A coaxial fine boring processing equipment for cylindrical gear rack bearing hole

Abstract

The application relates to a coaxial fine boring processing equipment for a cylindrical gear rack bearing hole, which comprises a machine base and a cutting adjusting seat, the upper end of the cutting adjusting seat is slidably provided with a compensation box, the inside of the compensation box is provided with an axial feed wear compensation mechanism, the axial feed wear compensation mechanism comprises a tool seat, an Archimedes eccentric wheel and a fixed push column, and the tool seat is slidably arranged at the upper end of the compensation box. According to the inherent physical law that the axial feed resistance increases due to tool wear in fine boring processing, the discarded resistance is used as a compensation power source to drive the tool seat to slide in the axial direction and sequentially drive a hydraulic damping assembly, a rack, a follow-up gear, a worm, a worm wheel and an Archimedes eccentric wheel, axial linear motion is converted into radial displacement through deceleration and torque increase, the compensation box and a boring tool are stepped out to the hole wall direction, and real-time automatic compensation of tool wear in the processing process is realized.

Description

Technical Field

[0001] This application relates to the field of precision boring equipment, and in particular to a coaxial precision boring machine for bearing holes of cylindrical gear racks. Background Technology

[0002] In the precision boring of bearing holes in cylindrical gear carriers (planetary carriers), the bearing holes are typically multiple sets of evenly distributed deep holes with thin walls, requiring extremely high standards for coaxiality, roundness, and surface roughness, usually reaching IT6 or higher precision. As the final finishing process, precision boring directly affects the meshing accuracy and service life of the gear transmission system.

[0003] Currently, commonly used precision boring equipment generally adopts a horizontal or vertical boring configuration where the workpiece rotates and the tool feeds radially. During the machining process, the operator ensures the consistency of the machining dimensions by manually adjusting the radial feed amount or relying on preset compensation parameters of the CNC system, based on the initial dimensions of the workpiece and the tool wear.

[0004] However, the aforementioned existing technologies have the following significant shortcomings: As boring time accumulates, the tool tip gradually wears, increasing cutting resistance. If this is not compensated for in time, it will directly lead to out-of-tolerance bearing hole dimensions. In existing technologies, tool wear compensation usually relies on the operator's experience or parameter correction after machine stop inspection. This is not only inefficient, but also the compensation accuracy is greatly affected by human factors, making it difficult to achieve real-time, adaptive compensation during the machining process. Furthermore, under ultra-low speed feed conditions (typically 0.05–0.15 mm / r) in precision boring, the transmission mechanism (such as gears, racks, lead screws, and nuts) is prone to creeping due to differences in dynamic and static friction. This causes radial fine-tuning to be a stepped jump rather than a continuous and smooth feed, severely affecting the linearity of micron-level compensation and the surface quality of the hole wall.

[0005] Secondly, the existing rigid transmission mechanism will directly transmit this impact load to the fine-tuning actuator. On the one hand, it is easy to cause chatter of the boring bar and reduce the quality of the machined surface. On the other hand, it is easy to cause the fine-tuning mechanism to loosen in reverse under the action of vibration, causing the compensated tool tip position to drift and lose the compensation effect. Summary of the Invention

[0006] Therefore, it is necessary to provide a coaxial precision boring machine for the bearing bore of cylindrical gear racks to address the above-mentioned technical problems.

[0007] To address the aforementioned problems, this invention provides a technical solution for coaxial precision boring equipment for cylindrical gear carrier bearing holes:

[0008] A coaxial precision boring machine for bearing holes of cylindrical gears includes a machine base and a cutting adjustment seat. A compensation box is slidably mounted on the upper end of the cutting adjustment seat. The compensation box is equipped with a feed wear compensation mechanism, which includes a tool holder, an Archimedes eccentric wheel, and a fixed push column. The tool holder is slidably disposed on the upper end of the compensation box. The Archimedes eccentric wheel is rotatably disposed on the bottom of the compensation box. The fixed push column is fixedly mounted on the upper end of the cutting adjustment seat and is in contact with the arc surface of the Archimedes eccentric wheel.

[0009] An anti-rotation assembly is provided on the outside of the compensation box. The anti-rotation assembly includes a ratchet and a pawl block. The ratchet is rotatably disposed on the outside of the compensation box, and the pawl block is engaged inside the ratchet groove of the ratchet.

[0010] A hydraulic damping assembly is provided at the upper end of the compensation box. The hydraulic damping assembly includes a hydraulic damping sleeve, which is fixedly installed on the upper left side of the compensation box.

