Induction rotor and permanent magnet speed regulating device

Abstract

The application belongs to the technical field of permanent magnet speed regulation devices, and particularly relates to an induction rotor, which comprises a ring-shaped iron core and an induction part for cutting magnetic lines and generating induced current, and the induction part comprises a hollow columnar conductor strip and a ring-shaped conductor plate, the conductor strip is annularly arranged on the iron core and penetrates the iron core in the axial direction. The hollow columnar conductor strip is directly arranged on the iron core, the conductor strip is used for cutting magnetic lines to generate induced electromotive force, so that induced current is generated in a closed loop, compared with the existing induction rotor, the application has the advantages of good heat dissipation condition, good utilization of the physical principle of current flow through the extrusion flow effect of the conductor strip and the like. The production process of the application is simple, and the cost is low. The heat generated by the conductor strip can be directly discharged to the external environment through the openings at both ends, and the heat dissipation effect is good. The fluid medium can directly enter the inside of the conductor strip, which helps to reduce the cooling difficulty of the induction rotor and improve the heat dissipation performance.

Description

Technical Field

[0001] This application relates to the field of permanent magnet speed control device technology, specifically to an induction rotor and a permanent magnet speed control device. Background Technology

[0002] A cylindrical permanent magnet speed controller is a transmission device that transmits torque through an air gap. Existing cylindrical permanent magnet speed controllers mainly consist of two parts: an induction rotor and a permanent magnet rotor. The permanent magnet rotor and the induction rotor are connected to the motor and the load shaft, respectively. An air gap exists between the induction rotor and the permanent magnet rotor. By adjusting the air gap distance or coupling area between the permanent magnet rotor and the induction rotor, the output power on the load shaft can be changed, thereby adjusting the load speed.

[0003] In existing large-scale cylindrical permanent magnet speed controllers, the induction rotor consists of at least two parts: an iron core and an induction section. The iron core is used for magnetic conduction, and the induction section is used for cutting magnetic lines of force. The induction section is usually coated on the surface of the iron core using methods such as casting.

[0004] However, the induction rotor of the existing speed controller has the following problems:

[0005] 1. During the operation of the speed controller, the heat is concentrated on the surface of the induction layer. The heat load per unit area of ​​the induction layer is high, and the cooling requirements are stringent.

[0006] 2. The resistance of a monolithic iron core is relatively small, and a large eddy current will be formed inside the iron core, which increases iron loss.

[0007] 3. The iron core of the induction rotor needs to be forged and the induction layer needs to be cast on the surface of the iron core, which makes the production process complex and costly.

[0008] Therefore, there is an urgent need to design an induction rotor for permanent magnet speed control devices that is simple to manufacture and easy to dissipate heat. Summary of the Invention

[0009] To address the aforementioned issues, this application provides an induction rotor that simplifies the manufacturing process, reduces production costs, and facilitates heat dissipation by inserting hollow cylindrical conductor strips into the iron core instead of the covering induction layer.

[0010] According to a first aspect of the embodiments of this application, an induction rotor is provided, comprising:

[0011] A ring-shaped iron core is used to guide magnetic lines of force to form a closed magnetic circuit;

[0012] The sensing element generates an induced current by cutting magnetic lines of force to produce an induced electromotive force.

[0013] The sensing element includes a hollow cylindrical conductor strip that is arranged around the iron core and passes through the iron core axially.

[0014] Preferably, the sensing unit further includes conductive end plates respectively disposed at both ends of the conductor strip, the conductive end plates short-circuiting the corresponding ends of the conductor strip.

[0015] Preferably, the iron core is formed by stacking silicon steel sheets along the axial direction.

[0016] Preferably, the iron core has a clearance hole for the conductor strip to pass through, and the sidewall of the clearance hole has a clearance groove along the radial direction of the iron core; the clearance groove extends to the circumferential wall where the magnetic lines of force enter the iron core.

[0017] Preferably, the induction rotor is an inner rotor, and the clearance groove extends through to the outer peripheral wall of the iron core.

[0018] Preferably, the induction rotor includes at least two rows of conductor strips distributed radially along the iron core, and the clearance slots on the same radial direction of the iron core partially overlap.

[0019] Preferably, the induction rotor further includes an annular support; the iron core is sleeved on the outer peripheral wall of the annular support.

