High-torque, wide-speed-range permanent magnet torque spindle motor

Abstract

A high-torque, wide-speed-range permanent magnet torque spindle motor, comprising a housing (1) and a spindle shaft (2) arranged within the housing (1); n permanent magnet power modules, each having a multi-phase winding output terminal connected in a symmetrical manner; each permanent magnet power module comprises one or more permanent magnet drive subunits (3), and each permanent magnet drive subunit (3) is sequentially arranged in an axial direction of the spindle shaft (2); at least one of the permanent magnet power modules Mi, excluding the permanent magnet power module M1, has a parallel branch Qi connected in parallel; an input terminal of the permanent magnet power module M1 is connected to a power supply; a control unit Si is respectively provided between the output terminal of each multiphase winding of each permanent magnet power module Mi, excluding the permanent magnet power module Mn, and a respective corresponding neutral point Oi; and each control unit Si selects to connect some or all of the permanent magnet power modules in series to drive the spindle shaft (2), so as to enable the motor to output a speed and torque adjustable over a wide range.

Description

High torque, wide speed range permanent magnet spindle motor Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a high-torque, wide-speed-adjustable permanent magnet spindle motor. Background Technology

[0002] The stator structure of a traditional DC motor is fixed, and its final output performance is thus determined. However, with the rapid development of precision CNC machine tools in recent years, which utilize DC motors for driving force, the output characteristics of these machine tools vary under different operating conditions. This necessitates replacing the DC motor with one possessing different characteristics to meet these requirements.

[0003] To meet the drive requirements of precision CNC machine tools, DC motors with adjustable torque have emerged. For example, the technical solution disclosed in Chinese CN208767879U uses multi-phase windings connected in parallel, with each phase winding including multiple coil groups connected in parallel. By controlling the number of parallel windings, the speed and torque requirements under various operating conditions can be met. However, this technical solution has the following shortcomings:

[0004] 1. The large current in each parallel circuit will result in a large total current in the main circuit, which in turn will require the current resources of the external DC motor driver, requiring the driver to have a large current output capacity.

[0005] 2. When any one of the parallel coil groups is disconnected, the corresponding windings are not energized and cannot act on the magnetic track. This will cause uneven additional torque generated by the coil group on the magnet, which will lead to instability and unevenness of the rotor during rotation, and will not meet the requirements of DC motor in high-precision operating environments.

[0006] 3. The adjustable range of speed and torque is small, making it difficult to meet the driving requirements of the motor under various working conditions. Summary of the Invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a high-torque, wide-speed-adjustable permanent magnet spindle motor. The adjustable range of speed and torque allows the motor to meet the driving requirements under various working conditions.

[0008] This invention proposes a high-torque, wide-speed-adjustable permanent magnet spindle motor, which includes:

[0009] The housing and the spindle housed within the housing;

[0010] n permanent magnet power modules M1, M2, ... and M n Each permanent magnet power module has symmetrically connected multi-phase output terminals;

[0011] Each permanent magnet power module includes one or more permanent magnet drive sub-units, with a total number of k permanent magnet drive sub-units. Each permanent magnet drive sub-unit includes a permanent magnet rotor fixedly connected to the main shaft and a stator coil for driving the permanent magnet rotor to rotate. The stator coil includes multi-phase coil windings.

[0012] k permanent magnet drive sub-units are arranged sequentially in the axial direction of the spindle, and no two permanent magnet drive sub-units interfere with each other's drive of the spindle;

[0013] At least one of the permanent magnet power modules M1 and M2 i The bypass branch Q with parallel connection i Side branch Q i One end is connected to the permanent magnet power module M i Connect the outgoing terminal to the branch line Q. i The other end is designated as a bypass terminal, which is relative to the permanent magnet power module M. i The incoming line is connected to the suspended configuration;

[0014] The input terminal of the permanent magnet power module M1 is connected to the power supply. (The last part, "the permanent magnet power module M1," appears to be unrelated and likely refers to another component.) n Other permanent magnet power modules M i The lead-out terminals of each multiphase coil winding and their respective neutral points O i Control units S are respectively provided between them. i Each control unit S i Corresponding to the permanent magnet power module M i The outgoing end and the neutral point O i Permanent magnet power module M i+1 The incoming line and the bypass branch Q i+1 Connect one of the three side terminals to the permanent magnet power modules M1, M2, ... and M n Some or all of them are connected in series to drive the spindle;

[0015] Where n is a natural number greater than 2, i is a natural number less than n, and k is a natural number greater than or equal to n.

