Permanent magnet synchronous linear motor

Abstract

The permanent magnet synchronous linear motor comprises a casing, a rotor and a screw rod module, the rotor is arranged in the casing and is of a hollow structure, the screw rod module comprises a main screw rod and a planetary roller, the main screw rod is movably located in the hollow structure of the rotor, one end of the main screw rod is movably arranged in the casing in a penetrating mode and extends out of the casing, and the other end of the main screw rod is connected with the planetary roller. And the planetary roller is in threaded connection with the inner wall of the hollow structure of the rotor and is in threaded connection with the main screw rod, and when in use, the rotor drives the planetary roller to rotate in the rotating process, so that rotation of the rotor is converted into linear motion of the main screw rod. By adopting the design mode, the screw rod module is arranged in the hollow structure of the rotor, so that the structure of the whole permanent magnet synchronous linear motor is more compact, and the miniaturization design of the permanent magnet synchronous linear motor is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to a permanent magnet synchronous linear motor. Background Art

[0002] There are mainly two types of permanent magnet synchronous linear motors commonly found on the market. One is to drive the slider to perform linear motion on the sliding track support or flexible cable support by setting a sliding track support or flexible cable support through the electromagnetic interaction between the coil winding and the permanent magnet. However, with such a design, a special sliding track support or flexible cable support needs to be set up, which makes the permanent magnet synchronous linear motor larger in size. The other is to achieve linear motion through a rotating motor plus a planetary roller screw. However, with such a design, two separate rotating motors and planetary roller screws are often assembled together through an interface, which also makes the permanent magnet synchronous linear motor larger in size. Utility Model Content

[0003] In order to overcome at least one of the defects of the prior art described above, the utility model provides a permanent magnet synchronous linear motor to solve the problem of large size of the permanent magnet synchronous linear motor in the prior art.

[0004] The utility model is a technical solution adopted to solve the problem. In the first aspect, the embodiment of the utility model discloses a permanent magnet synchronous linear motor, including a casing, a rotor and a screw module. The rotor is arranged in the casing, and the rotor is a hollow structure. The screw module includes a main screw and planetary rollers. The main screw can be movably located in the hollow structure of the rotor, and one end of the main screw is movably penetrated through the casing and extends outside the casing. The planetary roller is threadedly connected to the inner wall of the hollow structure of the rotor and is threadedly connected to the main screw to convert the rotation of the rotor into linear motion of the main screw.

[0005] As an optional implementation, in an embodiment of the utility model, the permanent magnet synchronous linear motor also includes a guide sleeve, which is arranged at the front end of the housing, and the guide sleeve is provided with a guide hole adapted for a main screw rod, and the main screw rod is movably inserted into the guide hole.

[0006] As an optional implementation, in an embodiment of the utility model, the permanent magnet synchronous linear motor also includes a ball bearing, a four-point contact ball bearing and a bearing sleeve, the ball bearing sleeve is arranged at the front end of the rotating shaft of the rotor, the bearing sleeve is arranged at the rear end of the rotating shaft of the rotor, and the four-point contact ball bearing sleeve is arranged on the bearing sleeve.

[0007] As an optional implementation, in an embodiment of the utility model, the casing includes a main shell and a front cover, the front cover covers the front end of the main shell, the front cover is provided with a front cover stop, the front cover stop limits the ball bearing, and there is a floating gap between the ball bearing and the front cover stop.

[0008] As an optional implementation, in an embodiment of the utility model, the casing includes a main shell and a transition ring, the transition ring is connected to the rear end of the main shell, the permanent magnet synchronous linear motor also includes a bearing pressure plate, the bearing pressure plate is located at the rear end of the rotor shaft to limit the bearing sleeve, the inner ring of the four-point contact ball bearing is clamped between the bearing pressure plate and the bearing sleeve, and the outer ring of the four-point contact ball bearing is clamped between the transition ring and the main shell.

