A dynamic balancing process for an external rotor motor

Abstract

A dynamic balancing process for an external rotor motor includes the following steps: A) punching guide holes, round holes, and inner stator counting; B) punching external rotor slots; C) punching shaft holes, weight reduction holes, inner stator riveting, and external rotor counting; D) punching external rotor slots; E) cutting the air gap; F) punching the outer rotor riveting and center hole; G) punching the outer rotor blank; H) cutting the scrap to obtain a semi-finished product; I) casting aluminum from the semi-finished product using horizontal die casting technology to obtain the finished product. This invention utilizes a 0.2mm air gap design on one side for the rotor core mold and a horizontal die casting aluminum design for the rotor mold. Furthermore, when punching the external rotor slots, the slot holes are punched first, followed by the slot openings. This eliminates stress during the die casting process, preventing deformation and ensuring good rotor concentricity (less than 5C). The cast aluminum is also full, improving the rotor's impact resistance, resulting in higher rotor density and a higher proportion of aluminum, reducing resistance and improving rotor energy efficiency and electrical efficiency.

Description

Technical Field

[0001] This invention relates to the field of external rotor machining technology, and in particular to a dynamic balancing machining process for an external rotor motor. Background Technology

[0002] Chinese Patent Document No. CN113333709A, dated September 3, 2012, discloses a centrifugal casting method for a conductor rotor. The method employs centrifugal casting to manufacture the conductor rotor, which involves steps such as melting, centrifugal forming, cooling after shutdown, and machining. The raw material for the conductor ring is heated to T1℃ and melted completely into a liquid state. The conductor cylinder is preheated to T2℃ and maintained at a constant temperature. The molten liquid raw material of the conductor ring is poured into the conductor cylinder. The centrifuge is started, causing the conductor cylinder to rotate. The centrifugal force of the conductor cylinder evenly distributes the liquid raw material of the conductor ring on the inner circumference of the conductor cylinder. After the temperature of the conductor cylinder drops to T2℃, the centrifuge continues to rotate for 10 minutes, then the machine is stopped, the conductor cylinder is removed, and cooled to room temperature. The conductor ring and conductor cylinder are then machined to form an integral conductor rotor. The centrifugal casting method of the conductor rotor uses a gapless design for the stamping die of the rotor core and centrifugal die casting (using a vertical centrifuge for die casting, with aluminum poured into the rotor slots). This results in rotor deformation, poor concentricity (20-30°C), and incomplete aluminum casting, leading to poor rotor dynamic balance.

[0003] Therefore, further improvements are necessary. Summary of the Invention

[0004] The purpose of this invention is to provide a dynamic balancing process for an external rotor motor that ensures rotor non-deformation, good rotor concentricity, full aluminum casting, good rotor dynamic balance, and high practicality, thereby overcoming the shortcomings of the prior art.

[0005] A dynamic balancing process for an external rotor motor designed for this purpose is characterized by the following steps: A. Punch the guide hole, round hole and inner stator lamination counting hole respectively; B. External rotor slot type; C. Punch shaft holes, weight reduction holes and outer rotor lamination counting holes respectively, and rivet the inner stator; D. External rotor slot type; E. Cut the air gap, and connect the air gap with the slot opening; F. External rotor stacking and riveting, and punching the center hole; G. Material is discharged from the outer rotor; H. Cut the waste material to obtain a semi-finished product; I. The semi-finished product is cast into aluminum using horizontal die casting technology to obtain the finished product.

[0006] In step D, when punching the outer rotor slot, punch the slot hole first, and then punch the slot opening.

[0007] In step I, cast aluminum is injected into the semi-finished product sequentially through the air gap, slot, and hole.

[0008] In step E, the thickness of the air gap is a, where a = 0.15 to 0.25 mm.

[0009] In step B, the outer rotor slot includes irregular short holes and irregular long holes.

[0010] In step D, when punching the outer rotor groove, punch one half of the groove first, and then punch the other half of the groove.

[0011] The stamping in steps A, B, and C is controlled by a cylinder drawing plate.

[0012] The stamping in step G is driven by a stepper motor to twist.

[0013] In step I, when the waste material is cut, an overlap is formed, and the thickness of the overlap is b, where b = 1.5 to 2 mm.

