Liquid-cooled motor

Abstract

The present invention provides a liquid-cooled motor that can prevent deformation or damage to its components due to force generation resulting from the use of dissimilar materials in the housing and stator. [Solution] The housing comprises a housing 3, a rotor 8 that rotates about an axis X relative to the housing 3, a stator 9 fixed to the housing 3 and at least a portion of which is made of a material with a different coefficient of thermal expansion than the housing 3, a partition wall 4 provided between the rotor 8 and the stator 9 along the direction of axis X to partition the flow path through which the cooling liquid passes within the housing 3, a partition wall support portion 11 provided along the partition wall 4 to support the portion of the partition wall 4 that does not overlap with the stator 9 in the direction of axis X, the partition wall support portion 11 being composed of multiple members, at least one of which is made of a different material than the other members, and a buffer portion 12 interposed between the housing 3 and the partition wall support portion 11, the buffer portion 12 being made of a material with a smaller modulus of elasticity than the housing 3 and the partition wall support portion 11.

Description

Technical Field

[0001] The present invention relates to a liquid-cooled motor that cools a stator with a cooling liquid.

Background Art

[0002] In recent years, in the electrification of aircraft and automobiles, lightweight and high-output (high output density) drive motors have been demanded. In such motors, the heat generation density of the stator coil becomes high, and the temperature rise of the motor becomes a problem. Therefore, a method of flowing a cooling medium inside the stator to directly cool the stator coil is used.

[0003] In a cooling method for directly cooling a stator coil, for example, as shown in FIG. 1 of Patent Document 1, a sealing means as a partition wall for partitioning the stator and the rotor is arranged between the stator and the rotor, thereby constructing a sealed space on the stator side.

[0004] By the way, in order to increase the output density of the motor, high torque and high efficiency are required. In order to achieve this, the management of the air gap between the stator and the rotor is important. Since this air gap directly affects the performance of the motor, a fiber reinforced plastic (FRP) that can form a non-magnetic and thin-walled cylindrical shape is used for the partition wall.

[0005] Since the cooling liquid circulates in the sealed space, pressure acts on the partition wall for constructing the sealed space on the stator side from the radially outer side toward the radially inner side. Therefore, the partition wall is closely fitted to the stator core or attached (fixed) by press fitting. In the coil end portion where the partition wall cannot be attached to the stator core, support means (protrusions) as partition wall support portions are arranged on a portion corresponding to the coil end portion (projecting axially outward from the end face of the stator core) to mechanically support the partition wall.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] In particular, in the field of electric aircraft, aluminum alloys are used for the motor housing to reduce weight. When this aluminum alloy is used over a wide temperature range, forces are generated due to forced displacement caused by the difference in linear expansion between it and the stator (stator core), which is a magnetic material. When forces are generated in the thin bulkheads and bulkhead supports, there is a risk of deformation or damage to the bulkheads, bulkhead supports, and other components.

[0008] Therefore, the object of the present invention is to provide a liquid-cooled motor that can suppress deformation and damage caused by the dissimilar materials of the housing and stator. [Means for solving the problem]

[0009] The liquid-cooled motor of the present invention comprises a housing, a rotor that rotates about an axis relative to the housing, a stator fixed to the housing and generating a magnetic force for the rotation of the rotor, the stator being formed in part from a material having a different coefficient of thermal expansion than the housing, a partition wall provided between the rotor and the stator along the axial direction to partition a flow path for the cooling liquid within the housing, a partition wall support portion provided along the partition wall to support the portion of the partition wall that does not overlap with the stator in the axial direction, the partition wall support portion being composed of multiple members, at least one of the multiple members being made of a different material from the other members, and a buffer portion interposed between the housing and the partition wall support portion, the buffer portion being made from a material having a smaller modulus of elasticity than the housing and the partition wall support portion.

[0010] According to the present invention, the partition support section can use materials with performance suitable for each part for the required function, thereby satisfying the function of the partition support section. Furthermore, since a buffer section is placed between the housing and the partition support section, the buffer section can mitigate forces caused by the housing and stator being made of different materials, and can also accommodate displacement. Therefore, deformation and damage caused by the housing and stator being made of different materials can be suppressed.