[0020] Preferably, a limiting shoulder protruding outward is formed on the outer peripheral wall of one end of the annular bracket, and a limiting pressure plate is connected to the other end of the annular bracket; the limiting pressure plate and the limiting pressure plate are used to limit the axial displacement of the iron core on the annular bracket.

[0021] Preferably, the iron core and the annular bracket are provided with matching keyways, and a flat key is installed in the keyway.

[0022] According to a second aspect of the embodiments of this application, a permanent magnet speed regulating device is provided, including the aforementioned induction rotor.

[0023] This application involves directly inserting a hollow, cylindrical conductor bar onto an iron core. The induced electromotive force generated by the conductor bar cutting magnetic lines of force forms an induced current. Compared to existing induction rotors where the induction layer is cast onto the iron core surface, this application boasts a simpler manufacturing process and lower cost. The conductor bar is hollow inside and has openings at both ends, resulting in a large contact area with the external environment. Heat generated by the conductor bar can be directly discharged to the external environment through these openings, providing excellent heat dissipation. The fluid medium used to cool the induction rotor can directly enter the conductor bar, helping to reduce the cooling difficulty of the induction rotor and improve heat dissipation performance. Furthermore, the conductor bar of this application can effectively adapt to the current-squeezing effect generated when current flows through it. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the exploded structure of this application;

[0025] Figure 2This is a schematic cross-sectional view of the assembled structure of this application;

[0026] Figure 3 for Figure 2 A magnified view of a portion of the image;

[0027] Figure 4 This is a schematic diagram of a partial structure of the iron core.

[0028] In the figure, the components are: iron core 1, clearance hole 11, clearance groove 12, conductor strip 2, conductive end plate 3, connecting hole 31, annular bracket 4, limiting shoulder 41, annular protrusion 42, limiting pressure plate 5, cover plate 51, limiting part 52, keyway 6, and flat key 7. Detailed Implementation

[0029] The following detailed explanation illustrates the specific implementation methods:

[0030] This embodiment relates to a cylindrical permanent magnet speed regulating device, including a coaxially arranged permanent magnet rotor and an induction rotor, wherein the permanent magnet rotor is provided with circumferentially distributed permanent magnets (not shown in the figure). Figure 1 As shown, the induction rotor includes an iron core 1 for guiding magnetic lines of force and an induction unit for cutting the magnetic lines of force and generating an induced electromotive force. The iron core 1 can concentrate the dispersed magnetic field, so that most of the magnetic lines of force pass through the iron core 1 to form a closed magnetic circuit. The induction unit causes the induced electromotive force to form an induced current in the closed circuit.

[0031] The iron core 1 is composed of multiple silicon steel sheets stacked axially. Each silicon steel sheet is a circular ring, and its surface is coated with an insulating coating composed of insulating varnish or insulating oxide. During the operation of the induction rotor, the eddy currents generated by the iron core 1 circulate only within the corresponding single silicon steel sheet. Due to the large resistance of the narrow loop formed by the silicon steel sheet and the high resistivity of the silicon steel sheet itself, the eddy currents are reduced. Therefore, the iron core 1 in this embodiment can significantly reduce eddy current losses and has lower iron losses.

[0032] Figure 1 The induction unit shown specifically includes a conductor strip 2 and a conductive end plate 3. The conductor strip 2 is a hollow column, meaning it is hollow inside and has openings at both ends. Several conductor strips 2 are arranged in a circular array on the iron core 1, with the center of the core as the midpoint. The conductor strips 2 penetrate the iron core 1 axially to ensure that the induction rotor can cut magnetic lines of force during rotation. The conductor strip 2 can be made of common metals with good conductivity, such as aluminum, copper, and their alloys. In this embodiment, considering both economic and conductivity performance, a copper tube with a circular cross-section is preferred as the conductor strip 2.

[0033] In this embodiment, the induction rotor mainly utilizes conductor strip 2 to cut magnetic lines of force, and the heating component of the induction rotor is primarily conductor strip 2. Because conductor strip 2 is hollow, compared to rotors using solid conductor strip 2, this embodiment's induction rotor, while generating the same induced current, increases the contact area between conductor strip 2 and the iron core 1, as well as between conductor strip 2 and the external environment. The hollow conductor strip 2 can quickly disperse some heat into the iron core 1, preventing heat concentration and facilitating heat dissipation. Both ends of conductor strip 2 are open, and the contact area with the external environment is large, allowing the heat generated by conductor strip 2 to be directly discharged into the external environment through the openings, resulting in good heat dissipation.

