Permanent magnet synchronous motor structure for vertical mill

Abstract

The invention relates to the technical field of permanent magnet synchronous motors, and discloses a permanent magnet synchronous motor structure for a vertical mill, which comprises a rotating shaft, a motor shell, an upper end cover mounted at the top end of the motor shell, a lower end cover mounted at the bottom end of the motor shell, and a stator assembly mounted in the motor shell, a supporting assembly is installed at the center of the top of the lower end cover and connected to the surface of a rotating shaft, and the top end of the rotating shaft penetrates through the upper end cover and extends to the outside of the motor shell. The surface of the rotating shaft is connected with an installation disc, the installation disc is located above the supporting assembly, and an umbrella-shaped magnet yoke is installed on the installation disc. According to the permanent magnet synchronous motor structure supporting assembly for the vertical mill, the upper bearing and the lower bearing of the motor are installed in the bearing shell base, the bearing shell base is installed on the fixing base of the upper end cover, compared with the mode that the bearings are arranged above and below the magnet yoke respectively, the upper end cover of the motor does not need to bear the installation weight of the upper bearing, and the overall load is reduced; therefore, the thickness of the upper end cover structure can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet synchronous motors, and specifically to a structure of a permanent magnet synchronous motor for a vertical mill. Background Art

[0002] The drive system of a vertical mill (hereinafter referred to as a vertical mill) used in a thermal power unit mainly consists of a drive motor, a gearbox, and a mill main mechanism. In the traditional drive mode of a vertical mill system, an asynchronous motor is transmitted through a bevel gear, and then to the gearbox reducer, and finally to the mill end. With the development of permanent magnet synchronous motor technology, a semi-direct drive solution has been formed in which the traditional asynchronous motor plus bevel gear is replaced by a vertical motor and connected to the mill through a reducer. Compared with the traditional asynchronous drive form, the permanent magnet drive eliminates the complex multi-stage reduction structure, and both the overall efficiency and reliability are improved.

[0003] In the permanent magnet semi-direct drive system of a vertical mill, the structure from bottom to top is the motor, the gearbox reducer, and the mill respectively. When the semi-direct drive solution replaces the traditional asynchronous drive solution, the overall dimensions and interfaces of the mill and the gearbox in the original system remain unchanged, so the overall outer boundary of the permanent magnet motor needs to be compatible with the size arrangement of the original system. Especially in the axial direction, the motor needs to meet the requirements of high power, overload capacity, and structural reliability in a small space.

[0004] The existing permanent magnet semi-direct drive system solutions for vertical mills mainly have the following deficiencies:

[0005] In the existing solutions, two sets of bearings are mainly arranged inside the motor through the upper and lower end covers, and the bearing seats are respectively installed on the upper and lower end covers. Therefore, the end covers need to bear the load of rotor support, which has high requirements for the end cover structure. The designed thickness of the end cover is large, occupying axial space. In addition, during assembly, since the upper end cover and the bearing are installed behind the rotor, the rotor needs to be equipped with an auxiliary tooling support, and it is difficult to install the bearing due to the influence of the connecting end cover.

[0006] For the upper and lower end cover bearing solutions, since the rotor yoke rotates between the bearings, the bearing oil injection and drainage pipelines cannot be collected and shared, and separate oil injection and drainage need to be arranged, increasing the complexity of the structure and assembly.

[0007] In the existing solutions, the motor mostly adopts the form of stator back water jacket cooling. When the heat load is high, there is a high-temperature area far from the back water jacket cooling. Due to the internal bearings and pipelines occupying space, it is impossible to arrange additional fans, and an internal circulating air path of the motor needs to be formed through external blowing. Summary of the Invention

[0008] Aiming at the deficiencies of the prior art, the present invention provides a structure of a permanent magnet synchronous motor for a vertical mill, which solves the problems mentioned in the above background.

