Axially reinforced carbon fiber motor sheath

Abstract

The present invention discloses an axially reinforced carbon fiber motor sheath, wherein the carbon fiber motor sheath comprises, from outside to inside, an outer circumferential winding layer, an intermediate spiral winding layer, and an inner circumferential winding layer, and the three-layer structure is a cylindrical structure. The outer circumferential winding layer and the inner circumferential winding layer are circumferential winding molding structures, and the intermediate spiral winding layer is a spiral winding molding structure. The present invention enhances the axial stiffness of the carbon fiber sheath by adding a spiral layer to the carbon fiber sheath to form a three-layer composite structure of ring-spiral-ring, thereby improving the stiffness of the entire motor shaft.

Description

Technical Field

[0001] The invention belongs to the field of motor rotors, and in particular relates to an axially reinforced carbon fiber motor sheath. Background Art

[0002] High-speed motors have the advantages of high power density and high efficiency, and have been used more and more widely. High-speed motors generally include structures such as stators, rotors, bearing systems, cooling systems, and housings. During the operation of the motor, the rotor rotates at high speed, which may cause vibration, mechanical stress, and potential friction. The motor rotor sleeve is an important component to ensure the safe, stable, and efficient operation of the motor. It plays a key role in the reliability of the motor by providing physical protection, increasing mechanical stability, preventing foreign matter intrusion, and assisting axial positioning.

[0003] Carbon fiber composite materials have the characteristics of light weight, high strength, low thermal expansion coefficient, excellent electrical insulation, high corrosion resistance and wear resistance, high damping, and the ability to form complex geometric shapes, making them widely used in high-speed motor sheaths. During the design and use of carbon fiber sheaths, their strength and displacement constraints on magnetic steel are important assessment indicators. This is because on the one hand, the carbon fiber sheath needs to fix the permanent magnet to prevent it from loosening and slipping at high speeds; on the other hand, in addition to its own centrifugal load, the carbon fiber sheath also bears the entire centrifugal force of the permanent magnet, which requires sufficient strength.

[0004] The design of ordinary carbon fiber sheaths mainly needs to consider their strength under centrifugal force fields and the limitation of magnetic steel displacement. However, with the increase in the types of motors, carbon fiber sheaths are required to provide a certain degree of axial stiffness. In addition, some motor rotors also require axial stiffness for the sheaths, which cannot be met by general carbon fiber sheaths that are generally formed by hoop winding. Summary of the invention

[0005] Based on the above problems, the purpose of the present invention is to provide an axially reinforced carbon fiber motor sheath, which has a simple structure and is divided into a three-layer structure, and is suitable for occasions where the motor rotor requires axial stiffness of the sheath.

[0006] The general carbon fiber sheath adopts the method of pure hoop winding, and the carbon fiber filaments are arranged in parallel in the axial direction. The axial stiffness is mainly provided by the resin matrix in the middle of the carbon fiber filaments, and the value is much smaller than the winding direction of the carbon fiber filaments. In order to meet the index requirements of some motor sheaths for axial stiffness, the present invention adds a spiral layer structure inside. The spiral layer is distributed with carbon fiber filaments arranged at a specific winding angle in the axial direction, so that the axial stiffness of the carbon fiber motor sheath is significantly improved.

[0007] In order to achieve the above objectives, this application provides the following technical solutions:

[0008] One of the technical solutions of the present invention provides an axially reinforced carbon fiber motor sheath, which is divided into a three-layer winding layer structure, which are: an outer annular winding layer, an intermediate spiral winding layer, and an inner annular winding layer from the outside to the inside; the three-layer structure is a cylindrical structure; the outer annular winding layer and the inner annular winding layer are annular winding molding structures, and the intermediate spiral winding layer is a spiral winding molding structure.

[0009] The outer annular winding layer and the inner annular winding layer of the present invention are responsible for providing the strength and circumferential stiffness of the motor under high-speed rotation to prevent the magnetic steel inside the motor from being damaged or detached; the middle spiral winding layer is used to increase the stiffness of the entire motor shaft and enhance its dynamic characteristics.

[0010] Furthermore, the angle of the intermediate spiral winding layer ranges from 15° to 70°. The angle is selected according to customization requirements and there is no preferred angle.

[0011] Furthermore, the angle of the middle spiral winding layer refers to the angle between the tangent line of the winding direction and the straight generatrix of the cylindrical surface passing through the tangent point.

[0012] Furthermore, the raw materials of the three winding layers are carbon fiber and resin matrix material.

[0013] In some embodiments, the resin matrix material raw materials include epoxy resin, modifier, curing agent, and accelerator. Among them, epoxy resin is used as a carbon fiber binder; the modifier is used to improve the mechanical properties of the finished composite material; the curing agent is used to promote the reaction of the resin matrix and convert it into a hard and stable solid form; the accelerator is used to accelerate the reaction and curing speed.

