Pressing structure of rotor laminations, pressing tooling and rotor lamination processing method

Abstract

A pressing structure for a rotor lamination, wherein a positioning protrusion is provided on the outer circumference of the lamination body. A pressing tool, comprising a cylinder with an inner hole, wherein the inner wall of the cylinder is provided with a plurality of positioning grooves, the number of which is the same as the number of rotor laminations. The positioning grooves are spaced clockwise or counterclockwise around the inner hole and are parallel to the axis of the inner hole. A method for processing a rotor lamination, wherein the rotor laminations are stacked in sequence in the inner hole through the positioning protrusions according to the distribution order of the positioning grooves in the positioning tool, pressed and demolded, and then the positioning protrusions are cut by electric spark wire cutting, and finally the surface processing of the outer circumference of the rotor lamination is completed by grinding. Due to the addition of the positioning protrusions on the rotor laminations and the coordination of the positioning grooves in the pressing tool, the pressure to which the rotor laminations are subjected during the pressing process acts vertically on the surface of the rotor laminations, thus avoiding stress on the skew grooves, improving the consistency and uniformity of the width of the skew grooves of the rotor laminations, and ensuring the uniformity of the magnetic properties of the rotor laminations, thereby ensuring the accuracy of the product.

Description

Technical Field

[0001] The invention belongs to the technical field of sine-cosine rotary transformer processing, and relates to a rotor lamination, a lamination pressing tool and a rotor lamination processing method in a transformer. Background Art

[0002] In the sine-cosine rotary transformer, the rotor lamination assembly is made up of multiple rotor laminations pressed together. Each rotor lamination is provided with multiple slots, which are evenly distributed around the circumference of the rotor lamination. Figure 1 and Figure 2 As shown, the rotor lamination 1 after being pressed and formed has an inclined groove 2, and the inclined groove 2 is formed by rotating the upper and lower rotor laminations in sequence by a certain angle.

[0003] The tooling and pressing methods used in the existing rotor lamination pressing are as follows:

[0004] Existing rotor laminations use the rotor laminations' own slots for rotational positioning during lamination. The corresponding tooling is equipped with a locating key aligned with the angle of the slots. For example, if there are 20 slots on a rotor lamination and 16 rotor laminations are required to form a rotor lamination, during lamination lamination pressing, the laminations are first rotated, positioned, and stacked by fitting one slot in each of the upper and lower rotor laminations onto the locating key. Then, copper inserts are placed in the remaining skews to assist in positioning. Finally, lamination is performed. Problems with existing lamination tooling and positioning pressing methods include the inability to meet the performance requirements of the rotor lamination when high product precision is required. The reasons are: 1. When positioning the rotor laminations on the skew slots of the existing tooling, the laminations are relatively soft, and the slots that directly contact the locating key may be squeezed and deformed, thereby damaging the rotor lamination assembly structure and magnetic properties. 2. When applying pressure to the rotor lamination, the locating key has an oblique angle, so the laminations must rotate according to the angle of the tooling locating key. It is very easy to cause uneven force, which may lead to cracking and other problems, which will also damage the rotor laminated component structure and magnetic properties. Summary of the Invention

[0005] In view of this, the present invention provides a rotor lamination, a lamination pressing tool and a rotor lamination processing method, which can effectively avoid damage to the rotor lamination during the positioning and pressing process, thereby ensuring the magnetic properties of the entire rotor lamination.

[0006] The technical solution adopted by the present invention is: a pressed structure of a rotor lamination, including an annular lamination body, with multiple slots evenly distributed on the circumference of the lamination body, characterized in that: the lamination body is provided with a positioning protrusion on the outer circle, the positioning protrusion is located at the center position between any two adjacent slots, the width of the positioning protrusion is smaller than the width of the outer circle of the lamination body between adjacent slots, and the thickness of the positioning protrusion is consistent with the thickness of the lamination body.

[0007] Furthermore, the positioning protrusion is rectangular and has chamfered corners.

[0008] A pressing tool is characterized by: it is a cylinder with an inner hole, the diameter of the inner hole is adapted to the diameter of the laminate body, forming a clearance fit; a plurality of positioning grooves are opened on the inner wall of the cylinder, and the number of positioning grooves is consistent with the number of rotor laminations required to form the rotor lamination; the positioning grooves are distributed clockwise or counterclockwise around the inner hole and are parallel to the axis of the inner hole; the width of the positioning grooves is adapted to the width of the positioning protrusions, forming a clearance fit.

[0009] Furthermore, the minimum angle φ corresponding to the positioning grooves is specifically determined as follows:

[0010] Assume that m is the number of slots on the rotor lamination and θ is the angle between adjacent slots on the same rotor lamination:

[0011] θ=360° / m;

[0012] Assuming that n rotor laminations are required, the difference between the first rotor lamination and the nth rotor lamination is a slot angle θ. The angle α that the slots between two adjacent rotor laminations need to be rotated is:

[0013] α=θ / (n-1);

[0014] Minimum angle φ between positioning grooves:

[0015] φ=θ+α.

