a V shaft (12); the first helical gear shaft (6) and the second helical gear shaft (7) are symmetrically distributed and have the same rotation direction; the outer edges of the first helical gear shaft (6) and the second helical gear shaft (7) are meshed with the helical rack (2); an upper end cover (13) and a lower end cover (14) are fixedly mounted on the inner sides of the top and bottom of the reduction box (4), respectively; the first helical gear shaft (6) and the second helical gear shaft (7) are symmetrically distributed and have the same rotation direction; the outer edges of the first helical gear shaft (6) and the second helical gear shaft (7) are meshed with the helical rack (2); the inner sides of the top and bottom of the reduction box (4) are respectively fixedly mounted with an upper end cover (13) and a lower end cover (14); (6) the outer fixed sleeve at the bottom end is provided with a first gear (15) for meshing transmission with the I shaft (8), the outer fixed sleeve at the bottom end of the second helical gear shaft (7) is provided with a second gear (16) for meshing transmission with the II shaft (9), the outer fixed sleeve at the top end of the I shaft (8) is provided with a first helical gear (17), the outer fixed sleeve at the bottom end of the II shaft (9) is provided with a second helical gear (18), the top of the upper end cover (13) is internally threadedly sleeved with a first jacking screw (19), and the bottom of the lower end cover (14) is internally threadedly sleeved with a second jacking screw (20); The upper end cover (13) and the lower end cover (14) are both movably sleeved with symmetrically distributed piston shafts (21); a thrust bearing (22) is sleeved on the inner side of one end of the piston shaft (21); an anti-backlash shaft (23) is sleeved between the thrust bearings (22); a first transmission gear (24), a second transmission gear (25) and a third transmission gear (26) are movably sleeved on the outer side of the anti-backlash shaft (23) for meshing transmission with the first bevel gear (17), the second bevel gear (18) and the V-shaft (12), respectively; the first transmission gear (24), the second transmission gear (25) and the third transmission gear (26) are respectively sleeved on the outer side of the anti-backlash shaft (23); The first transmission gear (24) and the second transmission gear (25) have opposite rotation directions, the end faces on both sides of the second transmission gear (25) are provided with end teeth, and the end faces on one side of the first transmission gear (24) and the third transmission gear (26) are provided with end teeth meshing with the end face of the second transmission gear (25), and the outer side of the top end of the anti-backlash shaft (23) extending outside the first transmission gear (24) is respectively threadedly sleeved with a locking nut (27) and a limiting sleeve (28) located between the first transmission gear (24) and the locking nut (27).

2. The gear rack meshing mechanism for eliminating transmission clearance according to claim 1, characterized in that: A positioning hole (29) adapted to the first tightening screw (19) and the second tightening screw (20) is formed on an end surface of one side of the piston shaft (21).

3. The gear rack meshing mechanism for eliminating transmission clearance according to claim 1, characterized in that: The inner side of the limiting sleeve (28) is provided with symmetrically distributed limiting bosses (30), and the outer side of one end of the anti-backlash shaft (23) is provided with a limiting groove (31) adapted to the limiting boss (30), and the length of the limiting groove (31) is greater than the length of the limiting boss (30).

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