Iron core structure for frameless torque motor and end high winding reduction

Abstract

The application discloses a core structure for a frameless torque motor and a high-end winding reducing structure and relates to the technical field of motors. The inner side of the stator core is provided with a tooth portion, and the stator slot is a parallel slot. The flat wire winding is placed in the stator slot, and a coating process hole is formed at the inner included angle of the stator slot of the stator core. The coating process hole is formed at the two inner included angles of the stator slot, the insulating paint can flow into the inner included angle dead angle which is difficult to cover by conventional coating under the action of gravity and capillary force, the dead angle area is filled, the integrity and uniformity of the insulating layer in the stator slot are improved, the coating process hole can be designed as an inner concave arc or a two-arc tangent transition structure, a smooth transition fillet is arranged at the bottom, the insulating paint can flow more smoothly, the generation of air bubbles in the insulating paint is reduced, the compactness of the insulating layer is improved, and the insulating paint accumulation at the hole bottom is avoided.

Description

Technical Field

[0001] This invention relates to the field of motor technology, specifically to a frameless torque motor core structure and a low-end-height winding. Background Technology

[0002] Frameless torque motors are widely used in fields with extremely high requirements for space and performance, such as robotics, aerospace, and precision machine tools.

[0003] For example, Chinese patent CN121308395A discloses a straight-bar spliced ​​stator core for a frameless torque motor, which relates to the field of stator cores. The stator core body has an initial straight bar shape, and the stator core is arranged in a straight line. The inner protrusion of the stator core body is the stator core tooth, and coils are wound sequentially around the stator core teeth. After the coils are wound, the stator core body is welded in a circular manner. The stator core body adopts a straight bar design, and its split structure is arranged in a straight line. Each connection point of the split parts has a process hole. These process holes are specifically used to eliminate internal stress generated during manufacturing and operation. This layout not only simplifies the production process but also ensures the uniformity and stability of the core, effectively reduces stress concentration, improves production speed and efficiency, and reduces the need for manual intervention, thus facilitating large-scale manufacturing.

[0004] For example, Chinese patent CN121566803A discloses a method for manufacturing a frameless torque motor stator core. The stator core includes a stator yoke, stator teeth, and stator coils. The stator yoke is annular, and the stator teeth have a sun tooth structure. The stator teeth include annular rings, tooth shoes, and tooth bodies. The stator teeth are fitted inside the stator yoke, and multiple tooth bodies are evenly distributed. The surfaces of the stator yoke and stator teeth are coated with a high-temperature resistant insulating film. The stator coils are fitted onto the tooth bodies. The manufacturing method includes the following steps: S100, making the stator yoke and stator teeth and performing a coating treatment; S200, winding and forming the stator coil; S300, assembling the stator core; S400, welding the wire feet; S500, potting and drying; S600, boring and shaping: boring the inner side of the annular part and the cured potting adhesive, boring away the annular part to completely isolate the two adjacent tooth shoe parts, thereby boring the closed slot of the stator core into an open slot; S700, performance testing.

[0005] Most of the aforementioned existing technologies improve the overall structure. However, when the stator core of the existing frameless torque motor is coated with insulation, the coating powder tends to accumulate at the corners of the stator slots, which reduces the effective space in the slots, affects the winding winding, and reduces the slot fill factor. Summary of the Invention

[0006] The purpose of this invention is to provide a core structure for a frameless torque motor and a winding with reduced end height, in order to solve the problem in the prior art where, during the insulation coating process of the stator core of an existing frameless torque motor, coating powder tends to accumulate at the included angles within the stator slots, resulting in a reduction of the effective space within the slots, affecting winding winding and reducing slot fill factor.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a frameless torque motor core structure and a low-end-height winding, comprising a stator core and a flat wire winding, wherein the inner side of the stator core is provided with teeth and the stator slots are parallel slots; The features are as follows: a flat wire winding is placed in the stator slot; a coating process hole is opened at the included angle of the stator slot in the stator core; a weight reduction process hole is opened in the tooth part of the stator core; the flat wire winding is a six-winding coil, or two sets of three-winding coils are welded together to form the six-winding coil.