[0009] As an optional implementation, in an embodiment of the utility model, the permanent magnet synchronous linear motor also includes a position detection device arranged at the rear end of the casing, and the position detection device is used to detect the absolute position vector of the permanent magnet synchronous linear motor and the number of motor rotations of the permanent magnet synchronous linear motor.

[0010] As an optional implementation, in an embodiment of the utility model, the position detection device includes a central gear set, an edge gear set, a first encoder and a second encoder, the central gear set is connected to the rotor, the central gear set rotates synchronously with the rotor under the drive of the rotor, the first encoder is used to measure the position of the central gear set, the edge gear set is meshed and connected to the central gear set, and the second encoder is used to measure the position of the edge gear set;

[0011] The edge gear set and the center gear set have the same module but different numbers of teeth.

[0012] As an optional implementation, in an embodiment of the utility model, the center gear group includes a first gear, a first position magnet and a first shielding magnetic ring, the first position magnet is embedded in the first gear, the first shielding magnetic ring is arranged outside the first gear, and the first encoder is a detection chip for sensing the first position magnet; the edge gear group includes a second gear, a second position magnet and a second shielding magnetic ring, the second position magnet is embedded in the second gear, the second shielding magnetic ring is arranged outside the second gear, and the second encoder is a detection chip for sensing the second position magnet.

[0013] As an optional implementation, in an embodiment of the utility model, the casing includes a back cover, the permanent magnet synchronous linear motor also includes a driver, a strain gauge is attached to the back cover, the back cover undergoes elastic deformation under the action of push-pull force so that the resistance value of the strain gauge changes, and the driver calculates the push-pull force of the motor through the resistance value of the strain gauge.

[0014] As an optional embodiment, in an embodiment of the utility model, the rotor includes a rotating shaft, a plurality of first magnets, a plurality of second magnets, a first skeleton, at least one second skeleton and a third skeleton, the rotating shaft is a hollow structure, the main screw and the planetary rollers are located in the hollow structure of the rotating shaft, the first skeleton, at least one second skeleton and the third skeleton are sequentially spaced and sleeved on the rotating shaft, a plurality of first positioning spaces distributed along the circumference of the rotating shaft are provided between the first skeleton and the second skeleton, a plurality of second positioning spaces distributed along the circumference of the rotating shaft are provided between the second skeleton and the third skeleton, a number of the first magnets and a number of the second magnets are alternately arranged in the plurality of the first positioning spaces in sequence, a number of the first magnets and a number of the second magnets are alternately arranged in the plurality of the second positioning spaces in sequence, and the magnets in the second positioning spaces and the first positioning spaces on the same axial direction are the same.

[0015] As an optional implementation, in an embodiment of the utility model, when there are more than two second skeletons, a plurality of third positioning spaces distributed along the circumference of the rotating shaft are provided between two adjacent second skeletons, and a plurality of the first magnets and a plurality of the second magnets are alternately arranged in the plurality of third positioning spaces in sequence, and the magnets in the third positioning spaces and the first positioning spaces on the same axial direction are the same.

[0016] As an optional implementation, in an embodiment of the utility model, the first skeleton is provided with a plurality of first positioning protrusions evenly distributed along the circumference of the first skeleton, the second skeleton is provided with a plurality of second positioning protrusions evenly distributed along the circumference of the second skeleton and corresponding to the first positioning protrusions, and the first positioning space is formed between two adjacent first positioning protrusions and two adjacent second positioning protrusions;

[0017] The third skeleton is provided with a plurality of third positioning protrusions evenly distributed along the circumference of the third skeleton, and the second skeleton is provided with a plurality of fourth positioning protrusions evenly distributed along the circumference of the second skeleton and corresponding to the third positioning protrusions, and the second positioning space is formed between two adjacent third positioning protrusions and two adjacent fourth positioning protrusions.

