Motor stator end portion potting structure and method

Abstract

This invention discloses a potting structure for the end of a motor stator, including a potting cover providing the potting boundary, a fixing slot wedge for fixing the potting cover, and a fastening rope for tightening the fixing slot wedge; it also discloses a potting method; this invention is applied to the stator core winding slot and end of a motor, providing a potting cavity for the end of the motor stator, ensuring the insulation and protection performance of the end of the motor stator, while simplifying the potting structure, reducing process cost and time, and improving potting quality, and is suitable for end potting of various types of motors.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, specifically relating to a stator end potting structure and potting method for an electric motor. Background Technology

[0002] Currently, in motor design, the losses of the motor end windings are relatively high. The commonly used end cooling method is forced air cooling. Although it can directly cool the heat-generating components of the motor, the cooling efficiency of air cooling is limited. For high power density and ultra-high power density motors, especially the motor winding ends, it cannot achieve the required cooling effect.

[0003] To address the heat dissipation issue of motor end windings, many small motors currently employ end potting solutions to reduce the thermal resistance between the end windings and the water-cooled frame. With the decreasing cost of high thermal conductivity potting compounds and the emergence of better end cooling solutions, end potting is increasingly being used in high power density and ultra-high power density medium and large motors.

[0004] For example, in invention patent ZL202010873064.8, a complete stator water cooling solution is proposed for high-power, high-power-density motors. High thermal conductivity silicone grease is filled into the end cavity formed between the end potting inner cover, the end potting outer cover and the integrated bracket, which can effectively reduce the end winding temperature and protect the end winding, thereby improving the reliability of the motor stator. However, the end potting inner and outer covers are made of stainless steel, and the processing, manufacturing and installation processes are complex. On-site welding and splicing are required, resulting in high process costs. Furthermore, on-site shaping is required after welding, which is quite difficult. Summary of the Invention

[0005] To address the shortcomings of the aforementioned technologies, one objective of this invention is to provide a stator end potting structure for motors, thereby solving the problems of difficult processing and installation of stainless steel end potting inner covers, high process costs, effectively improving the heat dissipation and protection performance of motor ends, reducing process costs, increasing the reliability of large and medium-sized motor stators, and extending motor lifespan.

[0006] The technical solution adopted by this invention to solve its technical problem is: a stator end potting structure for an electric motor, including a potting cover fixed in the stator core winding slot, a fixing wedge located at the stator core slot opening, and a fastening rope passing through the fixing hole at the end of the fixing wedge. The potting cover is made of insulating film, insulating paper, or insulating board. The axial length of the potting cover exceeds the axial length of the stator winding. A strip-shaped hole is opened at the position corresponding to the stator core tooth of the potting cover. The width h1 of the strip-shaped hole is greater than the width h0 of the stator core tooth. The length L1 of the strip-shaped hole is equal to the length L0 of the stator core tooth. The fixing wedge extends out of the stator core slot opening to the outside of the potting cover. The length of a single fixing wedge is determined according to the stator core length and the axial length of the stator winding end.

[0007] The aforementioned motor stator end potting structure has a potting cover thickness of 0.2–1.0 mm and a temperature resistance rating higher than that of the motor.

[0008] The aforementioned motor stator end potting structure has a fixing hole diameter of 2-5mm, which is determined based on the width of the fixing slot wedge, the number of stator core slots, and the inner and outer diameters of the stator, while the distance of the fixing slot wedge beyond the potting cover is determined based on the fixing hole diameter.

[0009] The aforementioned motor stator end potting structure has a fastening rope diameter of 2-5mm, which can be polyester fiberglass rope, glass fiberglass rope, etc. commonly used in electrical products, preferably able to pass through the fixing hole of the fixing slot wedge.

[0010] The second objective of this invention is to provide a method for potting the stator end of an electric motor, thereby solving problems such as the complexity of the potting process. The steps are as follows:

[0011] a. Install the prepared potting cover at the slot of the stator core, so that the strip hole of the potting cover corresponds to the tooth of the motor stator core, and use tape to stick and fix the joint of the potting cover.

[0012] b. Drive in the fixing wedges one by one, with the end of the hole facing outwards;

[0013] c. After passing one end of the fastening rope through the fixing hole at the end of the fixing groove wedge and tightening it, fix the other end of the fastening rope to a suitable position such as the end water collection pipe or machine base on the opposite side of the potting cover.

[0014] d. Apply high-temperature resistant sealant to the intersection of the potting cover and the motor stator core or gear plate;

[0015] e. After the sealant has cured, complete the stator end potting.

[0016] Compared with the prior art, the above-described technical solutions conceived in this invention have the following technical effects:

[0017] 1. The present invention uses non-metallic potting covers such as insulating paper or insulating board to replace stainless steel potting covers, which can reduce the difficulty of the process and shorten the process time.

[0018] 2. This invention uses inexpensive non-metallic potting covers such as insulating film, insulating paper or insulating board to replace high-precision and hard stainless steel potting covers, overcoming the difficulties of high processing precision, on-site installation and welding of stainless steel potting covers. It has a simple structure, good adaptability to motor size, and good processability, achieving excellent results at extremely low cost.