[0008] Furthermore, the height of the coating process hole is... The inner diameter of the stator core is The outer diameter of the stator core is The stator slot depth is The number of stator slots is The stator slot width is The radius of the bottom fillet of the stator slot is The thickness from the outer side of the hole to the outer circle in the weight reduction process is... Its characteristics satisfy: .

[0009] Furthermore, the weight reduction process hole is opened above the tooth, and the coating process hole has an inward arc transition. The coating process holes on both sides are symmetrical with the center line of the stator slot width.

[0010] Furthermore, the weight reduction process hole is opened on one side of the tooth width and on the edge of the stator core outer diameter. The coating process hole is two tangential arc transitions, and the coating process holes on both sides are symmetrical with the center line of the stator slot width.

[0011] Furthermore, the weight reduction process hole is a triangular weight reduction hole, with one vertex of the triangular weight reduction hole facing the center of the annular base of the stator core, and the opposite base is at the same angle as the outer diameter of the stator core.

[0012] Furthermore, the three vertices of the weight reduction process hole are all provided with smooth-transition rounded corners.

[0013] Furthermore, the bottom of the coating process hole is provided with a smooth transition rounded corner.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This frameless torque motor core structure and reduced end height winding features coating process holes at the two inner angles of the stator slots. The insulating varnish can flow into the dead corners of the inner angles that are difficult to cover by conventional coating under the action of gravity and capillary action, filling the dead corner areas and improving the integrity and uniformity of the insulation layer in the stator slots. The coating process holes can be designed as concave arcs or two tangent arc transition structures with smooth transition rounded corners at the bottom, which can guide the insulating varnish to flow more smoothly, reduce the generation of air bubbles inside the insulating varnish, improve the density of the insulation layer, and at the same time avoid the formation of insulating varnish accumulation at the bottom of the holes.

[0015] The process holes provide a dedicated channel for the inflow and containment of insulating varnish, preventing the varnish from accumulating at the corners of the stator slots and occupying the winding space, thus ensuring the effective utilization area of ​​the stator slots and maintaining a high slot fill factor.

[0016] Weight reduction process holes are opened in the non-main magnetic circuit area of ​​the tooth section to reduce the overall weight of the stator core while meeting structural strength requirements. The weight reduction process holes can be opened above the tooth section or on the outer diameter edge of the wide side of the tooth section. A triangular weight reduction hole design is adopted, with one vertex facing the center of the stator core annular base and the base flush with the outer diameter. Under the same weight reduction area, the effective blocking area of ​​the main magnetic circuit of the tooth section is smaller, and the magnetic circuit is smoothly conducted along the two sides of the triangle, resulting in low magnetic reluctance loss. All three vertices of the weight reduction process hole are provided with smooth transition rounded corners, making the magnetic circuit smoother when passing through the edge of the hole, reducing abrupt changes in magnetic flux, and reducing eddy current loss and hysteresis loss of the core.

[0017] Weight reduction process holes, especially those located on the outer edge of the stator core, have a more significant effect on reducing rotational inertia and can effectively improve the dynamic response speed of the motor.

[0018] The edges and apexes of the coating process holes and weight reduction process holes are all provided with smooth transition rounded corners, which can effectively disperse stress, reduce the stress concentration coefficient at the included angles in the stator slots and the edges of the weight reduction holes, improve the fatigue resistance of the stator core under alternating electromagnetic force and mechanical vibration, and reduce the risk of core cracking. At the same time, the rounded corner transition reduces the generation of burrs on the edges of silicon steel sheets during the stamping process, avoids burrs scratching the insulation layer of the flat wire winding, and reduces the probability of winding short circuit faults.