[0014] Furthermore, the type and thickness of the carbon fiber composite material of each winding layer are analyzed and designed according to the requirements of the actual motor; and the resin matrix material can be selected appropriately according to the requirements of the design indicators.

[0015] Furthermore, since the formula and dosage relationship of the carbon fiber composite material and the resin matrix material, and / or the curing agent do not belong to the core technical solution of the present application, they can be adopted as recognized by technical personnel in this field, and therefore, no excessive restrictions are made here.

[0016] A second technical solution of the present invention provides a method for manufacturing the above-mentioned axially reinforced carbon fiber motor sheath, the manufacturing method comprising the following steps:

[0017] S1. Select carbon fiber and resin matrix materials suitable for the use of the motor sheath; mix the components of the resin matrix material to prepare a slurry for standby use;

[0018] S2. The slurry prepared in S1 is placed in a winding machine, a mandrel of suitable size is selected, and the inner layer of the carbon fiber is wound on the mandrel in sequence by the winding machine, the middle layer is spirally wound, and the outer layer is wound on the mandrel; during winding, the carbon fiber is wound on the mandrel after being wetted with the slurry;

[0019] S3. After the curing and molding is completed, the carbon fiber motor sheath semi-finished product is demolded and cut into suitable lengths. Then, the cut surface of the carbon fiber motor sheath semi-finished product is evenly coated with the same resin matrix material as in S1 and cured again to finally obtain the carbon fiber motor sheath.

[0020] Furthermore, in step S2, the winding molding is carried out in a carbon fiber wet winding machine dedicated to the sheath.

[0021] Furthermore, in step S3, the cutting direction is radial, and the cutting is performed sequentially along the axial direction.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention has a simple structure and can be applied to situations where the motor rotor has requirements on the axial stiffness of the sheath. It increases the stiffness of the carbon fiber sheath without using additional metal materials, while also retaining the advantages of the carbon fiber composite material being light in weight and free from eddy current loss, thereby effectively reducing the eddy current loss of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of different plies of an axially reinforced carbon fiber motor sheath of the present invention;

[0025] Figure 2 is a cross-sectional view of the carbon fiber motor sheath;

[0026] Figure 3 A physical diagram provided for Example 1 of the present application;

[0027] The markings in the figure indicate that 1 is an outer circumferential winding layer; 2 is an intermediate spiral winding layer; and 3 is an inner circumferential winding layer. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail below in conjunction with specific embodiments. It should be noted that the following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, several variations and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0029] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0030] In the design stage of the sheath, it is necessary to analyze and calculate according to the actual needs of the motor shaft, the maximum speed, the magnetic steel gap, the axial stiffness and other requirements, and confirm the parameters such as the ply form, thickness, and angle of the spiral winding layer of the carbon fiber motor sheath. After completing the design, select a core mold of appropriate size, and perform inner layer circumferential winding molding, middle layer spiral winding molding, and outer layer circumferential winding molding on the winding equipment (carbon fiber winding machine) in turn according to the design results. After the molding and curing are completed, demolding and cutting are carried out into the required length size. Finally, the broken fibers on the cutting surface are coated with a resin matrix for curing and reinforcement. Considering that cutting will cause the carbon fiber to break, it is necessary to use the same resin matrix material used for molding to evenly apply it on the cutting surface and solidify it again to ensure that under high-speed rotation conditions, the carbon fiber composite material will not be damaged from the broken wire, and the axially reinforced carbon fiber motor sheath of the present invention can be completed.

[0031] Example 1 An axially reinforced carbon fiber motor sheath

[0032] (1) Size, material selection and design

[0033] The parameters of each layer in this embodiment are shown in Table 1 below:

[0034] Table 1

[0035]

[0036] (1) The raw materials of the above-mentioned resin matrix material are prepared into slurry as shown in Table 1 and set aside;

[0037] (2) placing the slurry in a special carbon fiber winding machine for the sheath, and using the special carbon fiber winding machine for the sheath to wind three layers of carbon fiber winding layers on the mandrel in sequence according to the thickness and angle shown in Table 1 and solidify and form; during winding, the carbon fiber is impregnated with the slurry and then wound on the mandrel;

[0038] (3) Demolding the molded carbon fiber and cutting it into small sections along the axial direction, with the section being radial; applying the same resin matrix material used for molding on the radial section, and curing it again to finally obtain a finished carbon fiber motor sheath.

[0039] Example 2 An axially reinforced carbon fiber motor sheath

[0040] The motor sheath of this embodiment and embodiment 1 has the same material (raw material), total thickness, thickness of each layer, and manufacturing method. The difference is that the angle of the middle spiral winding layer is 30°.

