Cylindrical linear motor and installation method thereof

Abstract

The invention discloses a cylinder type linear motor and an installation method thereof, the cylinder type linear motor comprises a secondary and a primary, the secondary comprises a shell and permanent magnets arranged on the inner surface of the shell, the outer surfaces of the permanent magnets are attached to the inner surface of the shell, the permanent magnets are arranged on the inner surface of the shell at intervals in a stepped mode, and the same-direction ends of the adjacent permanent magnets are different in polarity; the same-direction ends of two adjacent rows of permanent magnets in the axial direction of the shell have the same polarity; the primary stage comprises a cylindrical magnet yoke, circular ring teeth, a coil, a cooler and a sealing cover, the circular ring teeth are arranged on the cylindrical magnet yoke at equal intervals, an insulating heat conduction material is arranged between the adjacent circular ring teeth, and the coil is located in the insulating heat conduction material. The thrust density of the motor can be effectively improved by adopting the ring cylinder type design, the thrust pulsation during operation can be effectively reduced by adopting the special design of the permanent magnets and the cylindrical magnet yokes, the thrust density of the motor can be further effectively improved by adding the cooler part, the temperature rise and the thrust pulsation of the motor are reduced, and the service life of the motor is prolonged. Therefore, the acceleration and precision of motor operation are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of linear motors, and particularly to a tubular linear motor and an installation method thereof. Background Art

[0002] A linear motor is a transmission device that directly converts electrical energy into linear motion mechanical energy without any intermediate conversion mechanism. Due to the outstanding advantages of the linear motor such as zero transmission chain, non-contact, no backlash, high stiffness, and fast response, the linear motor is gradually replacing direct servo mechanisms such as servo motors and ball screws and becoming the core functional component of high-speed and high-precision equipment. At present, linear motors are widely used in many application fields and occasions such as numerical control machine tools, automated production lines, elevators, subways, and maglev trains.

[0003] At present, on the one hand, the thrust density of the commonly used linear motor is small, resulting in a small acceleration during operation. On the other hand, the temperature rise of the motor is high, which easily causes thermal expansion of the workpiece, resulting in a relatively reduced operating accuracy of the motor. Thirdly, the thrust ripple of the commonly used linear motor is relatively large, which also causes the operating accuracy of the motor to decrease. Summary of the Invention

[0004] The purpose of the present invention is to provide a tubular linear motor and an installation method thereof. The tubular design can effectively improve the thrust density of the motor. The special design of the permanent magnet and the cylindrical yoke can effectively reduce the thrust ripple during operation. Adding a cooler part can further effectively improve the thrust density of the motor and reduce the temperature rise of the motor, solving the above defects in the prior art.

[0005] A tubular linear motor includes a secondary 1 and a primary 2, and there is a gap between the inner surfaces of the secondary 1 and the primary 2:

[0006] The secondary 1 includes a housing 11 and a permanent magnet 12 provided on the inner surface of the housing 11. The outer surface of the permanent magnet 12 is in contact with the inner surface of the housing 11, and the permanent magnets 12 are arranged at intervals in a stepped manner on the inner surface of the housing 11. The polarities of the same ends of adjacent permanent magnets 12 are different. Along the axis direction of the housing 11, the polarities of the same ends of adjacent rows of permanent magnets 12 are the same. The difference between every two adjacent rows of permanent magnets 12 along the axis direction of the housing 11 is ɑ:

[0007] Where τ is the pole pitch of the linear motor, z is the number of effective ring teeth, k is the number of rows of magnets in each group of permanent magnets, and 2p is the number of pole pairs;

[0008] The primary 2 includes a cylindrical yoke 21, ring teeth 212, coils 211, a cooler 212, and a sealing cover 23. The ring teeth 212 are arranged on the cylindrical yoke 21 at equal intervals tc Arrangement: Among them, 2p is the number of pole pairs, τ is the pole pitch of the linear motor, z is the number of teeth of the ring, an insulating and heat-conducting material is provided between adjacent ring teeth 212, and the coil 211 is located in the insulating and heat-conducting material.

[0009] In one embodiment, the permanent magnets 12 are all in the shape of tiles, and the permanent magnets 12 are evenly arranged at intervals along the circumferential direction of the housing 11.

[0010] In one embodiment, the outer surface of the permanent magnet 12 and the inner surface of the housing 11 are adhesively connected.

[0011] In one embodiment, the in-phase coils in every three adjacent coils 211 are connected to form a fractional-slot winding, the tail ends of the fractional-slot windings are commonly connected, and the head ends of the three-phase lines are connected to a three-phase power supply.

