Fixed shaft linear motor with working position detection function

Abstract

The utility model discloses a fixed shaft linear motor with working position detection, a rotor assembly passes through a stator and then is connected with a bearing assembly, a nut is located in an inner hole of the rotor assembly and is fixed with the rotor assembly, a screw assembly passes through the nut and is in threaded connection with the nut, and a guide sleeve is fixed with one end of a shell. The screw assembly comprises a screw and a guide shaft, one end of the screw is fixed to the guide shaft, the guide shaft and the guide sleeve are fixed in the circumferential direction and are in sliding fit in the axial direction, the cover shell is fixed to the other end of the shell, the first Hall sensor is matched with the cover shell, and the first magnetic steel is matched with the screw. The first magnetic steel is used for detecting the first position of the screw assembly when matched with the first Hall sensor, the supporting component is fixed to the guide sleeve, the second Hall sensor is matched with the supporting component, the second magnetic steel is matched with the guide shaft, and the second magnetic steel is used for detecting the second position of the screw assembly when matched with the second Hall sensor. The utility model has the characteristics of simple structure and low cost.

Description

Technical Field

[0001] This utility model relates to linear motors, specifically to a fixed-axis linear motor with working position detection. Background Technology

[0002] The linear motor itself includes a housing, stator, bearing assembly, rotor assembly, nut, screw assembly, and guide sleeve. The stator, bearing assembly, and rotor assembly are all located inside the housing. The bearing assembly and stator are fixed to the housing respectively. The rotor assembly passes through the stator and connects to the bearing assembly. The nut is located in the inner hole of the rotor assembly and is fixed to the rotor assembly. The screw assembly passes through the nut and is threadedly connected to the nut. The guide sleeve is fixed to the housing. The screw assembly and the guide sleeve are fixed in the circumferential direction and have a sliding fit in the axial direction. During operation, the rotor assembly drives the nut to rotate, causing the screw assembly to move linearly.

[0003] With the development of precision manufacturing technology and CNC technology, high speed, high efficiency and high precision have become the current development direction of CNC machine tools. This has put forward higher requirements for the performance of various functional components in machine tools and other equipment. Linear motors are an indispensable part in these devices. Therefore, the accuracy requirements for the extension or retraction position of linear motors have also increased.

[0004] Position detection is a crucial aspect of linear motor control system research, directly impacting the control cost and performance of the linear motor. Position detection accuracy is paramount to the motor's control precision. Linear motor magnetic pole position detection methods are mainly divided into two categories: those with position sensors and those without. Currently, commonly used position sensors include magnetic gratings, optical gratings, and lever displacement sensors. While magnetic gratings and optical gratings offer high detection accuracy, their high cost, large size, and stringent environmental requirements severely limit their application range. Utility Model Content

[0005] This invention provides a fixed-axis linear motor with working position detection, which features a simple structure and low cost.

[0006] The technical solutions to the above technical problems are as follows:

[0007] A fixed-axis linear motor with working position detection includes a housing, a stator, a bearing assembly, a rotor assembly, a nut, a screw assembly, and a guide sleeve. The stator, bearing assembly, and rotor assembly are all installed inside the housing. The rotor assembly passes through the stator and connects to the bearing assembly. The nut is located in the inner hole of the rotor assembly and is fixed to the rotor assembly. The screw assembly passes through the nut and is threadedly connected to the nut. The guide sleeve is fixed to one end of the housing. The screw assembly includes a screw and a guide shaft. One end of the screw is fixed to the guide shaft. The guide shaft and the guide sleeve are fixed in the circumferential direction and have a sliding fit in the axial direction. The motor also includes a cover, a first Hall sensor, a first magnet, a support component, a second Hall sensor, and a second magnet. The cover is fixed to the other end of the housing. The first Hall sensor cooperates with the cover. The first magnet cooperates with the screw. When the first magnet cooperates with the first Hall sensor, it is used to detect the first position of the screw assembly. The support component is fixed to the guide sleeve. The second Hall sensor cooperates with the support component. The second magnet cooperates with the guide shaft. When the second magnet cooperates with the second Hall sensor, it is used to detect the second position of the screw assembly.

[0008] Furthermore, the housing is provided with a first mounting hole, the first Hall sensor is engaged with the first mounting hole, the other end of the screw is provided with an axial first receiving cavity, one end of the first magnet is engaged with the first receiving cavity, and the other end of the first magnet is exposed outside the first receiving cavity.