[0041] The schematic diagram of the three-layer winding layer of the sheath described in Examples 1 to 2 is as follows Figure 1 As shown, the axial section is Figure 2 As shown; the physical picture of the sheath described in Example 1 is as shown Figure 3 shown.

[0042] like Figure 1 As shown, an axially reinforced carbon fiber motor sheath has a three-layer structure from the outside to the inside, namely: an outer annular winding layer 1, an intermediate spiral winding layer 2, and an inner annular winding layer 3. Compared with the general carbon fiber motor sheath, an intermediate spiral winding layer 2 is added to improve the axial stiffness. This is because compared with the annular winding layer, the angle between the spirally wound carbon fiber composite material and the axial direction is much smaller than 90°, so the force in the axial direction will be largely decomposed into the fiber direction of the spiral layer, thereby improving the axial stiffness of the entire carbon fiber motor sheath. Therefore, the use of this sheath can effectively improve the axial stiffness of the motor shaft, and the structure of the all-carbon fiber composite material also maintains the advantages of light weight and no eddy current loss.

[0043] Comparative Example 1 A carbon fiber motor sheath

[0044] The motor sheaths of this comparative example and Example 1 have the same material (raw material), total thickness, thickness of each layer, and manufacturing method. The difference is that the winding method used for each layer is hoop winding.

[0045] Effect Example 1

[0046] The performance test of the motor sheath provided in Examples 1 to 2 and Comparative Example 1 was conducted on the axial bending stiffness thereof. The test results are shown in Table 2:

[0047] Table 2

[0048] Example 1 Example 2 Comparative Example 1 Helix Angle 15° 30° none Bending stiffness 58.58kN.m 47.62kN.m 9.61kN.m

[0049] It can be seen from the table that the motor sheaths of Examples 1 to 2 and Comparative Example 1 have higher performance in axial stiffness.

[0050] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. An axially reinforced carbon fiber motor sheath, characterized in that: The carbon fiber motor sheath is divided into a three-layer winding structure, which are: an outer circumferential winding layer, a middle spiral winding layer, and an inner circumferential winding layer from the outside to the inside; the three-layer structure is a cylindrical structure; the outer circumferential winding layer and the inner circumferential winding layer are circumferential winding molding structures, and the middle spiral winding layer is a spiral winding molding structure.

2. The axially reinforced carbon fiber motor sheath according to claim 1, characterized in that: The outer annular winding layer and the inner annular winding layer are responsible for providing the strength and circumferential stiffness of the motor under high-speed rotation, and preventing the magnetic steel inside the motor from being damaged or detached.

3. The axially reinforced carbon fiber motor sheath according to claim 1, characterized in that: The middle spiral winding layer is used to increase the rigidity of the entire motor shaft and improve its dynamic characteristics.

4. The axially reinforced carbon fiber motor sheath according to claim 1, characterized in that: The angle range of the middle spiral winding layer is 15° to 70°.

5. The axially reinforced carbon fiber motor sheath according to claim 1, characterized in that: The angle of the middle spiral winding layer refers to the angle between the tangent line of the winding direction and the straight generatrix of the cylindrical surface passing through the tangent point.

6. The axially reinforced carbon fiber motor sheath according to claim 1, characterized in that: The raw materials of the three winding layers are carbon fiber and resin matrix material.

7. The method for manufacturing an axially reinforced carbon fiber motor sheath according to claim 1, characterized in that: The production method comprises the following steps: S1. Select carbon fiber and resin matrix materials suitable for the use of the motor sheath; mix the components of the resin matrix material to prepare a slurry for standby use; S2. The slurry prepared in S1 is placed in a winding machine, a mandrel of suitable size is selected, and the inner layer of the carbon fiber is wound on the mandrel in sequence by the winding machine, the middle layer is spirally wound, and the outer layer is wound on the mandrel; during winding, the carbon fiber is wound on the mandrel after being wetted with the slurry; S3. After the curing and molding is completed, demolding is performed and the semi-finished carbon fiber motor sheath is cut into suitable lengths. The cut surface of the semi-finished carbon fiber motor sheath is evenly coated with a resin matrix material and cured again to finally obtain the carbon fiber motor sheath.

8. The method for manufacturing an axially reinforced carbon fiber motor sheath according to claim 7, characterized in that: In step S2, the winding molding is carried out in a carbon fiber wet winding machine dedicated to the sheath.

9. The method for manufacturing an axially reinforced carbon fiber motor sheath according to claim 7, characterized in that: In step S3, the cutting direction is radial, and the cutting is performed sequentially along the axial direction.

10. The method for manufacturing an axially reinforced carbon fiber motor sheath according to claim 7, characterized in that: The resin matrix material used in step S3 is the same as the resin matrix material used in step 1.

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