[0012] In one embodiment, a cooling cavity 222 is provided inside the cooler 22, two PU pipe joints 221 are provided above the cooler 22, and the cooler 22 is interconnected with the PU pipe 2211..

[0013] In one embodiment, a sealing cover 23 is provided below the cooler 22, the sealing cover 23 is fixed to the cooler 22 by bolts, and a sealing ring is provided between the sealing cover 23 and the cooler 22.

[0014] An installation method for a cylindrical linear motor, which is used for a cylindrical linear motor according to any one of the above, includes:

[0015] Step S1, installing the primary of the motor, including a cylindrical yoke, ring teeth, a coil, a cooler and a sealing cover;

[0016] Step S2, installing the secondary of the motor, including a housing and tile-shaped permanent magnets provided on the inner surface of the housing;

[0017] Step S3, inserting the secondary into the primary, and making the radial clearance between the secondary and the primary uniform through a circular tooling.

[0018] In one embodiment, the step S1 includes:

[0019] Step S11, inserting the ring teeth 212 into the cylindrical yoke 21, placing an insulating and heat-conducting material between every two adjacent ring teeth 212, the length of the insulating and heat-conducting material in the axial direction is equal to tc, the ring teeth 212 are arranged on the cylindrical yoke 21 at equal intervals tc, and a coil 211 is wound above each heat-conducting material;

[0020] Step S12, vacuum potting with epoxy resin glue;

[0021] Step S13: Two PU pipe connectors are provided above the cooler to connect the cooling cavity inside the cooler with the PU pipe connectors.

[0022] Step S14: The sealing cover is fixed below the cooler through bolts, and the inner wall of the cylindrical yoke is closely attached to the outer wall of the cooler.

[0023] In one embodiment, the said Step S2 includes:[[]]

[0024] Step S21: In the direction along the axis of the housing, the polarities of the same ends of adjacent rows of permanent magnets are the same, and every adjacent k rows of permanent magnets form a group.

[0025] Step S22: The distance between every two adjacent rows of the k rows of permanent magnets differs by ɑ in the direction along the axis of the housing, and the permanent magnets are evenly arranged at intervals in the circumferential direction of the housing.

[0026] The above technical solution has the following advantages or beneficial effects:[[]]

[0027] For this tubular linear motor and its installation method of the present invention, the tubular design can effectively improve the thrust density of the motor. The special designs of the permanent magnets and the cylindrical yoke can effectively reduce the thrust ripple during operation. Adding the cooler part can further effectively improve the thrust density of the motor, reduce the temperature rise and thrust ripple of the motor, thereby improving the acceleration and accuracy of the motor operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram of a tubular linear motor according to an embodiment of the present invention;

[0029] Figure 2 is a schematic cross-sectional structural diagram of a tubular linear motor according to an embodiment of the present invention;

[0030] Figure 3 is a schematic sectional structural diagram of a tubular linear motor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention is given with reference to the accompanying drawings.

[0032] Combined with Figure 1 — Figure 3 As shown, a tubular linear motor provided by the present invention aims to solve the problems of small thrust density, small acceleration, high temperature rise and low thrust ripple in the prior art, thereby improving the acceleration and accuracy of the motor operation.

[0033] A tubular linear motor, comprising a secondary 1 and a primary 2, with a gap provided between the inner surfaces of the secondary 1 and the primary 2:

[0034] The secondary 1 includes a housing 11 and permanent magnets 12 provided on the inner surface of the housing 11. The outer surface of the permanent magnet 12 is in contact with the inner surface of the housing 11, and the permanent magnets 12 are arranged at intervals in a stepped manner on the inner surface of the housing 11. The polarities of the same-direction ends of adjacent permanent magnets 12 are different. Along the axis direction of the housing 11, the polarities of the same-direction ends of adjacent rows of permanent magnets 12 are the same. The adjacent two rows of permanent magnets 12 are offset by ɑ along the axis direction of the housing 11:

[0035] Where τ is the pole pitch of the linear motor, z is the number of effective ring teeth, k is the number of rows of magnets in each group of permanent magnets, and 2p is the number of pole pairs;

[0036] The primary 2 includes a cylindrical yoke 21, ring teeth 212, coils 211, a cooler 212, and a sealing cover 23. The ring teeth 212 are arranged on the cylindrical yoke 21 at equal intervals t c arranged: Where 2p is the number of pole pairs, τ is the pole pitch of the linear motor, z is the number of ring teeth, an insulating and heat-conducting material is provided between adjacent ring teeth 212, and the coil 211 is located in the insulating and heat-conducting material.