[0016] In some preferred embodiments, each permanent magnet drive subunit is of the same specification, and the multiphase coil windings corresponding to multiple permanent magnet drive subunits in the same permanent magnet power module are connected in series sequentially.

[0017] In some preferred embodiments, via each control unit S i A number of j permanent magnet drive subunits are connected in series to achieve a motor output speed R when the motor reaches its maximum rated power P0. j and torque T jThe speed and torque of the motor output are adjusted inversely with j as a coefficient, so that the speed and torque of the motor output can be adjusted within a large range.

[0018] Wherein, rotational speed R j and torque T j They are: R j =R1 / j,T j =j*T1, where R1 and T1 are the maximum speed and minimum torque output by the motor when only one permanent magnet drive subunit drives the spindle, respectively, and j is a natural number less than k.

[0019] In some preferred embodiments, via each control unit S i When k permanent magnet drive subunits are connected in series in a coordinated manner, the minimum output speed R is reached when the motor reaches its maximum rated power P0. k and maximum torque T k， R k =R1 / k,T k =k*T1.

[0020] In some preferred embodiments, the control unit S i This includes one of the following: IGBT transistors, MOS transistors, relays, and contactors.

[0021] In some preferred embodiments, it also includes the functions of each control unit S. i The connected controller controls each control unit S. i Electrical operation.

[0022] In some preferred embodiments, a current driver is also included, which is connected to the input terminal of the permanent magnet power module M1.

[0023] In some preferred embodiments, the bypass branch Q i For the wire, in the control unit S i-1 permanent magnet power module M i The outgoing terminal and the bypass branch Q i When the side terminal is connected, the permanent magnet power module M i It is not connected in series with the permanent magnet power module M1.

[0024] In some preferred embodiments, n=4, k=8, permanent magnet power modules M1 and M2 each include one permanent magnet drive sub-unit, and permanent magnet power modules M3 and M4 each include three permanent magnet drive sub-units connected in series.

[0025] In some preferred embodiments, only the permanent magnet power module M2 is connected in parallel with the bypass branch Q2.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. This invention uses multiple permanent magnet drive sub-units connected in series to jointly drive the main shaft. By selecting the number j of permanent magnet drive sub-units connected in series, the speed and torque output characteristics of the motor can be adjusted. Moreover, the speed and torque output of the motor are inversely proportional to the number j of permanent magnet drive sub-units connected in series, thereby making the speed and torque output of the motor adjustable within a large range. This allows the motor to output both high speed and high torque, thus enabling the motor to meet the drive requirements under various working conditions.

[0028] 2. Since the permanent magnet drive sub-units are connected in series, the number of permanent magnet drive sub-units connected in series should not affect the drive current of the motor. Therefore, when a large number of permanent magnet drive sub-units are connected in series to enable the motor to obtain a large torque output, the drive current requirement of the current driver will not be increased, thereby reducing the current capacity requirement of the permanent magnet torque spindle motor for the current driver.

[0029] 3. Since each permanent magnet drive subunit is arranged sequentially in the axial direction of the main shaft, each permanent magnet drive subunit includes a permanent magnet rotor fixedly connected to the main shaft and a stator coil for driving the permanent magnet rotor to rotate. Therefore, in the process of adjusting torque and speed by selecting the number of permanent magnet drive subunits connected in series, the permanent magnet rotor is uniformly arranged 360 degrees relative to the main shaft, which helps to ensure the reliability and stability of motor operation. Attached Figure Description

[0030] Figure 1 is a three-dimensional structural schematic diagram of the permanent magnet torque spindle motor disclosed in this invention.