[0018] Implementing the embodiments of the present utility model will have the following beneficial effects:

[0019] The utility model is provided with a permanent magnet synchronous linear motor including a casing, a rotor and a screw module. The rotor is arranged in the casing, and the rotor is a hollow structure. The screw module includes a main screw and a planetary roller. The main screw can be movably arranged in the hollow structure of the rotor, and one end of the main screw is movably arranged in the casing and extends outside the casing. The planetary roller is threadedly connected to the inner wall of the hollow structure of the rotor and is threadedly connected to the main screw. When in use, the rotor drives the planetary roller to rotate during the rotation process to convert the rotation of the rotor into the linear motion of the main screw. With such a design, since the screw module is arranged in the hollow structure of the rotor, the structure of the entire permanent magnet synchronous linear motor is more compact, which is conducive to the miniaturized design of the permanent magnet synchronous linear motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a structural schematic diagram of a permanent magnet synchronous linear motor in an embodiment of the utility model;

[0022] Figure 2 It is a cross-sectional view of the permanent magnet linear synchronous motor in the embodiment of the utility model;

[0023] Figure 3 It is a structural schematic diagram of the screw rod module in the embodiment of the utility model;

[0024] Figure 4 This is a schematic diagram of the structure of the hidden rear cover of the permanent magnet synchronous linear motor in the embodiment of the utility model;

[0025] Figure 5 It is a schematic diagram of the structure of the driver in the embodiment of the utility model;

[0026] Figure 6 It is a structural schematic diagram of a permanent magnet synchronous linear motor in an embodiment of the utility model;

[0027] Figure 7 It is a schematic diagram of the structural decomposition of the permanent magnet linear synchronous motor in the embodiment of the utility model;

[0028] Figure 8 This is an end view of the first magnet in the embodiment of the utility model.

[0029] The meanings of the reference numerals are as follows:

[0030] 1- housing; 11- front cover; 12- main housing; 13- transition ring; 14- rear end; 2- rotor; 21- shaft; 211- positioning step; 22- first magnet; 23- second magnet; 24- first skeleton; 241- first positioning protrusion; 25- second skeleton; 251- second positioning protrusion; 252- fourth positioning protrusion; 26- third skeleton; 261- third positioning protrusion; 3- screw module; 31- main screw; 32- planetary roller; 4- guide sleeve; 5- ball bearing; 6- four-point contact ball bearing; 7- bearing sleeve; 8- bearing pressure plate; 9- center gear set; 91- first gear; 92- first position magnet; 93- first shielding magnetic ring; 10- edge gear set; 101- second gear; 102- second position magnet; 103- second shielding magnetic ring; 20- first encoder; 30- second encoder; 40- driver; 50- strain gauge. DETAILED DESCRIPTION

[0031] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0034] Example

[0035] Please also read Figures 1 to 5The embodiment of the utility model discloses a permanent magnet synchronous linear motor. The permanent magnet synchronous linear motor of the present scheme includes a housing 1, a rotor 2 and a screw module 3. The rotor 2 is arranged in the housing 1. The rotor 2 is a hollow structure. The screw module 3 includes a main screw 31 and a planetary roller 32. The main screw 31 can be movably located in the hollow structure of the rotor 2. One end of the main screw 31 is movably arranged in the housing 1 and extends outside the housing 1. The planetary roller 32 is threadedly connected to the inner wall of the hollow structure of the rotor 2 and is threadedly connected to the main screw 31. When in use, the rotor 2 drives the planetary roller 32 to rotate during the rotation process to convert the rotation of the rotor 2 into the linear motion of the main screw 31. With such a design, since the screw module 3 is arranged in the hollow structure of the rotor 2, the structure of the entire permanent magnet synchronous linear motor is more compact, which is conducive to the miniaturization design of the permanent magnet synchronous linear motor.

[0036] Assuming that the length of the thread in the rotor 2 is L, the length of the planetary roller 32 is M, and the lead is S, the maximum number of rotations of the motor is n=(LM) / S.

[0037] The housing 1 of the present solution comprises a front cover 11 , a main housing 12 , a transition ring 13 and a rear cover which are arranged in sequence. The front cover 11 , the main housing 12 , the transition ring 13 and the rear cover together enclose a cavity for installing the rotor 2 .