[0011] Preferably, a boring bar is bolted inside the tool holder, and a boring tool is fixedly mounted at the end of the boring bar away from the tool holder. The fixed push pin passes through the elongated hole at the bottom of the compensation box and is slidably connected to the elongated hole at the bottom of the compensation box. Two symmetrically distributed guide pins are fixedly mounted on the upper end of the cutting adjustment seat. The guide pins are slidably connected inside the waist hole at the bottom of the compensation box, and the guide pins can guide the movement of the compensation box.

[0012] Preferably, the feed wear compensation mechanism further includes an I-beam frame. The I-beam frame is bolted to the outer side of the tool holder. The I-beam frame passes through the long slot at the top of the compensation box and is slidably connected to the compensation box. Two symmetrically distributed racks are fixedly installed at the lower end of the I-beam frame. A worm gear is installed inside the compensation box via bearings. Follower gears are fixedly installed on the outer sides of the two connecting shafts of the worm gear. The racks mesh with the follower gears. A worm wheel is installed on the outer side of the central shaft in the middle of the inner side of the compensation box via bearings. An Archimedes eccentric wheel is fixedly installed at the lower end of the worm wheel. The worm wheel meshes with the worm. As the worm drives the Archimedes eccentric wheel to rotate at a small angle through the worm wheel, the contact diameter between the Archimedes eccentric wheel and the fixed push post gradually increases, which can push the compensation box and the boring tool to perform a small compensation in the feed direction.

[0013] Preferably, two symmetrically distributed guide rod frames are fixedly installed at the upper end of the compensation box, the tool holder is slidably connected to the outside of the guide rod frames, two symmetrically distributed trapezoidal rails are fixedly installed at the top inner side of the compensation box, and two symmetrically distributed trapezoidal frames are fixedly installed above the lower horizontal bar of the I-beam frame. The trapezoidal frames are slidably connected to the outside of the trapezoidal rails. The guide rod frames can guide the movement of the tool holder, and the trapezoidal rails can guide the movement of the I-beam frame and the rack through the trapezoidal frames.

[0014] Preferably, the anti-rotation assembly further includes a hexagonal nail, which is fixedly installed on the front of the connecting shaft of the worm gear. A movable sleeve is slidably connected to the outer side of the hexagonal shaft of the hexagonal nail, and the movable sleeve contacts the worm gear. A crank is fixedly installed on the outer side of the movable sleeve. A support spring is provided on the outer side of the hexagonal shaft of the hexagonal nail. One end of the support spring is fixedly connected to the nail head of the hexagonal nail, and the other end of the support spring is fixedly connected to the movable sleeve. After processing, the displacement of the compensation box can be reset by pulling the crank to drive the ratchet on the outer side of the movable sleeve to disengage from the pawl block.

[0015] Preferably, the ratchet is fixedly installed on the outside of the movable sleeve, a fixing pin is fixedly installed on the outside of the compensation box, the pawl block is installed on the outside of the fixing pin through a bearing, a torsion spring is provided on the outside of the fixing pin, one end of the torsion spring is fixedly connected to the inner wall of the pawl block, and the other end of the torsion spring is fixedly connected to the fixing pin. The pawl block can lock the reverse rotation of the worm gear through the ratchet, which can prevent the worm gear from rotating in the reverse direction due to vibration or accidental contact during the processing.

[0016] Preferably, a positioning rod is fixedly installed on the front of the compensation box and below the pawl block. The positioning rod contacts the pawl block and can position the flip angle of the pawl block to prevent the pawl block from flipping excessively under the elastic force of the torsion spring after the ratchet is disengaged, thus preventing the ratchet from failing to reset.

[0017] Preferably, the hydraulic damping assembly further includes a piston rod slidably connected inside the hydraulic damping sleeve. A damping rod is fixedly installed at one end of the piston rod near the tool holder, and the damping rod is fixedly installed on the outside of the tool holder. A throttling cap is threaded onto one end of the hydraulic damping sleeve, and a capillary tube is fixedly installed inside the throttling cap. The end of the capillary tube away from the throttling cap is fixedly installed inside the side opening of the hydraulic damping sleeve. When the tool holder is pushed during the cutting process, the piston rod can be moved by the damping rod, and the piston rod can drive the silicone oil inside the hydraulic damping sleeve to flow.

[0018] Preferably, two symmetrically distributed sealing rings are provided inside the outer groove of the piston rod. The sealing rings are slidably connected to the inner wall of the hydraulic damping sleeve. A sealing sleeve is provided at the connection between the damping rod and the hydraulic damping sleeve. A return spring is provided on the outer side of the damping rod. The two ends of the return spring are fixedly connected to the inside of the piston rod and the hydraulic damping sleeve, respectively. The return spring can assist the piston rod in returning to its original position.

