Rotor assembly, motor and air compressor

Abstract

The invention provides a rotor assembly, a motor and an air compressor. The rotor assembly comprises a rotating shaft sleeved with a rotor iron core; the rotor iron core is provided with a first rotor iron core and a second rotor iron core along the axial direction of the rotating shaft, the first rotor iron core is provided with a magnetic steel groove, and magnetic steel is arranged in the magnetic steel groove; the second rotor iron core is provided with a tooth groove, a conducting bar is arranged in the tooth groove, and two ends of the conducting bar are provided with end rings. The squirrel cage rotor and the permanent magnet rotor are arranged in the axial direction of the rotating shaft, the advantages of an induction motor and a permanent magnet motor are integrated, and compared with a traditional asynchronous motor, the motor has the advantages of being lower in torque pulsation, higher in efficiency, low in cost and high in efficiency.

Description

Technical Field

[0001] The present application belongs to the technical field of air compressors, and specifically relates to a rotor assembly, a motor and an air compressor. Background Art

[0002] An air compressor is a machine that can compress gas. The air compressor is driven by an electric motor, which converts the mechanical energy of the motor into the pressure energy of the gas. It plays a core role in most modern industrial production processes.

[0003] With the continuous improvement of the research and development level of air compressors, it has developed from the original traditional piston type to the current screw type. The structure and performance requirements of screw air compressors have the characteristics of high efficiency, low energy consumption and miniaturization, so this also puts forward some requirements for the selection and design of its drive motor, and the starting torque, torque pulsation, working efficiency, heat dissipation performance, speed regulation ability and other factors of the drive motor should be fully considered.

[0004] At present, most air compressors use asynchronous motors as drive motors. The rotor of the asynchronous motor is located in the rotating magnetic field formed by the stator winding. The induced current in the rotor winding (pure aluminum) interacts with the stator magnetic field to generate a torque to drive the rotor to rotate. However, the disadvantage of asynchronous motors is that the working efficiency is relatively low, which will cause energy waste. Summary of the invention

[0005] Therefore, the present application provides a rotor assembly, a motor and an air compressor, which can solve the problem of relatively low working efficiency of asynchronous motors in the prior art.

[0006] In order to solve the above problems, the present application provides a rotor assembly, comprising:

[0007] A rotating shaft, sleeved with a rotor core;

[0008] The rotor core is provided with a first rotor core and a second rotor core along the axial direction of the rotating shaft, the first rotor core is provided with a magnetic steel slot, and the magnetic steel is arranged in the magnetic steel slot; the second rotor core is provided with a tooth slot, and the tooth slot is provided with a guide bar, and end rings are provided at both ends of the guide bar.

[0009] In some embodiments,

[0010] A baffle is provided between the first rotor core and the second rotor core.

[0011] In some embodiments,

[0012] Two second rotor cores are provided, which are respectively located at two axial ends of the first rotor core.

[0013] In some embodiments,

[0014] A heat sink is provided on the end ring away from the first rotor core.

[0015] In some embodiments,

[0016] The heat sink comprises fins, and the fins are arranged on the axial end surface of the end ring.

[0017] In some embodiments,

[0018] The fins are provided in plurality and are evenly distributed along the outer periphery of the end ring.

[0019] According to another aspect of the present application, a motor is provided, comprising the rotor assembly as described above.

[0020] In some embodiments,

[0021] The motor also includes a stator assembly, and the rotor assembly is inserted into the stator assembly; the stator assembly includes a stator core and an end winding, the first rotor core corresponds to the position of the stator core, and the second rotor core corresponds to the position of the end winding.

[0022] In some embodiments,

[0023] The axial length of the first rotor core is the same as the axial length of the stator core.

[0024] According to another aspect of the present application, an air compressor is provided, comprising the rotor assembly as described above or the motor as described above.

