A coaxial splicing spindle motor and its assembly method

Abstract

The present invention discloses a coaxial splicing spindle motor and its assembly method. Among them, the spindle motor includes a housing, a cooling water jacket, and multiple permanent magnet motors. The permanent magnet motor includes a rotating shaft, a rotor, and a stator. The multiple permanent magnet motors are installed in the cooling water jacket, and the rotating shafts of adjacent permanent magnet motors are connected in series; there are fourth and first positioning structures between the housing and the cooling water jacket and between the stator and the cooling water jacket to keep the mechanical angles of the multiple stators consistent after the permanent magnet motors are connected in series; there are second and third positioning structures between the rotating shaft and the yoke and between the yoke and the magnet to keep the mechanical angles of the multiple rotors consistent after the permanent magnet motors are connected in series. Since the coaxial splicing spindle motor disclosed by the present invention is provided with multiple positioning structures, after the multi-stage permanent magnet motors are connected in series, the mechanical angles of each stage of permanent magnet motors can be kept consistent, thereby ensuring the electrical angles of each stage of permanent magnet motors are consistent, ensuring the output torque after the permanent magnet motors are connected in series, and improving the output efficiency after the connection in series.

Description

Technical Field

[0001] The present invention relates to the technical field of numerical control machining, and particularly relates to a main shaft motor with coaxial splicing and an assembly method thereof. Background Art

[0002] The electric spindle is a power component that integrates a driving motor to achieve the integration of the motor and spindle functions. It is characterized by a compact structure and is suitable for high-speed cutting machining. The driving motor installed inside is generally borne by a permanent magnet motor. Therefore, the permanent magnet motor has an important influence on the functions and performance of the electric spindle.

[0003] Generally, a single permanent magnet motor only has a set of stator and rotor components. According to the known technical constraint relationships of "Power = Rotational Speed × Torque ÷ Constant Coefficient" and "The effective volume of the motor is proportional to the torque", it can be known that under the condition of the same high rotational speed, only by increasing the torque can high power be obtained. However, increasing the torque will inevitably increase the effective volume of the permanent magnet motor, either thickening or lengthening. From the perspective of the use of the electric spindle, the compact structure cannot provide unlimited volume increase. Generally, the volume is lengthened, that is, the rotating shaft of the permanent magnet motor is usually designed into a slender structure, and then multiple sets of stator and rotor components are installed on the rotating shaft. When the rotating shaft is a single-piece slender shaft, due to the large length-diameter ratio of the rotating shaft, the structural rigidity of the rotating shaft is poor, the shafting support structure is complex, the machining difficulty is large, and it is extremely easy to generate flexible deformation. When the permanent magnet motor runs at high speed, the synchronous control logic of multiple sets of stator and rotor components is complex, and it is difficult to achieve torque multiplication of multiple sets of stator and rotor components under high-speed synchronization, that is, the rotational speed drops, the torque output is limited, and the power output is greatly reduced at the same time. Therefore, under the condition of a certain space size, it is urgent to propose a new motor structure with multiple sets of permanent magnet motors spliced coaxially, and from the perspective of synchronously improving the mechanical structure rigidity and the electrical structure rigidity, solve the torque multiplication of multiple sets of stator and rotor components of the "series form" permanent magnet motor under high-speed synchronization, and then achieve power multiplication. Summary of the Invention

[0004] The present invention discloses a main shaft motor with coaxial splicing and an assembly method thereof, which solves the above technical problems that the existing series motors cannot solve.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] A coaxial spliced main shaft motor, comprising a machine shell, a cooling water jacket and multiple permanent magnet motors. The permanent magnet motors include a rotating shaft, a rotor and a stator. The rotor is arranged on the rotating shaft. The rotor includes a yoke and a magnetic steel arranged on the yoke. The cooling water jacket is fixedly installed in the machine shell. The stator is fixedly installed in the cooling water jacket. Multiple permanent magnet motors are fixedly installed in the cooling water jacket in sequence, and the rotating shafts of two adjacent permanent magnet motors are connected in series through a rotating shaft connection structure. The rotating shaft at one end of the main shaft motor extends out of the machine shell to form a main shaft motor output shaft, and an encoder is arranged on the rotating shaft at the other end of the main shaft motor.