[0019] Preferably, two symmetrically distributed transverse guide rails are fixedly installed on the upper end of the machine base. A manual longitudinal adjustment box is provided on the outer side of the two transverse guide rails. A cutting adjustment seat is slidably connected to the outer side of the upper slide rail of the manual longitudinal adjustment box. A spindle box is fixedly installed on the upper left side of the machine base. A three-jaw chuck is installed on the outer side of the hollow rotating shaft of the spindle box to clamp the workpiece. The manual longitudinal adjustment box can adjust the feed rate of boring. Then, the tool above the manual longitudinal adjustment box can be driven by the machine base to perform boring feed.

[0020] The beneficial effects of this invention are:

[0021] This invention utilizes the inherent physical law of increased axial feed resistance caused by tool wear during precision boring. It uses this waste resistance as a compensation power source to drive the tool holder to slide axially and sequentially drive the hydraulic damping assembly, rack, follower gear, worm, worm wheel and Archimedes eccentric wheel. The axial linear motion is converted into radial displacement after deceleration and torque amplification, which pushes the compensation box and boring tool to step out towards the hole wall, thus realizing real-time automatic compensation for tool wear during the machining process.

[0022] The adaptive compensation mechanism of this invention relies entirely on the change in cutting force, without the need for external power sources, sensors, or CNC compensation programs. The compensation speed is automatically adjusted according to the degree of wear. The faster the wear and the greater the increase in resistance, the faster the compensation speed will automatically increase. When the wear slows down or the resistance decreases, the compensation action will automatically slow down or stop. This constitutes a purely mechanical self-sensing, self-driving, and self-compensating closed-loop control system, which fundamentally solves the problems of low efficiency and accuracy dispersion caused by the reliance on manual intervention or machine stop inspection in existing technologies. It significantly improves the consistency and long-term stability of batch processing of bearing holes, and makes the coaxiality stable to the precision level.

[0023] This invention utilizes a hydraulic damping assembly at the upper end of the compensation box. During axial sliding of the tool holder, a damping rod pushes a piston to compress silicone oil. The silicone oil slowly flows out through capillary micro-holes, generating a throttling damping effect. This filters out instantaneous impacts and feed rate fluctuations from the tool holder, ensuring a smooth and uniform driving force for the subsequent rack. This effectively eliminates the crawling phenomenon caused by dynamic and static friction differences in rigid transmission mechanisms under ultra-low speed feed conditions in precision boring, guaranteeing continuous linearity and micron-level stepping accuracy in the compensation action. Simultaneously, a ratchet and pawl block one-way locking mechanism is installed on the front of the worm gear connecting shaft. Combined with the reverse self-locking characteristics of the worm gear pair itself, a double anti-rotation safety system of internal self-locking and external locking is formed. This effectively absorbs the impact load generated by intermittent cutting, preventing worm gear reverse rotation and tool tip position drift caused by vibration or accidental contact. This ensures the compensation position is absolutely locked throughout the machining process, significantly improving the stability and surface quality of the hole wall in precision boring.

[0024] This invention highly integrates components such as the tool holder, hydraulic damping assembly, rack, worm gear, and Archimedes eccentric wheel into the compensation box, both inside and outside. Combined with the sliding guidance of the guide pin and the waist hole, the maintenance of the linearity of the trapezoidal rail and the trapezoidal frame, and the sliding support of the tool holder on the guide rod frame, the overall structure is compact and orderly, facilitating disassembly and maintenance without increasing the machine tool's floor space. Simultaneously, by setting a quick zeroing mechanism on the front of the worm gear connecting shaft, consisting of a hexagonal pin, a moving sleeve, a crank handle, a support spring, and a positioning rod, after machining, simply pulling the crank handle simultaneously releases the ratchet lock and the worm gear. This, along with the return spring, enables the compensation box to quickly return to its original position and the boring tool to its initial position. Tool changing and zeroing operations are simple and reliable, significantly reducing auxiliary working time and improving equipment utilization. Attached Figure Description

[0025] Figure 1 This is a perspective view of the overall structure of a coaxial precision boring machine for a cylindrical gear rack bearing hole in one embodiment;

[0026] Figure 2 One embodiment is a coaxial precision boring machine for bearing bores of cylindrical gears. Figure 1 A three-dimensional view of the compensation box;