[0019] The flat wire winding adopts a six-coil structure, which can be made by winding six continuous coil units at one time using special equipment, or by welding two sets of three-coil windings together. This greatly reduces the number of welding points at the winding ends and effectively reduces the height of the winding ends, thus reducing the axial dimension of the motor. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the first type of iron core structure of the present invention; Figure 3 This is a schematic diagram of a partial structure of the first type of iron core of the present invention; Figure 4 This is a schematic diagram of the hole structure for the first weight reduction process of the present invention; Figure 5 This is a schematic diagram of the winding structure of the present invention; Figure 6 This is a schematic diagram of the second type of iron core structure of the present invention; Figure 7 This is a schematic diagram of a partial structure of the second type of iron core of the present invention; Figure 8 This is a schematic diagram of the second weight reduction process of the present invention; Figure 9 This is a schematic diagram of the dimensions of the lamination of the present invention; Figure 10 The curves show the influence of the diameter-to-length ratio on the torque volume density of the present invention and existing technologies.

[0021] In the diagram: 1. Stator core; 2. Flat wire winding; 3. Tooth section; 4. Stator slot; 5. Coating process hole; 6. Weight reduction process hole. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1: The stator core 1 is formed by layering silicon steel sheets. After stacking, evenly distributed teeth 3 are formed on the inner side. Adjacent teeth 3 form parallel stator slots 4. The slot walls of the parallel slots are parallel to each other, which facilitates the regular arrangement and tight fit of the flat wire windings 2. Coating process holes 5 are pre-opened at the two inner angles of the stator slots 4. The height of the coating process holes 5 is... according to Calculations show that this size can provide sufficient inflow channels for insulating varnish while ensuring the effective conduction area of ​​the stator core 1 magnetic circuit.

[0024] Weight reduction process holes 6 are opened in the non-main magnetic circuit area of ​​the tooth section 3. The thickness S from the outer side of the weight reduction process hole 6 to the outer circle of the stator core 1 is set according to the electromagnetic force and mechanical stress requirements during motor operation. Under the premise of meeting the structural strength, the overall weight of the stator core 1 is reduced. Flat wire winding 2 is adopted. Compared with round wire winding, it can obtain a higher slot fill factor and improve the power density of the motor.

[0025] Example 2: The flat wire winding 2 can be in the form of a six-coil winding. Six continuous coil units are wound at once using a special winding equipment to reduce the number of welding points at the ends of the winding. Alternatively, two sets of three-coil windings can be wound separately first, and then the corresponding ends of the two sets of three-coil windings can be connected into a six-coil winding by resistance welding or laser welding to adapt to different specifications of winding equipment.

[0026] In the stator insulation coating process, the insulating varnish flows into the inner corner of the stator slot 4 through the coating process hole 5 under the action of gravity and capillary action, filling the area that is difficult to cover by conventional coating methods and improving the integrity of the insulation layer inside the stator slot 4.

[0027] When the motor is running, the weight reduction process hole 6 is opened in the area of ​​the tooth 3 where the magnetic flux density is low. It will not have a significant impact on the conduction of the main magnetic circuit. At the same time, it can reduce the rotational inertia of the stator core 1 and improve the dynamic response performance of the motor.

[0028] Example 3: The weight reduction process hole 6 is located in the upper region of the tooth 3, near the slot opening of the stator slot 4. This region has a relatively low magnetic flux density, so the weight reduction process hole 6 has minimal impact on the magnetic circuit. The coating process hole 5 is designed with a concave arc-shaped transition structure. The coating process holes 5 on both sides are symmetrically distributed with the center line of the slot width of the stator slot 4 as the axis of symmetry. When machining the coating process hole 5, a punch matching the concave arc-shaped contour is used for one-time stamping. The concave arc-shaped transition can disperse the stress at the included angle of the stator slot 4, reducing the stress concentration.

[0029] During the insulation coating process, the concave arc-shaped coating process hole 5 can guide the insulating varnish to flow more smoothly into the inner angle area of ​​the stator slot 4, increasing the contact area between the insulating varnish and the inner wall of the stator core 1, and making the thickness of the insulation layer more uniform.