[0037] Further, in a preferred embodiment of the tubular linear motor of the present invention, the permanent magnets 12 are all in the shape of tiles, and the permanent magnets 12 are evenly arranged at intervals along the circumferential direction of the housing 11.

[0038] Further, in a preferred embodiment of the tubular linear motor of the present invention, the outer surface of the permanent magnet 12 and the inner surface of the housing 11 are connected by bonding.

[0039] Further, in a preferred embodiment of the tubular linear motor of the present invention, the in-phase coils in every adjacent three coils 211 are connected to form a fractional-slot winding. The tail ends of the fractional-slot windings are connected in common, and the heads of the three-phase lines are connected to a three-phase power supply.

[0040] Further, in a preferred embodiment of the tubular linear motor of the present invention, the cooler 22 is internally provided with a cooling cavity 222. There are two PU pipe joints 221 above the cooler 22, and the cooler 22 is interconnected with the PU pipe 2211..

[0041] Further, in a preferred embodiment of the tubular linear motor of the present invention, a sealing cover 23 is provided below the cooler 22. The sealing cover 23 and the cooler 22 are fixed by bolts, and a sealing ring is provided between the sealing cover 23 and the cooler 22.

[0042] A cylindrical linear motor mainly includes a primary 2 and a secondary 1. A gap is provided between the outer surface of the primary 2 and the inner surface of the secondary 1. The secondary 1 is composed of a shell 11 and a permanent magnet 1 provided on the inner surface of the shell 11. The permanent magnets 12 are all tile-shaped, and the outer contour of the tile is completely in line with the inner contour of the shell 11. The permanent magnets 12 are arranged in steps on the inner surface of the shell 11, and the permanent magnets 12 are evenly spaced along the circumferential direction of the shell 11. The polarities of the same-direction ends of two adjacent rows of permanent magnets 12 along the axial direction of the shell 11 are the same, and every k adjacent rows of permanent magnets 12 form a group. The difference between every two adjacent rows of permanent magnets 12 in the axial direction of the shell is a:

[0043] Wherein: τ is the pole pitch of the linear motor, z is the number of effective annular teeth, k is the number of rows of magnets in each set of permanent magnets 12, and 2p is the number of pole pairs. The outer surface of the permanent magnet 12 is bonded to the inner surface of the housing 11, and then vacuum-encapsulated with epoxy resin glue.

[0044] The primary 2 is composed of a cylindrical yoke 21, an annular teeth 212, a coil 211, a cooler 212, and a sealing cover 23. The annular teeth 212 are arranged on the cylindrical yoke 21 at an equal spacing tc. Where tc: Where: 2p is the number of pole pairs, τ is the pole pitch of the linear motor, and z is the number of ring teeth.

[0045] In order to reduce thrust pulsation and increase thrust density, the annular teeth 212 are inserted into the cylindrical yoke 21, and a layer of high insulation and high thermal conductivity material is placed between each two adjacent annular teeth 212. The length of the insulation and thermal conductivity material along the axis direction is equal to tc. The coil 211 is located in the high insulation and high thermal conductivity material so that the heat generated by the coil is effectively transferred to the cooler, and then the cooling medium in the cooler circulates and flows away this part of the heat, thereby effectively reducing the temperature rise of the motor. The coil is wound on top of each high insulation and high thermal conductivity material, and then vacuum potted with epoxy resin glue.

[0046] Every three adjacent coils 211 from top to bottom form a unit winding, and the same-phase coils in each unit winding are connected in parallel to form a fractional slot winding. The tail ends of the fractional slot winding lines are connected together, and the head ends of the three-phase lines are connected to a three-phase power supply.

[0047] A cooling cavity 222 is provided inside the cooler 22, and two PU pipe joints 221 are provided above the cooler 22, which are interconnected with the PU pipe 2211. A sealing cover 23 is provided below the cooler 22, and the sealing cover 23 and the cooler 22 are fixed with bolts. A sealing cover is provided below the cooler, and a sealing ring is provided between the sealing cover and the cooler, which has a good sealing effect. The medium in the cooler can be water, air, alcohol, kerosene and other media that can be used for cooling.

[0048] The invention solves the problems of small thrust density, small acceleration, and high temperature rise in the prior art, thereby improving the acceleration and accuracy of the motor operation.