[0009] Furthermore, a second receiving cavity is provided on the circumferential surface of the guide shaft, and the second magnet is located in the second receiving cavity.

[0010] Furthermore, the support component includes a first sleeve and a second sleeve, with one end of the first sleeve and the second sleeve fixed together. The first sleeve is fitted onto the guide sleeve and fixed thereto. An assembly groove is provided on the inner wall of the second sleeve, and the second Hall sensor cooperates with the assembly groove.

[0011] Furthermore, the assembly groove extends through the axial end face of the other end of the second sleeve, and at least a portion of the assembly groove is tapered.

[0012] Furthermore, the outer circumferential surface of the guide sleeve is provided with a protrusion, and the inner wall of the first sleeve is provided with a first engagement groove. The first engagement groove and the protrusion are fitted together with a clearance to fix the support component and the guide sleeve in the circumferential direction.

[0013] When the fixed-axis linear motor rotates forward, it causes the screw assembly to move linearly from left to right (screw assembly retracts). The screw assembly, along with the first and second magnets, moves linearly from left to right, causing the first magnet to gradually move closer to the first Hall sensor, while the second magnet gradually moves away from the second Hall sensor. When the first Hall sensor detects the first magnet, the screw assembly retracts to its limit position. The first Hall sensor then feeds back the detection signal to the PLC controller. The PLC controller then controls the fixed-axis linear motor to stop working, or it controls the fixed-axis linear motor to reverse, causing the screw assembly to move linearly from right to left. When the fixed-axis linear motor reverses, it causes the screw assembly to move linearly from right to left (the screw assembly extends). The screw assembly, along with the first and second magnets, moves linearly from right to left, causing the first magnet to gradually move away from the first Hall sensor and the second magnet to gradually move closer to the second Hall sensor. When the second Hall sensor detects the second magnet, the screw assembly extends to its limit position. The second Hall sensor then feeds back the detection signal to the PLC controller. The PLC controller then controls the fixed-axis linear motor to stop working, or it controls the fixed-axis linear motor to rotate forward, causing the screw assembly to move linearly from left to right.

[0014] This invention modifies an existing linear motor by adding several low-cost components, thereby controlling the extension and retraction strokes of the screw assembly. It is not only simple in structure but also low in cost. Attached Figure Description

[0015] Figure 1 A 3D view of a fixed-axis linear motor with working position detection capabilities.

[0016] Figure 2 An exploded view of a fixed-axis linear motor capable of detecting working position.

[0017] Figure 3 This is a schematic diagram showing how the first sensor and the first sensor work together to detect the first position of the screw assembly.

[0018] Figure 4 This is a schematic diagram showing how the second sensor, in conjunction with the second sensor unit, is used to detect the second position of the screw assembly.

[0019] Figure 5 This is a structural diagram of the supporting components.

[0020] Figure 6 This is an assembly diagram of the support component and the second magnet.

[0021] Labels in the attached diagram:

[0022] Housing 1, stator 2, bearing assembly 3, rotor assembly 4, nut 5, screw assembly 6, screw 6a, guide shaft 6b, first receiving cavity 6c, second receiving cavity 6d, guide sleeve 7, protrusion 7a, cover 8, first mounting hole 8a, first clearance hole 8b, first Hall sensor 9, first magnet 10, support component 11, first sleeve 11a, second sleeve 11b, assembly groove 11c, first mating groove 11d, second Hall sensor 12, second magnet 13. Detailed Implementation

[0023] like Figures 1 to 6 As shown, the fixed-axis linear motor with working position detection of this utility model includes a housing 1, a stator 2, a bearing assembly 3, a rotor assembly 4, a nut 5, a screw assembly 6, a guide sleeve 7, a cover 8, a first Hall sensor 9, a first magnet 10, a support component 11, a second Hall sensor 12, and a second magnet 13. The following is a detailed description of each part and the relationship between them.

[0024] The stator 2, bearing assembly 3, and rotor assembly 4 are all installed inside the housing 1. There are two bearing assemblies 3. The stator 2 is located between the two bearing assemblies 3. The rotor assembly 4 passes through the stator 2 and is connected to the bearing assembly 3. The nut 5 is located in the inner hole of the rotor assembly 4 and is fixed to the rotor assembly 4. The screw assembly 6 passes through the nut 5 and is threadedly connected to the nut 5. The screw assembly 6 includes a screw 6a and a guide shaft 6b. One end of the screw 6a is fixed to the guide shaft 6b. The guide sleeve 7 is fixed to one end of the housing 1. In this utility model, the guide shaft 6b is preferably a spline shaft, and the guide sleeve 7 is preferably a spline sleeve. After the guide shaft 6b passes through the guide sleeve 7, the guide shaft 6b and the guide sleeve 7 form a fixed circumferential direction and a sliding fit in the axial direction.