[0027] Figure 3 One embodiment is a coaxial precision boring machine for bearing bores of cylindrical gears. Figure 2 A three-dimensional sectional view;

[0028] Figure 4 One embodiment is a coaxial precision boring machine for bearing bores of cylindrical gears. Figure 3 A three-dimensional diagram of a worm gear;

[0029] Figure 5One embodiment is a coaxial precision boring machine for bearing bores of cylindrical gears. Figure 3 A three-dimensional diagram of the I-beam frame;

[0030] Figure 6 One embodiment is a coaxial precision boring machine for bearing bores of cylindrical gears. Figure 2 A three-dimensional view of the knife holder;

[0031] Figure 7 One embodiment is a coaxial precision boring machine for bearing bores of cylindrical gears. Figure 3 A three-dimensional diagram of a worm gear;

[0032] Figure 8 One embodiment is a coaxial precision boring machine for bearing bores of cylindrical gears. Figure 2 A three-dimensional sectional view of the hydraulic damping assembly;

[0033] Figure 9 One embodiment is a coaxial precision boring machine for bearing bores of cylindrical gears. Figure 7 A 3D diagram of a ratchet;

[0034] Figure 10 One embodiment is a coaxial precision boring machine for bearing bores of cylindrical gears. Figure 2 Enlarged view of the A-section structure;

[0035] Figure 11 One embodiment is a coaxial precision boring machine for bearing bores of cylindrical gears. Figure 10 A 3D view of the pawl block.

[0036] In the diagram: 1. Machine base; 2. Cutting adjustment seat; 3. Compensation box; 4. Feed wear compensation mechanism; 5. Anti-rotation assembly; 6. Hydraulic damping assembly; 7. Transverse guide rail; 8. Manual longitudinal adjustment box; 9. Spindle box; 41. Guide rod holder; 42. Tool holder; 43. Boring bar; 44. Boring tool; 45. I-beam; 46. Worm gear; 47. Follower gear; 48. Rack; 49. Worm wheel; 410. Archimedes eccentric wheel; 41 1. Fixed push post; 412. Guide pin; 413. Trapezoidal rail; 414. Trapezoidal frame; 51. Hexagonal pin; 52. Moving sleeve; 53. Ratchet; 54. Fixed pin; 55. Pawl block; 56. Torsion spring; 57. Positioning rod; 58. Crank handle; 59. Support spring; 61. Hydraulic damping sleeve; 62. Piston column; 63. Damping rod; 64. Throttling cap; 65. Capillary tube; 66. Return spring; 67. Sealing ring. Detailed Implementation

[0037] like Figure 1-11 As shown, the specific implementation adopts the following technical solution:

[0038] Example:

[0039] A coaxial precision boring machine for bearing holes of cylindrical gears includes a machine base 1 and a cutting adjustment seat 2. A compensation box 3 is slidably mounted on the upper end of the cutting adjustment seat 2. The compensation box 3 is equipped with a feed wear compensation mechanism 4 inside. The feed wear compensation mechanism 4 includes a tool holder 42, an Archimedes eccentric wheel 410, and a fixed pusher 411. The tool holder 42 is slidably mounted on the upper end of the compensation box 3, the Archimedes eccentric wheel 410 is rotatably mounted on the bottom of the compensation box 3, and the fixed pusher 411 is fixedly mounted. At the upper end of the cutting adjustment seat 2, the fixed push column 411 contacts the arc surface of the Archimedes eccentric wheel 410; an anti-rotation component 5 is provided on the outside of the compensation box 3, the anti-rotation component 5 includes a ratchet 53 and a pawl block 55, the ratchet 53 is rotatably located on the outside of the compensation box 3, and the pawl block 55 is engaged in the ratchet groove of the ratchet 53; a hydraulic damping component 6 is provided at the upper end of the compensation box 3, the hydraulic damping component 6 includes a hydraulic damping sleeve 61, and the hydraulic damping sleeve 61 is fixedly installed on the upper left side of the compensation box 3.

[0040] The tool holder 42 is bolted to a boring bar 43. A boring tool 44 is fixedly installed at the end of the boring bar 43 away from the tool holder 42. A fixed pusher 411 passes through the elongated hole at the bottom of the compensation box 3 and is slidably connected to the elongated hole at the bottom of the compensation box 3. Two symmetrically distributed guide pins 412 are fixedly installed at the upper end of the cutting adjustment seat 2. The guide pins 412 are slidably connected inside the waist hole at the bottom of the compensation box 3. The guide pins 412 can guide the movement of the compensation box 3.