[0049] The invention also provides an installation method for a tubular linear motor, which can improve the thrust density, reduce the temperature rise and thrust ripple of the motor. The method steps are as follows:

[0050] An installation method for a tubular linear motor, which is used for any one of the above-mentioned tubular linear motors, includes:

[0051] Step S1, installing the primary of the motor, including a cylindrical yoke, ring teeth, coils, a cooler, and a sealing cover;

[0052] Step S2, installing the secondary of the motor, including a housing and tile-shaped permanent magnets provided on the inner surface of the housing;

[0053] Step S3, inserting the secondary into the primary, and making the radial clearance between the secondary and the primary uniform through an annular tooling.

[0054] Further, in a preferred embodiment of the installation method of the tubular linear motor of the invention, the step S1 includes:

[0055] Step S11, inserting the ring teeth 212 into the cylindrical yoke 21, placing insulating and heat-conducting materials between every two adjacent ring teeth 212, the length of the insulating and heat-conducting materials in the axial direction being equal to tc, arranging the ring teeth 212 on the cylindrical yoke 21 at equal intervals tc, and winding coils 211 above each heat-conducting material;

[0056] Step S12, vacuum encapsulating with epoxy resin glue;

[0057] Step S13, providing two PU pipe joints above the cooler, and connecting the cooling cavity inside the cooler with the PU pipe joints;

[0058] Step S14, fixing the sealing cover below the cooler through bolts, and closely fitting the inner wall of the cylindrical yoke with the outer wall of the cooler.

[0059] Further, in a preferred embodiment of the installation method of the tubular linear motor of the invention, the step S2 includes:

[0060] Step S21, the polarities of the same ends of the adjacent two rows of permanent magnets in the axial direction of the housing are the same, and every adjacent k rows of permanent magnets are taken as a group;

[0061] Step S22, making the distance between every two adjacent rows of the k rows of permanent magnets different by ɑ in the axial direction of the housing, and arranging the permanent magnets at uniform intervals in the circumferential direction of the housing.

[0062] Step S1 provides a primary of a tubular linear motor 2, and the primary of the tubular linear motor 2 is composed of a cylindrical yoke 21, a ring tooth 212, a coil 211, a cooler 22, and a sealing cover 23.

[0063] In step S11, first, the ring tooth 212 is inserted into the cylindrical yoke 21, and a high-insulation and high-thermal-conductivity material is placed between every two adjacent ring teeth 212. The length of the insulating and heat-conducting material along the axial direction is equal to tc, ensuring that the ring teeth 212 are arranged on the cylindrical yoke 21 at equal intervals tc. After placing the insulating and heat-conducting material and the ring teeth 212, the coil 211 is wound above each high-insulation and high-thermal-conductivity material;

[0064] In step S12, vacuum encapsulation is performed with epoxy resin glue;

[0065] In step S13, there are two PU pipe joints 221 above the cooler 22, and the cooling cavity 222 inside the cooler is communicated with the two PU pipe joints 221;

[0066] In step S14, the sealing cover 23 is fixed below the cooler 22 by bolts. Among them, there is a sealing ring between the sealing cover 23 and the cooler 22, and the inner wall of the cylindrical yoke 21 is closely attached to the outer wall of the cooler 22, completing the installation of the primary of the tubular linear motor 2.

[0067] Step S2 provides a secondary of a cylindrical linear motor 1, and the secondary is composed of a housing 11 and a tile-shaped permanent magnet 12 provided on the inner surface of the housing 11.

[0068] In step S21, the polarities of the same ends of the permanent magnets in adjacent two rows of permanent magnets are the same along the axial direction of the housing 11, and every adjacent k rows of permanent magnets are taken as a group;

[0069] In step S22: The distance between every two adjacent rows of k rows of permanent magnets 12 along the axial direction of the housing 11 differs by a. The permanent magnets 12 are evenly spaced along the circumferential direction of the housing 11.

[0070] In step S3, the secondary 1 is inserted into the primary 2. As shown in the figure, a circular tooling 3 is used to ensure that the radial clearance between the secondary and the primary is uniform.

[0071] In summary, for this tubular linear motor and its installation method of the present invention, the tubular design can effectively improve the thrust density of the motor. The special designs of the permanent magnet and the cylindrical yoke can effectively reduce the thrust pulsation during operation. Adding a cooler part can further effectively improve the thrust density of the motor, reduce the temperature rise and thrust pulsation of the motor, thereby improving the acceleration and accuracy of the motor operation.