[0025] A rotor assembly provided in the present application includes: a rotating shaft, on which a rotor core is sleeved; the rotor core is provided with a first rotor core and a second rotor core along the axial direction of the rotating shaft, the first rotor core is provided with a magnetic steel slot, and a magnetic steel is provided in the magnetic steel slot; the second rotor core is provided with a tooth slot, and a guide bar is provided in the tooth slot, and end rings are provided at both ends of the guide bar.

[0026] This application has the following beneficial effects:

[0027] By arranging a squirrel cage rotor and a permanent magnet rotor in the axial direction of the rotating shaft, the advantages of the induction motor and the permanent magnet motor are integrated. Compared with the traditional asynchronous motor, it has lower torque pulsation and higher efficiency, and has the beneficial effects of low cost and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the implementation methods or the prior art descriptions. The drawings described below are merely exemplary, and for those of ordinary skill in the art, other implementation drawings can be derived from the provided drawings without creative work.

[0029] Figure 1 This is a schematic structural diagram of a rotor assembly according to an embodiment of the present application;

[0030] Figure 2 This is a schematic structural diagram of a first rotor core according to an embodiment of the present application;

[0031] Figure 3 This is a schematic structural diagram of a second rotor core according to an embodiment of the present application;

[0032] Figure 4 Schematic diagram of the structure of the motor according to the embodiment of the present application.

[0033] The reference numerals are as follows:

[0034] 1. Rotating shaft;

[0035] 2. second rotor core; 21. guide bar; 22. end ring; 221. fin;

[0036] 3. First rotor core; 31. Magnetic steel slot;

[0037] 4. Baffle; 5. Shell; 6. Rear end cover; 7. Front end cover;

[0038] 8. stator assembly; 81. stator core; 82. end winding. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0041] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0042] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0043] See also Figures 1 to 4 As shown, according to an embodiment of the present application, a rotor assembly includes:

[0044] The rotating shaft 1 is sleeved with a rotor core;

[0045] The rotor core is provided with a first rotor core 3 and a second rotor core 2 along the axial direction of the rotating shaft 1. The first rotor core 3 is provided with a magnetic steel slot 31, and a magnetic steel is provided in the magnetic steel slot 31; the second rotor core 2 is provided with a tooth slot, and a guide bar 21 is provided in the tooth slot, and end rings 22 are provided at both ends of the guide bar 21.

[0046] The present application integrates the advantages of an induction motor and a permanent magnet motor by arranging a squirrel cage rotor and a permanent magnet rotor in the axial direction of the rotating shaft 1. Compared with a traditional asynchronous motor, the present application has lower torque pulsation and higher efficiency, and has the beneficial effects of low cost and high efficiency.

[0047] The first rotor core 3 is provided with a magnetic steel slot 31, and a magnetic steel is installed in the magnetic steel slot 31 accordingly, so as to form a permanent magnet rotor; and the second rotor core 2 is provided with tooth slots, guide bars 21 are passed through the tooth slots, and end rings 22 are provided at both ends of the guide bars 21, so as to form a traditional squirrel cage rotor structure.

[0048] Although traditional permanent magnet synchronous motors are small in size, have low starting current, and are energy-efficient, they have high production costs, require the addition of a frequency converter drive, and have a complex control system. Because the rotor inertia is large and the magnetic field rotates too fast, the stationary permanent magnet rotor cannot follow the stator magnetic field to start rotating, so it cannot be started directly by three-phase AC power.

[0049] In the rotor assembly of the present application, the squirrel cage rotor generates a starting torque under the action of the rotating magnetic field generated by the stator, driving the rotating shaft 1 to rotate. After the speed rises to a certain level, the permanent magnet rotor interacts with the rotating magnetic field generated by the stator and gradually reaches the synchronous speed. In other words, by using the rotor assembly of the present application, the motor does not need to be driven by a frequency converter to achieve synchronous rotation, which reduces the manufacturing cost and can also improve the motor's overload capacity, motor efficiency and operating stability.