[0030] The symmetrically distributed coating process holes 5 ensure consistent insulation coating on both sides of the stator slot 4, avoiding insulation failure caused by excessively thin insulation layers on one side. During motor operation, the weight-reduction process holes 6 above the teeth 3 effectively reduce the weight of the teeth 3. At the same time, due to the low magnetic flux density in this area, the increase in magnetic reluctance of the magnetic circuit is within an acceptable range and will not have a significant adverse effect on the electromagnetic performance of the motor.

[0031] Example 3: The weight reduction process hole 6 is opened on the wider side of the tooth 3, on the outer diameter edge of the stator core 1. This area is located at the connection between the annular base 10 and the tooth 3 of the stator core 1, and has high mechanical strength. After opening the weight reduction process hole 6, the overall structural stability of the stator core 1 will not be significantly reduced.

[0032] The coating process holes 5 are designed as two tangent circular arc transitions. The coating process holes 5 on both sides are also symmetrically distributed with the center line of the stator slot 4 as the axis of symmetry. When machining the coating process holes 5, a special punch with two tangent circular arc contours is used for stamping. The smooth transition surface formed by the two tangent circular arcs can further reduce the stress concentration coefficient at the included angle in the stator slot 4 and improve the fatigue resistance of the stator core 1 under the action of alternating electromagnetic force.

[0033] During the insulation coating process, the coating process hole 5 formed by two tangent arcs can form a smoother flow channel, allowing the insulating varnish to slowly and evenly cover the inner corner surface of the stator slot 4, reducing the generation of air bubbles inside the insulating varnish and improving the density of the insulation layer.

[0034] When the motor is running, the weight reduction process hole 6 located on the outer diameter edge of the wide side of the tooth section 3 can reduce the weight of the stator core 1 to the maximum extent without blocking the main magnetic circuit of the tooth section 3. Moreover, since this area is close to the outer circle of the stator core 1, the weight reduction effect has a more significant effect on reducing the rotational inertia of the motor.

[0035] Example 4: The weight reduction process hole 6 is designed as a triangular weight reduction hole. One vertex of the triangular weight reduction hole faces the center of the annular base 10 of the stator core 1, and the opposite bottom edge is at the same angle as the outer diameter of the stator core 1.

[0036] When machining triangular weight-reducing holes, a punch matching the triangular contour is used for stamping. The triangular structure can ensure a certain weight-reducing area while making the stress distribution more uniform at the edge of the hole, avoiding the occurrence of sharp corner areas where stress is concentrated.

[0037] The apex of the triangular weight-reducing hole faces the center of the circle, which allows the main magnetic circuit of tooth 3 to be smoothly conducted along the two sides of the triangle, reducing the degree of bending of the magnetic circuit and reducing magnetic reluctance loss.

[0038] Compared with circular or square weight-reduction holes, triangular weight-reduction holes have a smaller effective blocking area for the three magnetic circuits of the teeth under the same weight-reduction area, and can better balance the weight reduction effect and electromagnetic performance.

[0039] When the motor is running, the bottom edge of the triangular weight reduction hole is flush with the outer diameter of the stator core 1, which can ensure the integrity of the outer circle of the stator core 1 and facilitate the interference fit installation of the stator core 1 and the motor housing. At the same time, the flush bottom edge can reduce the subsequent machining allowance of the outer circle of the stator core 1 and reduce the machining cost.

[0040] Example 5: Smoothly rounded corners are provided at the three vertices of the triangular weight-reducing hole. When machining the triangular weight-reducing hole, a punch with corresponding rounded corners at the three vertices is used to form it in one stamping. The smooth rounded corners at the three vertices can effectively eliminate stress concentration at the sharp corners, improve the structural reliability of the stator core 1 under long-term alternating electromagnetic force and mechanical vibration, and reduce the risk of core cracking.

