Rotor for low-inertia asynchronous servo motor

Abstract

The utility model relates to a rotor for a low-inertia asynchronous servo motor, which not only has a good heat dissipation effect, but also can improve the cast aluminum filling rate of the rotor, and is convenient for the installation of an encoder, a cast aluminum rotor is sleeved on a cast aluminum rotor installation shaft section in a rotating shaft, and the length of the cast aluminum rotor is greater than or equal to twice the diameter of the cast aluminum rotor. A plurality of ventilation slots are formed in the outer circular surface of the cast-aluminum rotor mounting shaft section, the ventilation slots are parallel to the symmetrical center line of the rotating shaft, and the length of the ventilation slots is greater than that of the cast-aluminum rotor; an annular positioning shaft shoulder composed of a plurality of protruding blocks is arranged on the outer circle face of the cast-aluminum rotor installation shaft section. When the rear end face of the cast-aluminum rotor arranged on the cast-aluminum rotor installation shaft section in a sleeving mode makes face-to-face contact with the front end face of the annular positioning shaft shoulder, groove heads on the two sides of the ventilation groove are exposed out of the corresponding ends of the cast-aluminum rotor. The rotor for the low-inertia asynchronous servo motor has the advantages that the heat dissipation effect is good, the cast aluminum filling rate of the rotor can be improved, and meanwhile, the encoder is convenient to install.

Description

Technical Field

[0001] This utility model belongs to the field of asynchronous servo motor manufacturing technology, specifically relating to a rotor for a low-inertia asynchronous servo motor. Background Technology

[0002] The rotors of asynchronous servo motors are mostly squirrel-cage cast aluminum rotors (such as CN 209233593). U, entitled "A Structure for Preventing the Retraction of a Cast Aluminum Rotor in an Explosion-Proof Motor", includes a cast aluminum rotor and a shaft. The cast aluminum rotor is heat-fitted onto the shaft. The shaft is equipped with a core stop, a core stop platform, and a bearing stop. The core stop is located in the middle of the shaft as a positioning joint for the cast aluminum rotor. The outer diameter of the cast aluminum rotor is D, and its length is L. The distance from the root of the bearing stop to the root of the core stop platform is L2. L1-L2 represents the retraction amount of the cast aluminum rotor. When D < 200mm and L < 300mm, the retraction amount (L1-L2) is 0-2mm. When 200 ≤ D < 400mm and 300 ≤ L < 500mm, the retraction amount (L1-L2) is 2-4mm. When 400mm ≤ D and 500mm ≤ L, the retraction amount (L1-L2) is 4-5mm. To meet the fast response characteristics of the servo motor, it is necessary to reduce the moment of inertia. Since the moment of inertia is proportional to the square of the outer diameter and the length, the design of the rotor—the most important rotating component inside the motor—is crucial. To maintain the motor's torque, power, and other performance characteristics while keeping the rotor volume constant, the rotor needs to be made thin and long.

[0003] Currently, cast aluminum rotors are mainly manufactured using pressure casting or centrifugal casting. For cast aluminum rotors with a large length-to-diameter ratio (length ≥ 2 times diameter), it is difficult to guarantee the aluminum filling rate regardless of the method. This often results in incomplete filling, large air holes in the end rings, or thin or broken bars in the guide bars, which affects the motor performance. Furthermore, as the length of the cast aluminum rotor increases, heat will accumulate and be difficult to dissipate, eventually leading to excessively high temperatures.

[0004] To address the two issues mentioned above with asynchronous servo motors, our company has developed a rotor for low-inertia asynchronous servo motors. Utility Model Content

[0005] Design objective: To avoid the shortcomings of the prior art, this paper designs a rotor for a low-inertia asynchronous servo motor that not only has good heat dissipation but also improves the aluminum filler ratio of the rotor and facilitates encoder installation.

[0006] Design scheme: To achieve the above design objectives.

