A shaft part grinding clamp with adjustable axial pre-tightening force and processing method

Abstract

The application provides an adjustable shaft part grinding clamp with axial pre-tightening force and a machining method, and relates to the field of aviation equipment manufacturing.The clamp comprises a flange seat, a pull rod fixedly installed on the flange seat through a locking nut, an active sleeve sleeved on the outside of the pull rod, a spring fixedly installed on the inside of the active sleeve and located on the outside of the pull rod, an adjusting nut limiting and pressing the outer end of the spring and installed on the end of the pull rod, the adjusting nut being located on the inside of the active sleeve and forming a clearance fit, an adjusting snap ring fixedly installed on the outside of the active sleeve, and a top pin installed on the adjusting snap ring in a radial direction through a threaded fit.The clamp can apply a tensioning force to the workpiece and top the tail center, the stress state of the part is changed from the original single top tightness to the current tensioning force and top tightness, the bending deformation trend of the part is inhibited, the machining vibration is improved, the grinding process is more stable, and the product quality is improved.

Description

Technical Field

[0001] This invention relates to the field of machining equipment, and in particular to a grinding fixture and machining method for shaft parts with adjustable axial preload. Background Technology

[0002] When grinding shaft parts, grinding equipment currently mainly uses a chuck as a clamp for clamping, as detailed in CN223589122U, a chuck for an external cylindrical grinding machine. This type of clamp has poor versatility, and the axial force when clamping the parts is applied by the center, which is very unfavorable for grinding slender shafts, easily causing vibration and resulting in unqualified product surface quality or scrap. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a grinding fixture and processing method for shaft parts with adjustable axial preload. This fixture can apply a tension force to the workpiece, which is pressed against the tail tip. The stress state of the workpiece is changed from the original single clamping force to the current combined action of tension force and clamping force. The bending deformation tendency of the workpiece is suppressed, the processing vibration is improved, the grinding process is more stable, and the product quality is improved.

[0004] To achieve the above objectives, the present invention provides the following solution: The first aspect of the present invention provides a grinding fixture for shaft parts with adjustable axial preload, including a flange seat, a pull rod fixedly mounted on the flange seat by a locking nut, a movable sleeve sleeved on the outside of the pull rod, a spring positioned inside the movable sleeve and located outside the pull rod, the outer end of the spring being limited and pressed by an adjusting nut mounted on the end of the pull rod, the adjusting nut being located inside the movable sleeve and forming a clearance fit, an adjusting retaining ring fixedly mounted on the outside of the movable sleeve, and a set screw being threadedly mounted on the radial direction of the adjusting retaining ring.

[0005] Preferably, the flange seat has an internal cavity, a flange hole is machined on the edge of the flange seat, a central hole for the tail tip to pass through is machined in the center of the flange seat, and a tie rod through hole for the tie rod to pass through is machined on the flange seat.

[0006] Preferably, during clamping, the flange seat is fixedly connected to the end face of the grinding machine spindle by bolts passing through the flange hole; The tail tip is located at the center of the outer end face of the grinding machine spindle.

[0007] Preferably, the tail of the pull rod is machined with a limiting seat, and the rod body at the end where the limiting seat is located is machined with a first threaded section. The first threaded section and the locking nut form a threaded engagement. The other end of the first threaded section is a smooth shaft section, and the other end of the smooth shaft section is a second threaded section. The second threaded section and the adjusting nut form a threaded engagement and adjust the clamping force of the spring.

[0008] Preferably, the movable sleeve has a spring cavity machined inside, and the end of the movable sleeve that mates with the adjusting ring has an annular groove machined on the outside.

[0009] Preferably, the adjusting ring is provided with a connecting seat, which is fitted onto the outside of the movable sleeve. A set screw is installed in the radial direction of the connecting seat, and the set screw is matched with the annular groove for limiting engagement.

[0010] Preferably, the end of the adjusting nut is machined with an open groove.

[0011] Preferably, a gasket is provided between the locking nut and the flange seat.

[0012] Preferably, the number of pull rods is three and they are evenly arranged in a circle.

[0013] Preferably, the number of set screws is three and they are evenly arranged in a circle.