[0007] A fourth positioning structure and a first positioning structure for keeping the mechanical angles of multiple stators consistent after multiple permanent magnet motors are connected in series are sequentially arranged between the machine shell and the cooling water jacket and between the stator and the cooling water jacket.

[0008] A second positioning structure and a third positioning structure for keeping the mechanical angles of multiple rotors consistent after multiple permanent magnet motors are connected in series are sequentially arranged between the rotating shaft and the yoke and between the yoke and the magnetic steel.

[0009] Further, the first positioning structure and the second positioning structure are key positioning structures or pin positioning structures.

[0010] The third positioning structure is a positioning groove structure arranged on the outer diameter of the yoke in the same radial direction as the second positioning structure.

[0011] Further, the machine shell includes multiple sub-machine shells connected in series in sequence, and the cooling water jacket includes multiple sub-cooling water jackets fixedly installed in the machine shell in sequence.

[0012] The fourth positioning structure is arranged between the sub-machine shell and the sub-cooling water jacket.

[0013] Further, the fourth positioning structure is a key positioning structure or a pin positioning structure arranged between the previous-stage sub-machine shell and the next-stage sub-cooling water jacket.

[0014] Further, the sub-cooling water jacket includes a cooling water jacket body and a bearing installation part arranged on the cooling water jacket body for installing a bearing, and a cooling flow channel is arranged on the outer diameter of the cooling water jacket body.

[0015] Further, the rotating shaft connection structure is a spline structure, and a fifth positioning structure corresponding to the second positioning structure is arranged on the spline structure.

[0016] Further, the rotating shaft connection structure is an adjusting disc structure, and a sixth positioning structure corresponding to the second positioning structure is arranged on the adjusting disc structure.

[0017] Further, the fifth positioning structure and the sixth positioning structure are dowel pin structures.

[0018] A method for assembling the coaxial spliced main shaft motor of the present invention includes the following steps:

[0019] S1: Bond the permanent magnets. With the third positioning structure on the yoke as a reference, paste the permanent magnets so that the center line of the first permanent magnet aligns with the center line of the third positioning structure, and then sequentially bond the permanent magnets to the yoke to form a rotor.

[0020] S2: Install the rotor on the rotating shaft through the second positioning structure so that the center line of the permanent magnets on the rotor aligns with the center line of the second positioning structure on the rotating shaft.

[0021] Install the stator in the cooling water jacket through the first positioning structure, and then install the cooling water jacket with the stator installed in the machine housing through the fourth positioning structure.

[0022] S3: Install the rotating shaft with the rotor installed therein into the stator, and sequentially connect the rotating shafts of each stage of permanent magnet motors through the rotating shaft connection structure.

[0023] The beneficial effects of the assembling method of the coaxial spliced main shaft motor disclosed by the present invention: Since positioning structures are provided between the machine housing and the positioning water jacket, the stator and the positioning water jacket, the rotating shaft and the yoke, and the yoke and the permanent magnets, after multiple stages of permanent magnet motors are connected in series, the mechanical angles of each stage of permanent magnet motors can be kept consistent, and further, the electrical angles of each stage of permanent magnet motors can be ensured to be consistent, thereby ensuring the output torque of the permanent magnet motors after being connected in series and improving the output efficiency after being connected in series. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is an axial sectional view of the first embodiment of the coaxial spliced main shaft motor disclosed by the present invention;

[0026] Figure 2 is Figure 1 an enlarged view of the dashed box in

[0027] Figure 3 It is a relationship curve graph between the percentage reduction of the output torque of the permanent magnet motor and the electrical angle deviation value;

[0028] Figure 4 Radial sectional view of the first embodiment of the coaxial spliced spindle motor disclosed by the present invention;

