Ball screw auxiliary device

Abstract

The invention discloses a ball screw auxiliary device which comprises a control system and an annular supporting base, and a plurality of supporting assemblies are arranged on the base in the circumferential direction. Each assembly comprises a rolling body, a movable part and a sleeve connected with the driving unit; the output end of the driving unit is connected with the tail end of the movable part in an abutting mode through a first magnet and a second magnet which repel each other to form a non-contact magnetic spring. A radial necking part is arranged in the sleeve and is matched with the plummer block part of the movable piece for guiding and limiting; and a pressure sensor is arranged in a shaft hole of the rolling body. The sensor monitors the supporting force in real time and transmits the supporting force to the control system, and when the pressure deviates from a preset value, the output end of the driving unit is controlled to advance and retreat, the magnet gap is adjusted, the movable piece conducts self-adaptive displacement, and the rolling body is kept attached to the workpiece. Dynamic flexible supporting of the slender and variable-diameter workpiece is achieved, machining vibration and deformation are effectively restrained, and precision and reliability are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of mechanical processing, and relates to an auxiliary device, in particular to a ball screw auxiliary device. BACKGROUND

[0002] As a precision transmission component, the ball screw has very high requirements for the straightness and roundness of the screw shaft. When machining the ball screw, especially the ball screw with a large length-diameter ratio, the workpiece is prone to deflection and vibration under the action of its own gravity, cutting force, thermal deformation and other factors, resulting in a decrease in machining precision and deterioration of surface quality, and even causing waste products.

[0003] In the prior art, a fixed center bracket or a follow-up tool holder is often used to provide auxiliary support. However, the fixed center bracket has the following defects: the positions of the support claws need to be manually pre-adjusted according to the diameter of the workpiece, which is highly dependent on the experience of the operator and low in efficiency; for workpieces with slight initial bending or slight changes in diameter, uniform and flexible support cannot be achieved, which may cause "alternative force" or insufficient support. SUMMARY

[0004] The present application aims to solve the above problems by providing a ball screw auxiliary device.

[0005] The present application can be achieved by the following technical scheme: a ball screw auxiliary device, characterized in that it comprises a control system and a support seat arranged on a machining tool and movable, the support seat being arranged in a ring structure; A plurality of support assemblies are arranged on the support seat in a circumferential direction, each of the support assemblies being provided with a driving unit, the support assembly comprising a rolling body in active contact with the outside of the workpiece, a movable piece for active installation of the rolling body, and a sleeve fixedly connected with the output end of the driving unit; The output end of the driving unit penetrates into the inside of the sleeve and is connected in abutment with the end of the movable piece, the output end of the driving unit is provided with a first magnet, the end of the movable piece is provided with a second magnet, and the first magnet and the second magnet repel each other by magnetic force; The inside end of the sleeve is provided with a radial necking portion, the movable piece is provided with a shaft table portion extending radially outward, the shaft table portion is in abutment with the radial necking portion, and the shaft table portion can move axially along the inner wall of the sleeve; The rolling body is movably connected to the movable piece through a rotating shaft, the end of the movable piece is provided with an axle hole for the rotating shaft to pass out, a movable bearing is embedded and installed in the axle hole, and the inner wall of the axle hole is further provided with a pressure sensor for force monitoring; The pressure sensor is used to monitor the force on the rolling element in real time and is connected to the control system signal. When the pressure value detected by the pressure sensor exceeds the preset value, the control system controls the drive unit to move its output end slightly in the retraction direction, so that a gap is formed between the output end and the end of the movable part. The movable part can make slight displacement adjustments according to the external force, and the magnetic repulsion between the first magnet and the second magnet keeps the rolling element in close contact with the workpiece surface at all times. When the pressure value detected by the pressure sensor is less than the preset value, the control system controls the drive unit to drive its output end to continue to move towards the workpiece until the pressure value is restored to the preset value.

[0006] In the aforementioned ball screw auxiliary device, the drive unit is a drive cylinder, and its output end is connected to an air port connector.

[0007] In the aforementioned ball screw auxiliary device, the output end of the drive unit is a connecting shaft, which is connected to a nut inside the sleeve to convert rotational motion into axial movement.

[0008] In the aforementioned ball screw auxiliary device, the rolling element is a rolling bearing or a roller, and its outer surface makes rolling contact with the workpiece surface.