[0041] The feed wear compensation mechanism 4 also includes an I-beam frame 45. The I-beam frame 45 is bolted to the outside of the tool holder 42. The I-beam frame 45 passes through the long slot at the top of the compensation box 3 and is slidably connected to the compensation box 3. Two symmetrically distributed racks 48 are fixedly installed at the lower end of the I-beam frame 45. A worm gear 46 is installed inside the compensation box 3 through bearings. Follower gears 47 are fixedly installed on the outside of the two connecting shafts of the worm gear 46. The racks 48 mesh with the follower gears 47. A worm wheel 49 is installed on the outside of the central shaft in the middle of the inner side of the compensation box 3 through bearings. An Archimedes eccentric wheel 410 is fixedly installed at the lower end of the worm wheel 49. The worm wheel 49 meshes with the worm gear 46. As the worm gear 46 drives the Archimedes eccentric wheel 410 to rotate at a small angle through the worm wheel 49, the contact diameter between the Archimedes eccentric wheel 410 and the fixed push column 411 gradually increases, which can push the compensation box 3 and the boring tool 44 to perform small compensation in the feed direction.

[0042] The compensation box 3 has two symmetrically distributed guide rod frames 41 fixedly installed at its upper end. The tool holder 42 is slidably connected to the outside of the guide rod frame 41. The compensation box 3 has two symmetrically distributed trapezoidal rails 413 fixedly installed at its inner top. The I-beam frame 45 has two symmetrically distributed trapezoidal frames 414 fixedly installed above its lower horizontal bar. The trapezoidal frames 414 are slidably connected to the outside of the trapezoidal rails 413. The guide rod frames 41 can guide the movement of the tool holder 42. The trapezoidal rails 413 can guide the movement of the I-beam frame 45 and the rack 48 through the trapezoidal frames 414.

[0043] The anti-rotation component 5 also includes a hexagonal nail 51, which is fixedly installed on the front of the connecting shaft of the worm gear 46. A movable sleeve 52 is slidably connected to the outer side of the hexagonal rod of the hexagonal nail 51. The movable sleeve 52 contacts the worm gear 46. A crank handle 58 is fixedly installed on the outer side of the movable sleeve 52. A support spring 59 is provided on the outer side of the hexagonal rod of the hexagonal nail 51. One end of the support spring 59 is fixedly connected to the nail head of the hexagonal nail 51, and the other end of the support spring 59 is fixedly connected to the movable sleeve 52. After processing, the displacement of the compensation box 3 can be reset by pulling the crank handle 58 to drive the ratchet 53 on the outer side of the movable sleeve 52 to disengage from the pawl block 55.

[0044] The ratchet 53 is fixedly installed on the outside of the movable sleeve 52. A fixing pin 54 is fixedly installed on the outside of the compensation box 3. The pawl block 55 is installed on the outside of the fixing pin 54 via a bearing. A torsion spring 56 is provided on the outside of the fixing pin 54. One end of the torsion spring 56 is fixedly connected to the inner wall of the pawl block 55, and the other end of the torsion spring 56 is fixedly connected to the fixing pin 54. The pawl block 55 can lock the reverse rotation of the worm gear 46 through the ratchet 53, which can prevent the worm gear 46 from rotating in the opposite direction due to vibration or accidental contact during the processing. A positioning rod 57 is fixedly installed on the front of the compensation box 3 and below the pawl block 55. The positioning rod 57 contacts the pawl block 55 and can position the flip angle of the pawl block 55, preventing the pawl block 55 from over-flipping under the elastic force of the torsion spring 56 after the ratchet 53 is disengaged, which would cause the ratchet 53 to fail to reset.

[0045] The hydraulic damping assembly 6 also includes a piston rod 62, which is slidably connected inside the hydraulic damping sleeve 61. A damping rod 63 is fixedly installed at one end of the piston rod 62 near the tool holder 42. The damping rod 63 is fixedly installed on the outside of the tool holder 42. A throttle cap 64 is threaded onto one end of the hydraulic damping sleeve 61. A capillary tube 65 is fixedly installed inside the throttle cap 64. The end of the capillary tube 65 away from the throttle cap 64 is fixedly installed inside the side opening of the hydraulic damping sleeve 61. The thrust experienced by the tool holder 42 during the feed process can be damped. The pull rod 63 drives the piston rod 62 to move, and the piston rod 62 can drive the silicone oil inside the hydraulic damping sleeve 61 to flow. Two symmetrically distributed sealing rings 67 are provided inside the outer groove of the piston rod 62. The sealing rings 67 are slidably connected to the inner wall of the hydraulic damping sleeve 61. A sealing sleeve is provided at the connection between the damping pull rod 63 and the hydraulic damping sleeve 61. A return spring 66 is provided on the outer side of the damping pull rod 63. The two ends of the return spring 66 are fixedly connected to the piston rod 62 and the hydraulic damping sleeve 61 respectively. The return spring 66 can assist the piston rod 62 to return to its original position.