[0029] Figure 5 Stator structure diagram of the coaxial spliced spindle motor disclosed by the present invention;

[0030] Figure 6 Structure diagram of the sub-cooling water jacket of the coaxial spliced spindle motor disclosed by the present invention;

[0031] Figure 7 Structure diagram of the shaft connection of the coaxial spliced spindle motor disclosed by the present invention, and an adjustment disk is used for connection in the figure;

[0032] Figure 8 Front view of the adjustment disk;

[0033] Figure 9 Schematic diagram of the shaft connection structure being a spline shaft, and a schematic diagram of a spline hole is shown in the figure;

[0034] Figure 10 Structure diagram of the spline shaft;

[0035] Figure 11 Axial sectional view of the second embodiment of the coaxial spliced spindle motor disclosed by the present invention;

[0036] Figure 12 Radial sectional view of the second embodiment of the coaxial spliced spindle motor disclosed by the present invention.

[0037] In the figure: 1. Machine shell; 10. Sub-machine shell; 2. Cooling water jacket; 20. Sub-cooling water jacket; 21. Sub-cooling water jacket body; 22. Bearing installation part; 24. Water inlet; 25. Water outlet; 3. Permanent magnet motor; 30. Rotating shaft; 31. Rotor; 310. Yoke; 311. Permanent magnet; 32. Stator; 320. Stator core; 321. Coil U-phase; 33. Front end cover; 34. Rear end cover; 4. Shaft connection structure; 40. Adjustment disk; 401. Positioning hole on the adjustment disk; 402. Connection hole on the adjustment disk; 41. Spline hole; 411. Positioning hole on the spline hole or spline shaft; 42. Spline shaft; 5. Encoder; 60. First positioning structure; 61. Second positioning structure; 62. Third positioning structure; 63. Fourth positioning structure; 64. Fifth positioning structure; 65. Sixth positioning structure. Detailed implementation manners

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will combine the accompanying drawings in the embodiments of the present invention Figure 1-12, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0039] Embodiment 1

[0040] As Figure 1 、 Figure 2 The first embodiment of the coaxial spliced main shaft motor disclosed by the present invention is shown in the figure, including a machine shell 1, a cooling water jacket 2 and multiple groups of permanent magnet motors 3. In this embodiment, both the machine shell 1 and the cooling water jacket 2 are split structures, that is, the machine shell 1 includes multiple sub-machine shells 10 connected in series in sequence, and the cooling water jacket 2 includes multiple sub-cooling water jackets 20 fixedly installed in the machine shell 1 in sequence. In this embodiment, the sub-cooling water jacket 20 is arranged in the sub-machine shell 10 and fixed by bolts. Sealing rings are provided between both ends of the sub-cooling water jacket 20 and the sub-machine shell 10 for water sealing. A spiral cooling flow channel is processed on the outer diameter of the sub-cooling water jacket 20. The sub-machine shell 10 is provided with a water inlet 24 and a water outlet 25 communicated with the cooling flow channel. The water inlet 24 and the water outlet 25 are connected to a cooling machine through pipelines; the permanent magnet motor 3 includes a rotating shaft 30, a rotor 31 and a stator 32. The rotor 31 is arranged on the rotating shaft 30. The rotor 31 includes a yoke 310 and magnetic steel 311 arranged on the yoke 310. The sub-cooling water jacket 20 is fixedly installed in the sub-machine shell 10, and the stator 32 is fixedly installed in the sub-cooling water jacket 20. Multiple groups of permanent magnet motors are fixedly installed in the cooling water jacket in sequence, and the rotating shafts between adjacent two permanent magnet motors are connected in series through a rotating shaft connection structure 4; a front end cover 33 is provided at one end of the main shaft motor. In this embodiment, the front end cover 33 is fixedly connected to the machine shell by bolts. The rotating shaft at one end of the front end cover 33 extends out of the machine shell to form a main shaft motor output shaft. A rear end cover 34 is provided at the other end of the main shaft motor. The rear end cover 34 is fixedly connected to the machine shell by bolts. An encoder 5 is arranged on the rotating shaft at one end of the rear end cover 34. By connecting the encoder 5 to the permanent magnet motor, the motor operation can be more accurately controlled through a controller and the encoder, and the operation state of the permanent magnet motor can be feedback.