[0014] A second aspect of the present invention provides a grinding method for shaft parts with adjustable axial preload, the method comprising the following steps: S1 Fixture Assembly and Installation: Fix the tie rod to the flange seat, fit a movable sleeve with a built-in spring on the outside of the tie rod, tighten the end of the spring by screwing the adjusting nut on the end of the tie rod, and then fix the adjusting ring to the outside of the movable sleeve to complete the fixture body assembly; fix the fixture to the end face of the grinding machine spindle through the flange seat, so that the tail tip protrudes from the center of the flange seat; S2 Workpiece radial clamping: Loosen the adjusting nut to release the spring preload, align the center hole at the end of the shaft workpiece to be processed with the tail tip and insert it, adjust the set screw on the adjusting ring to make the set screw radially press against the outer circle of the workpiece, thus completing the radial positioning and clamping of the workpiece. S3 Axial Preload Adjustment: Tighten the adjusting nut to move it along the pull rod axis, compress the spring and push the movable sleeve to move axially, and pull the workpiece towards the tail tip side through the adjusting ring. Adjust to the set axial preload according to the workpiece specifications and grinding process requirements. S4 Rotary Grinding: Start the grinding machine. The grinding machine spindle drives the workpiece to rotate synchronously through the flange seat, tie rod, movable sleeve and adjusting ring in sequence. The grinding tool performs cutting on the outer cylindrical surface of the workpiece. S5 workpiece removal and unloading: After the grinding process is completed, stop the grinding machine, turn the adjusting nut in the opposite direction to release the axial preload, loosen all the set screws and remove the workpiece.

[0015] The present invention has the following beneficial effects: 1. This invention allows the compression of the spring to be changed by rotating the adjusting nut, thereby adjusting the axial tension force on the workpiece. This allows the workpiece to be simultaneously subjected to axial tension force and the clamping force of the tail tip, changing the single force state of the traditional clamping method that relies solely on the clamping of the tail tip. This effectively counteracts the cutting vibration during the grinding process, suppresses the bending deformation of slender shaft parts, improves the surface quality and dimensional accuracy of the machined parts, and reduces the scrap rate.

[0016] 2. The adjusting ring of this invention has set screws that are evenly arranged along the circumference and can be radially extended and retracted, which can center and clamp shaft workpieces of different diameters. It can adapt to the processing of workpieces of various specifications without changing the main body of the fixture. At the same time, the three tie rods are evenly distributed in a circular structure, and the force is symmetrical and uniform, ensuring the coaxiality of the workpiece rotation.

[0017] 3. The fixture of this invention has a compact overall structure. The main components can be manufactured using ordinary 45# carbon steel. The locking nuts, springs, set screws, etc. are all standard purchased parts. The processing and assembly are simple, the maintenance cost is low, and it is suitable for mass production and on-site promotion and use.

[0018] 4. The clamping and unclamping of the workpiece of the present invention can be completed by adjusting the set screw and the adjusting nut. The operation steps are simple and no special tools are required. Moreover, the entire fixture is directly connected to the end face of the grinding machine spindle through the flange seat, which makes the installation and positioning quick and can effectively shorten the auxiliary time.

[0019] 5. The fixture of the present invention is not only applicable to the external cylindrical grinding process of various slender shafts and stepped shafts, but can also be extended to the precision machining clamping of other rotating parts, which can effectively improve the stress state and machining quality of shaft parts during grinding. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a three-dimensional view from the first perspective of the present invention.

[0022] Figure 2 This is a three-dimensional view from the first perspective of the present invention.

[0023] Figure 3 This is a three-dimensional view from the first perspective of the present invention.

[0024] Figure 4 This is a top view of the present invention.

[0025] Figure 5 For the present invention Figure 4 AA view.

[0026] Figure 6 This is a first-view 3D view of the present invention after removing the workpiece, adjusting ring, and part of the movable sleeve.

[0027] Figure 7 This is a second-view 3D diagram of the present invention after removing the workpiece, adjusting ring, and part of the movable sleeve.