[0009] The present invention provides the following technical solution: a permanent magnet synchronous motor structure for a vertical mill, comprising: a rotating shaft, a motor housing, an upper end cover installed at the top of the motor housing, a lower end cover installed at the bottom of the motor housing, and a stator assembly installed inside the motor housing;

[0010] A support assembly is installed at the center of the top of the lower end cover, the support assembly is connected to the surface of the rotating shaft, and the top end of the rotating shaft passes through the upper end cover and extends to the outside of the motor housing;

[0011] An installation disk is connected to the surface of the rotating shaft, the installation disk is located above the support assembly, an umbrella-shaped magnetic yoke is installed on the installation disk, and rotor magnetic poles are arranged on the surface of the umbrella-shaped magnetic yoke;

[0012] The support assembly includes a bearing housing seat, an upper bearing and a lower bearing. The upper bearing and the lower bearing are both installed on the surface of the rotating shaft, and the surfaces of the upper bearing and the lower bearing are both connected to the inner wall of the bearing housing seat. A fixed base is arranged at the center of the top of the lower end cover, and the bearing housing seat is installed at the top of the fixed base.

[0013] Preferably, the stator assembly includes a stator core installed inside the motor housing and coils installed on the stator core.

[0014] Preferably, a connecting plate is arranged on the surface of the bearing housing seat, a plurality of first bolts are uniformly arranged along the circumferential direction on the top of the connecting plate, and the connecting plate is installed on the top of the fixed base through the first bolts.

[0015] Preferably, a top sealing cover is arranged at the top end of the bearing housing seat, and a bottom sealing cover is arranged at the bottom end of the bearing housing seat.

[0016] Preferably, an oil inlet pipe and an oil drain pipe are respectively arranged inside the motor housing. One end of the oil inlet pipe and one end of the oil drain pipe both extend to the outside of the motor housing. The other end of the oil inlet pipe is connected to the surface of the top sealing cover, and the other end of the oil drain pipe is connected to the surface of the bottom sealing cover.

[0017] Preferably, a plurality of support rib plates are uniformly arranged on the surface of the fixed base, and an oil storage cavity is formed between the bottom sealing cover and the bearing housing seat.

[0018] Preferably, the inner wall of the installation disk is welded to the surface of the rotating shaft, a plurality of second bolts are uniformly arranged along the circumferential direction on the top of the umbrella-shaped magnetic yoke, and the installation disk is connected to the umbrella-shaped magnetic yoke through the second bolts.

[0019] Preferably, a fan is installed on the top of the umbrella-shaped magnetic yoke, and through holes are uniformly formed on the surface of the umbrella-shaped magnetic yoke.

[0020] Preferably, a water jacket for cooling is coated on the outside of the stator core.

[0021] Preferably, a concave groove for the rotation shaft to pass through is provided on the surface of the upper end cover.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. In the present invention, by providing a support assembly, the upper bearing and the lower bearing of the motor are installed in the bearing housing seat, and the bearing housing seat is installed on the fixed base of the upper end cover. Compared with the bearings arranged respectively above and below the yoke, the upper end cover of the motor does not need to bear the weight of the upper bearing installation, and the overall load is reduced. Therefore, the thickness of the upper end cover structure can be reduced.

[0024] 2. In the present invention, by providing a mounting plate, during the assembly of the whole machine, first fix the lower end cover, and install the motor housing and the stator assembly in place. On this basis, continue to install the bearing housing seat, the rotation shaft, the umbrella-shaped yoke from bottom to top in sequence, and finally install the upper end cover. When installing, the double-bearing support structure is preferably fixed at one time, the operation process is simplified, and the previously installed rotation shaft can provide axial and radial support during the assembly of the umbrella-shaped yoke and the rotor poles, alleviating the adsorption force between the magnetic rotor and the machine base during installation.