[0041] A first positioning structure 60 for keeping the mechanical angles of multiple groups of stators consistent after multiple groups of permanent magnet motors are connected in series is provided between the stator 32 and the sub-cooling water jacket. A second positioning structure 61 and a third positioning structure 62 for keeping the mechanical angles of multiple groups of rotors consistent after multiple groups of permanent magnet motors are connected in series are sequentially provided between the rotating shaft 30 and the yoke 310 and between the yoke 310 and the magnetic steel 311; a fourth positioning structure 63 for keeping the mechanical angles of multiple groups of stators consistent after multiple groups of permanent magnet motors are connected in series is provided between the sub-machine shell 10 and the sub-cooling water jacket 20.

[0042] As Figure 3The figure shows a relationship curve between the electrical angle deviation value of a permanent magnet motor and the percentage reduction of the motor output torque; in a separately used permanent magnet motor, the mechanical angle is the mechanical or geometric angle corresponding to one revolution of the rotor; the electrical angle refers to the angle of change of the induced electromotive force or induced current in the stator and rotor windings when the rotor makes one revolution. When the so-called "one revolution" is represented by the number of slots Z on the inner surface circumference of the stator, the number of pole pairs is represented by p, and the electrical angle is represented by α, the relationship between the electrical angle and the mechanical angle is as follows: α = p × (360 / Z).

[0043] As can be seen from Figure 3 it that, the larger the electrical angle deviation value of the permanent magnet motor, the smaller the motor output torque. Taking the series connection of 3-stage motors as an example, as shown in Table 1, without considering other condition constraints, when the electrical angle deviation of each stage of the permanent magnet motor from the reference permanent magnet motor is 5°, assuming the output torque of the reference permanent magnet motor is 100%, then the output torque loss of the second-stage permanent magnet motor is 8.7%, and the output torque loss of the third-stage permanent magnet motor is 8.7%. If the first-stage permanent magnet motor, the second-stage permanent magnet motor, and the third-stage permanent magnet motor are used in series, the overall output torque is 282.6% (100% + (100% - 8.7%) + (100% - 8.7%)), which is much lower than the sum of the output torques of the three-stage motors, 300%.

[0044] Table 1 Relationship between the electrical angle deviation value of the permanent magnet motor and the torque output

[0045]

[0046] Since there is the following corresponding relationship between the electrical angle and the mechanical angle of the permanent magnet motors in series:

[0047] (A0 - B0) = (A1 - B1) / C

[0048] wherein, A0 is the mechanical angle degree of the permanent magnet motor to be connected in series;

[0049] B0 is the mechanical angle degree of the reference permanent magnet motor;

[0050] The value of A0 - B0 is the mechanical angle difference between the two permanent magnet motors after series connection;

[0051] A1 is the electrical angle degree of the permanent magnet motor to be connected in series;

[0052] B1 is the electrical angle degree of the reference permanent magnet motor;

[0053] A1 - B1 is the electrical angle difference between the two permanent magnet motors after series connection;

[0054] C is the number of groups of magnetic steels of the permanent magnet motor rotor.

[0055] From the above, it can be seen that there is a corresponding relationship between the electrical angle and the mechanical angle after the permanent magnet motors are connected in series.

[0056] In the present invention, due to the provision of a plurality of positioning structures, after the multi-stage permanent magnet motors 3 are connected in series, the mechanical angles of the stator 32 and the rotor 31 of the multi-stage permanent magnet motors 3 can be kept consistent, thereby ensuring that the electrical angles can also be kept consistent after the multi-stage permanent magnet motors 3 are connected in series, and further improving the output torque after the permanent magnet motors 3 are connected in series.