[0050] In some embodiments,

[0051] A baffle 4 is provided between the first rotor core 3 and the second rotor core 2 .

[0052] A baffle 4 is arranged between the squirrel cage rotor and the permanent magnet rotor, so that when the two rotors are sleeved on the rotating shaft 1, it can play a buffering role and avoid the squirrel cage rotor core and the permanent magnet rotor core from directly contacting and being squeezed and deformed.

[0053] In some embodiments,

[0054] Two second rotor cores 2 are provided, which are respectively located at two axial ends of the first rotor core 3 .

[0055] There are two second rotor cores 2, which are arranged at the two axial ends of the first rotor core 3 to form a three-section rotor structure. The squirrel cage rotors at both ends provide starting torque to drive the shaft 1 to rotate, with good balance and high operating stability.

[0056] In some embodiments,

[0057] A heat sink is provided on the end ring 22 away from the first rotor core 3 .

[0058] In this solution, a heat sink is arranged on the end ring 22 of the squirrel cage rotor away from the permanent magnet rotor, so that during the operation of the motor, the flow of the airflow nearby is accelerated, the heat of the motor is quickly dissipated, the heat dissipation of the motor is increased, the temperature rise of the motor is reduced, and the motor efficiency and operation stability are improved.

[0059] In some embodiments,

[0060] The heat sink includes fins 221 , and the fins 221 are disposed on the axial end surface of the end ring 22 .

[0061] The heat sink adopts fins 221 to dissipate heat, has a simple structure, and is easy to manufacture. The fins 221 can be fixed on the axial end face of the end ring 22 by welding, or can be directly manufactured in one piece.

[0062] In some embodiments,

[0063] There are multiple fins 221 , which are evenly distributed along the outer periphery of the end ring 22 .

[0064] A plurality of fins 221 are arranged and evenly distributed along the outer periphery of the end ring 22, which can drive the surrounding airflow to the greatest extent, accelerate the heat dissipation of the motor, increase the heat dissipation of the motor, reduce the temperature rise of the motor, and thus improve the motor efficiency and operation stability.

[0065] According to another aspect of the present application, a motor is provided, comprising the rotor assembly as described above.

[0066] The squirrel cage bars and magnetic steel of the existing asynchronous start permanent magnet synchronous motor rotor are mostly in the same rotor core, occupying each other's space. The present application adopts a segmented rotor to solve this problem. Figure 4 The internal structure of the motor shown is that a stator assembly 8 and a rotor assembly are arranged in a chamber surrounded by a housing 5, a front cover 7 and a rear cover 6. The outer periphery of the stator assembly 8 is fixedly connected to the inner wall of the housing 5, and the rotor assembly is inserted into the stator assembly 8. A squirrel cage rotor, a permanent magnet rotor and a squirrel cage rotor are axially sleeved on the rotating shaft 1 of the rotor assembly in sequence. In this way, the iron core part of the asynchronous squirrel cage rotor is not restricted by the space occupied by the magnetic steel, and the cast aluminum notch on the iron core of the squirrel cage rotor can be more freely optimized and designed to improve the starting ability and load capacity of the motor.

[0067] When the motor of the present application is operating normally, after three-phase AC is supplied to the stator winding of the motor, the squirrel cage rotor starts to rotate, providing the motor with starting torque to drive the shaft 1 to operate. As the motor speed gradually increases to a certain speed, the permanent magnetic field in the permanent magnetic rotor interacts with the rotating magnetic field generated by the stator, and gradually reaches the synchronous speed of the motor to operate normally. Therefore, the motor does not need to use a frequency converter, but only needs to be normally connected to three-phase AC. Compared with traditional three-phase asynchronous motors, it is more efficient and has a higher power factor, achieving low cost and high energy efficiency.