[0025] 3. In the present invention, by providing an oil inlet pipe and an oil drain pipe, the oil inlet pipe runs along the bearing housing seat inside the motor, and the top sealing cover is connected to supply oil to the upper bearing. Then, the oil returns to the lower bearing by gravity from the upper bearing inside the bearing housing seat, and is led to the outside of the motor housing through the oil drain pipe on the bottom sealing cover. The pipeline layout and installation are simpler. The oil storage cavity formed between the bottom sealing cover and the base has a certain oil storage space and can store the oil leaked from the bearing.

[0026] 4. In the present invention, by providing a fan, through holes and a water jacket, the original coupling structure of the rotor support and the upper end cover of the stator is separated, releasing the space and load requirements of the upper end cover of the motor. The upper end cover of the motor can adopt a thinner thickness, so that an axial fan can be arranged inside the motor to enhance the cooling effect. The fan assembled at the end of the umbrella-shaped yoke rotates with the rotor to form an end air path. A circle of through holes is opened on the surface of the umbrella-shaped yoke, which can reduce the weight of the yoke and allow the air path formed by the fan to pass through to form a return flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic cross-sectional structure diagram of the present invention.

[0028] In the figure: 1. Rotating shaft; 2. Motor housing; 3. Upper end cover; 4. Lower end cover; 51. Stator core; 52. Coil; 61. Bearing housing seat; 62. Upper bearing; 63. Lower bearing; 7. Mounting plate; 8. Umbrella-shaped yoke; 9. Rotor pole; 10. Fixed base; 11. Connecting plate; 12. First bolt; 13. Top sealing cover; 14. Bottom sealing cover; 15. Oil inlet pipe; 16. Oil drain pipe; 17. Support rib plate; 18. Oil storage cavity; 19. Second bolt; 20. Fan; 21. Through hole; 22. Water jacket. Specific implementation mode

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0030] Please refer to Figure 1 , a permanent magnet synchronous motor structure for a vertical mill, including: a rotating shaft 1, a motor housing 2, an upper end cover 3 installed at the top of the motor housing 2, a lower end cover 4 installed at the bottom of the motor housing 2, and a stator assembly installed inside the motor housing 2; a support assembly is installed at the center of the top of the lower end cover 4, the support assembly is connected to the surface of the rotating shaft 1, the top of the rotating shaft 1 passes through the upper end cover 3 and extends to the outside of the motor housing 2; a mounting plate 7 is connected to the surface of the rotating shaft 1, the mounting plate 7 is located above the support assembly, an umbrella-shaped yoke 8 is installed on the mounting plate 7, and rotor poles 9 are arranged on the surface of the umbrella-shaped yoke 8; the support assembly includes a bearing housing seat 61, an upper bearing 62 and a lower bearing 63, both the upper bearing 62 and the lower bearing 63 are installed on the surface of the rotating shaft 1, and the surfaces of the upper bearing 62 and the lower bearing 63 are both connected to the inner wall of the bearing housing seat 61. A fixed base 10 is arranged at the center of the top of the lower end cover 4, and the bearing housing seat 61 is installed at the top of the fixed base 10. The entire support assembly 6 is located below the umbrella-shaped yoke 8, and the upper bearing 62 and the lower bearing 63 are arranged separately up and down, which can effectively reduce the radial swing of the rotating shaft 1.

[0031] The stator assembly includes a stator core 51 installed inside the motor housing 2 and a coil 52 installed on the stator core 51. The upper bearing 62 and the lower bearing 63 of the motor are installed in the bearing housing seat 61, and the bearing housing seat 61 is installed on the fixed base 10 of the upper end cover 3. Compared with the arrangement of the bearings above and below the yoke respectively, the upper end cover 3 of the motor does not need to bear the weight of the installation of the upper bearing 62, and the overall load is reduced. Therefore, the structural thickness of the upper end cover 3 can be reduced.