[0057] Furthermore, the first positioning structure 60 and the second positioning structure 61 are key positioning structures or pin positioning structures; the third positioning structure 62 is a positioning groove structure provided on the outer diameter of the yoke 310 and in the same radial direction as the second positioning structure 61; the fourth positioning structure 63 is a key positioning structure or a pin positioning structure provided between the front-stage sub-housing 10 and the rear-stage sub-cooling water jacket 20.

[0058] Specifically, in this embodiment, as Figure 4 、 Figure 5 shown, a keyway or key structure is machined at the center line position of the coil U-phase 321 on the outer diameter of the stator core 320, and a key or keyway corresponding to the keyway or key structure is provided in the sub-cooling water jacket 20. When the stator 32 is installed in the sub-cooling water jacket 20, the key and the keyway cooperate to ensure the circumferential positioning of the stator 32 in the cooling water jacket 2;

[0059] A key or keyway structure (positioning pin or positioning pin hole) is also provided at a position on the outer wall of the sub-cooling water jacket 20 corresponding to the key or keyway provided in the sub-cooling water jacket 20. A keyway or key (positioning pin hole or positioning pin) corresponding to the key or keyway on the outer wall of the sub-cooling water jacket 20 is provided in the sub-housing 10. When two adjacent permanent magnet motors 3 are connected, the keys and keyways (positioning pins and positioning pin holes) between the front-stage sub-housing 10 and the rear-stage sub-cooling water jacket 20 cooperate with each other, thereby ensuring that the center lines of the coil U-phases of the front and rear two-stage permanent magnet motors are on the same straight line, so as to ensure the consistency of the mechanical angles of the stators 32 in the front and rear two-stage permanent magnet motors 3;

[0060] A key or keyway structure (locating pin or locating pin hole) is machined on the inner diameter of the yoke 310, and a keyway or key (locating pin hole or locating pin) corresponding to the key or keyway structure (locating pin or locating pin hole) on the inner diameter of the yoke 310 is machined on the rotating shaft 30. A positioning structure is machined on the end rotating shaft connection structure 4 of the rotating shaft 30 and the keyway or key (locating pin hole or locating pin) machined on the rotating shaft 30 in the same circumferential indexing direction. A positioning groove is machined at a position on the outer diameter of the yoke 310 corresponding to the position where the key or keyway structure (locating pin or locating pin hole) is machined on the inner diameter. When the permanent magnet 311 is adhered to the yoke 310, circumferential bonding starts with the center line of this positioning groove as the reference (i.e., the center line of the first permanent magnet 311 is consistent with the center line of this positioning groove). By arranging a second positioning structure 61 between the rotating shaft 30 and the yoke 310 and a third positioning structure 62 between the yoke 310 and the permanent magnet 311, when adjacent two-stage permanent magnet motors 3 are connected in series, the permanent magnets 311 of the rotors 31 of the front and rear two-stage permanent magnet motors 3 can be aligned in the axial direction, that is, the mechanical angles of the rotors 31 are ensured to be the same, and further the electrical angles of the permanent magnet motors 3 can be ensured to be the same, improving the output torque after the motors are connected in series. At the same time, in this application, the machine shell 1 and the cooling water jacket 2 are both split structures. When one or more stages of permanent magnet motors 3 fail, the faulty permanent magnet motor 3 can be conveniently separated from other permanent magnet motors 3 for maintenance and replacement, reducing the difficulty of maintenance and replacement and improving the maintenance efficiency. At the same time, when one or more of the permanent magnet motors 3 fail, due to the connection between the multiple rotating shafts 30 and the fact that the other permanent magnet motors 3 are in normal working states, the rotor 31 of the faulty permanent magnet motor 3 can rotate under the action of the normally working permanent magnet motors 3, thus ensuring the normal operation of the whole machine.