[0011] Furthermore, in the liquid-cooled motor of the present invention, at least two of the plurality of members are combined radially, and the first separating member, which is radially separated from the partition wall, may have lower conductivity than the first proximity member, which is radially close to the partition wall.

[0012] With this configuration, the first separation member has lower conductivity than the first proximity member, making the first separation member less conductive than the first proximity member. In other words, because the first separation member can be less conductive than the first proximity member, insulation reliability can be improved and eddy current losses can be reduced.

[0013] Furthermore, in the liquid-cooled motor of the present invention, at least one of the first proximity member and the first separation member has a higher Young's modulus than the partition wall, and the first separation member may be non-conductive and non-magnetic.

[0014] With this configuration, at least one of the first proximity member and the first separation member has a higher Young's modulus than the partition wall, thus enabling miniaturization of the liquid-cooled motor. Furthermore, since the first separation member is non-conductive and non-magnetic, leakage flux can be reduced.

[0015] Furthermore, at least two of the plurality of members are combined in the axial direction, and the second proximity member, which is closer to the stator core of the stator, may have weaker magnetism than the second separation member, which is further away from the stator core.

[0016] With this configuration, the second proximity member has weaker magnetism than the second separation member, resulting in higher magnetic resistance and reduced magnetic flux leakage. In other words, because the magnetic resistance is increased and magnetic flux leakage is reduced, eddy current losses can be reduced.

[0017] Furthermore, the second separating member may have a higher Young's modulus than the second adjacent member.

[0018] With this configuration, the second separation member has a higher Young's modulus than the second proximity member, thus allowing for higher rigidity compared to a configuration where the bulkhead support is formed solely by the second proximity member. In other words, the rigidity of the bulkhead and the bulkhead support can be increased, thus reducing the deflection of the bulkhead and the bulkhead support.

[0019] Furthermore, the liquid-cooled motor comprises a housing, a rotor that rotates about an axis relative to the housing, a stator fixed to the housing and generating a magnetic force for the rotation of the rotor, the stator being formed in part from a material with a different coefficient of thermal expansion than the housing, a partition wall provided between the rotor and the stator along the axial direction to partition a passage through which the cooling liquid passes within the housing, a partition wall support portion provided along the partition wall to support the portion of the partition wall that does not overlap with the stator in the axial direction, and a buffer portion interposed between the housing and the partition wall support portion, the buffer portion being formed from a material with a smaller modulus of elasticity than the housing and the partition wall support portion, wherein the partition wall support portion is The structure comprises: a first region radially separated from the partition wall and axially close to the stator core of the stator; a second region radially separated from the partition wall and axially separated from the stator core of the stator more than the first region; a third region radially closer to the partition wall more than the first region and axially closer to the stator core of the stator more than the second region; and a fourth region radially closer to the partition wall more than the first region and axially separated from the stator core of the stator more than the third region, wherein the first region is formed of a non-magnetic and non-conductive material, the third region is formed of a non-magnetic material, and the second and fourth regions may be formed of materials not limited by magnetism and conductivity.

[0020] With this configuration, it is possible to satisfy the performance requirements of the components for each part while suppressing deformation and damage caused by the housing and stator being made of different materials. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a liquid-cooled motor that can suppress deformation and damage caused by the housing and stator being made of different materials. [Brief explanation of the drawing]

[0022] [Figure 1] This is a longitudinal cross-sectional view of the liquid-cooled motor of the present invention. [Figure 2] It is an enlarged view of part II in FIG. 1. [Figure 3] It is a diagram showing a modified example of the partition support part. [Figure 4] It is a diagram showing another modified example of the partition support part. [Figure 5] It is a diagram showing yet another modified example of the partition support part. [Figure 6] It is a diagram showing yet another modified example of the partition support part. [Figure 7] It is a diagram showing yet another modified example of the partition support part.

Mode for Carrying Out the Invention

[0023] Hereinafter, an embodiment of the liquid-cooled motor (hereinafter, may be simply referred to as "motor") of the present invention will be described based on the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and the description will not be repeated.

[0024] Referring to FIGS. 1 and 2, the liquid-cooled motor 1 according to an embodiment of the present invention will be described. FIG. 1 is a longitudinal sectional view of the liquid-cooled motor 1 of the present invention. FIG. 2 is an enlarged view of part II in FIG. 1.