[0038] In some embodiments, in order for the main screw 31 to convert the rotation of the planetary roller 32 into its own linear motion, the main screw 31 is a square rod, and the permanent magnet synchronous linear motor also includes a guide sleeve 4, which is disposed at the front end of the housing 1. The guide sleeve 4 is provided with a square guide hole adapted for the main screw 31, and the main screw 31 is movably inserted into the guide hole.

[0039] In some embodiments, in order to better rotate the rotor 2 in the housing 1, the permanent magnet synchronous linear motor further includes a ball bearing 5, a four-point contact ball bearing 6 and a bearing sleeve 7, the ball bearing 5 is sleeved on the front end of the rotating shaft 21 of the rotor 2, the bearing sleeve 7 is sleeved on the rear end 14 of the rotating shaft 21 of the rotor 2, and the four-point contact ball bearing 6 is sleeved on the bearing sleeve 7. With such a design, the rotation of the rotor 2 relative to the housing 1 is achieved through the rolling of the ball bearing 5 and the four-point contact ball bearing 6.

[0040] Furthermore, the housing 1 includes a main housing 12 and a front cover 11. The front cover 11 covers the front end of the main housing 12. The front cover 11 is provided with a front cover stopper, which limits the ball bearing 5. There is a floating gap between the ball bearing 5 and the front cover stopper. With such a design, the ball bearing 5 can withstand radial loads.

[0041] Furthermore, the housing 1 includes a main housing 12 and a transition ring 13, the transition ring 13 is connected to the rear end 14 of the main housing 12, the permanent magnet synchronous linear motor also includes a bearing pressure plate 8, the bearing pressure plate 8 is located at the rear end 14 of the rotating shaft 21 of the rotor 2 to limit the bearing sleeve 7, the inner ring of the four-point contact ball bearing 6 is clamped between the bearing pressure plate 8 and the bearing sleeve 7, and the outer ring of the four-point contact ball bearing 6 is clamped between the transition ring 13 and the main housing 12. With such a design, the four-point contact ball bearing 6 can withstand the axial push and pull force and radial load of the permanent magnet synchronous linear motor.

[0042] In some embodiments, the permanent magnet synchronous linear motor further includes a position detection device disposed at the rear end 14 of the housing 1, and the position detection device is used to detect the absolute position vector of the permanent magnet synchronous linear motor and the number of motor rotations of the permanent magnet synchronous linear motor.

[0043] Further, the position detection device includes a central gear set 9, an edge gear set 10, a first encoder 20 and a second encoder 30. The central gear set 9 is connected to the rotor 2. The central gear set 9 rotates synchronously with the rotor 2 when driven by the rotor 2. The first encoder 20 is used to measure the position of the central gear set 9. The edge gear set 10 is meshed and connected to the central gear set 9. The second encoder 30 is used to measure the position of the edge gear set 10. The edge gear set 10 has the same module as the central gear set 9 but a different number of teeth. With such a design, since the edge gear set 10 has the same module as the central gear set 9 but a different number of teeth, the angular velocities of the central gear set 9 and the edge gear set 10 will be different. The position of the central gear set 9 can be measured by the first encoder 20, and the position of the edge gear set 10 can be measured by the second encoder 30. By comparing the position difference between the central gear set 9 and the edge gear set 10, the multi-turn position of the motor can be calculated, and the extension length of the main screw can be calibrated using the differential principle.

[0044] Preferably, the central gear set 9 is fixed on the bearing pressure plate 8 , and the edge gear set 10 is fixed on the transition ring 13 .

[0045] Furthermore, the center gear group 9 includes a first gear 91, a first position magnet 92 and a first shielding magnetic ring 93, the first position magnet 92 is embedded in the first gear 91, the first shielding magnetic ring 93 is arranged outside the first gear 91, and the first encoder 20 is a detection chip for sensing the first position magnet 92; the edge gear group 10 includes a second gear 101, a second position magnet 102 and a second shielding magnetic ring 103, the second position magnet 102 is embedded in the second gear 101, the second shielding magnetic ring 103 is arranged outside the second gear 101, and the second encoder 30 is a detection chip for sensing the second position magnet 102.