[0061] Further, as Figure 6 shown, the sub-cooling water jacket 20 includes a cooling water jacket body 21 and a bearing mounting portion 22 provided on the cooling water jacket body 21 for mounting bearings. A spiral cooling flow channel is provided on the outer diameter of the cooling water jacket body 21. The machine shell 1 is provided with a water inlet 24 and a water outlet 25 communicating with the cooling flow channel. The water inlet and the water outlet are connected to the cooling machine through pipelines. Preferably, a shut-off valve (not shown in the figure) is also installed on each water outlet pipe (the pipeline connecting the water outlet and the cooling machine) to control the flow rate of the cooling water. At the same time, by controlling the number of opened shut-off valves, it is convenient to separately cool different numbers of permanent magnet motors 3. When multiple shut-off valves are opened simultaneously, multiple permanent magnet motors 3 can be cooled synchronously, or the flow rate of the cooling water can be controlled according to the working states of different permanent magnet motors 3 to intelligently control the temperature of the permanent magnet motors 3.

[0062] The sub-cooling water jacket body 21 is provided with a bearing installation part 22 for installing bearings. Bearings are installed on the bearing installation part 22. Both ends of the rotating shaft are installed on the bearing installation part through bearings, and the rotating shaft can be supported under the action of the bearings, thereby increasing the overall stiffness of the rotating shaft 30 after multiple permanent magnet motors 3 are connected in series.

[0063] Further, each permanent magnet motor 3 is connected to an electric driver. The electric driver (not shown in the figure) can be one or multiple. When there are multiple electric drivers, each permanent magnet motor is respectively connected to an electric driver to achieve separate control of multiple permanent magnet motors, and thus facilitate the control of the rotational speed and torque of the whole machine; when there is a single electric driver, multiple permanent magnet motors are electrically connected to the electric driver, and multiple permanent magnet motors are driven by the same electric driver, which can ensure the electrical synchronization of multiple permanent magnet motors, and thus can improve the driving accuracy, reduce the error between adjacent permanent magnet motors, and improve the rotation accuracy.

[0064] Further, as Figure 7 and Figure 8 shown, the rotating shaft connection structure 4 is an adjusting disk structure, and the adjusting disk structure is provided with a sixth positioning structure 65 corresponding to the second positioning structure 61.

[0065] Specifically, adjusting disks 40 are fixed at both ends of the rotating shaft 30. Positioning holes 401 and connection holes 402 are machined on the adjusting disks 40. The positioning holes 401 on the adjusting disks 40 correspond to the positions of the second positioning structures on the rotating shaft 30. In this embodiment, the center line of the positioning holes on the adjusting disks 40 and the center line of the key or keyway on the rotating shaft 30 are on the same circumferential indexing, which also makes the center line of the positioning holes on the adjusting disks 40 coincide with the center line of the magnet steel 311 (the first piece of magnet steel when pasted) of the rotor. Further, when the front and rear two-stage permanent magnet motors 3 are connected, the adjusting disks 40 at the adjacent ends of the rotating shafts 30 of the front and rear two-stage permanent magnet motors 3 are positioned by inserting positioning pins into the positioning holes, thereby ensuring the mechanical angles of the rotors 31 of the front and rear two-stage permanent magnet motors are the same, and thus ensuring the electrical angles of the front and rear two-stage motors are the same, improving the performance of the permanent magnet motors 3 after being connected in series. After the adjusting disks 40 are positioned by positioning pins, they are then fixedly connected by bolts.

[0066] The rotating shaft connection structure 4 can be an adjusting disk 40 structure, as Figure 9 and Figure 10As shown, the shaft connection structure 4 of the rotating shaft 30 can also be a spline structure. When a spline structure is adopted, a fifth positioning structure 64 corresponding to the second positioning structure 61 is provided on the spline structure. Specifically, a spline hole 41 is machined at one end of the rotating shaft 30, and a spline shaft 42 is machined at the other end. Positioning holes 411 are provided at both the end of the spline shaft 42 and the spline hole. The position of the center line of the positioning hole 411 is on the same circumferential pitch as the center line of the key or keyway on the rotating shaft 30 and is aligned with the center of one spline tooth on the spline hole (spline shaft). This makes the center line of the positioning hole on the spline shaft (hole) coincide with the center line of the magnet 311 (the first magnet during pasting) of the rotor. When the front and rear two-stage permanent magnet motors 3 are connected, the spline hole and the spline shaft are positioned through the positioning pin and the positioning hole, thereby ensuring the mechanical angle of the rotors 31 of the front and rear two-stage permanent magnet motors is the same, ensuring the electrical angle of the front and rear two-stage motors is the same, improving the performance of the permanent magnet motor after series connection. After the adjustment disc 40 is positioned by the positioning pin, it is then fixedly connected by bolts.