[0009] In the aforementioned ball screw auxiliary device, the moving part is a rod-shaped structure with the second magnet at its end and the rolling element mounted at its front end via the rotating shaft.

[0010] In the aforementioned ball screw auxiliary device, the first magnet and the second magnet are permanent magnets or electromagnets.

[0011] In the aforementioned ball screw auxiliary device, the control system includes a controller and a signal processing module. The monitoring signal from the pressure sensor is transmitted to the signal processing module, and the controller controls the operation of the drive unit based on the processing result.

[0012] Compared with existing technologies, this ball screw auxiliary device has the following advantages: 1. Real-time monitoring and dynamic fine-tuning of the support force are achieved through pressure sensors and a closed-loop control system, which effectively suppresses workpiece vibration and deformation and improves machining accuracy; 2. It adopts non-contact magnetic coupling transmission, which provides constant flexible preload while having buffer and overload protection functions, improving reliability and adaptability; 3. It can intelligently identify working conditions and coordinate multiple support units to synchronously track changes in workpiece diameter, achieving continuous and stable support during variable diameter machining. Overall, it realizes adaptive intelligent support for high-precision machining of slender, thin-walled workpieces. Attached Figure Description

[0013] Figure 1 This is a three-dimensional structural diagram of the ball screw auxiliary device.

[0014] Figure 2 This is a partial cross-sectional schematic diagram of the ball screw auxiliary device.

[0015] In the figure, 1 is the support base; 2 is the rolling element; 3 is the moving part; 4 is the sleeve; 5 is the output end; 6 is the first magnet; 7 is the second magnet; 8 is the radial constriction; 9 is the shaft platform; 10 is the rotating shaft; and 11 is the pressure sensor. Detailed Implementation

[0016] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.

[0017] like Figure 1 , Figure 2As shown, this ball screw auxiliary device includes a control system and a movable support base mounted on a machine tool. The support base has a ring-shaped structure. Multiple support components are spaced circumferentially on the support base, each component being equipped with a drive unit. Each support component includes a rolling element 2 that makes external contact with the workpiece, a movable part 3 for mounting the rolling element 2, and a sleeve 4 fixedly connected to the output end 5 of the drive unit. The output end 5 of the drive unit extends into the sleeve 4 and abuts against the end of the movable part 3. The output end 5 of the drive unit is equipped with a first magnet 6, and the end of the movable part 3 is equipped with a second magnet 7. The first magnet 6 and the second magnet 7 repel each other magnetically. The inner end of the sleeve 4 has a radially constricted portion 8, and the outer surface of the movable part 3 has a radially outwardly extending shaft portion 9. The shaft portion 9 abuts against the radially constricted portion 8 and can move axially along the inner wall of the sleeve 4. The rolling element 2 is movably connected via a rotating shaft 10. The movable part 3 is attached to the movable part 3. The end of the movable part 3 has a shaft hole through which the rotating shaft 10 passes. A movable bearing is installed in the shaft hole, and the inner wall of the shaft hole is also provided with a pressure sensor 11 for force monitoring. The pressure sensor 11 is used to monitor the force on the rolling element 2 in real time and is connected to the control system signal. When the pressure value detected by the pressure sensor 11 exceeds the preset value, the control system controls the drive unit to drive its output end 5 to move slightly in the retracting direction, so that a gap is formed between the output end 5 and the end of the movable part 3. The movable part 3 can make small displacement adjustments according to the external force, and the magnetic repulsion between the first magnet 6 and the second magnet 7 keeps the rolling element 2 in close contact with the workpiece surface. When the pressure value detected by the pressure sensor 11 is less than the preset value, the control system controls the drive unit to drive its output end 5 to continue to move in the direction of the workpiece until the pressure value returns to the preset value.

[0018] The drive unit is a drive cylinder, and its output end 5 is connected to an air port connector. The output end 5 of the drive unit is a connecting shaft, which is connected to a nut inside the sleeve 4 to convert rotational motion into axial movement. The rolling element 2 is a rolling bearing or roller, and its outer surface makes rolling contact with the workpiece surface. The moving part 3 is a rod-shaped structure with a second magnet 7 at its end and the rolling element 2 mounted on its front end via a rotating shaft 10. The first magnet 6 and the second magnet 7 are permanent magnets or electromagnets. The control system includes a controller and a signal processing module. The monitoring signal from the pressure sensor 11 is transmitted to the signal processing module, and the controller controls the operation of the drive unit according to the processing result.