[0031] Figure 2 is a schematic diagram of part of the internal structure of the permanent magnet torque spindle motor disclosed in this invention.

[0032] Figure 3 is a schematic diagram of the electrical connections of each permanent magnet drive subunit in the permanent magnet torque spindle motor disclosed in this invention.

[0033] Figure 4 is a schematic diagram of the torque-speed curve of the permanent magnet torque spindle motor.

[0034] Figure 5 is a schematic diagram of the electrical connection of one embodiment of Figure 3.

[0035] Figure 6 is a schematic diagram of the torque-speed curve of the permanent magnet torque spindle motor in the embodiment of Figure 5.

[0036] Figure 7 is a schematic diagram of the power-speed curve of the permanent magnet torque spindle motor in the embodiment of Figure 5. Detailed Implementation

[0037] To further illustrate the technical means and effects adopted by this application to achieve its intended purpose, the specific implementation methods, structures, features, and effects according to this application are described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0038] In the formulas provided in this application, the symbol * represents multiplication and the symbol / represents division.

[0039] Referring to Figures 1 and 2, this invention discloses a high-torque, wide-speed-adjustable permanent magnet spindle motor (hereinafter referred to as "permanent magnet spindle motor" or "motor"), comprising a housing 1, a spindle 2 disposed within the housing 1, and k permanent magnet drive sub-units 3 coaxially arranged sequentially along the axial direction of the spindle 2. Any two permanent magnet drive sub-units 3 do not interfere with each other's driving of the spindle 2. One end of the spindle 2 penetrates the housing 1 and has a connecting shaft 21, which is used to drive other machine tools.

[0040] Each permanent magnet drive subunit 3 is essentially an independent sub-motor used to drive the main shaft 2. Each permanent magnet drive subunit 3 includes a permanent magnet rotor 31 fixedly connected to the main shaft 2 and a stator coil 32 for driving the permanent magnet rotor 31 to rotate. The stator coil 32 includes multi-phase coil windings.

[0041] The present invention uses some or all of the k permanent magnet drive sub-units 3 connected in series to drive the spindle 2, so that the output speed and torque of the spindle 2 can be adjusted within a large range, so that the permanent magnet torque spindle motor can meet the driving requirements of different machine tools under various working conditions.

[0042] Among them, the series connection of permanent magnet drive sub-units 3 refers to the series connection of two or more permanent magnet drive sub-units 3, and the multi-phase coil windings of each permanent magnet drive sub-unit 3 are connected in series in sequence.

[0043] Further referring to Figure 3, which is a schematic diagram of the electrical connections of each permanent magnet drive subunit in the permanent magnet torque spindle motor, to reduce the wiring complexity when several permanent magnet drive subunits 3 are connected in series one by one, in some preferred embodiments, one or more permanent magnet drive subunits 3 are pre-assembled into a permanent magnet power module. That is, in the permanent magnet torque spindle motor of the present invention, n permanent magnet power modules M1, M2, ... and M are coaxially arranged in sequence in the axial direction of the spindle 2 within the housing 1. n n is a natural number greater than 2, and k is a natural number greater than or equal to n.

[0044] For ease of description, the two opposite ends of the spindle 2 in the axial direction are defined as the head end and the tail end, respectively. Therefore, the connecting shaft 21 is fixed at either the head end or the tail end of the spindle 2, which is not limited here. The permanent magnet power module at the head end refers to M1, and the permanent magnet power module at the tail end refers to M. n .

[0045] Furthermore, each permanent magnet power module includes one or more permanent magnet drive sub-units, and the multi-phase output terminals of each permanent magnet power module are connected symmetrically using one of the following methods, such as a star connection at the neutral point O. When the permanent magnet power module includes only one permanent magnet drive sub-unit, the input and output terminals of that permanent magnet drive sub-unit are the input and output terminals of the permanent magnet power module, respectively. When the permanent magnet power module includes multiple permanent magnet drive sub-units, the input terminal of the permanent magnet drive sub-unit closest to the head end is the input terminal of the permanent magnet power module, and the input terminal of the permanent magnet drive sub-unit closest to the tail end is the output terminal of the permanent magnet power module.