[0028] In the diagram: 1. Workpiece; 2. Adjusting ring; 3. Set screw; 4. Adjusting nut; 5. Connecting seat; 6. Set screw; 7. Movable sleeve; 8. Tie rod; 9. Locking nut; 10. Flange seat; 11. Flange hole; 12. Grinding spindle; 13. Tail end center; 14. Washer; 15. Spring. Opening groove 401; Spring cavity 701, annular groove 702; Limiting seat 801, first threaded section 802, optical shaft section 803, second threaded section 804; Internal cavity 1001, central hole 1002, pull rod through hole 1003. Detailed Implementation

[0029] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0030] Example 1: See Figure 1-7 This embodiment provides a grinding fixture for shaft parts with adjustable axial preload. The fixture adopts a modular, split structure design to facilitate independent processing, assembly, and subsequent maintenance and replacement of each component. The fixture mainly consists of a flange seat 10, tie rods 8, movable sleeves 7, springs 15, adjusting nuts 4, adjusting rings 2, and set screws 3. The flange seat 10 serves as the load-bearing base and torque input component of the entire fixture, and is bolted to the end face of the grinding machine spindle 12. Three tie rods 8 are evenly arranged circumferentially and inserted into the flange seat 10. Each tie rod 8 is fitted with a movable sleeve 7. A spring 15 is installed inside the movable sleeve 7, and the preload is infinitely adjustable via the adjusting nut 4. The outer ends of the movable sleeves 7 are connected to the adjusting ring 2, which has three radially distributed set screws 3 for clamping the outer diameter of the workpiece. This constitutes a three-stage composite clamping structure of flange drive, spring preload, and radial clamping. Its advantages include relatively independent functional modules, a clear assembly sequence, and convenient maintenance and replacement.

[0031] Furthermore, to ensure the rotational accuracy and structural rigidity of the fixture, the flange seat 10 is made of No. 45 carbon steel, which is forged and machined as a whole, and then tempered to a hardness of HB220~250. The flange seat 10 has an internal cavity 1001 machined inside to accommodate the tail of the tie rod 8, while reducing the overall weight of the fixture to lower the moment of inertia. Six flange holes 11 are evenly machined around the edge of the flange seat 10 for bolts to fasten the flange seat 10 to the end face of the grinding machine spindle 12. A center hole 1002 is machined in the center of the flange seat 10. The center hole 1002 is coaxially set with the grinding machine spindle 12 and is used for the grinding machine's own tail tip 13 to pass through and to clamp and position the end of the workpiece. Three tie rod through holes 1003 are also evenly machined around the circumference of the flange seat 10. The centers of the three tie rod through holes 1003 are located on the same pitch circle and are used to install three tie rods 8. The flange seat is characterized by being integrally forged and heat-treated, resulting in high structural rigidity and stable rotational accuracy. The internal cavity design effectively reduces the moment of inertia, and the multiple sets of evenly distributed holes ensure symmetrical force distribution.

[0032] Furthermore, to ensure a reliable connection between the tie rod 8 and the flange seat 10 and to transmit the axial preload, the tie rod 8 is also made of 45# carbon steel and heat-treated. Its body is divided into three sections along the axial direction. A limiting seat 801 is machined at the tail end of the tie rod 8. The limiting seat 801 is a circular boss with a diameter larger than the rod body, which abuts against the inner end face of the flange seat 10 during assembly to achieve axial positioning. A first threaded section 802 is machined on the rod body at the end where the limiting seat 801 is located. The first threaded section 802 passes through the tie rod through hole 1003 and forms a threaded engagement with the locking nut 9. A washer 14 is placed between the locking nut 9 and the outer end face of the flange seat 10. Tightening the locking nut 9 securely fixes the tie rod 8 to the flange seat 10. The other end of the first threaded section 802 is a smooth shaft section 803, the surface of which is ground. It is used to form a clearance fit with the inner hole of the movable sleeve 7 and to provide guidance for the axial movement of the movable sleeve 7; the other end of the smooth shaft section 803 is the second threaded section 804, which forms a threaded fit with the adjusting nut 4. By rotating the adjusting nut 4, its axial position on the tie rod 8 can be changed, thereby adjusting the compression and preload of the spring 15. Its feature is that the tie rod adopts a three-section differentiated structure design. The tail threaded section realizes the fastening connection with the flange seat, the smooth shaft section provides precision guidance for the movable sleeve, and the front threaded section realizes stepless adjustment of the preload. Each section has a clear function and good machinability.