[0025] The cover 8 is a cylindrical body with an opening at one end and a closed shape at the other end. The cover 8 is fixed to the other end of the housing 1. The open end of the cover 8 is fitted onto the housing 1 and the cover 8 and housing 1 are fastened together by screws or rivets.

[0026] The first Hall sensor 9 is fitted with the housing 8, and the first magnet 10 is fitted with the screw 6a. In this invention, the housing 8 has a first mounting hole 8a, which is located at the closed end of the housing 8 and is arranged radially along the housing 8. The first Hall sensor 9 is fitted with the first mounting hole 8a and consists of a first Hall sensor body and a first signal line. The first Hall sensor body is interference-fitted with the first mounting hole 8a, and the first signal line extends to the outside of the first mounting hole 8a for connecting to a PLC controller (not shown in the figure). The other end of the screw 6a has an axial first receiving cavity 6c. One end of the first magnet 10 is fitted with the first receiving cavity 6c, and the other end of the first magnet 10 is exposed outside the first receiving cavity 6c. When the first magnet 10 is fitted with the first Hall sensor 9, it is used to detect the first position of the screw assembly 6. The first Hall sensor 9 detects the first magnet 10 by magnetic field induction, that is, when the first magnet 10 is close to the first Hall sensor 9, a magnetic field is generated around the first Hall sensor 9. The semiconductor material of the first Hall sensor 9 senses this magnetic field and generates a potential difference on both sides of it, which is then converted into an electrical signal.

[0027] A first clearance hole 8b is also provided at the closed end of the housing 8. When the first magnet 10 approaches the first Hall sensor 9, since the first clearance hole 8b is connected to the first mounting hole 8a, the first Hall sensor 9 can avoid reducing the induction of the first magnet 10 by the blockage of the magnetic field by the closed end of the housing 8.

[0028] The supporting component 11 is fixed to the guide sleeve 7. The supporting component 11 includes a first sleeve 11a and a second sleeve 11b. One end of the first sleeve 11a and the second sleeve 11b are fixed. The first sleeve 11a is fitted onto the guide sleeve 7 and fixed thereto. A protrusion 7a is provided on the outer circumferential surface of the guide sleeve 7. A first engaging groove 11d is provided on the inner wall of the first sleeve 11a. The first engaging groove 11d and the protrusion 7a are clearance-fitted to fix the supporting component 11 and the guide sleeve 7 in the circumferential direction, thereby preventing the supporting component 11 from rotating. The guide sleeve 7 and the first sleeve 11a are fastened with screws or rivets.

[0029] The second Hall sensor 12 mates with the support component 11. In this invention, the inner wall of the second sleeve 11b is provided with an assembly groove 11c. The second Hall sensor 12 mates with the assembly groove 11c, which penetrates the axial end face of the other end of the second sleeve 11b. At least a portion of the assembly groove 11c is tapered. The second Hall sensor 12 consists of a second Hall sensor body and a second signal line. The second Hall sensor body is interference-fitted with the assembly groove 11c, and the second signal line is bent and connected to the PLC controller.

[0030] The second magnet 13 cooperates with the guide shaft 6b, and a second receiving cavity 6d is provided on the circumferential surface of the guide shaft 6b, within which the second magnet 13 is located. When the second magnet 13 cooperates with the second Hall sensor 12, it is used to detect the second position of the screw assembly 6. The second Hall sensor 12 detects the second magnet 13 through magnetic field induction; that is, when the second magnet 13 approaches the second Hall sensor 12, a magnetic field is generated around the second Hall sensor 12. The semiconductor material within the second Hall sensor 12 senses this magnetic field and generates a potential difference on both sides, which is converted into an electrical signal. The change in the magnetic field of the magnet by the Hall sensor is prior art and will not be described further in this invention.