[0016] Furthermore, the angle between adjacent positioning grooves may also be dθ+α, where d is a natural number greater than 1.

[0017] Furthermore, the positioning groove is marked with a serial number;

[0018] Furthermore, the number of notches of the rotor lamination is 20, and 16 rotor laminations are required to form one rotor lamination. The pressing tool is provided with 16 positioning grooves, and the minimum angle between two adjacent positioning grooves is 19.2°.

[0019] Furthermore, among the 16 positioning grooves, the angles between the 4th and 5th, the 8th and 9th, and the 12th and 13th are 37.2°.

[0020] A method for machining rotor laminations, characterized in that;

[0021] Step 1: stack the rotor laminations in the inner hole in sequence according to the distribution order of the positioning grooves in the positioning tool through the positioning protrusions, and then apply a pressing force perpendicular to the surface of the rotor laminations for pressing;

[0022] Step 2: After the rotor laminations are pressed and formed, they are demoulded;

[0023] Step 3: Cut the positioning protrusions on the outer circle of the rotor laminate in step 2 by wire electric discharge cutting, and finally complete the surface processing of the outer circle of the rotor laminate by grinding.

[0024] The beneficial effects of the present invention are as follows: a positioning protrusion is added to the outer circle of the rotor lamination, and is positioned in conjunction with the positioning groove in the pressing tool, so that the pressure exerted on the rotor lamination during the pressing process acts vertically on the surface of the rotor lamination, avoiding the force on the skewed groove, thereby achieving the purpose of uniform force, improving the consistency and uniformity of the width of the rotor lamination skewed groove, ensuring the uniformity of the magnetic properties of the rotor lamination, and thus ensuring the accuracy of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the rotor lamination structure.

[0026] Figure 2 Top view of the rotor laminations.

[0027] Figure 3 It is a schematic diagram of the structure of the rotor lamination.

[0028] Figure 4 It is a structural diagram of the pressing tooling.

[0029] Figure 5 Schematic diagram of the rotor laminations stacked in the pressing tooling.

[0030] Figure 6 It is a schematic diagram of the rotor laminated structure without processed outer circle.

[0031] In the figure: 1. rotor lamination, 2. skew groove, 3. rotor lamination, 4. notch, 5. positioning protrusion, 6. pressing tool, 7. inner hole, 8. positioning groove, 9. rotor lamination with unprocessed outer circle. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 3 As shown, the pressed structure of the rotor laminations 3 comprises an annular lamination body with multiple notches 4 evenly distributed around its circumference. A positioning protrusion 5 is provided on the outer circumference of the lamination body. This positioning protrusion 5 is located at the center between any two adjacent notches 4. The width of the positioning protrusion 5 is less than the width of the outer circumference of the lamination body between adjacent notches 4. The thickness of the positioning protrusion 5 is consistent with the thickness of the lamination body. The positioning protrusion 5 is rectangular.

[0034] like Figure 4 As shown, the press-fitting tool 6 is a cylinder with an inner hole 7. The diameter of the inner hole 7 matches the diameter of the lamination body. There is a clearance fit between the inner hole 7 and the lamination. A plurality of positioning grooves 8 are defined on the inner wall of the cylinder. The positioning grooves 8 are spaced clockwise or counterclockwise around the inner hole 7. The positioning grooves 8 are parallel to the axis of the inner hole 7. The number of positioning grooves 8 corresponds to the number of rotor laminations 3 required to form the rotor lamination 1.

[0035] According to the design principle of the angle of the skew slot 2 on the rotor lamination 1;

[0036] Assume that there are m slots 4 on the rotor lamination 3 and the angle θ between adjacent slots 4 on the same rotor lamination 3 is 360° / m.

[0037] Assume that n rotor laminations 3 are required. It is required that the first rotor lamination 3 and the nth rotor lamination 3 differ by an angle θ.

[0038] The angle α=θ / (n-1) by which the slot 4 between two adjacent rotor laminations 3 needs to be rotated is required.

[0039] Therefore, the minimum angle φ between the two positioning grooves 8 is θ+α.

[0040] Taking into account the rationality of the distribution of the positioning grooves 8 , the angle between two positioning grooves 8 may also be dθ+α, where d is a natural number greater than 1.

[0041] Since the positioning grooves 8 need to be distributed within the range of 7360° of the inner hole, the present invention is mainly designed for rotor laminations 1 with n≤20.

[0042] For example, if the number of notches 4 of the rotor lamination 3 is 20 and 16 rotor laminations 3 are required to form one rotor lamination 1:

[0043] The angle between adjacent slots 4 is 18°. According to the rotor skew angle design principle, the difference between the first and last rotor laminations 3 should be 18°. In other words, the desired skew angle for rotor lamination 1 can be achieved by rotating the rotor lamination 3 15 times, with each rotation of 1.2°.