[0033] Furthermore, to accommodate the spring 15 and transmit the axial preload, the movable sleeve 7 is made of 45# carbon steel, and has a spring cavity 701 machined inside. The spring cavity 701 has a stepped hole structure, with the large-diameter section used to accommodate the spring 15 and the small-diameter section forming a clearance fit with the optical axis section 803 of the pull rod 8. The spring 15 is fitted outside the optical axis section 803 of the pull rod 8 and located inside the spring cavity 701. The inner end of the spring 15 abuts against the stepped surface of the spring cavity 701, and the outer end of the spring 15 is limited and pressed by the adjusting nut 4 screwed onto the second threaded section 804 of the pull rod 8. The adjusting nut 4 is located inside the spring cavity 701 of the movable sleeve 7 and forms a clearance fit with the inner wall of the cavity. The end of the adjusting nut 4 is machined with an open slot 401 for easy adjustment using a flathead screwdriver. When the adjusting nut 4 is rotated in the forward direction, the adjusting nut 4 moves towards the flange seat side along the second thread section 804, compressing the spring 15 to generate an axial elastic force. This elastic force acts on the stepped surface of the movable sleeve 7, pushing the movable sleeve 7 to move towards the flange seat side along the tie rod 8. When the adjusting nut 4 is rotated in the reverse direction, the compression of the spring 15 decreases, and the axial preload decreases accordingly. Its features include a built-in spring cavity and adjusting nut in the movable sleeve, a compact structure, a small axial dimension, and continuous stepless adjustment of the spring preload through the adjusting nut. The open slot design facilitates quick on-site adjustment.

[0034] Furthermore, to achieve radial clamping and centering of workpieces with different diameters, the adjusting ring 2 is made of 45# carbon steel and heat-treated, with an overall annular structure. A connecting seat 5 is provided on one side of the inner hole of the adjusting ring 2. The connecting seat 5 and the adjusting ring 2 are integrally machined. The connecting seat 5 is fitted onto the outside of the movable sleeve 7. The connecting seat 5 has a threaded hole machined in the radial direction and a set screw 6 is installed. The end of the movable sleeve 7 that mates with the adjusting ring 2 has an annular groove 702 machined on its outside. The end of the set screw 6 extends into the annular groove 702 and forms an axial limiting fit, which not only prevents the adjusting ring 2 from falling off the movable sleeve 7, but also allows the adjusting ring 2 to be finely adjusted in circumferential angle during assembly. The adjusting retaining ring 2 has three threaded through holes evenly machined along its circumference in the radial direction. Each threaded through hole has a set screw 3 installed in it through threaded engagement. The axes of the three set screws 3 intersect on the central axis of the adjusting retaining ring 2. The inner end of the set screw 3 has a flat head or ball head structure to increase the contact area with the outer circle of the workpiece. Tightening the set screw 3 can change its radial extension length, thereby enabling radial clamping and centering positioning of shaft workpieces of different diameters. Its feature is that the adjusting retaining ring achieves quick connection and circumferential positioning with the movable sleeve through the connecting seat and the set screw. The three evenly distributed set screws can adapt to the clamping requirements of workpieces of different diameters. Radial clamping and axial preload are independent of each other and do not interfere with each other.

[0035] Furthermore, the assembly and operation process of the fixture described in this embodiment is as follows: During assembly, first, the three tie rods 8 are passed through the corresponding tie rod through holes 1003 from the inside of the flange seat 10. After installing the gasket 14 on the first threaded section 802 of each tie rod 8, the locking nut 9 is screwed in and tightened, so that the limiting seat 801 of the tie rod 8 is tightly attached to the inner end face of the flange seat 10, thus completing the assembly of the tie rod assembly and the flange seat. Then, the springs 15 are installed into the spring cavities 701 of each movable sleeve 7, and the movable sleeve 7 is then inserted from the front end of the tie rod 8. The inner hole of spring 15 is inserted into the optical shaft section 803, and then the adjusting nut 4 is screwed into the second threaded section 804 to initially press the end of spring 15. The connecting seat 5 of adjusting ring 2 is fitted onto the outer end of the three movable sleeves 7. After adjusting the circumferential position, the set screw 6 is screwed in so that the end of the set screw is engaged in the annular groove 702 to complete the axial fixation. Finally, the entire fixture is fastened to the end face of the grinding machine spindle 12 with bolts through the flange hole 11, so that the tail tip 13 passes through the center hole 1002, thus completing the installation of the fixture on the machine tool. When clamping the workpiece, first rotate each adjusting nut 4 in the reverse direction to release the spring force of spring 15. Align the center hole of one end of the shaft-type workpiece to be processed with the tail tip 13 and insert it. Adjust the three set screws 3 in sequence to make the workpiece radially centered and clamped. Then rotate the adjusting nut 4 in the forward direction to compress the spring 15. Through the movable sleeve 7 and the adjusting retaining ring 2, the workpiece is pulled towards the tail tip side to make the center hole of the workpiece fit tightly with the tip. After adjusting the preload to a suitable value according to the length-to-diameter ratio of the workpiece and the grinding process requirements, the grinding machine can be started for grinding. After processing, first rotate the adjusting nut 4 in the reverse direction to release the preload, and then loosen the set screws 3 to remove the workpiece. Its advantages are that the entire clamping and disassembly process is simple to operate, the auxiliary time is short, and the axial preload and radial clamping force can be adjusted independently, making it highly adaptable.