[0007] 1. A cast aluminum rotor is mounted on the cast aluminum rotor mounting shaft section of the rotating shaft. The length of the cast aluminum rotor is greater than or equal to twice the diameter of the cast aluminum rotor. Multiple ventilation grooves are provided on the outer circular surface of the cast aluminum rotor mounting shaft section, and the ventilation grooves are arranged parallel to the symmetrical center line of the rotating shaft. The length of the ventilation grooves is greater than the length of the cast aluminum rotor. An annular positioning shoulder composed of multiple protrusions is provided on the outer circular surface of the cast aluminum rotor mounting shaft section, and the annular positioning shoulder is located at the rear end of the rotating shaft. When the rear end face of the cast aluminum rotor mounted on the cast aluminum rotor mounting shaft section and the front end face of the annular positioning shoulder are in full contact, the groove heads on both sides of the ventilation groove are exposed at the corresponding ends of the cast aluminum rotor. This design is one of the technical features of this utility model. The purpose of this design is as follows: a cast aluminum rotor is mounted on the cast aluminum rotor mounting shaft section of the rotating shaft. The length of the cast aluminum rotor is greater than or equal to twice the diameter of the cast aluminum rotor. Multiple ventilation grooves are provided on the outer circular surface of the cast aluminum rotor mounting shaft section, and the ventilation grooves are arranged parallel to the symmetrical center line of the rotating shaft. The length of the ventilation grooves is greater than the length of the cast aluminum rotor. An annular positioning shoulder composed of multiple protrusions is provided on the outer circular surface of the cast aluminum rotor mounting shaft section, and the annular positioning shoulder is located at the rear end of the rotating shaft. When the rear end face of the cast aluminum rotor mounted on the cast aluminum rotor mounting shaft section and the front end face of the annular positioning shoulder are in full contact, the groove heads on both sides of the ventilation grooves are exposed at the corresponding ends of the cast aluminum rotor. The arrangement of multiple ventilation grooves (6) on the rotating shaft not only increases the heat dissipation area of ​​the rotating shaft, but also forms multiple air paths between the inner circle of the cast aluminum rotor and the rotating shaft, thereby improving the heat dissipation effect of the rotor.

[0008] 2. The cast aluminum rotor is constructed by welding a left half of the cast aluminum rotor and a right half of the cast aluminum rotor. The length of the cast aluminum rotor is 600mm and the diameter of the cast aluminum rotor is 168.5mm. The length of the left half of the cast aluminum rotor is 290mm, the length of the right half of the cast aluminum rotor is 290mm, and the weld spacing between the left half of the cast aluminum rotor and the right half of the cast aluminum rotor is 20mm. This is the second technical feature of this utility model. The purpose of this design is that the cast aluminum rotor is constructed by welding a left half and a right half of the cast aluminum rotor together. The length of the cast aluminum rotor is 600mm and the diameter is 168.5mm. The length of the left half of the cast aluminum rotor is 290mm, and the length of the right half of the cast aluminum rotor is 290mm. The weld spacing between the left and right half of the cast aluminum rotor is 20mm. The cast aluminum rotor is constructed by welding two equal-length left and right cast aluminum rotors together. The length of each shorter cast aluminum rotor does not exceed twice the outer diameter of the rotor. This allows for a significant improvement in the cast aluminum filling rate of the rotor using normal casting processes, thereby improving the performance of the motor.

[0009] 3. A welded section is formed between the left and right halves of the cast aluminum rotor by welding. An annular groove is formed between the inner circular surface of the welded section, the inner surface of the left and right halves of the cast aluminum rotor, and the outer circular surface of the welded section is flush with the outer circular surface of the cast aluminum rotor. This is the third technical feature of this utility model. The purpose of this design is that the welded section between the left and right halves of the cast aluminum rotor, the annular groove formed between the inner circular surface of the welded section, the inner surface of the left and right halves of the cast aluminum rotor, and the outer circular surface of the welded section being flush with the outer circular surface of the cast aluminum rotor, allows multiple ventilation slots to be identical, thus further improving the heat dissipation effect of the rotor.

[0010] 4. The fourth technical feature of this utility model is that the ventilation slot has a width of 16mm and a depth of 6mm, with the exposed end portion of the cast aluminum rotor in the ventilation slot having a length of not less than 9.5mm. This design aims to balance the strength of the rotating shaft with the ventilation effect of the ventilation slot.