[0034] Since both ends of the conductor strip 2 in this embodiment are open, the fluid medium used to cool the induction rotor can directly enter the interior of the conductor strip 2 from the opening at one end of the conductor strip 2 and then flow out from the opening at the other end of the conductor strip 2, which can reduce the cooling difficulty of the induction rotor and improve the cooling effect of the induction rotor.

[0035] like Figure 2 and Figure 3 As shown, the conductive end plate 3 in this embodiment is annular, with two conductive end plates 3 respectively attached to the two end faces of the iron core 1. The two conductive end plates 3 connect the two ends of the corresponding conductor strip 2 to form a closed circuit. The conductive end plate 3 in this embodiment is preferably made of brass. In this embodiment, the conductor strip 2 can also restrict circumferential rotation between the stacked silicon steel sheets, and the conductive end plate 3 can also restrict the stacked silicon steel sheets from spreading out axially, ensuring the structural strength of the iron core 1. In this embodiment, the conductor strip 2 can be directly inserted into the iron core 1, and then the conductive end plate 3 is welded and fixed to the conductor strip 2. The manufacturing process is simple, and the conductor strip 2 and conductive end plate 3 can be processed from standard materials. Compared with the induction rotor where the induction layer is cast onto the surface of the iron core, this embodiment can save more than 30% of the production cost.

[0036] In this embodiment, both ends of the conductor strip 2 extend beyond the end face of the iron core 1. A connecting hole 31 is provided on the conductive end plate 3 relative to the conductor strip 2. The portion of the conductor strip 2 extending beyond the iron core 1 passes through the connecting hole 31 and is fixed to the conductor strip 2 end plate by welding. To ensure that the end face of the conductor strip 2 is flush with the end face of the conductive end plate 3 away from the inductive iron core 1, the length of the conductor strip 2 extending beyond the iron core 1 is the same as the thickness of the conductive end plate 3. It should be noted that the length of the conductor strip 2 includes, but is not limited to, the form shown in the figure. In some embodiments, the end face of the conductor strip 2 may extend beyond the end face of the conductive end plate 3 away from the iron core 1. In some embodiments, the end face of the conductor strip 2 is located inside the connecting hole 31.

[0037] like Figure 1 and Figure 4As shown, in this embodiment, the induction rotor is located inside the permanent magnet rotor. Three rows of conductor strips 2 are arranged radially along the core 1, with the three rows of conductor strips 2 close to the outer peripheral wall of the core 1. Three rows of clearance holes 11 corresponding to the conductor strips 2 are formed on the core 1, allowing the conductor strips 2 to pass through. Clearance grooves 12 are formed on the sidewalls of the clearance holes 11 to allow magnetic lines of force to enter the core 1. Since the induction rotor in this embodiment is an inner rotor, the clearance grooves 12 extend radially along the core 1 to the outer peripheral wall of the core 1. The clearance grooves 12 not only allow magnetic lines of force to enter the core 1, preventing the core 1 from interfering with the conductor strips 2 cutting the magnetic lines of force, but also form a slit structure on the outer peripheral surface of the core 1, accommodating the thermal expansion and contraction of the core 1. Furthermore, a fluid medium can enter the clearance grooves 12 to cool the outer peripheral wall of the conductor strips 2, resulting in better heat dissipation. It should be noted that the number and rows of conductor strips 2 are set according to actual needs. To prevent conductor strips 2 from slipping out of the clearance holes 11, the width of the clearance groove 12 is smaller than the diameter of the clearance groove 12. Since the clearance grooves 12 on each row of clearance holes 11 penetrate radially to the outer peripheral wall of the iron core 1, the clearance grooves 12 on the row of clearance holes 11 closest to the inner peripheral wall of the iron core 1 will pass through the other rows of clearance holes 11 on the same radial direction of the iron core 1 in sequence, and coincide with the clearance grooves 12 on the other rows of clearance holes 11. Therefore, when there are at least two rows of conductor strips 2 distributed on the iron core 1, the clearance grooves 12 on the same radial direction of the iron core 1 will partially overlap.

[0038] In some embodiments, the induction rotor is an outer rotor, the conductor bar 2 is close to the inner peripheral wall of the iron core 1, and the clearance groove 12 extends through the inner peripheral wall of the iron core 1.