[0046] In some embodiments, considering that the rear cover will be subjected to push-pull force and produce stress deformation when the permanent magnet synchronous linear motor is running, the permanent magnet synchronous linear motor also includes a driver 40, and a strain gauge 50 is attached to the rear cover. The rear cover undergoes elastic deformation under the push-pull force, so that the resistance value of the strain gauge 50 changes, and the driver 40 calculates the push-pull force of the motor through the resistance value of the strain gauge 50. With such a design, the axial length of the motor can be effectively shortened by replacing the external push-pull force sensor with this integrated structure, which is conducive to the miniaturization design of the permanent magnet synchronous linear motor.

[0047] Please also read Figures 6 to 8 In some embodiments, the rotor 2 structure includes a rotating shaft 21, a plurality of first magnets 22, a plurality of second magnets 23, a first skeleton 24, at least one second skeleton 25 and a third skeleton 26. The rotating shaft 21 is a hollow structure. The main screw 31 and the planetary rollers 32 are located in the hollow structure of the rotating shaft 21. The first skeleton 24, at least one second skeleton 25 and the third skeleton 26 are sequentially and spaced apart on the rotating shaft 21. A plurality of first positioning spaces distributed along the circumference of the rotating shaft 21 are provided between the first skeleton 24 and the second skeleton 25. A plurality of second positioning spaces distributed along the circumference of the rotating shaft 21 are provided between the second skeleton 25 and the third skeleton 26. A plurality of first magnets 22 and a plurality of second magnets 23 are alternately arranged in the plurality of first positioning spaces in sequence. A plurality of first magnets 22 and a plurality of second magnets 23 are alternately arranged in the plurality of second positioning spaces in sequence. The magnets in the second positioning spaces and the first positioning spaces on the same axial direction are the same. By adopting such a design, the first skeleton 24, the second skeleton 25 and the third skeleton 26 are used to locate the axial position and the circumferential position of the first magnet 22 and the second magnet 23, so as to reduce the assembly deviation of the first magnet 22 and the second magnet 23, and reduce the cogging torque and pulsating torque of the permanent magnet synchronous motor. In addition, since the skeleton production cost is lower than that of the mold opening mold, the production cost of the motor is reduced.

[0048] The magnetic poles of the adjacent ends of the first magnet 22 and the second magnet 23 are opposite.

[0049] Further, at least one second skeleton 25 includes one second skeleton 25 and more than two second skeletons 25. When there are more than two second skeletons 25, a plurality of third positioning spaces distributed along the circumference of the rotating shaft 21 are provided between two adjacent second skeletons 25. A plurality of first magnets 22 and a plurality of second magnets 23 are alternately provided in the plurality of third positioning spaces in sequence. The magnets in the third positioning spaces and the first positioning spaces on the same axial direction are the same. This embodiment only takes the second skeleton 25 as an example.

[0050] In some embodiments, in order to form a first positioning space between the first skeleton 24 and the second skeleton 25 brackets, the first skeleton 24 is provided with a plurality of first positioning protrusions 241 evenly distributed along the circumference of the first skeleton 24, and the second skeleton 25 is provided with a plurality of second positioning protrusions 251 evenly distributed along the circumference of the second skeleton 25 and corresponding to the first positioning protrusions 241, and a first positioning space is jointly formed between two adjacent first positioning protrusions 241 and two adjacent second positioning protrusions 251.

[0051] Similarly, in order to form a second positioning space between the second skeleton 25 and the third skeleton 26, the third skeleton 26 is provided with a plurality of third positioning protrusions 261 evenly distributed along the circumference of the third skeleton 26, and the second skeleton 25 is provided with a plurality of fourth positioning protrusions 252 evenly distributed along the circumference of the second skeleton 25 and corresponding to the third positioning protrusions 261, and a second positioning space is formed between two adjacent third positioning protrusions 261 and two adjacent fourth positioning protrusions 252.