[0046] All k permanent magnet drive subunits are arranged sequentially along the axial direction of the spindle, and no two permanent magnet drive subunits 3 interfere with each other's drive of the spindle 2. Furthermore, each permanent magnet drive subunit 3 is of the same specification. Moreover, the multi-phase coil windings corresponding to multiple permanent magnet drive subunits in the same permanent magnet power module are connected in series. This structure allows the permanent magnet torque spindle motor to obtain a smoother torque-speed curve, and allows the output torque and speed of the permanent magnet torque spindle motor to be adjustable within a wider range to meet the drive requirements of a large machining range.

[0047] It is understood that the number of phases in the power supply, the number of phases in each permanent magnet power module, and the number of phases in each permanent magnet drive subunit are all the same. The specification and figures of this application are described with the power supply, each permanent magnet power module, and each permanent magnet drive subunit all being three-phase. In this case, each permanent magnet drive subunit includes a three-phase coil.

[0048] Specifically, in some preferred embodiments, to meet the needs of the permanent magnet torque spindle motor for adjusting the output torque and speed, the permanent magnet power module M1 has only one permanent magnet drive subunit, whose three-phase coil windings are denoted as U1, V1, and W1, respectively; the permanent magnet power module M2 also has only one permanent magnet drive subunit, whose three-phase coil windings are denoted as U2, V2, and W2, respectively; and the other permanent magnet power modules M1 after permanent magnet power module M2... n Then, it can be configured as one or more permanent magnet drive sub-units as needed.

[0049] For example, as shown in Figure 3, permanent magnet power module M n-1 There are y permanent magnet power modules, where y is a natural number greater than 1, and the three-phase coil windings U （n-1）1 V （n-1）1 and W（n-1）1 For a permanent magnet drive subunit near the head end, with a three-phase coil winding U （n-1）1 V （n-1）1 and W （n-1）1 The input end serves as the permanent magnet power module M n-1 The input terminal; with three-phase coil winding U （n-1）y V （n-1）y and W （n-1）y The output end serves as the permanent magnet power module M n-1 The output end, and the permanent magnet power module M n-1 The three-phase outgoing terminals are connected in a star configuration to the neutral point Q. n-1 Similarly, the three-phase coil winding U （n-1）y V （n-1）y and W （n-1）y For a permanent magnet drive subunit near the tail end, permanent magnet power module M n Suppose there are x permanent magnet power modules, where x is a natural number greater than 1, and M of permanent magnet power modules. n The three-phase output terminals are the three-phase coil windings U nx V nx and W nx The three terminals are connected in a star configuration at the neutral point Q. n .

[0050] Furthermore, at least one of the permanent magnet power modules M1 and M2 is included. i It has a bypass branch Q connected in parallel. i Side branch Q i One end is connected to the permanent magnet power module M i Connect the outgoing terminal to the branch line Q. i The other end is designated as a bypass terminal, which is relative to the permanent magnet power module M. i The input terminals are connected and left suspended, where i is a natural number less than n. That is, in the permanent magnet power module M2 to M... n At least one of the permanent magnet power modules M i It has a bypass branch Q connected in parallel. i For example, permanent magnet power module M2 has a bypass branch Q2 connected in parallel with it, and permanent magnet power module M3 also has a bypass branch Q3 connected in parallel with it.

[0051] The input terminal of the permanent magnet power module M1 is connected to the power supply. (The last part, "the permanent magnet power module M1," appears to be unrelated and likely refers to another component.) n Other permanent magnet power modules M i The output terminals of their respective multiphase coil windings are connected to their respective neutral points O. i Control units S are respectively provided between them. i In other words, permanent magnet power modules M1, M2, ... and Mn-1 The output terminals of each multiphase coil winding and their corresponding neutral points O1, O2, ... and O n-1 Control units S1, S2, ... and S are respectively provided between them. n-1 .