[0067] Embodiment 2

[0068] As shown in Fig. 11 and Figure 12 The figure shows the second embodiment of the coaxial spliced main shaft motor disclosed by the present invention. The difference between this embodiment and Embodiment 1 is that in Embodiment 1, both the housing 1 and the cooling water jacket 2 are split structures, while in this embodiment, the housing 1 and the cooling water jacket 2 are integral structures. The cooling water jacket 2 is installed inside the housing 1, and multiple permanent magnet motors 3 are installed inside the cooling water jacket 2. Only the connection of two-stage permanent magnet motors 3 is shown in the figure. The permanent magnet motor 3 includes a rotating shaft 30, a rotor 31, and a stator 32. The rotor 31 is arranged on the rotating shaft 30. The rotor 31 includes a yoke 310 and magnets 311 arranged on the yoke 310. The cooling water jacket 2 is fixedly installed inside the housing 1, and the stator 32 is fixedly installed inside the cooling water jacket 2. Multiple groups of permanent magnet motors 3 are sequentially and fixedly installed inside the cooling water jacket 2, and the rotating shafts 30 between adjacent two permanent magnet motors 3 are connected in series through the rotating shaft 30 connection structure; the rotating shaft 30 at one end of the main shaft motor extends out of the housing 1 to form the main shaft motor output shaft, and an encoder 5 is arranged on the rotating shaft at the other end of the main shaft motor;

[0069] A fourth positioning structure 63 and a first positioning structure 60 for keeping the mechanical angles of multiple groups of stators 32 consistent after multiple groups of permanent magnet motors 3 are connected in series are sequentially provided between the housing 1 and the cooling water jacket 2 and between the stator 32 and the cooling water jacket 2;

[0070] A second positioning structure 61 and a third positioning structure 62 for keeping the mechanical angles of multiple groups of rotors consistent after multiple groups of permanent magnet motors are connected in series are sequentially provided between the rotating shaft 30 and the yoke 310 and between the yoke 310 and the magnets 311.

[0071] Embodiment 3

[0072] A method for assembling the coaxial splicing main shaft motor of the present invention includes the following steps:

[0073] S1: Bond the permanent magnet 311. With the third positioning structure 62 on the yoke 310 as a reference, paste the permanent magnet 311 so that the center line of the first piece of permanent magnet 311 is aligned with the center line of the third positioning structure 62, and sequentially bond the permanent magnets 311 to the yoke 310 to form the rotor 31;

[0074] S2: Install the rotor 31 on the rotating shaft 30 through the second positioning structure 61, so that the center line of the permanent magnet 311 on the rotor 31 is aligned with the center line of the second positioning structure 61 on the rotating shaft 30;

[0075] Install the stator 32 in the cooling water jacket 2 through the first positioning structure 60, and then install the cooling water jacket 2 with the stator 32 installed therein in the housing 1 through the fourth positioning structure 63;

[0076] S3: Install the rotating shaft 30 with the rotor 31 installed thereon in the stator 32, and sequentially connect the rotating shafts 30 of each stage of the permanent magnet motor 3 through the rotating shaft 30 connection structure.