[0031] like Figure 3 When the fixed-axis linear motor rotates forward, it causes the screw assembly 6 to move linearly from left to right (screw assembly 6 retracts). The screw assembly 6, along with the first magnet 10 and the second magnet 13, moves linearly from left to right, causing the first magnet 10 to gradually approach the first Hall sensor 9, while the second magnet 13 gradually moves away from the second Hall sensor 12. When the first Hall sensor 9 detects the first magnet 10, the screw assembly 6 retracts to its limit position. The first Hall sensor 9 feeds back the detection signal to the PLC controller. The PLC controller controls the fixed-axis linear motor to stop working, or the PLC controller controls the fixed-axis linear motor to reverse, causing the screw assembly 6 to move linearly from right to left.

[0032] like Figure 4 When the fixed-axis linear motor reverses, it causes the screw assembly 6 to move linearly from right to left (the screw assembly 6 extends). The screw assembly 6, along with the first magnet 10 and the second magnet 13, moves linearly from right to left, causing the first magnet 10 to gradually move away from the first Hall sensor 9 and the second magnet 12 to gradually move closer to the second Hall sensor 13. When the second Hall sensor 12 detects the second magnet 13, the screw assembly 6 extends to its limit position. The second Hall sensor 12 feeds back the detection signal to the PLC controller. The PLC controller controls the fixed-axis linear motor to stop working, or the PLC controller controls the fixed-axis linear motor to rotate forward, causing the screw assembly 6 to move linearly from left to right.

Claims

1. A fixed-shaft linear motor with working position detection, comprising a housing (1), a stator (2), a bearing assembly (3), a rotor assembly (4), a nut (5), a screw rod assembly (6), and a guide sleeve (7), the stator (2), the bearing assembly (3), and the rotor assembly (4) are all installed in the housing (1), the rotor assembly (4) is connected with the bearing assembly (3) after passing through the stator (2), the nut (5) is located in the inner hole of the rotor assembly (4) and is fixed with the rotor assembly (4), the screw rod assembly (6) passes through the nut (5) and is threadedly connected with the nut (5), the guide sleeve (7) is fixed with one end of the housing (1), the screw rod assembly (6) comprises a screw rod (6a) and a guide shaft (6b), one end of the screw rod (6a) is fixed with the guide shaft (6b), the guide shaft (6b) is fixed with the guide sleeve (7) in the circumferential direction and is in sliding fit with the guide sleeve (7) in the axial direction, characterized in that, The shell (8) is fixed to the other end of the housing (1), the first Hall sensor (9) is matched with the shell (8), the first magnetic steel (10) is matched with the screw rod (6a), the first magnetic steel (10) is matched with the first Hall sensor (9) to detect the first position of the screw rod assembly (6), the support component (11) is fixed with the guide sleeve (7), the second Hall sensor (12) is matched with the support component (11), the second magnetic steel (13) is matched with the guide shaft (6b), and the second magnetic steel (13) is matched with the second Hall sensor (12) to detect the second position of the screw rod assembly (6).

2. The fixed-shaft linear motor with working position detection according to claim 1, characterized in that, The shell (8) is provided with a first mounting hole (8a), the first Hall sensor (9) is matched with the first mounting hole (8a), the screw rod (6a) is provided with an axial first accommodating cavity (6c) at the other end, one end of the first magnetic steel (10) is matched with the first accommodating cavity (6c), and the other end of the first magnetic steel (10) is exposed outside the first accommodating cavity (6c).

3. The fixed-shaft linear motor with working position detection according to claim 1, characterized in that, The guide shaft (6b) is provided with a second accommodating cavity (6d) on the peripheral surface, and the second magnetic steel (13) is located in the second accommodating cavity (6d).

4. The fixed-shaft linear motor with working position detection according to any one of claims 1 to 3, characterized in that, The support component (11) includes a first sleeve (11a) and a second sleeve (11b), the first sleeve (11a) is fixed with one end of the second sleeve (11b), the first sleeve (11a) is sleeved on the guide sleeve (7) and fixed with the guide sleeve (7), the inner wall of the second sleeve (11b) is provided with an assembly groove (11c), and the second Hall sensor (12) is matched with the assembly groove (11c).

5. The fixed-shaft linear motor with working position detection according to claim 4, characterized in that, The assembly groove (11c) penetrates the axial end face of the other end of the second sleeve (11b), and at least a part of the assembly groove (11c) is tapered.

6. The fixed-shaft linear motor with working position detection according to claim 4, characterized in that, The outer peripheral surface of the guide sleeve (7) is provided with a protrusion (7a), the inner wall of the first sleeve (11a) is provided with a first combining groove (11d), and the first combining groove (11d) is matched with the protrusion (7a) in a clearance fit to form a circumferential fixation between the support component (11) and the guide sleeve (7).

Images