[0052] Control Unit S i Used to select permanent magnet power module M i The outgoing end and the neutral point O i Permanent magnet power module M i+1 The incoming line and the bypass branch Q i+1 One of the three side terminals is connected to connect the permanent magnet power modules M1, M2... and M... n Some or all of them are connected in series to drive the main spindle, where i is a natural number less than n.

[0053] Among them, the side branch Q i For the wire, in the control unit S i-1 permanent magnet power module M i The outgoing terminal and the bypass branch Q i When the side terminal is connected, the permanent magnet power module M i It is not connected in series with the permanent magnet power module M1.

[0054] For example, a bypass branch Q2 is usually provided in parallel with the permanent magnet power module M2, so as to facilitate the use of the bypass branch Q2 to connect the permanent magnet power module M2, or the permanent magnet power module M2... and M n All of them were chosen not to be connected in series with the permanent magnet power module M1.

[0055] And control unit S i This includes, but is not limited to, one of the following: IGBT transistors, MOS transistors, relays, and contactors.

[0056] Of course, the permanent magnet torque spindle motor can also include various control units S i The connected controller controls each control unit S. i The electrical state, so that through each control unit S i Can be connected in series with corresponding permanent magnet power modules M as needed i .

[0057] Furthermore, the input terminals of the permanent magnet power module M1 located at the head end are connected to the power supply U, V and W. Usually, a power switch is provided between the permanent magnet power module M1 and the power supply. Of course, the power switch can also be integrated with the control unit S1.

[0058] In addition, the permanent magnet torque spindle motor also includes a current driver connected to the input terminal of the permanent magnet power module M1. This is achieved through various control units S... iThe one or more permanent magnet drive sub-units used to drive spindle 2 are connected in series. Regardless of the number of permanent magnet drive sub-units selected to drive spindle 2, only the output characteristics of the permanent magnet torque spindle motor will be changed, without increasing the drive current requirement of the current driver. This reduces the current capacity requirement of the permanent magnet torque spindle motor for the current driver.

[0059] Further referring to Figure 4, which shows the torque-speed curve of the permanent magnet torque spindle motor output, this invention utilizes various control units S... i Working in tandem, some or all of the permanent magnet power modules are connected in series and then connected to the power supply, i.e., through each control unit S i The number of series-connected energized permanent magnet drive sub-units is controlled collaboratively to jointly drive the spindle, thereby achieving adjustable torque and speed output characteristics of the permanent magnet torque spindle motor within a wide range to meet the drive power requirements of machining over a wide range. Its working principle is as follows:

[0060] Because permanent magnet motors have relatively low equivalent resistance and current during operation, the back electromotive force E0 generated by the motor is close to the input voltage U applied to the motor by the power supply. in ,Right now:

[0061] E0≈U in (1)

[0062] The back electromotive force E0 of the motor is determined by the motor speed R, magnetic flux B and winding length L, that is: E0=B*L*R (2)

[0063] Among them, the magnetic flux B is related to the magnetic track of the rotor of the permanent magnet drive subunit. For ease of understanding, it is assumed that both the magnetic flux B and the winding length L are constant values.

[0064] The relationship between the motor output speed R, the radius r of the main shaft 2, and the angular velocity ω is as follows:

[0065] R=r*ω (3)

[0066] That is, the linear velocity of spindle 2 is the speed R output by the motor, while the radius R of spindle 2 is a constant value.

[0067] Meanwhile, the relationship between the motor's maximum rated power P0, the motor's output speed R, and the motor's output torque T is as follows:

[0068] P0=T*ω=T*R / r (4)

[0069] According to equation (4), when the motor is operating at its maximum rated power, the output speed R of the motor is inversely proportional to the output torque T of the motor. When the motor outputs its highest speed, its corresponding output torque is the minimum, and conversely, when the motor outputs its lowest speed, its corresponding output torque is the maximum.