[0044] like Figure 4 As shown, the corresponding pressing tool 6 is provided with 16 counterclockwise locating slots 8. To ensure the rational distribution of the locating slots 8 on the pressing tool 6, the rotor laminations 3 are rotated one more slot 4. Therefore, the minimum angle between two adjacent locating slots 8 is 19.2°. This ensures a 1.2° difference between the previous lamination and the next lamination.

[0045] In addition, if Figure 3As shown, during the machining of the rotor laminations 3, the magnetic field is stronger in the rolling direction, i.e., the radial direction. To improve the uniformity of the magnetic field throughout the rotor lamination 1, the symmetry of the rotor laminations 3 in the rolling direction is comprehensively considered, and the 16 rotor laminations 3 are evenly distributed around the circumference in the rolling direction. Therefore, every four rotor laminations 3 are rotated an additional notch 4 angle on the original included angle. Figure 4 As shown, the rotor laminations 1 are rotated 37.2° between the 4th and 5th laminations, between the 8th and 9th laminations, and between the 12th and 13th laminations. Correspondingly, the included angles between the 4th and 5th laminations, the 8th and 9th laminations, and the 12th and 13th laminations on the positioning slots 8 are designed to be 37.2°.

[0046] like Figure 5 As shown, the rotor laminations 3 are stacked in the inner space of the pressing tool 6 in the order of the distribution of the positioning grooves 8 through the positioning protrusions 5, and then pressed, dried and demolded. Finally, the rotor lamination 9 with an unprocessed outer circle is obtained, as shown in FIG. Figure 6 shown.

[0047] For the rotor lamination 9 without outer circle machining, the positioning protrusion 5 of the outer circle of the rotor lamination 1 is cut by the electric spark wire cutting process, and then the outer circle surface machining is completed by grinding, and finally it becomes as follows Figure 1 The rotor lamination 1 is formed in the middle. Wire EDM and grinding are both conventional process methods.

Claims

1. A rotor lamination pressing tool, characterized by: A rotor lamination with a pressed structure comprises an annular lamination body with a plurality of notches evenly distributed on its circumference. The lamination body is provided with a positioning protrusion on its outer circumference, the positioning protrusion being located at the center between any two adjacent notches, the width of the positioning protrusion being less than the width of the outer circumference of the lamination body between the adjacent notches, and the thickness of the positioning protrusion being consistent with the thickness of the lamination body; the pressing tool is a cylinder with an inner hole, the diameter of the inner hole being adapted to the diameter of the outer circumference of the lamination body to form a clearance fit; a plurality of positioning grooves are provided on the inner wall of the cylinder, the number of the positioning grooves being consistent with the number of rotor laminations required to form the rotor lamination; the positioning grooves are spaced clockwise or counterclockwise around the inner hole and are parallel to the axis of the inner hole; the width of the positioning grooves is adapted to the width of the positioning protrusion to form a clearance fit; The minimum angle φ between the positioning grooves is specifically determined as follows: Assume that m is the number of slots on the rotor lamination; θ is the angle between adjacent slots on the same rotor lamination: θ=360° / m Assume that n rotor laminations are required, n≤20, and the difference between the first rotor lamination and the nth rotor lamination is a slot angle θ. The angle α that the slots between two adjacent rotor laminations need to be rotated is: α=θ / (n-1); φ=θ+α.

2. The rotor lamination pressing tool according to claim 1, characterized in that: The positioning protrusion is rectangular and has chamfered corners.

3. The rotor lamination pressing tool according to claim 1, characterized in that: The minimum angle φ is d*θ+α, where d is a natural number greater than 1.

4. The rotor lamination pressing tool according to claim 1, characterized in that: The positioning grooves are marked with serial numbers. The number of slots in the rotor lamination is 20. 16 rotor laminations are required to form one rotor lamination. 16 positioning grooves are provided on the pressing tool. The minimum angle φ between two adjacent positioning grooves is 19.2°.

5. The pressing tool according to claim 4, characterized in that: Among the 16 positioning grooves, the angles between the 4th and 5th, the 8th and 9th, and the 12th and 13th are 37.2°.

6. A method for machining rotor laminations using the pressing tool according to claim 1, characterized in that ； Step 1: After the rotor laminations are stacked in the inner hole in sequence through the positioning protrusions according to the distribution order of the positioning grooves in the pressing tool, a pressing force perpendicular to the surface of the rotor laminations is applied for pressing; Step 2: After the rotor laminations are pressed and formed, they are demoulded; Step 3: Cut the positioning protrusions on the outer circle of the rotor laminate in step 2 by wire electric discharge cutting, and finally complete the surface processing of the outer circle of the rotor laminate by grinding.

Images