[0046] The upper end of the machine base 1 is fixedly equipped with two symmetrically distributed transverse guide rails 7. The outer side of the two transverse guide rails 7 is jointly provided with a manual longitudinal adjustment box 8. The outer side of the upper slide rail of the manual longitudinal adjustment box 8 is slidably connected to the cutting adjustment seat 2. The upper left part of the machine base 1 is fixedly equipped with a spindle box 9. A three-jaw chuck is installed on the outer side of the hollow rotating shaft of the spindle box 9, which can clamp the workpiece. The manual longitudinal adjustment box 8 can adjust the feed rate of boring. Then, the machine base 1 can drive the tool above the manual longitudinal adjustment box 8 to perform boring feed.

[0047] The usage state of this invention is as follows: During processing, after the equipment is started, the spindle box 9 drives the cylindrical gear rack to rotate around its bearing hole axis, providing the main cutting motion. The cutting adjustment seat 2 drives the compensation box 3 above the machine base 1 to make axial feed along the transverse guide rail 7, so that the boring tool 44 contacts the workpiece hole wall and cuts in. Under stable cutting conditions, the workpiece hole wall generates an axial reaction force on the tool tip, that is, the axial feed resistance. As the boring time accumulates, the tool tip of the boring tool 44 gradually wears down, the cutting edge becomes blunt, the cutting resistance increases accordingly, and the axial feed resistance increases synchronously. This increased axial force is transmitted to the tool holder 42 through the boring bar 43. The tool holder 42 slides axially under the guidance of the guide rod frame 41, thereby converting the wear information into mechanical displacement.

[0048] When the tool holder 42 moves axially, the piston 62 inside the hydraulic damping sleeve 61 is pushed by the damping rod 63 to compress the silicone oil. The positive stroke working state of the hydraulic damping assembly 6 is as follows: the piston 62 squeezes the silicone oil, and the silicone oil flows out slowly through the capillary 65 on the throttle cover 64. The microporous structure of the capillary 65 generates a throttling damping effect, which filters out the instantaneous impact and feed speed fluctuation of the tool holder 42, so that the silicone oil pushes the piston 62 to move at a constant flow rate, and then transmits the smooth axial displacement to the subsequent mechanism through the damping rod 63.

[0049] The sealing ring 67 ensures the high-pressure chamber is sealed to prevent leakage. The reverse stroke working state of the hydraulic damping component 6 is as follows: the feed resistance disappears, the return spring 66 assists the piston column 62 to reset, and the silicone oil flows back through the capillary tube 65 to achieve rapid return without affecting the retraction operation. This hydraulic damping component 6 converts rigid impact into viscous smooth motion, which eliminates the crawling phenomenon caused by the difference between dynamic and static friction in the transmission mechanism under ultra-low speed feed conditions of precision boring, and ensures the continuity and linearity of the compensation action.

[0050] The smooth axial displacement output by the hydraulic damping component 6 drives the I-beam 45 to move along the guide direction of the trapezoidal rail 413 and the trapezoidal frame 414. The two symmetrically distributed racks 48 fixedly installed at the lower end of the I-beam 45 move along with it and mesh with two follower gears 47 respectively. When the follower gears 47 rotate, they drive the worm gear 46 to rotate synchronously through the same connecting shaft. The worm gear 46 meshes with the worm wheel 49 to form a speed reduction transmission.

[0051] An Archimedes eccentric wheel 410 is fixedly installed at the lower end of the worm gear 49. When the worm gear 49 rotates slowly under the drive of the worm 46, the Archimedes eccentric wheel 410 deflects accordingly. The outline of the Archimedes eccentric wheel 410 is an Archimedes spiral, and its radius of rotation increases linearly with the rotation angle. The fixed push column 411 is fixedly installed on the upper end of the cutting adjustment seat 2, passes through the elongated hole at the bottom of the compensation box 3, and its top end is in contact with the arc surface of the Archimedes eccentric wheel 410.