[0032] Therefore, a connecting plate 11 is provided on the surface of the bearing housing 61. A plurality of first bolts 12 are evenly arranged along the circumference on the top of the connecting plate 11. The connecting plate 11 is installed on the top of the fixed base 10 through the first bolts 12. A top cover 13 is provided at the top end of the bearing housing 61, and a bottom cover 14 is provided at the bottom end of the bearing housing 61. An oil inlet pipe 15 and an oil drain pipe 16 are respectively arranged inside the motor housing 2. One ends of the oil inlet pipe 15 and the oil drain pipe 16 both extend to the outside of the motor housing 2. The other end of the oil inlet pipe 15 is connected to the surface of the top cover 13, and the other end of the oil drain pipe 16 is connected to the surface of the bottom cover 14. The oil inlet pipe 15 runs along the bearing housing 61 inside the motor, and the top cover 13 feeds oil to the upper bearing 62. Then, the oil returns by gravity from the upper bearing 62 to the lower bearing 63 inside the bearing housing 61 and is led to the outside of the motor housing 2 through the oil drain pipe 16 on the bottom cover 14. The pipeline layout and installation are simpler. The oil storage cavity 18 formed between the bottom cover 14 and the base has a certain oil storage space and can store the oil leaking from the bearing.

[0033] A plurality of support rib plates 17 are evenly arranged on the surface of the fixed base 10. An oil storage cavity 18 is formed between the bottom cover 14 and the bearing housing 61. Arranging the support rib plates 17 around the fixed base 10 increases the bending stiffness of the base. The oil storage cavity 18 has a certain oil storage space and can store the oil leaking from the lower bearing 63 to prevent it from entering the motor interior.

[0034] The inner wall of the mounting disc 7 is welded to the surface of the rotating shaft 1. A plurality of second bolts 19 are evenly arranged along the circumference on the top of the umbrella-shaped yoke 8. The mounting disc 7 is installed and connected to the umbrella-shaped yoke 8 through the second bolts 19. A fan 20 is installed on the top of the umbrella-shaped yoke 8. A plurality of through holes 21 are evenly formed on the surface of the umbrella-shaped yoke 8. Separating the original rotor support and the coupling structure of the upper end cover 3 of the stator releases the space and load-bearing requirements of the upper end cover 3 of the motor. The upper end cover 3 of the motor can adopt a thinner thickness, so that an axial fan 20 can be arranged inside the motor to enhance the cooling effect. The fan 20 assembled at the end of the umbrella-shaped yoke 8 rotates with the rotor to form an end air path. A circle of through holes 21 is formed on the surface of the umbrella-shaped yoke 8, which can reduce the weight of the yoke and at the same time allow the air path formed by the fan 20 to pass through to form a backflow.

[0035] A water jacket 22 for cooling is coated on the outside of the stator core 51. A concave groove for the rotating shaft 1 to pass through is provided on the surface of the upper end cover 3. The concave groove 23 of the upper end cover 3 is used to install a seal to prevent the oil in the gearbox above the motor from leaking into the motor interior.

[0036] During the overall assembly, first fix the lower end cover 4 and the base, and install the coil 52, the stator core 51, and the motor housing 2 in place. On this basis, continue to install the bearing housing seat 61 from bottom to top in sequence. The connecting plate 11 of the bearing housing seat 61 is installed on the top of the fixed base 10 through the first bolt 12. Install the rotating shaft 1 into the inside of the bearing housing seat 61. Use the second bolt 19 to install the umbrella-shaped yoke 8 onto the mounting plate. Assemble the rotor poles 9 on the surface of the umbrella-shaped yoke 8. At the same time, assemble the fan 20 at the top of the umbrella-shaped yoke 8 to form an end air path as the rotor rotates. The air path passes through the through holes 21 on the surface of the umbrella-shaped yoke 8 to form an internal air path circulation. These umbrellas can also reduce the weight and load of the umbrella-shaped yoke 8, and finally install the upper end cover 3. When installing, preferably fix the support structures of the upper bearing 62 and the lower bearing 63 at one time. And when the previously installed rotating shaft 1 is assembled with the umbrella-shaped yoke 8 and the rotor poles 9, it can provide axial and radial support to relieve the adsorption force between the magnetic rotor and the machine base during installation.