[0070] When the control unit S1 is connected to the neutral point O1, only the permanent magnet power module M1 is connected to the power supply. At this time, only one permanent magnet drive subunit drives the main shaft to rotate. The back electromotive force E1 generated by this permanent magnet drive subunit is E0. At this time, the motor output speed R1 is the maximum but the torque T1 is the minimum. When the motor runs to the maximum rated power P0, its output characteristic is at point a1 in Figure 4.

[0071] When control unit S1 is connected to the input terminal of permanent magnet power module M2, control unit S2 to S n Connect the output terminals of the permanent magnet power modules M2 to M2 respectively to the corresponding neutral points O2 to Q. n When connected, assuming that the permanent magnet power module M2 also contains only one permanent magnet drive sub-unit, the permanent magnet power module M1 and the permanent magnet power module M2 are connected in series, and the main shaft is driven by the two permanent magnet drive sub-units connected in series. At the same time, each permanent magnet drive sub-unit is of the same specification, and each permanent magnet drive sub-unit is arranged sequentially in the axial direction of the main shaft, and no two permanent magnet drive sub-units interfere with each other in driving the main shaft. Therefore, the back electromotive force E2=E0 / 2 generated by the two permanent magnet drive sub-units connected to the power supply is given by equation (2). It can be seen from equation (2) that when the two permanent magnet drive sub-units connected in series drive the main shaft together, the speed output of the motor is R2=R1 / 2. At the same time, according to equation (4), it can be seen that the speed output of the motor is T2=2*T1. When the motor runs to the maximum rated power P0, its output characteristic is at point a2 in Figure 4.

[0072] When through each control unit S i Collaboratively enabling all permanent magnet power modules M1 to M n When all are connected in series and then connected to the power supply, assuming all permanent magnet power modules M1 to M... n The total number of permanent magnet drive sub-units is k, where k is a natural number greater than n. These k permanent magnet drive sub-units are connected in series and jointly drive the spindle rotation. At this time, the back electromotive force E generated by each individual permanent magnet drive sub-unit is... k =E0 / k, using equation (2), we can know the motor output speed R. k =R1 / k; At the same time, according to equation (4), the torque T output by the motor at this time is... k =k*T1, when the motor runs to its maximum rated power P0, its output characteristic is as shown in Figure 4. k Point. At this moment, the rotational speed R k Torque T kThese are the minimum speed and maximum torque output by the motor, respectively.

[0073] Therefore, when through each control unit S i By coordinating the selection of the number j of permanent magnet drive sub-units connected in series to the power supply, where j is a natural number less than k, the motor output speed R can be changed. j and the corresponding torque T j When the motor operates at its maximum rated power P0, its output characteristic is as shown in Figure 4a. j Point, rotational speed R j =R1 / j, torque T j =j*T1.

[0074] Since each permanent magnet drive subunit is of the same specification, through each control unit S i When different numbers of permanent magnet drive subunits are connected in series to jointly drive the spindle, in Figure 4, a1, a2... and a... k Connecting each point sequentially and fitting the curves forms an approximately smooth straight line, indicating that the motor's output speed R and torque T can be adjusted as needed within a large range.

[0075] For ease of understanding, further referring to Figure 5, in a practical application, the permanent magnet torque spindle motor includes four permanent magnet power modules M1 to M4, comprising a total of eight permanent magnet drive sub-units. These eight sub-units are coaxially arranged on the spindle 2, and each permanent magnet drive sub-unit 3 is of the same specification, with no interference between any two permanent magnet drive sub-units 3 in driving the spindle.

[0076] The permanent magnet power module M1 includes a first permanent magnet drive subunit, whose three-phase coil windings are denoted as U1, V1, and W1, and whose three-phase output terminals are all connected to the neutral point O1. A control unit S1 is provided between the output terminals of the permanent magnet power module M1 and the neutral point O1. The control unit S1 can selectively connect one of the three: the neutral point O1, the input terminal of the permanent magnet power module M2, and the bypass terminal of the bypass branch Q2.