[0052] As the Archimedes eccentric wheel 410 rotates with the worm gear 49, the radius of rotation of its contact point with the fixed pusher 411 gradually increases. The arc surface of the Archimedes eccentric wheel 410 pushes the fixed pusher 411. Since the fixed pusher 411 is stationary, the reaction force pushes the entire compensation box 3 to slide along the direction defined by the guide pin 412. The sliding direction of the compensation box 3 is perpendicular to the axis of the workpiece hole, i.e., radial, which drives the tool holder 42 and boring tool 44 mounted on the upper end of the compensation box 3 to move radially as a whole. The tool tip extends towards the hole wall. After being decelerated by the worm gear pair, the displacement of each compensation is in micrometer-level steps. At the same time, the worm gear pair has a reverse self-locking characteristic. Even if the cutting force fluctuates or vibrates, the worm gear 49 cannot drive the worm 46 in the reverse direction, thus ensuring the absolute stability of the compensation position during the machining process.

[0053] The anti-rotation component 5 is located on the front of the connecting shaft of the worm 46 and is used to control the compensation direction and zeroing operation. During the machining process, when the worm 46 rotates in the forward direction for compensation, the ratchet 53 on the outside of the moving sleeve 52 is engaged in the ratchet groove by the pawl block 55 under the action of the torsion spring 56. The ratchet 53 is fixedly connected to the moving sleeve 52, and the moving sleeve 52 and the connecting shaft of the worm 46 are slidably engaged by the hexagonal nail 51. Therefore, the worm 46 is locked to allow only unidirectional rotation, effectively preventing the worm 46 from rotating in the reverse direction due to cutting vibration or accidental contact.

[0054] Positioning rod 57 limits the rotation angle of pawl block 55, ensuring that pawl block 55 can reliably reset after disengagement. When machining is completed or the boring tool 44 needs to be replaced, the operator pulls crank handle 58 to overcome the elastic force of support spring 59, causing moving sleeve 52 to slide outward along the hexagonal rod of hexagonal nail 51. At this time, ratchet 53 disengages from the pawl block 55's locking constraint, and worm gear 46 can rotate freely in the opposite direction. Under the return spring 66 and manual operation, worm gear 46, worm wheel 49, Archimedes eccentric wheel 410, and compensation box 3 return to their initial zero positions, and boring tool 44 retracts to its initial radial position, achieving quick tool change and safe zeroing. After releasing crank handle 58, support spring 59 pushes moving sleeve 52 to reset, and pawl block 55 re-engages into the ratchet groove of ratchet 53 under the action of torsion spring 56, restoring the one-way locking state.

[0055] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

Claims

1. A coaxial precision boring machine for bearing holes of cylindrical gears, comprising a machine base (1) and a cutting adjustment seat (2), characterized in that: A compensation box (3) is slidably installed on the upper end of the cutting adjustment seat (2). The compensation box (3) is provided with a feed wear compensation mechanism (4). The feed wear compensation mechanism (4) includes a tool holder (42), an Archimedes eccentric wheel (410), and a fixed push column (411). The tool holder (42) is slidably installed on the upper end of the compensation box (3). The Archimedes eccentric wheel (410) is rotatably installed on the bottom of the compensation box (3). The fixed push column (411) is fixedly installed on the upper end of the cutting adjustment seat (2). The fixed push column (411) is in contact with the arc surface of the Archimedes eccentric wheel (410). An anti-rotation assembly (5) is provided on the outside of the compensation box (3). The anti-rotation assembly (5) includes a ratchet (53) and a pawl block (55). The ratchet (53) is rotatably disposed on the outside of the compensation box (3), and the pawl block (55) is engaged in the ratchet groove of the ratchet (53). The upper end of the compensation box (3) is provided with a hydraulic damping assembly (6), which includes a hydraulic damping sleeve (61) and is fixedly installed on the upper left side of the compensation box (3).

2. The coaxial precision boring equipment for cylindrical gear frame bearing holes according to claim 1, characterized in that: A boring bar (43) is bolted inside the tool holder (42). A boring tool (44) is fixedly installed at the end of the boring bar (43) away from the tool holder (42). The fixed pusher (411) passes through the elongated hole at the bottom of the compensation box (3) and is slidably connected to the elongated hole at the bottom of the compensation box (3). Two symmetrically distributed guide pins (412) are fixedly installed at the upper end of the cutting adjustment seat (2). The guide pins (412) are slidably connected inside the waist hole at the bottom of the compensation box (3).