[0036] The beneficial effects of the fixture described in this embodiment are as follows: the axial preload is continuously adjustable through the cooperation of spring 15 and adjusting nut 4, so that the workpiece is subjected to the bidirectional action of axial tension force and tail tip clamping force, which effectively suppresses the bending deformation and cutting vibration of slender shaft parts during the grinding process, and significantly improves the surface quality and dimensional accuracy of the machined parts; by adjusting the radial extension and retraction of the three evenly distributed set screws 3 on the retaining ring 2, it can adapt to the clamping requirements of shaft workpieces of different diameters and specifications, and has strong versatility; the fixture has a compact overall structure, and the parts are all conventional machined parts and standard purchased parts, resulting in low manufacturing cost, simple assembly and maintenance, and is suitable for widespread application on various cylindrical grinding machines.

[0037] Working principle of the invention: This fixture uses the flange seat 10 as the rotating bearing base and transmits torque and axial preload through the tie rod assembly to achieve synchronous rotation of the workpiece and optimized axial force.

[0038] The rotational torque of the grinding spindle 12 is transmitted through the flange seat 10 to three circumferentially distributed tie rods 8. The tie rods drive the workpiece to rotate synchronously through the movable sleeve 7, adjusting ring 2, and set screw 3, completing the rotary motion of the grinding feed. The spring 15 is built into the spring cavity 701 of the movable sleeve, with one end abutting against the step on the inner wall of the movable sleeve and the other end limited by the adjusting nut 4. Rotating the adjusting nut can move along the axial direction of the tie rod 8, changing the compression deformation of the spring, thereby applying a continuously adjustable axial thrust to the movable sleeve. This thrust is converted into the axial tension force of the workpiece through the adjusting ring, forming a bidirectional force balance with the clamping force of the tail tip 13, so that the workpiece always maintains a stable axial preload during the grinding process, effectively suppressing the bending vibration caused by the radial cutting force.

[0039] Example 2: This embodiment provides a machining method for a grinding fixture with adjustable axial preload for shaft parts, including the following steps: S1 Fixture Assembly and Installation: Fix the tie rod 8 to the flange seat 10, fit the movable sleeve 7 with the built-in spring 15 on the outside of the tie rod 8, tighten the end of the spring 15 by screwing the adjusting nut 4 on the end of the tie rod 8, and then fix the adjusting ring 2 to the outside of the movable sleeve 7 to complete the fixture body assembly; fix the fixture to the end face of the grinding machine spindle 12 through the flange seat 10, so that the tail tip 13 passes through the center of the flange seat 10; S2 Workpiece radial clamping: Loosen the adjusting nut 4 to release the preload of the spring 15, align the center hole at the end of the shaft workpiece to be processed with the tail tip 13 and insert it, adjust the set screw 3 on the adjusting ring 2 so that the set screw 3 radially presses against the outer circle of the workpiece, thus completing the radial positioning and clamping of the workpiece. S3 Axial preload adjustment: Tighten the adjusting nut 4 to move it axially along the pull rod 8, compress the spring 15 and push the movable sleeve 7 to move axially, and drive the workpiece to the tail tip 13 side by adjusting the snap ring 2. Adjust to the set axial preload according to the workpiece specifications and grinding process requirements. S4 Rotary Grinding Process: Start the grinding machine. The grinding machine spindle 12 drives the workpiece to rotate synchronously through the flange seat 10, the tie rod 8, the movable sleeve 7 and the adjusting ring 2 in sequence. The grinding tool performs cutting processing on the outer cylindrical surface of the workpiece. S5 Workpiece disassembly and unloading: After the grinding process is completed, stop the grinding machine, turn the adjusting nut 4 in the opposite direction to release the axial preload, loosen each set screw 3 and then remove the workpiece.