[0011] 5. The fifth technical feature of this utility model is that the tail end of the rotating shaft is provided with an encoder mounting post, and the center line of symmetry of the encoder mounting post coincides with the center line of symmetry of the rotating shaft. One side of the outer circular surface of the encoder mounting post is milled into a flat surface. The purpose of this design is that the encoder is easily fixed to the encoder mounting post by set screws.

[0012] Technical solution: A rotor for a low-inertia asynchronous servo motor includes a shaft and a cast aluminum rotor. A cast aluminum rotor is mounted on a shaft section of the shaft. The length of the cast aluminum rotor is greater than or equal to twice its diameter. Multiple ventilation slots are provided on the outer circumference of the shaft section, and these slots are parallel to the symmetrical center line of the shaft. The length of each ventilation slot is greater than the length of the cast aluminum rotor. An annular positioning shoulder, composed of multiple protrusions, is located on the outer circumference of the shaft section at the rear end of the shaft. When the rear end face of the cast aluminum rotor mounted on the shaft section is in surface contact with the front end face of the annular positioning shoulder, the two sides of the ventilation slots expose the corresponding ends of the cast aluminum rotor.

[0013] Compared with the prior art, the rotor for a low-inertia asynchronous servo motor not only has good heat dissipation, but also improves the aluminum filling rate of the rotor, and facilitates encoder installation. Attached Figure Description

[0014] Figure 1 This is a cross-sectional structural diagram of a rotor for a low-inertia asynchronous servo motor.

[0015] Figure 2 This is a schematic diagram of the main structure of the rotating shaft.

[0016] Figure 3 yes Figure 2 Schematic diagram of the cross-sectional structure at point BB.

[0017] Figure 4 yes Figure 2 A schematic diagram of the cross-sectional structure at point CC.

[0018] Figure 5 This is a schematic diagram of the main structure of the left half of the cast aluminum rotor.

[0019] Figure 6 This is a schematic diagram of the left-side structure of the left half of the cast aluminum rotor.

[0020] Figure 7 This is a schematic diagram of the main structure of the right half of the cast aluminum rotor.

[0021] Figure 8 This is a schematic diagram of the right half of the cast aluminum rotor from the right. Detailed Implementation

[0022] Example 1: Refer to Appendix Figures 1-8 A rotor for a low-inertia asynchronous servo motor includes a shaft 1 and a cast aluminum rotor 2. The cast aluminum rotor 2 is mounted on a cast aluminum rotor mounting shaft section 11 in the shaft 1. The length of the cast aluminum rotor 2 is greater than or equal to twice its diameter. Multiple ventilation grooves 12 are provided on the outer circular surface of the cast aluminum rotor mounting shaft section 11, and the ventilation grooves 12 are arranged parallel to the symmetrical center line of the shaft 1. The length of the ventilation grooves 12 is greater than the length of the cast aluminum rotor 2. An annular positioning shoulder composed of multiple protrusions 13 is provided on the outer circular surface of the cast aluminum rotor mounting shaft section 11, and the annular positioning shoulder is located at the rear end of the shaft 1. When the rear end face of the cast aluminum rotor 2 mounted on the cast aluminum rotor mounting shaft section 11 is in surface contact with the front end face of the annular positioning shoulder, the groove heads on both sides of the ventilation groove 12 expose the corresponding ends of the cast aluminum rotor 2.

[0023] The cast aluminum rotor 2 is constructed by welding a left half of the cast aluminum rotor 21 and a right half of the cast aluminum rotor 22. The length of the cast aluminum rotor 2 is 600mm and the diameter is 168.5mm. The length of the left half of the cast aluminum rotor 21 is 290mm, and the length of the right half of the cast aluminum rotor 22 is 290mm. The weld spacing between the left half of the cast aluminum rotor 21 and the right half of the cast aluminum rotor 22 is 20mm. A welded part 23 is formed between the left half of the cast aluminum rotor 21 and the right half of the cast aluminum rotor 22 by welding. An annular groove 24 is formed between the inner circular surface of the welded part 23, the inner surface of the left half of the cast aluminum rotor 21, and the inner surface of the right half of the cast aluminum rotor 22. The outer circular surface of the welded part 23 is flush with the outer circular surface of the cast aluminum rotor 2. The ventilation groove 12 has a width of 16mm and a depth of 6mm. The length of the exposed end portion of the cast aluminum rotor 2 in the ventilation groove 12 is not less than 9.5mm. The diameter of the cast aluminum rotor mounting shaft section 11 is 80mm.