[0025] As shown in FIG. 1, the motor 1 includes a housing 3 for housing a motor unit 2 that generates power. Inside the housing 3, a partition 4 for forming a space for flowing a cooling liquid is provided. The housing 3 is made of, for example, aluminum or an aluminum alloy in order to cope with weight reduction. Hereinafter, the direction along the axis of the rotating shaft 5 described later in FIG. 1 will be referred to as the axial direction, and the direction orthogonal to the axial direction (the vertical direction in FIG. 1) will be referred to as the radial direction for description.

[0026] The housing 3 is equipped with an inlet IN and an outlet OUT for the cooling liquid. The inlet IN is connected to a guide pipe (not shown) that guides the cooling liquid supplied by a pump (not shown) from a tank (not shown) which is an external storage section for storing the cooling liquid, and the outlet OUT is connected to a discharge pipe (not shown) that returns the cooling liquid that has cooled the stator coil 92 (described later) back to the tank. In this embodiment, cooling oil is used as the cooling liquid, but water or various other cooling media may also be used.

[0027] Motor 1 is configured as an inner rotor type, with a rotor 8 (described later) mounted radially inside the stator 9 (described later) so as to rotate integrally with a rotating shaft 5 that is rotatably supported approximately at the center of the housing 3. Motor 1 can be used, for example, as an electric motor for aircraft or automobiles, as a drive source for actuators such as robots, as a drive source for pumps or compressors, as a flywheel energy storage device, or for other purposes.

[0028] As shown in Figure 1, the housing 3 comprises a cylindrical housing body 31 and a pair of lids 32 and 33 that close the openings at both axial ends of the housing body 31. An inlet IN for the cooling liquid is formed at one of the axial ends of the housing body 31 (the upper and right side in Figure 1), and an outlet OUT for the cooling liquid is formed at the other axial end of the housing body 31 (the upper and left side in Figure 1). The cooling liquid from the inlet IN enters the annular inlet-side space K1 formed by the partition support 11, the lids 33, the housing body 31, the stator core 91, the stator coil 92, and the buffer 12, and then enters the right end of a plurality of slots (not shown) formed on the inner circumference of the stator core 91. The cooling liquid then passes between the plurality of slots in the left-right direction, that is, it passes in the left-right direction of the stator core 91, cooling the stator coil described later. The cooling liquid, having passed through multiple channels formed by multiple slots and partition walls 4, is discharged from the left end of each of the multiple slots into an annular outlet-side space K2 formed by the partition wall support 11, lid 32, housing body 31, stator core 91, stator coil 92, and buffer 12, and then discharged to outlet OUT which communicates with the outlet-side space K2. However, the flow of the cooling liquid is not limited to this.

[0029] A pair of through holes 31A and 31B are formed in the radial center of the pair of covers 32 and 33, through which the rotating shaft 5 passes in the axial direction. A pair of left and right bearings 6 and 7 are fitted into the through holes 31A and 31B to serve as bearings that rotatably support the rotating shaft 5 that passes through the through holes 31A and 31B. In addition, a pair of annular flange portions 31C and 31D are formed on the pair of covers 32 and 33, projecting inward in the axial direction and positioned opposite each other in the axial direction.

[0030] The motor unit 2 includes a rotor 8 that is fitted onto a rotating shaft 5 so as to be integrally rotatable with respect to the housing 3 so as to rotate about axis X, and a stator 9 that is positioned between the partition wall 4 and the housing body 31. In other words, the stator 9 is located radially outward from the rotor 8. The rotor 8 is provided with a plurality of permanent magnets (not shown) along its circumference. In this embodiment, a permanent magnet type rotor is used, but any type of rotor, such as a wound rotor or an induction motor cage rotor, may be used.

[0031] The stator 9 generates a magnetic force to rotate the rotor 8 and comprises a stator core 91 that forms multiple magnetic poles, a stator coil 92 mounted on the stator core 91, and an insulating member (not shown) that insulates the stator core 91 and the stator coil 92. The stator core 91 is made of a laminate of electromagnetic steel sheets made of iron, which is a different material (metal) from the housing 3. In other words, the stator 9 is made of a material with a different coefficient of thermal expansion than the housing 3. In this embodiment, the stator core 91 is made of a laminate of electromagnetic steel sheets, but it can also be made of materials such as silicon steel sheets, permendur (cobalt steel), or permalloy.