[0052] In some embodiments, in order to improve the fit between the first frame 24, at least one second frame 25, and the third frame 26 and the rotating shaft 21, the contour of the inner arc surface of the first frame 24, at least one second frame 25, and the third frame 26 in contact with the rotating shaft 21 is an arc surface adapted to the circumferential surface of the rotating shaft 21. With such a design, the inner sidewall of the first frame 24, at least one second frame 25, and the third frame 26 in contact with the rotating shaft 21 is an arc surface, and its diameter is equal to the diameter of the outer circle of the rotating shaft 21, so that the contact surfaces of the two are completely fitted, the fit is tighter, and the positioning accuracy is higher.

[0053] In some embodiments, in order to facilitate the installation of the first frame 24, the at least one second frame 25 and the third frame 26 on the rotating shaft 21, the first frame 24, the at least one second frame 25 and the third frame 26 and the rotating shaft 21 are matched in a transition fit.

[0054] In some embodiments, the first magnet 22 and the first positioning space are matched in a clearance fit in the circumferential direction of the rotating shaft 21 , and the second magnet 23 and the second positioning space are matched in a clearance fit in the circumferential direction of the rotating shaft 21 .

[0055] In some embodiments, since the first magnet 22 and the second magnet 23 are directly attached to the rotating shaft 21, in order to make the first magnet 22 and the second magnet 23 have a good fit with the rotating shaft 21, the contours of the inner arc surfaces of each first magnet 22 and each second magnet 23 in contact with the rotating shaft 21 are all arc surfaces that match the circumferential surface of the rotating shaft 21. With such a design, the arc diameter is the same as the outer diameter of the portion where the rotating shaft 21 is attached, so that the first magnet 22 and the second magnet 23 are completely fitted with the circumferential surface of the rotating shaft 21, so that the first magnet 22 and the second magnet 23 are firmly installed, thereby improving the performance of the motor.

[0056] Furthermore, the inner and outer arc surfaces of the first magnet 22 have eccentricity, and the magnetization method of the first magnet 22 is parallel magnetization; the inner and outer arc surfaces of the second magnet 23 have eccentricity, and the magnetization method of the second magnet 23 is parallel magnetization. With such a design, the first magnet 22 and the second magnet 23 can obtain a perfect sinusoidal air gap magnetic field as much as possible, reducing radial electromagnetic force harmonics and torque pulsation.

[0057] In some embodiments, in order to better position the above-mentioned skeleton and magnet, a positioning step 211 is provided at one end of the rotating shaft 21, and the first skeleton 24, at least one second skeleton 25 and the third skeleton 26 are sequentially arranged from one end of the rotating shaft 21 where the positioning step 211 is located to the other end, and the first skeleton 24 abuts against the positioning step 211. With such a design, during assembly, the first skeleton 24 is first installed, and the first magnet 22 and the second magnet 23 are sequentially inserted into the first positioning space, and then the second skeleton 25 is installed, and then the first magnet 22 and the second magnet 23 are installed in sequence, and finally the third skeleton 26 is installed.

[0058] In some embodiments, the first frame 24, the at least one second frame 25 and the second frame 25 are made of plastic material. The frame made of plastic material is easy to shape, has low energy consumption and low production cost.

[0059] In some embodiments, in order to fix the first magnet 22 and the second magnet 23 on the rotating shaft 21 , the first magnet 22 and the second magnet 23 are glued to the rotating shaft 21 using special magnetic steel glue.