[0040] Example 3: This embodiment provides a machining method for a grinding fixture with adjustable axial preload for shaft parts, which includes the following steps: Step 1. Fixture Assembly: First, assemble the tie rod assembly. Pass the end of the tie rod 8 with the limit seat 801 through the tie rod through hole 1003 from the inside of the flange seat 10. After installing the gasket 14, screw the lock nut 9 into the first threaded section 802 and tighten it to fix the tie rod to the flange seat. Install the spring 15 into the spring cavity 701 of the movable sleeve 7, and then slide the entire movable sleeve into the front end of the tie rod so that the inner hole of the spring passes through the optical shaft section 803. Screw the adjusting nut 4 into the second threaded section 804 of the tie rod to press the end of the spring, completing the assembly of the spring preload assembly. Then, install the connecting seat 5 on the outer circle of the front end of the movable sleeve 7, adjust the position, and tighten the set screw 6 so that the end of the set screw is engaged in the annular groove 702, realizing the axial fixation and circumferential limitation of the adjusting ring 2 and the movable sleeve. Finally, the assembled fixture is fastened to the end face of the grinding machine spindle 12 through the flange hole 11 with bolts, so that the tail tip 13 of the grinding machine passes through the center hole 1002 of the flange seat, thus completing the docking of the fixture with the machine tool.

[0041] Step 2. Workpiece clamping: First, rotate the adjusting nut 4 in the opposite direction to relax the spring 15. Align the center hole of one end of the shaft workpiece to be processed with the tail tip 13 and insert it so that the end of the workpiece fits against the tip. Adjust the three set screws 3 on the adjusting ring 2 evenly in the radial direction so that the ends of each set screw abut against the outer cylindrical surface of the workpiece simultaneously, thus completing the radial centering and clamping of the workpiece.

[0042] Step 3. Preload adjustment: Rotate the adjusting nut 4 in the forward direction to push the movable sleeve 7 along the pull rod 8 towards the flange seat side. The compression spring 15 generates axial elastic force, which drives the workpiece towards the tail tip side through the adjusting snap ring 2 until the center hole of the workpiece and the tail tip are tightly fitted. According to the length-to-diameter ratio of the workpiece, the material stiffness and the grinding process parameters, continue to rotate the adjusting nut to adjust the spring compression and set a suitable axial preload to ensure that the workpiece has no axial movement or radial chatter during the grinding process.

[0043] Step 4. Grinding: Start the grinding machine. The grinding machine spindle 12 drives the flange seat 10, tie rod 8, movable sleeve 7, adjusting ring 2 and the workpiece to rotate synchronously and uniformly. The grinding tool cuts the outer surface of the workpiece. During the processing, the spring always maintains a stable preload state, automatically compensates for small gaps, and maintains a constant axial force.

[0044] Step 5. Workpiece removal: After the grinding process is completed, stop the machine tool, first rotate the adjusting nut 4 in the opposite direction to release the axial preload, and then loosen each set screw 3 in sequence to remove the workpiece from the fixture; when changing to the next workpiece, repeat the above clamping and adjustment steps.

Claims

1. An axial preload adjustable shaft part grinding jig characterized by, Includes a flange seat (10), on which a pull rod (8) is fixedly installed by a locking nut (9), and a movable sleeve (7) is fitted on the outside of the pull rod (8). A spring (15) is installed inside the movable sleeve (7) and positioned outside the pull rod (8). The outer end of the spring (15) is limited and pressed by an adjusting nut (4) installed at the end of the pull rod (8). The adjusting nut (4) is located inside the movable sleeve (7) and forms a clearance fit. An adjusting ring (2) is fixedly installed on the outside of the movable sleeve (7). A set screw (3) is installed in the radial direction of the adjusting ring (2) by a threaded fit.