[0019] 3. The present invention uses a flexible potting structure to replace the rigid stainless steel potting cover, which can effectively reduce the difference in expansion coefficient between the potting cover and the potting compound, avoid cracking of the potting compound under alternating hot and cold temperatures, and improve end protection performance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the potting structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the unfolded potting cap of the present invention;

[0022] Figure 3 This is a schematic diagram of the fixed groove wedge of the present invention.

[0023] The labels on the attached drawings are as follows: 1—filler cover, 1.1—strip hole, 2—fixing groove wedge, 2.1—fixing hole, 3—fastening rope. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0025] Example 1

[0026] Reference Figure 1 , Figure 2As shown, this invention discloses a stator end potting structure for a motor. The applied motor is a conventional motor comprising a winding slot, a core slot opening, stator core teeth, a tooth pressure plate, a water collection pipe, and a frame. It includes a potting cover 1 fixed within the winding slot of the motor stator core, a fixing wedge 2 located at the stator core slot opening, and a fastening rope 3 passing through a fixing hole 2.1 at the end of the fixing wedge 2. The potting cover 1 is made of non-metallic materials such as insulating film, insulating paper, or insulating board. The thickness of the potting cover 1 is 0.2–1.0 mm, and its temperature resistance rating is higher than that of the motor. The axial length of the potting cover exceeds the axial length of the motor stator winding. A strip-shaped opening is formed at the position corresponding to the motor stator core teeth on the potting cover 1. Hole 1.1, the width h1 of the strip hole 1.1 is greater than the width h0 of the stator core tooth, and the length L1 of the strip hole 1.1 is equal to the length L0 of the stator core tooth. The fixing slot wedge 2 extends out of the stator core slot to the outside of the potting cover 1. The distance beyond the potting cover 1 is determined according to the diameter of the fixing hole 2.1. The length of a single fixing slot wedge 2 is flexibly determined according to the length of the stator core and the axial length of the stator winding end. If the axial length of the stator core is relatively short, the fixing slot wedge 2 can be a single piece with fixing holes 2.1 at both ends; if the axial length of the stator core is relatively long, the fixing slot wedge 2 can have a fixing hole 2.1 at one end, and the fixing slot wedge 2 can be driven into the stator core from both ends. The fixing holes 2.1 are located in the end areas on both sides. After the fixing slot wedge 2 is installed, the other end of the fastening rope 3 is fixed to the water pipe on the outside. The cast aluminum yoke, the potting cover, and the motor stator core together form the potting cavity open at both ends of the motor.

[0027] The diameter of the fixing hole 2.1 is 2-5mm, and can be polyester fiberglass rope, glass fiberglass rope, etc., commonly used in electrical products. The diameter is determined based on the width of the fixing wedge 2, the number of stator core slots, and the inner and outer diameters of the stator, so that the fixing hole 2.1 can pass through the fixing wedge 2. The distance of the fixing wedge 2 beyond the potting cover 1 is determined according to the diameter of the fixing hole 2.1.

[0028] The fastening rope 3 has a diameter of 2-5mm and can be a polyester fiberglass rope or glass fiberglass rope commonly used in electrical products, preferably one that can pass through the fixing hole 2.1 of the fixing groove wedge 2.

[0029] Reference Figure 3 As shown, the fixing wedge 2 of the present invention serves to fix the coil, the slot water pipe (if any) and the potting cover 1.

[0030] The present invention discloses a method for potting the end of an electric motor stator, the steps of which are as follows.

[0031] a. Install the prepared potting cover 1 at the stator core slot, so that the strip hole 1.1 of the potting cover 1 corresponds to the motor stator core tooth, and use tape to stick and fix the joint of the potting cover 1.

[0032] b. Drive in the fixing wedge 2 in each groove, with one end of the hole facing outwards.

[0033] c. After passing one end of the fastening rope 3 through the fixing hole 2.1 at the end of the fixing groove wedge 2 and tightening it, fix the other end of the fastening rope 3 to a suitable position such as the end water collection pipe or machine base on the opposite side of the potting cover.

[0034] d. Apply high-temperature resistant sealant to the intersection of the potting cover 1 and the motor stator core or gear plate.

[0035] e. After the sealant has cured, complete the stator end potting.

[0036] In this embodiment, the axial direction of the potting cover 1 is flush with the cast aluminum of the yoke. The width w1 of the strip hole 1.1 is w0 + 1.8 mm, that is, the sum of the gaps between the two sides of the end potting cover strip hole 1.1 and the stator core teeth is 1.8 mm (0.9 mm on average on one side). This value is the process gap, which is adjusted according to the tooth width and process level to ensure that the end potting cover 1 is installed smoothly. The axial length of the stator core is 400 mm, and the axial length of the end winding is 150 mm. Each stator winding slot has a fixed slot wedge 2 at both ends, each segment is 360 mm long, and there is a fixing hole 2.1 on one side. The fixing hole 2.1 has a diameter of 5 mm, and is driven in at both ends, with one side of the fixing hole 2.1 facing outward.