[0014] This invention employs a single-sided 0.2mm air gap design for the rotor core mold and a horizontal die-cast aluminum design for the rotor mold. Furthermore, when punching the outer rotor slots, the slot holes are punched first, followed by the slot openings. This eliminates stress during the die-casting process, preventing deformation and ensuring good rotor concentricity (less than 5C). The full aluminum casting improves the rotor's impact resistance, resulting in higher rotor density and a higher aluminum content, reducing resistance and improving rotor energy efficiency and electrical efficiency (saving electricity) while minimizing production losses. Attached Figure Description

[0015] Figure 1 This is a schematic diagram illustrating the dynamic balancing process of an external rotor motor in one embodiment of the present invention.

[0016] Figure 2 for Figure 1 A magnified structural diagram at point c.

[0017] Figure 3 for Figure 1 A magnified structural diagram at point d. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] See Figures 1-3 , Figure 1 The plate is a mold. The dynamic balancing process for the external rotor motor includes the following steps: A. Punch the positive hole 1, the round hole 2, and the inner stator lamination counting hole respectively; B. External rotor slot type; C. Punch shaft hole 3, weight reduction hole 4 and outer rotor lamination counting hole respectively, and rivet the inner stator 5; D. External rotor slot type; E. Cut the air gap 6, and connect the air gap 6 with the slot 11; F. External rotor stacking and riveting 7 and punching center hole 8; G. External rotor blanking 9; H. Cut the waste material to obtain a semi-finished product; I. The semi-finished product is cast into aluminum using horizontal die casting technology to obtain the finished rotor.

[0020] In step D, when punching the outer rotor slot, first punch the slot hole 10, then punch the slot opening 11. This step is the key to the stress elimination during rotor die casting. The existing process punches the slot hole 10 and the slot opening 11 at the same time, which results in high stress during rotor die casting.

[0021] In step I, aluminum is injected into the semi-finished product through air gap 6, slot 11 and slot 10 in sequence. By designing air gap 6 and using horizontal die casting technology to cast aluminum into the semi-finished product, the aluminum is made full.

[0022] In step E, the thickness of the air gap 6 is a, where a = 0.2 mm.

[0023] In step B, the outer rotor slot includes irregular short holes 12 and irregular long holes 13.

[0024] In step D, when punching the outer rotor groove, punch one half of the groove first, and then punch the other half of the groove.

[0025] The stamping in steps A, B, and C is controlled by a cylinder drawing plate.

[0026] The stamping in step G is driven by a stepper motor to twist.

[0027] In step I, when the waste material is cut, an overlap 14 is formed. The thickness of the overlap 14 is b, b=1.5mm, and the mold pitch is e, e=195.5mm.

[0028] The above describes the preferred embodiments of the present invention, illustrating and describing the basic principles, main features, and advantages of the invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A dynamic balancing process for an external rotor motor, characterized in that: Includes the following steps: A. Punch the guide hole (1), the round hole (2) and the inner stator lamination counting hole respectively; B. External rotor slot type; C. Punch the shaft hole (3), weight reduction hole (4) and outer rotor lamination counting hole respectively, and rivet the inner stator (5); D. External rotor slot type; E. Cut the air gap (6), and connect the air gap (6) with the slot (11); F, outer rotor stacking and riveting (7) and punching center hole (8); G. Punching the outer rotor to discharge material (9); H. Cut the waste material to obtain a semi-finished product; I. The semi-finished product is cast into aluminum using horizontal die casting technology to obtain the finished product; In step B, the outer rotor slot includes irregular short holes (12) and irregular long holes (13); In step D, when punching the outer rotor slot, first punch the slot hole (10), then punch the slot opening (11); In step I, cast aluminum is injected into the semi-finished product sequentially through the air gap (6), the slot (11), and the hole (10).

2. The dynamic balancing process for an external rotor motor according to claim 1, characterized in that: In step E, the thickness of the air gap (6) is a, where a = 0.15 to 0.25 mm.

3. The dynamic balancing process for an external rotor motor according to claim 1, characterized in that: In step D, when punching the outer rotor groove, punch one half of the groove first, and then punch the other half of the groove.

4. The dynamic balancing process for an external rotor motor according to claim 1, characterized in that: The stamping in steps A, B, and C is controlled by a cylinder drawing plate.

5. The dynamic balancing process for an external rotor motor according to claim 1, characterized in that: The stamping in step G is driven by a stepper motor to twist.

6. The dynamic balancing process for an external rotor motor according to claim 1, characterized in that: In step I, when the waste material is cut, an overlap (14) is formed, and the thickness of the overlap (14) is b, where b = 1.5~2mm.

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