[0019] Working principle It provides stable radial support for the workpiece (such as a slender shaft) during machining to suppress vibration and bending caused by cutting forces, self-weight, or thermal deformation, thereby improving machining accuracy. A pressure sensor 11 is installed in the shaft hole of each support assembly. It monitors the radial pressure generated when the rolling element 2 contacts the workpiece in real time, acting as the supporting force. The monitored pressure signal is transmitted to the signal processing module of the control system and compared with a preset value.

[0020] When the pressure is too high, it indicates that the workpiece may be pressing outward against the rolling element 2 due to instantaneous force or a small protrusion. The control system immediately instructs the corresponding drive unit, such as a cylinder, to slightly retract its output end 5, creating a small gap between the magnets. At this time, the magnetic repulsion force and the external pressure form a dynamic balance, and the moving part 3 can adaptively retract, avoiding over-constraint or damage to the workpiece.

[0021] When the pressure is too low, it indicates that the workpiece may be moving away from the rolling element 2 due to material removal or minor dents. The control system commands the drive unit to push the output end 5 forward, reducing the gap with the moving part 3, thereby pushing the moving part 3 and its rolling element 2 to fit tightly against the workpiece through magnetic repulsion, restoring the preset support force.

[0022] The repulsive force between the first magnet 6 and the second magnet 7 forms a non-contact magnetic spring structure. This replaces traditional rigid connections or mechanical springs, providing a constant preload that keeps the rolling element 2 in contact with the workpiece surface, while allowing for frictionless and hysteresis-free micro-displacement. When the workpiece shape changes abruptly or is subjected to abnormal impact, the magnetic repulsive force allows the moving part 3 to be instantly compressed and retracted, acting as a buffer to protect the device and the workpiece. The radial constriction 8 inside the sleeve 4 cooperates with the axle portion 9 of the moving part 3, primarily serving two purposes: first, to prevent the moving part 3 from completely dislodging from the sleeve 4 under the action of magnetic repulsion; and second, to act as a precision guide surface for axial movement, ensuring the accurate movement trajectory of the rolling element 2 and preventing wobbling.

[0023] The process of machining a slender precision lead screw on a CNC lathe is as follows: Mount the annular support onto the machine tool post or a separate movable slide, ensuring its center is roughly aligned with the machine tool spindle axis. Clamp the slender lead screw blank to be machined using the chuck and tailstock center. Start the device; the control system sets a suitable preset support force value (e.g., 200N) according to process requirements.

[0024] In this embodiment, the driving unit is a driving cylinder. When ventilated, it propels the output ends 5 of all support components and the sleeve 4 forward until each rolling element 2 contacts the workpiece surface. Under the action of magnetic repulsion, the readings of each pressure sensor 11 gradually increase to near the preset value. The machine tool begins thread cutting. Due to factors such as cutting force and vibration, the instantaneous stiffness of the workpiece varies at different positions.

[0025] When machining reaches the weakest section of the workpiece: the workpiece vibrates slightly outward, compressing the rolling element 2. The pressure sensor 11 at the corresponding location detects that the pressure has risen to 250N (>200N). The control system immediately commands the solenoid valve of the cylinder at that location to reverse, causing the piston rod (output end 5) to retract by 0.1mm. The first magnet 6 then retracts slightly, and the repulsive force between it and the second magnet 7 decreases instantaneously. The moving part 3 adaptively retracts under the workpiece pressure, and the pressure value quickly drops and stabilizes at around 200N. The magnetic repulsive force keeps the rolling element 2 from detaching from the workpiece.

[0026] When the turning reaches a relatively rigid section of the workpiece: the workpiece deformation is small, and it appears to be "away" from the roller. The pressure sensor 11 reading drops to 180N (<200N). The control system commands the cylinder piston rod to extend 0.05mm, reducing the magnet gap, increasing the magnetic repulsion force, pushing the moving part 3 to make the rolling element 2 fit more tightly against the workpiece, and the pressure returns to 200N.