[0041] Rounded corners can reduce the generation of burrs on the edges of silicon steel sheets during the stamping process, improve the surface quality of stator core 1, and prevent burrs from scratching the insulation layer of flat wire winding 2.

[0042] When the motor is running, the smooth transition of the rounded corners makes the magnetic circuit smoother when passing through the edge of the weight reduction process hole 6, reducing the sudden change in magnetic flux, thereby reducing the eddy current loss and hysteresis loss of the iron core, which helps to improve the operating efficiency of the motor.

[0043] Example 6: A smooth-transition rounded corner is provided at the bottom of the coating process hole 5. When processing the coating process hole 5, a punch with a corresponding rounded corner at the bottom is used for stamping. The smooth-transition rounded corner at the bottom can further disperse the stress at the included angle in the stator slot 4 and improve the mechanical strength of the stator core 1.

[0044] During the insulation coating process, the rounded corners at the bottom can guide the insulating varnish to flow more smoothly, avoiding the accumulation of insulating varnish or residual air bubbles at the bottom of the coating process hole 5, thus ensuring the uniformity and density of the insulation layer.

[0045] The smooth transition of the rounded corners can reduce the sharp burrs generated during the stamping process, prevent the burrs from scratching the insulation of the flat wire winding 2 during winding installation, and reduce the probability of winding short circuit faults.

[0046] When the motor is running, the rounded corners at the bottom of the coating process hole 5 can make the magnetic resistance change more gradual when the magnetic circuit passes through this area, reducing the additional loss of the iron core.

[0047] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" or "linked" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0048] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A frameless torque motor core structure and a low-end height winding, comprising a stator core (1) and a flat wire winding (2), wherein the inner side of the stator core (1) is provided with teeth (3) and the stator slot (4) is a parallel slot; Its features are: The flat wire winding (2) is placed in the stator slot (4), and a coating process hole (5) is opened at the included angle of the stator slot (4) of the stator core (1). A weight reduction process hole (6) is opened on the tooth part (3) of the stator core (1). The flat wire winding (2) is a six-winding coil, or two sets of three-winding coils are welded together to form the six-winding coil.

2. The frameless torque motor core structure and reduced end height winding according to claim 1, characterized in that: The height of the coating process hole (5) is The inner diameter of the stator core (1) is The outer diameter of the stator core (1) is The stator slot (4) has a depth of [missing information]. The width of the stator slot (4) is The number of slots in stator slot (4) is The radius of the bottom fillet of the stator slot (4) is The thickness from the outer side to the outer circle of the weight reduction process hole (7a) is Its characteristics satisfy: H = D 1 - D i 1 2 - L t - S + W s - d c sin 360 ∘ Z .

3. The frameless torque motor core structure and reduced end height winding according to claim 1, characterized in that: The weight reduction process hole (6) is opened above the tooth (3), and the coating process hole (5) has an inward arc transition. The coating process holes (5) on both sides are symmetrical with the center line of the stator groove (4).

4. The frameless torque motor core structure and reduced end height winding according to claim 1, characterized in that: The weight reduction process hole (6) is opened on one side of the tooth (3) and on the outer diameter edge of the stator core (1). The coating process hole (5) is two arcs that are tangent to each other. The coating process holes (5) on both sides are symmetrical with the center line of the stator slot (4) width.

5. The frameless torque motor core structure and reduced end height winding according to claim 4, characterized in that: The weight reduction process hole (6) is a triangular weight reduction hole. One vertex of the triangular weight reduction hole faces the center of the annular base of the stator core (1), and the opposite bottom edge is at the same angle as the outer diameter of the stator core (1).

6. The frameless torque motor core structure and reduced end height winding according to claim 5, characterized in that: The three vertices of the weight reduction process hole (6) are all provided with rounded corners that have a smooth transition.

7. The frameless torque motor core structure and reduced end height winding according to claim 6, characterized in that: The bottom of the coating process hole (5) is provided with a smooth transition rounded corner.

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