[0024] The tail end of the rotating shaft 1 is provided with an encoder mounting post 14, and the center line of symmetry of the encoder mounting post 14 coincides with the center line of symmetry of the rotating shaft 1. One side of the outer circular surface of the encoder mounting post 14 is milled into a plane 15.

[0025] Comparison of effects:

[0026] Taking a 37KW servo motor with a rated speed of 1150rpm as an example, the diameter of the cast aluminum rotor 2 is 168.5mm, the length of the cast aluminum rotor is 600mm, and the length-to-diameter ratio of the cast aluminum rotor 2 is 3.56.

[0027]

[0028] As can be seen from the table, the rotor of this patent has significant improvements over the traditional rotor in three aspects: aluminum filling rate, rotor temperature, and encoder loosening rate.

[0029] It should be understood that although the above embodiments provide a relatively detailed textual description of the design concept of this utility model, these textual descriptions are merely simple textual descriptions of the design concept of this utility model, and not limitations on the design concept of this utility model. Any combination, addition, or modification that does not exceed the design concept of this utility model shall fall within the protection scope of this utility model.

Claims

1. A rotor for a low-inertia asynchronous servo motor, comprising a shaft (1) and a cast aluminum rotor (2), wherein the cast aluminum rotor (2) is mounted on a cast aluminum rotor mounting shaft section (11) in the shaft (1), and the length of the cast aluminum rotor (2) is greater than or equal to twice the diameter of the cast aluminum rotor (2), characterized in that: The outer circular surface of the cast aluminum rotor mounting shaft section (11) is provided with multiple ventilation grooves (12), and the ventilation grooves (12) are arranged parallel to the symmetrical center line of the rotating shaft (1). The length of the ventilation grooves (12) is greater than the length of the cast aluminum rotor (2). The outer circular surface of the cast aluminum rotor mounting shaft section (11) is provided with an annular positioning shoulder composed of multiple protrusions (13), and the annular positioning shoulder is located at the rear end of the rotating shaft (1). When the rear end face of the cast aluminum rotor (2) fitted on the cast aluminum rotor mounting shaft section (11) and the front end face of the annular positioning shoulder make face-to-face contact, the groove heads on both sides of the ventilation groove (12) are exposed at the corresponding ends of the cast aluminum rotor (2).

2. The rotor for a low-inertia asynchronous servo motor according to claim 1, characterized in that: The cast aluminum rotor (2) is constructed by welding a left half cast aluminum rotor (21) and a right half cast aluminum rotor (22). The length of the cast aluminum rotor (2) is 600 mm and the diameter of the cast aluminum rotor (2) is 168.5 mm. The length of the left half cast aluminum rotor (21) is 290 mm and the length of the right half cast aluminum rotor (22) is 290 mm. The weld spacing between the left half cast aluminum rotor (21) and the right half cast aluminum rotor (22) is 20 mm.

3. The rotor for a low-inertia asynchronous servo motor according to claim 2, characterized in that: A welded part (23) is formed between the left half cast aluminum rotor (21) and the right half cast aluminum rotor (22) by welding. An annular groove (24) is formed between the inner circular surface of the welded part (23), the inner side surface of the left half cast aluminum rotor (21), and the inner side surface of the right half cast aluminum rotor (22). The outer circular surface of the welded part (23) is flush with the outer circular surface of the cast aluminum rotor (2).

4. A rotor for a low-inertia asynchronous servo motor according to claim 1 or 2, characterized in that: The ventilation slot (12) has a width of 16mm and a depth of 6mm, and the length of the exposed end portion of the cast aluminum rotor (2) in the ventilation slot (12) is not less than 9.5mm.

5. A rotor for a low-inertia asynchronous servo motor according to claim 1, characterized in that: The tail end of the rotating shaft (1) is provided with an encoder mounting post (14) and the center line of the encoder mounting post (14) coincides with the center line of the rotating shaft (1). One side of the outer circular surface of the encoder mounting post (14) is milled into a plane (15).

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