[0060] The utility model provides a permanent magnet synchronous linear motor, which includes a housing 1, a rotor 2 and a screw module 3. The rotor 2 is arranged in the housing 1, and the rotor 2 is a hollow structure. The screw module 3 includes a main screw 31 and a planetary roller 32. The main screw 31 can be movably located in the hollow structure of the rotor 2, and one end of the main screw 31 is movably arranged in the housing 1 and extends outside the housing 1. The planetary roller 32 is threadedly connected to the inner wall of the hollow structure of the rotor 2 and is threadedly connected to the main screw 31. When in use, the rotor 2 drives the planetary roller 32 to rotate during the rotation process, so as to convert the rotation of the rotor 2 into the linear motion of the main screw 31. With such a design, since the screw module 3 is arranged in the hollow structure of the rotor 2, the structure of the entire permanent magnet synchronous linear motor is more compact, which is conducive to the miniaturization design of the permanent magnet synchronous linear motor.

[0061] The technical means disclosed in the solution of the utility model are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical solutions composed of any combination of the above technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model, and these improvements and modifications are also regarded as the protection scope of the utility model.

Claims

1. A permanent magnet synchronous linear motor, characterized in that: The invention comprises a housing (1), a rotor (2) and a screw module (3), wherein the rotor (2) is arranged in the housing (1), the rotor (2) is a hollow structure, the screw module (3) comprises a main screw (31) and a planetary roller (32), the main screw (31) is movably located in the hollow structure of the rotor (2), one end of the main screw (31) is movably arranged in the housing (1) and extends outside the housing (1), and the planetary roller (32) is threadedly connected to the inner wall of the hollow structure of the rotor (2) and is threadedly connected to the main screw (31) so as to convert the rotation of the rotor (2) into the linear motion of the main screw (31).

2. The permanent magnet linear synchronous motor according to claim 1, characterized in that: The permanent magnet synchronous linear motor further comprises a guide sleeve (4), the guide sleeve (4) being arranged at the front end of the housing (1), the guide sleeve (4) being provided with a guide hole adapted for a main screw rod (31), and the main screw rod (31) being movably arranged through the guide hole.

3. The permanent magnet linear synchronous motor according to claim 1, characterized in that: The permanent magnet synchronous linear motor further comprises a ball bearing (5), a four-point contact ball bearing (6) and a bearing sleeve (7); the ball bearing (5) is sleeved on the front end of the rotating shaft (21) of the rotor (2); the bearing sleeve (7) is sleeved on the rear end (14) of the rotating shaft (21) of the rotor (2); and the four-point contact ball bearing (6) is sleeved on the bearing sleeve (7).

4. The permanent magnet synchronous linear motor according to claim 3, characterized in that: The casing (1) comprises a main shell (12) and a front cover (11), wherein the front cover (11) covers the front end of the main shell (12), and the front cover (11) is provided with a front cover stop, wherein the front cover stop limits the ball bearing (5), and a floating gap is provided between the ball bearing (5) and the front cover stop.

5. The permanent magnet linear synchronous motor according to claim 3, characterized in that: The housing (1) comprises a main housing (12) and a transition ring (13), wherein the transition ring (13) is connected to the rear end (14) of the main housing (12), and the permanent magnet synchronous linear motor further comprises a bearing pressure plate (8), wherein the bearing pressure plate (8) is located at the rear end (14) of the rotating shaft (21) of the rotor (2) to limit the position of the bearing sleeve (7), the inner ring of the bearing of the four-point contact ball bearing (6) is clamped between the bearing pressure plate (8) and the bearing sleeve (7), and the outer ring of the bearing of the four-point contact ball bearing (6) is clamped between the transition ring (13) and the main housing (12).

6. The permanent magnet synchronous linear motor according to claim 1, characterized in that: The permanent magnet synchronous linear motor also includes a position detection device arranged at the rear end (14) of the housing (1), the position detection device being used to detect the absolute position vector of the permanent magnet synchronous linear motor and the number of motor rotations of the permanent magnet synchronous linear motor.