[0077] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coaxially spliced spindle motor, characterized in that, It includes a housing (1), a cooling water jacket (2), and multiple sets of permanent magnet motors (3). The permanent magnet motor (3) includes a rotating shaft (30), a rotor (31), and a stator (32). The rotor (31) is arranged on the rotating shaft (30). The rotor (31) includes a yoke (310) and permanent magnets (311) arranged on the yoke (310). The cooling water jacket (2) is fixedly installed in the housing (1). The stator (32) is fixedly installed in the cooling water jacket (2). Multiple sets of the permanent magnet motors (3) are fixedly installed in the cooling water jacket (2) in sequence, and the rotating shafts (30) of two adjacent permanent magnet motors (3) are connected in series through a rotating shaft (30) connection structure; the rotating shaft (30) at one end of the main shaft motor extends out of the housing (1) to form a main shaft motor output shaft, and an encoder (5) is arranged on the rotating shaft (30) at the other end of the main shaft motor; A fourth positioning structure (63) and a first positioning structure (60) for keeping the mechanical angles of multiple sets of stators (32) consistent after multiple sets of the permanent magnet motors (3) are connected in series are sequentially arranged between the housing (1) and the cooling water jacket (2) and between the stator (32) and the cooling water jacket (2); A second positioning structure (61) and a third positioning structure (62) for keeping the mechanical angles of multiple sets of rotors (31) consistent after multiple sets of the permanent magnet motors (3) are connected in series are sequentially arranged between the rotating shaft (30) and the yoke (310) and between the yoke (310) and the permanent magnets (311); The housing (1) includes multiple sub-housings (10) connected in series in sequence, and the cooling water jacket (2) includes multiple sub-cooling water jackets (20) fixedly installed in the housing (1) in sequence; The fourth positioning structure (63) is arranged between the sub-housing (10) and the sub-cooling water jacket (20); The fourth positioning structure (63) is a key positioning structure or a pin positioning structure arranged between the previous-stage sub-housing (10) and the next-stage sub-cooling water jacket (20); The rotating shaft (30) connection structure is a spline structure, and a fifth positioning structure (64) corresponding to the second positioning structure (61) is arranged on the spline structure; or, the rotating shaft (30) connection structure is an adjusting disc (40) structure, and a sixth positioning structure (65) corresponding to the second positioning structure (61) is arranged on the adjusting disc (40) structure.

2. The coaxial spliced main shaft motor according to claim 1, characterized in that, The first positioning structure (60) and the second positioning structure (61) are key positioning structures or pin positioning structures; The third positioning structure (62) is a positioning groove structure arranged on the outer diameter of the yoke (310) in the same radial direction as the second positioning structure (61); 3. A coaxial spliced spindle motor according to claim 1, characterized in that, The sub-cooling water jacket (20) includes a cooling water jacket (2) body and a bearing installation part (22) arranged on the cooling water jacket (2) body for installing bearings. A cooling flow channel is arranged on the outer diameter of the cooling water jacket (2) body.

4. A coaxial spliced main shaft motor according to claim 1, characterized in that, The fifth positioning structure (64) and the sixth positioning structure (65) are positioning pin structures.

5. A method for assembling the coaxial splicing main shaft motor according to any one of claims 1 to 4, characterized in that, It includes the following steps: S1: Bond the permanent magnet (311). Taking the third positioning structure (62) on the yoke (310) as a reference, paste the permanent magnet (311) so that the center line of the first piece of permanent magnet (311) is aligned with the center line of the third positioning structure (62), and then bond the permanent magnets (311) to the yoke (310) in sequence to form the rotor (31). S2: Install the rotor (31) on the rotating shaft (30) through the second positioning structure (61) so that the center line of the permanent magnet (311) on the rotor (31) is aligned with the center line of the second positioning structure (61) on the rotating shaft (30). Install the stator (32) in the cooling water jacket (2) through the first positioning structure (60), and then install the cooling water jacket (2) with the stator (32) installed therein in the machine housing (1) through the fourth positioning structure (63). S3: Install the rotating shaft (30) with the rotor (31) installed thereon in the stator (32), and connect the rotating shafts (30) of each stage of the permanent magnet motor (3) in sequence through the rotating shaft (30) connection structure.

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