[0077] The permanent magnet power module M2 includes a second permanent magnet drive sub-unit, whose three-phase coil windings are denoted as U2, V2, and W3, and whose three-phase output terminals are all connected to the neutral point O2. A parallel bypass branch Q2 is provided in the permanent magnet power module M2. A control unit S2 is provided between the output terminals of the permanent magnet power module M2 and the neutral point O2. The control unit S2 can selectively connect the neutral point O2 or the input terminals of the permanent magnet power module M2 as needed.

[0078] The permanent magnet power module M3 includes a third permanent magnet drive subunit (its three-phase coil windings are denoted as U3, V3, and W3), a fourth permanent magnet drive subunit (its three-phase coil windings are denoted as U4, V4, and W4), and a fifth permanent magnet drive subunit (its three-phase coil windings are denoted as U5, V5, and W5) connected in series. All three phase output terminals are connected to the neutral point O3. A control unit S3 is provided between the output terminals of the permanent magnet power module M3 and the neutral point O3. The control unit S3 can selectively connect the neutral point O3 or the input terminal of the permanent magnet power module M4 as needed.

[0079] The permanent magnet power module M4 includes a 6th permanent magnet drive sub-unit (whose three-phase coil windings are denoted as U6, V6 and W6), a 7th permanent magnet drive sub-unit (whose three-phase coil windings are denoted as U7, V7 and W7), and an 8th permanent magnet drive sub-unit (whose three-phase coil windings are denoted as U8, V8 and W8) connected in series, with their three-phase output terminals connected to the neutral point O4.

[0080] Based on the driving requirements of the permanent magnet torque spindle motor for different processing conditions, the various control units S1 to S4 can be controlled to work together to select some or all of the four permanent magnet power modules M1 to M4 to drive the spindle 2, so that the permanent magnet torque spindle motor can output the torque and speed required for the driving as needed within a large adjustable range.

[0081] Further referencing Figures 6 and 7, for example, when control unit S1 is connected to neutral point O1, only the first permanent magnet drive subunit drives the spindle. When the motor runs to its maximum rated power P0, its output characteristic is at point a1 in Figure 6, with an output speed of 3000 rpm and an output torque of 70 Nm. At this time, the motor output characteristic is high speed and low torque, suitable for driving other machine tools for milling operations.

[0082] When control unit S1 is connected to the input terminal of permanent magnet power module M2, and control unit S2 connects the output terminal of permanent magnet power module M2 to neutral point O2, the first permanent magnet drive subunit and the second permanent magnet drive subunit are connected in series to drive the main shaft. When the motor runs to the maximum rated power P0, its output characteristic is at point a2 in Figure 6, with an output speed of 1500 rpm and an output torque of 140 Nm.

[0083] When control unit S1 is connected to the bypass branch Q2, and control unit S3 connects the output terminal of permanent magnet power module M3 to the neutral point O3, the first and third to fifth permanent magnet drive sub-units are connected in series, and the main shaft is driven by the four permanent magnet drive sub-units. When the motor runs to the maximum rated power P0, its output characteristic is at point a3 in Figure 6, with an output speed of 750 rpm and an output torque of 280 Nm.

[0084] When the motor is at points a2 and a3, it can be selected to output a higher speed or a larger torque, making it suitable for driving other machine tools to perform milling and turning operations.

[0085] If control units S1 to S3 are connected to the input terminals of permanent magnet power modules M2 to M3 respectively, the 1st to 8th permanent magnet drive subunits are connected in series to jointly drive the spindle. When the motor runs to its maximum rated power P0, its output characteristic is at point a4 in Figure 6, with an output speed of 375 rpm and an output torque of 560 Nm. At this time, the motor output characteristic is high torque, which is suitable for driving other machine tools for turning operations.