[0037] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0038] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A permanent magnet synchronous motor structure for a vertical mill, characterized in that, Comprising: A rotating shaft (1), a motor housing (2), an upper end cover (3) installed at the top of the motor housing (2), a lower end cover (4) installed at the bottom of the motor housing (2), and a stator assembly installed inside the motor housing (2); A support assembly is installed at the center of the top of the lower end cover (4), the support assembly is connected to the surface of the rotating shaft (1), and the top of the rotating shaft (1) passes through the upper end cover (3) and extends to the outside of the motor housing (2); A mounting disk (7) is connected to the surface of the rotating shaft (1), the mounting disk (7) is located above the support assembly, an umbrella-shaped yoke (8) is installed on the mounting disk (7), and rotor poles (9) are arranged on the surface of the umbrella-shaped yoke (8); The support assembly includes a bearing housing seat (61), an upper bearing (62) and a lower bearing (63), the upper bearing (62) and the lower bearing (63) are both installed on the surface of the rotating shaft (1), and the surfaces of the upper bearing (62) and the lower bearing (63) are both connected to the inner wall of the bearing housing seat (61), a fixed base (10) is arranged at the center of the top of the lower end cover (4), and the bearing housing seat (61) is installed at the top of the fixed base (10).

2. The structure of a permanent magnet synchronous motor for a vertical mill according to claim 1, characterized in that, The stator assembly includes a stator core (51) installed inside the motor housing (2) and coils (52) installed on the stator core (51).

3. The structure of a permanent magnet synchronous motor for a vertical mill according to claim 2, characterized in that, Therefore, a connecting plate (11) is arranged on the surface of the bearing housing seat (61), a plurality of first bolts (12) are evenly arranged along the circumferential direction on the top of the connecting plate (11), and the connecting plate (11) is installed on the top of the fixed base (10) through the first bolts (12).

4. The structure of a permanent magnet synchronous motor for a vertical mill according to claim 2, characterized in that, A top cover (13) is arranged at the top of the bearing housing seat (61), and a bottom cover (14) is arranged at the bottom of the bearing housing seat (61).

5. The structure of a permanent magnet synchronous motor for a vertical mill according to claim 4, characterized in that An oil inlet pipe (15) and an oil drain pipe (16) are respectively arranged inside the motor housing (2), one ends of the oil inlet pipe (15) and the oil drain pipe (16) both extend to the outside of the motor housing (2), the other end of the oil inlet pipe (15) is connected to the surface of the top cover (13), and the other end of the oil drain pipe (16) is connected to the surface of the bottom cover (14).

6. The structure of a permanent magnet synchronous motor for a vertical mill according to claim 4, characterized in that, A plurality of support rib plates (17) are evenly arranged on the surface of the fixed base (10), and an oil storage cavity (18) is formed between the bottom cover (14) and the bearing housing seat (61).

7. A permanent magnet synchronous motor structure for a vertical mill according to claim 1, characterized in that, The inner wall of the mounting disk (7) is welded to the surface of the rotating shaft (1), a plurality of second bolts (19) are evenly arranged along the circumferential direction on the top of the umbrella-shaped yoke (8), and the mounting disk (7) is installed and connected to the umbrella-shaped yoke (8) through the second bolts (19).

8. The structure of a permanent magnet synchronous motor for a vertical mill according to claim 1, characterized in that, A fan (20) is installed on the top of the umbrella-shaped yoke (8), and through holes (21) are evenly formed on the surface of the umbrella-shaped yoke (8).

9. The structure of a permanent magnet synchronous motor for a vertical mill according to claim 1, wherein A water jacket (22) for cooling is coated on the outside of the stator core (51).

10. A permanent magnet synchronous motor structure for a vertical mill according to claim 1, characterized in that, A concave groove for the rotating shaft (1) to pass through is arranged on the surface of the upper end cover (3).

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