[0068] In some embodiments,

[0069] The motor also includes a stator assembly 8, and the rotor assembly is inserted into the stator assembly 8; the stator assembly 8 includes a stator core 81 and an end winding 82, the first rotor core 3 corresponds to the position of the stator core 81, and the second rotor core 2 corresponds to the position of the end winding 82.

[0070] Normally, the axial lengths of the stator core 81 and the rotor core of the motor are equal, and the two axial ends of the core are basically aligned. In this way, during the operation of the motor, the utilization rate of the magnetic field generated by the end winding 82 of the stator core 81 is low. The squirrel cage rotor part of the present application corresponds to the position of the end winding 82 of the stator core 81, that is, it is aligned with the plane of the end of the stator enameled wire, which improves the utilization rate of the magnetic field generated by the stator end winding 82, reduces the height of the stator and rotor core of the motor to a certain extent, and reduces the volume of the motor; and the permanent magnet rotor corresponds to the position of the stator core 81, which can better achieve synchronous rotation.

[0071] In some embodiments,

[0072] The axial length of the first rotor core 3 is the same as the axial length of the stator core 81 .

[0073] More specifically, the axial length of the first rotor core 3 is the same as the axial length of the stator core 81, and the corresponding squirrel cage rotor is only directly opposite to the end winding 82, and the squirrel cage rotor is aligned with the end winding 82, that is, the end winding 82 does not protrude in the axial direction, and the internal space of the motor is fully utilized, which can effectively improve the utilization rate of the end winding 82 and improve the efficiency of the motor.

[0074] According to another aspect of the present application, an air compressor is provided, comprising the rotor assembly as described above or the motor as described above.

[0075] The air compressor of the present application integrates the advantages of permanent magnet motor and induction motor, and no frequency converter is needed, which reduces the manufacturing cost of the motor. Compared with the traditional asynchronous motor, the torque pulsation of the motor is lower and the efficiency is higher, achieving low cost and high efficiency.

[0076] It is easy for those skilled in the art to understand that the above-mentioned implementation modes can be freely combined and superimposed without conflict.

[0077] The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A rotor assembly, characterized in that: include: A rotating shaft (1) sleeved with a rotor core; The rotor core is provided with a first rotor core (3) and a second rotor core (2) along the axial direction of the rotating shaft (1); the first rotor core (3) is provided with a magnetic steel slot (31), and the magnetic steel is provided in the magnetic steel slot (31); the second rotor core (2) is provided with a tooth slot, and a guide bar (21) is provided in the tooth slot, and end rings (22) are provided at both ends of the guide bar (21).

2. The rotor assembly according to claim 1, characterized in that: A baffle (4) is provided between the first rotor iron core (3) and the second rotor iron core (2).

3. The rotor assembly according to claim 1 or 2, characterized in that: Two second rotor iron cores (2) are provided, respectively located at two axial ends of the first rotor iron core (3).

4. The rotor assembly according to claim 3, characterized in that: A heat sink is provided on the end ring (22) away from the first rotor core (3).

5. The rotor assembly according to claim 4, characterized in that: The heat sink comprises a fin (221), and the fin (221) is arranged on the axial end surface of the end ring (22).

6. The rotor assembly according to claim 5, characterized in that: A plurality of fins (221) are provided, which are evenly distributed along the outer periphery of the end ring (22).

7. A motor, characterized in that: Comprising a rotor assembly as described in any one of claims 1-6.

8. The motor according to claim 7, characterized in that: The motor further comprises a stator assembly (8), wherein the rotor assembly is inserted into the stator assembly (8); the stator assembly (8) comprises a stator core (81) and an end winding (82), wherein the first rotor core (3) corresponds to the position of the stator core (81), and the second rotor core (2) corresponds to the position of the end winding (82).

9. The motor according to claim 8, characterized in that: The axial length of the first rotor core (3) is the same as the axial length of the stator core (81).

10. An air compressor, characterized in that: It comprises the rotor assembly according to any one of claims 1 to 6 or the motor according to any one of claims 7 to 9.

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