[0032] The partition wall 4 is made of glass fiber reinforced plastic (GFRP), which is non-magnetic and can form a thin-walled cylindrical shape. Glass fiber reinforced plastic (GFRP) has a low coefficient of thermal expansion among plastics. The axial length of the partition wall 4 is longer than the axial length (shaft length) of the stator core 91. More specifically, the partition wall 4 is configured to protrude axially outward beyond the axial outer end of the stator coil 92, which protrudes axially outward from the stator core 91. Furthermore, the partition wall 4 is fixed to the entire inner surface 91A of the stator core 91 with adhesive 10. This ensures the rigidity of the partition wall 4. As shown in Figure 2, a gap S1 is formed between the axial outer end 4A of the partition wall 4 and the inner surface 3A of the housing 3 facing it.

[0033] A pair of partition wall support parts 11, 11 are provided along the partition wall 4 to support the portion of the partition wall 4 that does not overlap with the stator core 91 in the axial direction, that is, the pair of end portions 4T, 4T that protrude outward in the axial direction from both ends of the stator core 91. Each partition wall support part 11 extends outward from the axial outer end of the stator core 91 to the position of the axial outer end 4A of the partition wall 4. Note that the axial outer end of the partition wall 4 may be axially inward from the axial outer end of the partition wall support part 11. At a minimum, the partition wall 4 only needs to be able to fix the position of the partition wall support part 11, and the outer circumferential surface of the partition wall 4 should have a region that overlaps with the inner circumferential surface of the partition wall support part 11 in the axial direction. Therefore, the axially inward end of the partition wall support part 11 may be spaced apart from the axial outer end of the stator core 91.

[0034] Each partition support portion 11 is formed separately from the partition wall 4 and consists of a cylindrical member fixed to the radially outer surface of the partition wall 4 by adhesive 10. By bonding the partition support portions 11, 11 to the partition wall 4 in this way, a structure is created that mechanically supports the partition wall 4. It is preferable that the partition support portions 11 are made of the same material as the stator core 91 (iron in this embodiment) or a material having a similar coefficient of linear expansion. As a result, the deformation amounts of the stator core 91 and the partition support portions 11, which are the amount of contraction or expansion that changes due to the ambient environment and temperature changes of the motor, become equal, and these two members deform together, so that the radial deformation amount of the partition wall 4 becomes equal over its entire surface, making it less likely for cracks to occur in the partition wall 4.

[0035] Furthermore, it is preferable to use a non-magnetic material for the partition wall support 11 that is less susceptible to electromagnetic interference from the stator 9. This reduces leakage flux compared to the case where a magnetic material is used, thereby reducing eddy current losses in the partition wall support 11. Moreover, it is preferable that the material of the partition wall support 11 be both non-magnetic and non-conductive. This prevents eddy currents from flowing. Therefore, no eddy current losses occur in the partition wall support 11 during motor operation. In addition, dielectric breakdown due to contact between the partition wall support 11 and the stator coil 92 is less likely to occur, so the distance between the partition wall support 11 and the coil end (the part of the coil that protrudes axially outward from both axial ends of the stator core 91) can be reduced, making it easier to miniaturize and lighten the motor 1. Examples of non-magnetic materials include stainless steel, aluminum, and titanium. Examples of non-magnetic and non-conductive materials include ceramic materials, but zirconia material with a coefficient of thermal expansion close to that of the stator core 91 is preferred. As shown in Figure 2, the partition support 11 includes, for example, a first member 111 and a second member 112. The first member 111 corresponds to, for example, a "first proximity member" or a "second proximity member." The second member 112 corresponds to, for example, a "first separation member" or a "second separation member."

[0036] The first member 111 is the part of the partition wall support 11 that positions and holds the second member 112. Specifically, the first member 111 is a cylindrical member that extends from the axial end of the stator core 91 to the axial outer end 4A of the partition wall 4. The first member 111 is configured in an L-shape, with an L-shaped notch 111K formed at its axial outer end where the second member 112 fits.