[0037] Example 2

[0038] In this embodiment, the axial length of the stator core is 220mm, the axial length of the end winding is 70mm, and each stator winding slot has a fixed slot wedge 2 with a length of 300mm. Fixing holes 2.1 are opened on both sides, and the diameter of the fixing holes 2.1 is 3mm.

[0039] Example 3

[0040] In this embodiment, the axial length of the stator core is 1000mm, the axial length of the end winding is 150mm, and each stator winding slot has two fixed slot wedges 2 and ordinary slot wedges, each with a length of 325mm. The fixed slot wedges 2 and ordinary slot wedges are made of the same material. The fixed slot wedges 2 have a fixing hole 2.1 on one side with a diameter of 5mm. The ordinary slot wedges do not have holes and are located in the middle of the stator core. The fixed slot wedges 2 are distributed at both ends of the stator core, with the fixing hole 2.1 facing outwards on one side.

[0041] In all embodiments, the diameter of the fastening rope 3 is determined according to the diameter of the fixing hole 2.1 of the fixing slot wedge 2. One end of the fastening rope 3 is fixed to the fixing hole 2.1 of the fixing slot wedge 2, and the other end is fixed to the water collection pipe at the end of the stator. If the structure is different, the fixing position is determined according to the structure of the motor stator.

[0042] The cast aluminum on the outer yoke of the stator, the potting cover 1, and the stator core together form the potting cavity open at both ends of the motor. The flexible potting cover 1 is fixed to the motor stator by the fixing wedge 2 inserted into the stator core winding slot. The fixing wedge 2, which is circumferentially distributed in each winding slot and extends to the end, together with the potting cover 1, form the inner boundary of the semi-flexible potting cavity, reducing the difference in expansion coefficient between the potting cover and the potting glue, avoiding cracking of the potting glue caused by the curing process of the potting glue and the subsequent temperature changes during motor operation, and effectively improving the end protection performance.

[0043] The stator end potting structure of this invention uses inexpensive non-metallic potting covers such as insulating paper or insulating boards to replace the hard stainless steel potting covers. The potting structure and method adopted can reduce the difficulty of the process and shorten the process time. It overcomes the difficulties of high processing precision, on-site installation and welding of stainless steel potting covers. The structure is simple, adaptable to motor size, and has good processability, achieving excellent results at extremely low cost. The use of a potting structure with a certain degree of flexibility to replace the hard stainless steel potting cover can effectively avoid cracking of the potting compound under alternating hot and cold temperatures, improve the end potting quality, enhance end protection performance and cooling efficiency, further improve the reliability of the motor and enhance product competitiveness.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A potting structure for the end of a motor stator, characterized in that: The device includes a potting cover (1) fixed in the stator core winding slot, a fixing wedge (2) located at the opening of the stator core slot, and a fastening rope (3) passing through the fixing hole (2.1) at the end of the fixing wedge (2). One end of the fastening rope (3) passes through the fixing hole (2.1) and is tightened, while the other end is fixed to the end water collection pipe or machine base on the opposite side of the potting cover (1) to tighten the fixing wedge (2) and press the potting cover (1) into the stator core winding slot. The potting cover (1) is made of insulating thin film. The axial length of the potting cover (1) exceeds the axial length of the stator winding. The potting cover (1) has a strip hole (1.1) at the position corresponding to the stator core teeth. The width of the strip hole (1.1) is greater than the width of the stator core teeth. The length of the strip hole (1.1) is equal to the length of the stator core teeth. The fixed slot wedge (2) extends out of the stator core slot to the outside of the potting cover (1). A high-temperature resistant sealant layer is provided at the intersection of the potting cover (1) and the motor stator core or tooth pressure plate.

2. The stator end potting structure of a motor according to claim 1, characterized in that, The potting cover (1) has a thickness of 0.2 to 1.0 mm and its temperature resistance rating is higher than that of the motor.

3. The stator end potting structure of a motor according to claim 1, characterized in that, The diameter of the fixing hole (2.1) is 2-5 mm.

4. The stator end potting structure of a motor according to claim 1, characterized in that, The fastening rope (3) is a glass rope with a diameter of 2 to 5 mm.

5. A potting method for the stator end potting structure of a motor as described in claim 1, characterized in that, The steps are as follows: a. Install the prepared potting cover (1) at the slot of the stator core, so that the strip hole (1.1) corresponds to the motor stator core tooth, and use tape to stick and fix the joint of the potting cover (1); b. Drive in the fixed groove wedge (2) one by one, with the end of the hole facing outward; c. After passing one end of the fastening rope (3) through the fixing hole (2.1) of the fixing groove wedge (2) and tightening it, fix the other end of the fastening rope (3) to the end water collection pipe or / and machine base on the opposite side of the potting cover (1); d. Apply high-temperature resistant sealant to the intersection of the potting cover (1) and the motor stator core or tooth pressure plate; e. After the sealant has cured, the stator end is potted.

Images