[0039] In this embodiment, the induction rotor also includes an annular support 4 disposed inside the iron core 1, with the iron core 1 fitted onto the outer peripheral wall of the annular support 4. To ensure a firm connection between the annular support 4 and the iron core 1, a protruding limiting shoulder 41 is formed on the outer peripheral wall of one end of the annular support 4, and a limiting pressure plate 5 is connected to the other end of the annular support 4. The iron core 1 is fixed by the mutually cooperating limiting shoulder 41 and limiting pressure plate 5, ensuring that the iron core 1 is firmly installed. Since the conductive end plates 3 in this embodiment are respectively attached to the two end faces of the iron core 1, the limiting shoulder 41 abuts against the conductive end plate 3 on one end face of the iron core 1, and the limiting pressure plate 5 abuts against the conductive end plate 3 on the other end face of the iron core 1.

[0040] In this embodiment, the limiting pressure plate 5 includes a cover plate 51 attached to the end face of the annular bracket 4 and a limiting part 52 provided on the outer peripheral surface of the iron core 1. Bolts are threaded through the cover plate 51 to fix the limiting pressure plate 5 to the annular bracket 4, and the limiting part 52 protrudes from the outer peripheral wall of the annular bracket 4 to form a limiting structure. The limiting part 52 abuts against the end face of the conductive end plate 3 away from the iron core 1.

[0041] In this embodiment, in order to ensure that the annular bracket 4 and the iron core 1 can effectively transmit torque, keyways 6 that cooperate with each other are provided on the annular bracket 4 and the iron core 1, and a flat key 7 is installed in the keyway 6 to transmit torque.

[0042] In this embodiment, the inner peripheral wall of the annular bracket 4 has an inwardly protruding annular protrusion 42, and an axially penetrating mounting hole is provided on the annular protrusion 42. The load shaft assembly is connected through the annular protrusion 42, which is convenient for operation.

[0043] This application is not limited to the description in the specification and embodiments, and other advantages and modifications can be readily realized by those skilled in the art. Therefore, without departing from the spirit and scope of the general concept defined by the claims and their equivalents, this application is not limited to the specific details, representative devices and illustrated examples shown and described herein.

Claims

1. An induction rotor, comprising: A ring-shaped iron core is used to guide magnetic lines of force to form a closed magnetic circuit; The sensing element generates an induced current by cutting magnetic lines of force to produce an induced electromotive force. Its features are: The sensing element includes a hollow cylindrical conductor strip, which is arranged around the iron core and passes through the iron core axially. The iron core has a clearance hole for the conductor strip to pass through, and the sidewall of the clearance hole has a clearance groove along the radial direction of the iron core; the clearance groove extends to the circumferential wall where the magnetic lines of force enter the iron core; The induction rotor is an inner rotor, and the clearance groove extends through the outer peripheral wall of the iron core. The induction rotor includes at least two rows of conductor strips distributed radially along the iron core, and the clearance holes are distributed at intervals along the radial direction of the iron core corresponding to the conductor strips. The clearance slots on the same radial direction of the iron core partially overlap. The clearance groove serves three purposes: firstly, it allows magnetic lines of force to enter the iron core, preventing the iron core from interfering with the conductor strip's cutting magnetic force; secondly, it forms a slit structure on the outer circumference of the iron core to accommodate its thermal expansion and contraction; and thirdly, it allows fluid media to enter the clearance groove to cool the outer circumference of the conductor strip.

2. The induction rotor according to claim 1, characterized in that: The sensing unit also includes conductive end plates respectively disposed at both ends of the conductor strip, the conductive end plates short-circuiting the corresponding ends of the conductor strip.

3. The induction rotor according to claim 2, characterized in that: The iron core is made of silicon steel sheets stacked axially.

4. The induction rotor according to claim 1, characterized in that: The induction rotor also includes an annular support; the iron core is sleeved on the outer peripheral wall of the annular support.

5. The induction rotor according to claim 4, characterized in that: A limiting shoulder protruding outward is formed on the outer peripheral wall of one end of the annular bracket, and a limiting pressure plate is connected to the other end of the annular bracket; the limiting pressure plate and the limiting pressure plate are used to limit the axial displacement of the iron core on the annular bracket.

6. The induction rotor according to claim 5, characterized in that: The iron core and the annular bracket are provided with matching keyways, and a flat key is installed in the keyway.

7. A permanent magnet speed regulating device, characterized in that: Includes the induction rotor as described in any one of claims 1-6.

Images