[0037] As the material for the first member 111 is geographically close to the stator core 91, it is preferable to use a non-magnetic material that is less susceptible to electromagnetic influence from the stator core 91 and stator coil 92. This reduces leakage flux compared to the case where a magnetic material is used, thereby reducing eddy current losses in the first member 111. Furthermore, it is preferable that the material of the first member 111 be both non-magnetic and non-conductive. This prevents eddy currents from flowing. Therefore, no eddy current losses occur in the first member 111 during motor operation. In addition, dielectric breakdown due to contact between the first member 111 and the stator coil 92 is less likely to occur, so the distance between the first member 111 and the coil end portion (the part of the coil that protrudes axially outward from both axial ends of the stator core 91) can be reduced, making it easier to miniaturize and lighten the motor 1. Examples of non-magnetic materials include stainless steel, aluminum, and titanium. Examples of non-magnetic and non-conductive materials include ceramic materials, but zirconia material with a coefficient of thermal expansion close to that of the stator core 91 may also be used. Furthermore, like bulkhead 4, it may also be made of glass fiber reinforced plastic (GFRP).

[0038] The second member 112 holds the buffer portion 12. The buffer portion 12 is an O-ring. The second member 112 is an annular member located axially and radially outward of the bulkhead support portion 11. The second member 112 has a groove portion 112M capable of housing the buffer portion 12. The groove portion 112M is located in the axial middle portion of the second member 112 and radially outward. When the buffer portion 12 is housed in the groove portion 112M, the top of the buffer portion 12 protrudes slightly from the groove portion 112M. The second member 112 is fixed to the notch 111K with adhesive. Note that the first member 111 and the second member 112 may be integrated by means other than adhesive, such as fitting.

[0039] The material for the second member 112 can be any material that has sufficient strength to withstand the elastic restoring force generated when the O-ring, which is the buffer portion 12, is crushed by the pressing force from the housing 3. However, if good machinability for accurately forming the groove portion 112M and strength are required, a metal material is preferable. Alternatively, a ceramic material may also be used. When using this metal material, constructing the partition support portion 11 from multiple members rather than manufacturing the partition support portion 11 as a single structure leads to improved productivity and cost reduction. Furthermore, when constructing the partition support portion 11 from multiple members, using metal material in part improves processing accuracy, making it easier to obtain the required precision.

[0040] As shown in Figure 2, a buffer portion 12 is interposed between the radial outer surface 112A at the axial outer end of each bulkhead support portion 11 and the radial inner surface 31d of the flange portion 31D of the housing 3 which is radially opposite to it. This buffer portion 12 is provided to mitigate the force generated on the bulkhead 4 and bulkhead support portion 11 due to forced displacement caused by the difference in linear expansion between the housing 3 and the stator core 91 when temperature changes occur. A gap S2 is formed between the radial outer surface 112A and the radial inner surface 31d to provide this buffer portion 12.

[0041] The buffer portion 12 is made of a material with a lower modulus of elasticity than the housing 3 and the bulkhead support portion 11. Specifically, the buffer portion 12 is made of a highly versatile rubber O-ring that has elasticity around its entire circumference in the circumferential direction relative to the bulkhead support portion 11. Therefore, the buffer portion 12 can not only mitigate (reduce) the force generated on the bulkhead 4 and the bulkhead support portion 11 due to forced displacement caused by the difference in linear expansion between the housing 3 and the stator core 91, but also function as a sealing member that seals the gap S2 between the flange portion 31C or 31D and the bulkhead support portion 11 or 11. In addition, the buffer portion 12 also has the function of absorbing the change in gap dimensions caused by the difference in linear expansion between the housing 3 and the stator core 91 and maintaining airtightness. By mitigating (reduce) the aforementioned force, damage (cracking) to the bulkhead 4 and the bulkhead support portion 11 and peeling of the adhesive 10 between the bulkhead 4 and the stator core 91 can be suppressed. Furthermore, sealing the space between the housing 3 (flange portion 31C or 31D) and the bulkhead support portion 11 or 11 with an O-ring improves ease of assembly and disassembly. In addition, maintenance against oil leakage from the sealing portion between the housing 3 (flange portion 31C or 31D) and the bulkhead support portion 11 or 11 is improved by changing or replacing the O-ring through reassembly or by installing a new oil drain port.