[0086] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A high-torque, wide-speed-adjustable permanent magnet spindle motor, characterized in that, include: The housing and the spindle housed within the housing; n permanent magnet power modules M1, M2, ... and M n Each permanent magnet power module has symmetrically connected multi-phase output terminals; Each permanent magnet power module includes one or more permanent magnet drive sub-units, with a total number of k permanent magnet drive sub-units. Each permanent magnet drive sub-unit includes a permanent magnet rotor fixedly connected to the main shaft and a stator coil for driving the permanent magnet rotor to rotate. The stator coil includes multi-phase coil windings. k permanent magnet drive sub-units are arranged sequentially in the axial direction of the spindle, and no two permanent magnet drive sub-units interfere with each other's drive of the spindle; At least one of the permanent magnet power modules M1 and M2 i The bypass branch Q with parallel connection i Side branch Q i One end is connected to the permanent magnet power module M i Connect the outgoing terminal to the branch line Q. i The other end is designated as a bypass terminal, which is relative to the permanent magnet power module M. i The incoming line is connected to the suspended configuration; The input terminal of the permanent magnet power module M1 is connected to the power supply. (The last part, "the permanent magnet power module M1," appears to be unrelated and likely refers to another component.) n Other permanent magnet power modules M i The lead-out terminals of each multiphase coil winding and their respective neutral points O i Control units S are respectively provided between them. i Each control unit S i Corresponding to the permanent magnet power module M i The outgoing end and the neutral point O i Permanent magnet power module M i+1 The incoming line and the bypass branch Q i+1 Connect one of the three side terminals to the permanent magnet power modules M1, M2, ... and M n Some or all of them are connected in series to drive the spindle; Where n is a natural number greater than 2, i is a natural number less than n, and k is a natural number greater than or equal to n.

2. The high-torque, wide-speed-adjustable permanent magnet spindle motor according to claim 1, characterized in that, Each permanent magnet drive subunit is of the same specification, and the multiphase coil windings of multiple permanent magnet drive subunits in the same permanent magnet power module are connected in series in sequence.

3. The high-torque, wide-speed-adjustable permanent magnet spindle motor according to claim 1, characterized in that, Through each control unit S i A number of j permanent magnet drive subunits are connected in series to achieve a motor output speed R when the motor reaches its maximum rated power P0. j and torque T j The speed and torque of the motor output are adjusted inversely with j as a coefficient, so that the speed and torque of the motor output can be adjusted within a large range. Wherein, rotational speed R j and torque T j They are: R j =R1 / j,T j =j*T1, where R1 and T1 are the maximum speed and minimum torque output by the motor when only one permanent magnet drive subunit drives the spindle, respectively, and j is a natural number less than k.

4. The high-torque, wide-speed-adjustable permanent magnet spindle motor according to claim 3, characterized in that, Through each control unit S i When k permanent magnet drive subunits are connected in series in a coordinated manner, the minimum output speed R is reached when the motor reaches its maximum rated power P0. k and maximum torque T k， R k =R1 / k,T k =k*T1.

5. The high-torque, wide-speed-adjustable permanent magnet spindle motor according to claim 1, characterized in that, Control Unit S i This includes one of the following: IGBT transistors, MOS transistors, relays, and contactors.

6. The high-torque, wide-speed-adjustable permanent magnet spindle motor according to claim 5, characterized in that, It also includes the various control units S i The connected controller controls each control unit S. i Electrical operation.

7. The high-torque, wide-speed-adjustable permanent magnet spindle motor according to claim 1, characterized in that, It also includes a current driver connected to the input terminal of the permanent magnet power module M1.

8. The high-torque, wide-speed-adjustable permanent magnet spindle motor according to claim 1, characterized in that, Side path Q i For the wire, in the control unit S i-1 permanent magnet power module M i The outgoing terminal and the bypass branch Q i When the side terminal is connected, the permanent magnet power module M i It is not connected in series with the permanent magnet power module M1.

9. The high-torque, wide-speed-adjustable permanent magnet spindle motor according to any one of claims 1-8, characterized in that, With n=4 and k=8, permanent magnet power modules M1 and M2 each contain one permanent magnet drive sub-unit, while permanent magnet power modules M3 and M4 each contain three permanent magnet drive sub-units connected in series.

10. The high-torque, wide-speed-adjustable permanent magnet spindle motor according to claim 9, characterized in that, Only the permanent magnet power module M2 has a bypass branch Q2 connected in parallel.

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