2. The grinding fixture for shaft parts with adjustable axial preload as described in claim 1, characterized in that: The flange seat (10) has an internal cavity (1001) machined inside, a flange hole (11) machined on the edge of the flange seat (10), a central hole (1002) for passing through the tail tip (13) machined in the center of the flange seat (10), and a tie rod through hole (1003) for passing through the tie rod (8) machined on the flange seat (10).

3. The grinding fixture for shaft parts with adjustable axial preload as described in claim 2, characterized in that: During clamping, the flange seat (10) is fixedly connected to the end face of the grinding machine spindle (12) by bolts passing through the flange hole (11); The tail tip (13) is located at the center of the outer end face of the grinding machine spindle (12).

4. The grinding fixture for shaft parts with adjustable axial preload as described in claim 1, characterized in that: The tail of the pull rod (8) is machined with a limiting seat (801). The rod body at the end where the limiting seat (801) is located is machined with a first threaded section (802). The first threaded section (802) and the locking nut (9) form a threaded engagement. The other end of the first threaded section (802) is a smooth shaft section (803). The other end of the smooth shaft section (803) is a second threaded section (804). The second threaded section (804) and the adjusting nut (4) form a threaded engagement and adjust the clamping force of the spring (15).

5. The grinding fixture for shaft parts with adjustable axial preload as described in claim 1, characterized in that: The movable sleeve (7) has a spring cavity (701) inside, and the end of the movable sleeve (7) that mates with the adjusting ring (2) has an annular groove (702) on the outside.

6. A grinding fixture for shaft parts with adjustable axial preload as described in claim 5, characterized in that: The adjusting ring (2) is provided with a connecting seat (5), which is fitted on the outside of the movable sleeve (7). A set screw (6) is installed in the radial direction of the connecting seat (5), and the set screw (6) is matched with the annular groove (702).

7. The grinding fixture for shaft parts with adjustable axial preload according to claim 1, characterized in that: The end of the adjusting nut (4) is machined with an opening groove (401).

8. The grinding fixture for shaft parts with adjustable axial preload according to claim 1, characterized in that: A gasket (14) is provided between the locking nut (9) and the flange seat (10).

9. A grinding fixture for shaft parts with adjustable axial preload as described in claim 1, characterized in that: The number of the pull rods (8) is three and they are evenly arranged in a circle; The number of top screws (3) is three and they are evenly arranged in a circle.

10. A grinding method for shaft parts with adjustable axial preload, characterized in that, The machining is performed using the adjustable axial preload grinding fixture for shaft parts as described in any one of claims 1-9, and the machining method includes the following steps: S1 Fixture Assembly and Installation: Fix the tie rod (8) to the flange seat (10), fit the movable sleeve (7) with the built-in spring (15) on the outside of the tie rod (8), tighten the end of the spring (15) by screwing the adjusting nut (4) on the end of the tie rod (8), and then fix the adjusting ring (2) to the outside of the movable sleeve (7) to complete the fixture body assembly; fix the fixture to the end face of the grinding machine spindle (12) through the flange seat (10), so that the tail tip (13) passes through the center of the flange seat (10); S2 Workpiece radial clamping: Loosen the adjusting nut (4) to release the preload of the spring (15), align the center hole at the end of the shaft workpiece to be processed with the tail tip (13) and insert it, adjust the set screw (3) on the adjusting ring (2) so that the set screw (3) radially presses against the outer circle of the workpiece, and completes the radial positioning and clamping of the workpiece. S3 Axial preload adjustment: Tighten the adjusting nut (4) to move it axially along the pull rod (8), compress the spring (15) and push the movable sleeve (7) to move axially. Through the adjusting ring (2), the workpiece is pulled towards the tail tip (13) side. Adjust to the set axial preload according to the workpiece specifications and grinding process requirements. S4 Rotary Grinding: Start the grinding machine. The grinding machine spindle (12) drives the workpiece to rotate synchronously through the flange seat (10), tie rod (8), movable sleeve (7) and adjusting ring (2) in sequence. The grinding tool performs cutting processing on the outer cylindrical surface of the workpiece. S5 Workpiece disassembly and unloading: After the grinding process is completed, the grinding machine is stopped, the adjusting nut (4) is turned in the opposite direction to remove the axial preload, and the workpiece is removed after loosening each set screw (3).

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