3. The coaxial precision boring equipment for cylindrical gear frame bearing holes according to claim 1, characterized in that: The feed wear compensation mechanism (4) also includes an I-beam frame (45). The I-beam frame (45) is bolted to the outside of the tool holder (42). The I-beam frame (45) passes through the long slot at the top of the compensation box (3) and is slidably connected to the compensation box (3). Two symmetrically distributed racks (48) are fixedly installed at the lower end of the I-beam frame (45). A worm gear (46) is installed inside the compensation box (3) through a bearing. Follower gears (47) are fixedly installed on the outside of the two connecting shafts of the worm gear (46). The racks (48) mesh with the follower gears (47). A worm wheel (49) is installed on the outside of the central shaft in the middle of the inner side of the compensation box (3) through a bearing. An Archimedes eccentric wheel (410) is fixedly installed at the lower end of the worm wheel (49). The worm wheel (49) meshes with the worm gear (46).

4. The coaxial precision boring equipment for cylindrical gear frame bearing holes according to claim 3, characterized in that: Two symmetrically distributed guide rod frames (41) are fixedly installed at the upper end of the compensation box (3). The tool holder (42) is slidably connected to the outside of the guide rod frame (41). Two symmetrically distributed trapezoidal rails (413) are fixedly installed at the top of the inner side of the compensation box (3). Two symmetrically distributed trapezoidal frames (414) are fixedly installed above the lower horizontal bar of the I-beam frame (45). The trapezoidal frames (414) are slidably connected to the outside of the trapezoidal rails (413).

5. The coaxial precision boring equipment for cylindrical gear frame bearing holes according to claim 3, characterized in that: The anti-rotation assembly (5) also includes a hexagonal nail (51), which is fixedly installed on the front of the connecting shaft of the worm (46). A movable sleeve (52) is slidably connected to the outer side of the hexagonal rod of the hexagonal nail (51). The movable sleeve (52) is in contact with the worm (46). A crank (58) is fixedly installed on the outer side of the movable sleeve (52). A support spring (59) is provided on the outer side of the hexagonal rod of the hexagonal nail (51). One end of the support spring (59) is fixedly connected to the nail head of the hexagonal nail (51), and the other end of the support spring (59) is fixedly connected to the movable sleeve (52).

6. A coaxial precision boring machine for a cylindrical gear frame bearing hole according to claim 5, characterized in that: The ratchet (53) is fixedly installed on the outside of the movable sleeve (52), and a fixing pin (54) is fixedly installed on the outside of the compensation box (3). The pawl block (55) is installed on the outside of the fixing pin (54) through a bearing. A torsion spring (56) is provided on the outside of the fixing pin (54). One end of the torsion spring (56) is fixedly connected to the inner wall of the pawl block (55), and the other end of the torsion spring (56) is fixedly connected to the fixing pin (54).

7. A coaxial precision boring machine for a cylindrical gear frame bearing hole according to claim 5, characterized in that: A positioning rod (57) is fixedly installed on the front of the compensation box (3) and below the pawl block (55), and the positioning rod (57) is in contact with the pawl block (55).

8. The coaxial precision boring equipment for cylindrical gear frame bearing holes according to claim 1, characterized in that: The hydraulic damping assembly (6) further includes a piston rod (62), which is slidably connected inside the hydraulic damping sleeve (61). A damping rod (63) is fixedly installed at one end of the piston rod (62) near the tool holder (42). The damping rod (63) is fixedly installed on the outside of the tool holder (42). A throttle cap (64) is threaded onto one end of the hydraulic damping sleeve (61). A capillary tube (65) is fixedly installed inside the throttle cap (64). The end of the capillary tube (65) away from the throttle cap (64) is fixedly installed inside the side opening of the hydraulic damping sleeve (61).

9. A coaxial precision boring machine for a cylindrical gear frame bearing hole according to claim 8, characterized in that: Two symmetrically distributed sealing rings (67) are provided inside the outer groove of the piston rod (62). The sealing rings (67) are slidably connected to the inner wall of the hydraulic damping sleeve (61). A sealing sleeve is provided at the connection between the damping rod (63) and the hydraulic damping sleeve (61). A return spring (66) is provided on the outer side of the damping rod (63). The two ends of the return spring (66) are fixedly connected to the inside of the piston rod (62) and the hydraulic damping sleeve (61), respectively.

10. A coaxial precision boring machine for a cylindrical gear frame bearing hole according to claim 1, characterized in that: Two symmetrically distributed transverse guide rails (7) are fixedly installed on the upper end of the machine base (1). A manual longitudinal adjustment box (8) is provided on the outer side of the two transverse guide rails (7). A cutting adjustment seat (2) is slidably connected to the outer side of the slide rail at the upper end of the manual longitudinal adjustment box (8). A spindle box (9) is fixedly installed on the left side of the upper end of the machine base (1).

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