[0027] To address workpiece diameter changes, the leadscrew is designed with a variable diameter structure. When turning transitions from a large diameter section to a small diameter section, the contact pressure between all rolling elements 2 and the workpiece decreases simultaneously. The control system receives signals from multiple sensors indicating that the pressure is simultaneously below the preset value, determining that it is an overall diameter change rather than local deformation. Therefore, it coordinates and controls all drive cylinders to synchronously and slightly retract a certain distance, allowing each support component to re-establish a 200N support force at the new diameter position. The magnetic repulsion structure ensures that the rolling elements 2 never completely detach from the workpiece surface during the entire retraction and repositioning process, achieving a dynamic and smooth transition.

[0028] If a sudden abnormal situation such as chip entanglement causes severe radial runout of the workpiece, the impact force applied to one of the rolling elements 2 will be enormous. This impact force will rapidly compress the magnetic coupling, and the repulsive magnets will be quickly pressed closer. At the same time, the shaft portion 9 of the moving part 3 will impact the radial constriction portion 8 of the sleeve 4, forming a hard limit to prevent structural damage. After the impact, the magnetic repulsion force can automatically reset the assembly to the working position.

[0029] This device achieves intelligent, highly flexible, and highly responsive dynamic support for rotating or moving workpieces through closed-loop control of monitoring-feedback-fine-tuning and non-contact magnetic flexible transmission. It is particularly suitable for high-precision machining of easily deformable workpieces such as slender shafts and thin-walled cylinders.

[0030] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0031] Although this document uses a considerable amount of technical terms, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would be contrary to the spirit of the invention.

Claims

1. A ball screw assist device, characterized by, The utility model relates to a control system and movable support seat (1) on the processing machine bed, the support seat (1) is arranged in ring structure; The support seat (1) is provided with a plurality of support assemblies along the circumferential direction, each of the support assemblies is provided with a driving unit, the support assembly comprises a rolling body (2) in contact with the workpiece, a movable part (3) for the rolling body (2) and a sleeve (4) fixedly connected with the output end (5) of the driving unit; The output end (5) of the driving unit penetrates into the sleeve (4) and is connected with the end of the movable part (3), and the output end (5) of the driving unit is provided with a first magnet (6), and the end of the movable part (3) is provided with a second magnet (7), and the first magnet (6) and the second magnet (7) repel each other. The inner end of the sleeve (4) is provided with a radial necking portion (8), the movable part (3) extends radially outwardly, the shaft table portion (9) is matched with the radial necking portion (8), and the shaft table portion (9) can move axially along the inner wall of the sleeve (4). The rolling body (2) is movably connected to the movable part (3) through a rotating shaft (10), the end of the movable part (3) is provided with an axle hole for the rotating shaft (10) to pass through, a movable bearing is embedded and installed in the axle hole, and the inner wall of the axle hole is further provided with a pressure sensor (11) for force monitoring. The pressure sensor (11) is used for monitoring the force of the rolling body (2) in real time and is signal connected with the control system. When the pressure value monitored by the pressure sensor (11) exceeds the preset value, the control system controls the driving unit to drive the output end (5) to move back to the retreat direction with a small amplitude, so that a gap is formed between the output end (5) and the end of the movable part (3), the movable part (3) can be adjusted in small amplitude displacement according to the external force, and the magnetic repulsion between the first magnet (6) and the second magnet (7) makes the rolling body (2) always closely contact with the workpiece surface. When the pressure value monitored by the pressure sensor (11) is less than the preset value, the control system controls the driving unit to drive the output end (5) to continue to displace to the workpiece direction until the pressure value returns to the preset value.

2. A ball screw assist device as claimed in claim 1, wherein, The driving unit is a driving cylinder, and the output end (5) is connected with a gas hole joint.

3. The ball screw assist device of claim 1, wherein, The output end (5) of the driving unit is a connecting shaft, which is matched and connected with the nut inside the sleeve (4) to convert the rotary motion into axial movement distance.

4. The ball screw assist device of claim 1, wherein, The rolling body (2) is a rolling bearing or a roller, and the outer surface thereof is in rolling contact with the workpiece surface.

5. The ball screw assist device of claim 1, wherein, The movable part (3) is a rod structure, and the end thereof is provided with the second magnet (7), and the front end is provided with the rolling body (2) through the rotating shaft (10).

6. A ball screw assist device as claimed in claim 1, wherein, The first magnet (6) and the second magnet (7) are permanent magnets or electromagnets.

7. The ball screw assist device of claim 1, wherein, The control system comprises a controller and a signal processing module, the monitoring signal of the pressure sensor (11) is transmitted to the signal processing module, and the controller controls the action of the driving unit according to the processing result.

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