7. The permanent magnet linear synchronous motor according to claim 6, characterized in that: The position detection device comprises a central gear set (9), an edge gear set (10), a first encoder (20) and a second encoder (30); the central gear set (9) is connected to the rotor (2); the central gear set (9) rotates synchronously with the rotor (2) under the drive of the rotor (2); the first encoder (20) is used to measure the position of the central gear set (9); the edge gear set (10) is meshedly connected to the central gear set (9); and the second encoder (30) is used to measure the position of the edge gear set (10); The edge gear set (10) and the center gear set (9) have the same module but different numbers of teeth.

8. The permanent magnet linear synchronous motor according to claim 7, characterized in that: The central gear set (9) comprises a first gear (91), a first position magnet (92) and a first shielding magnetic ring (93); the first position magnet (92) is embedded in the first gear (91); the first shielding magnetic ring (93) is arranged outside the first gear (91); and the first encoder (20) is a detection chip for sensing the first position magnet (92); the edge gear set (10) comprises a second gear (101), a second position magnet (102) and a second shielding magnetic ring (103); the second position magnet (102) is embedded in the second gear (101); the second shielding magnetic ring (103) is arranged outside the second gear (101); and the second encoder (30) is a detection chip for sensing the second position magnet (102).

9. The permanent magnet linear synchronous motor according to claim 1, characterized in that: The housing (1) comprises a rear cover, and the permanent magnet synchronous linear motor further comprises a driver (40). A strain gauge (50) is attached to the rear cover. The rear cover undergoes elastic deformation under the action of a push-pull force, so that the resistance value of the strain gauge (50) changes. The driver (40) calculates the push-pull force of the motor through the resistance value of the strain gauge (50).

10. The permanent magnet linear synchronous motor according to any one of claims 1 to 9, characterized in that: The rotor (2) comprises a rotating shaft (21), a plurality of first magnets (22), a plurality of second magnets (23), a first frame (24), at least one second frame (25) and a third frame (26); the rotating shaft (21) is a hollow structure; the main screw (31) and the planetary rollers (32) are located in the hollow structure of the rotating shaft (21); the first frame (24), at least one second frame (25) and the third frame (26) are sequentially sleeved on the rotating shaft (21) at intervals; the first frame (24) and the second frame (25) are spaced apart from each other. A plurality of first positioning spaces are arranged between the second frame (25) and the third frame (26) and are distributed along the circumference of the rotating shaft (21); a plurality of second positioning spaces are arranged between the second frame (25) and the third frame (26) and are distributed along the circumference of the rotating shaft (21); a plurality of the first magnets (22) and a plurality of the second magnets (23) are arranged alternately in the plurality of the first positioning spaces in sequence; a plurality of the first magnets (22) and a plurality of the second magnets (23) are arranged alternately in the plurality of the second positioning spaces in sequence; and the magnets in the second positioning spaces and the first positioning spaces on the same axial direction are the same.

11. The permanent magnet linear synchronous motor according to claim 10, characterized in that: When there are more than two second skeletons (25), a plurality of third positioning spaces distributed along the circumference of the rotating shaft (21) are provided between two adjacent second skeletons (25); a plurality of first magnets (22) and a plurality of second magnets (23) are alternately provided in the plurality of third positioning spaces in sequence; and the magnets in the third positioning spaces and the first positioning spaces on the same axial direction are the same.

12. The permanent magnet linear synchronous motor according to claim 10, characterized in that: The first frame (24) is provided with a plurality of first positioning protrusions (241) uniformly distributed along the circumference of the first frame (24), the second frame (25) is provided with a plurality of second positioning protrusions (251) uniformly distributed along the circumference of the second frame (25) and corresponding to the first positioning protrusions (241), and the first positioning space is formed between two adjacent first positioning protrusions (241) and two adjacent second positioning protrusions (251); The third skeleton (26) is provided with a plurality of third positioning protrusions (261) uniformly distributed along the circumference of the third skeleton (26); the second skeleton (25) is provided with a plurality of fourth positioning protrusions (252) uniformly distributed along the circumference of the second skeleton (25) and corresponding to the third positioning protrusions (261); two adjacent third positioning protrusions (261) and two adjacent fourth positioning protrusions (252) together form the second positioning space.

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