[0072] The above are only the preferred embodiments of the present invention, and do not limit the implementation manners and protection scope of the present invention accordingly. For those skilled in the art, it should be realized that any equivalent substitution and obvious changes made by using the description and illustrations of the present invention should be included in the protection scope of the present invention.

[0073] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0074] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given with reference to the drawings.

[0075] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0076] The terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second" may explicitly or implicitly include at least one of such features.

Claims

1. A tubular linear motor, characterized in that, It includes a secondary (1) and a primary (2), and there is a gap between the inner surfaces of the secondary (1) and the primary (2): The secondary (1) includes a housing (11) and permanent magnets (12) provided on the inner surface of the housing (11). The outer surface of the permanent magnets (12) is in contact with the inner surface of the housing (11), and the permanent magnets (12) are arranged at intervals in a stepped manner on the inner surface of the housing (11). The distance between every two adjacent rows of the permanent magnets (12) differs by ɑ along the axis direction of the housing (11); The primary part (2) includes a cylindrical yoke (21), a ring gear (212), a coil (211), a cooler (212), and a sealing cover (23). The ring gears (212) are arranged on the cylindrical yoke (21) at equal intervals of t c and are arranged at intervals adjacent to each other.

2. A tubular linear motor according to claim 1, characterized in that, The polarities of the adjacent like ends of the permanent magnets (12) are different, and the polarities of the adjacent like ends of the permanent magnets (12) in two adjacent rows along the axis direction of the housing (11) are the same. The difference ɑ in the axis direction is 3. A tubular linear motor according to claim 2, characterized in that, All the permanent magnets (12) are in the shape of tiles, and the permanent magnets (12) are evenly distributed and arranged at intervals along the circumferential direction of the housing (11). The outer surface of the permanent magnets (12) is adhesively connected to the inner surface of the housing (11).

4. A tubular linear motor according to claim 1, characterized in that, The spacing t c is 5. A tubular linear motor according to claim 1, characterized in that, There is an insulating and heat-conducting material between adjacent ring teeth (212). The coil (211) is located in the insulating and heat-conducting material. The in-phase coils in every three adjacent coils (211) are connected to form a fractional-slot winding. The tail ends of the fractional-slot winding are commonly connected, and the heads of the three-phase lines are connected to a three-phase power supply.

6. A tubular linear motor according to claim 1, characterized in that, The cooler (22) is internally provided with a cooling cavity (222). There are two PU pipe joints (221) above the cooler (22), and the cooler (22) is interconnected with the PU pipe (2211).

7. A tubular linear motor according to claim 6, characterized in that, There is a sealing cover (23) below the cooler (22). The sealing cover (23) is fixed to the cooler (22) by bolts, and there is a sealing ring between the sealing cover (23) and the cooler (22).

8. An installation method of a tubular linear motor, for a tubular linear motor according to any one of claims 1 - 7, characterized in that, It includes: Step S1, installing the primary of the motor, including a cylindrical yoke, ring teeth, a coil, a cooler, and a sealing cover; Step S2, installing the secondary of the motor, including a housing and tile-shaped permanent magnets provided on the inner surface of the housing; Step S3, inserting the secondary into the primary, and making the gap between the secondary and the primary uniform in the radial direction through a circular tooling.

9. An installation method of a tubular linear motor according to claim 8, characterized in that, The step S1 includes: Step S11, inserting the ring teeth into the cylindrical yoke, placing an insulating and heat-conducting material between every two adjacent ring teeth. The length of the insulating and heat-conducting material along the axis direction is equal to tc. The ring teeth are arranged on the cylindrical yoke at equal intervals of tc, and a coil is wound above each heat-conducting material; Step S12, vacuum potting with epoxy resin glue; Step S13, making two PU pipe joints on the cooler, and communicating the cooling cavity inside the cooler with the PU pipe joints; Step S14, fixing the sealing cover to the lower part of the cooler by bolts, and the inner wall of the cylindrical yoke is closely attached to the outer wall of the cooler.

10. An installation method of a tubular linear motor according to claim 8, characterized in that, The step S2 includes: Step S21, for the permanent magnets, the polarities of the same-direction ends of two adjacent rows of permanent magnets are the same along the axis direction of the housing. Every k rows of permanent magnets are taken as a group; Step S22, making the distance between every two adjacent rows of the k rows of permanent magnets differ by ɑ along the axis direction of the housing, and the permanent magnets are evenly distributed and arranged at intervals along the circumferential direction of the housing.

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