[0042] Furthermore, by placing an O-ring as a sealing member on the radially outer side of the partition wall 4, a sealing member is not required on the radially inner side of the partition wall 4, and only the partition wall 4 aligned with the axial direction exists on the radially inner side. This makes the radially inner side of the partition wall 4 flat, so even if oil leaks from the partition wall 4 to the radially inner side, the oil will move along the flat radial inner surface of the partition wall 4, making it easy to create a mechanism to discharge the leaked oil to the outside of the housing 3, for example, by simply forming an outlet in the housing 3. Also, by discharging the leaked oil to the outside of the housing 3, it is made less likely for the leaked oil to accumulate in the air gap between the rotor 8 and the partition wall 4. This reduces the frictional force of the rotor 8 during rotation caused by the leaked oil. Furthermore, it is possible to prevent the motor 1 from burning out due to heat generated by friction with the leaked oil during the rotation of the rotor 8. Furthermore, by positioning the O-ring at the radially outer end of the partition wall 4, if the housing 3 is provided with a transparent section (not shown) radially inward from the radially inner surface 31d of the flange portion 31D, the condition of the seal boundary of the O-ring pressing against the flange portion 31C or 31D can be easily visually inspected from the transparent section. This allows for the rapid detection of oil leaks from the seal boundary, leading to improved productivity and early detection of malfunctions.

[0043] The buffer portion 12 is fitted into an annular groove portion 112M formed so as to be recessed radially inward at the axial outer end of the radial outer surface of each bulkhead support portion 11, with a portion of it protruding radially outward from the groove portion 112M. By using an O-ring with an inner diameter smaller than the inner diameter of the groove portion 112M as the buffer portion 12, the O-ring can be set in the groove portion 112M while taut, making it difficult for the O-ring to come off the groove portion 112M. Therefore, the O-ring can be prevented from falling out during assembly.

[0044] With the above configuration, the bulkhead support section 11 is composed of multiple members, and at least one of the multiple members is made of a different material from the other members. Therefore, a material with performance suitable for the function required for each part can be used, and the performance of the members can be satisfied. In other words, the buffer section 12 can be placed between the housing 3 and the bulkhead support section 11 while satisfying the performance requirements, so the force caused by the housing 3 and the stator 9 being made of different materials can be mitigated by the buffer section 12. Consequently, deformation and damage caused by the housing 3 and the stator 9 being made of different materials can be suppressed.

[0045] Next, a modified example of the partition wall support 11 will be described with reference to Figures 3 to 7. Figures 3 to 7 show partition wall support 11A to partition wall support 11E, which are modified examples of the partition wall support 11. Each of the partition wall support 11A to partition wall support 11E is composed of two (or more than three) members. As shown in Figure 3, the partition wall support 11A has, for example, a first member 113 and a second member 114. The first member 113 corresponds to, for example, a "first proximity member" or a "second separation member". The second member 114 also corresponds to, for example, a "first separation member" or a "second proximity member". Note that parts that are not described are the same as those in Figure 2, and are therefore given the same reference numerals and their description is omitted.

[0046] The first member 113 is the part of the partition support 11A that positions and holds the second member 114. Specifically, the first member 113 is an annular member located axially outward and radially inward of the partition support 11A. Since the first member 113 is separated radially and axially from the stator core 91 and coil end, it is less affected by magnetic flux. Therefore, there are no particular restrictions on material selection, and a material with a high Young's modulus, ferromagnetism, and high conductivity can be applied to the second member 114. This ensures the support rigidity of the partition 4, and as a result, the rigidity of the partition 4 can be increased.

[0047] The second member 114 holds the buffer portion 12. The second member 114 is a cylindrical member extending from the axial end of the stator core 91 to the axial outer end 4A of the partition wall 4. The second member 114 is configured in an L-shape, with an L-shaped notch 114K formed in a cross-sectional view where the first member 113 fits into the axial outer end. When the first member 113 is fitted into the second member 114, the radial inner surface of the first member 113 and the radial inner surface of the second member 114 are flush in the radial direction. The second member 114 has a groove 114M capable of housing the buffer portion 12. The groove 114M is located on the axial outer and radial outer sides of the second member 114.

[0048] Next, another modified example of the partition support 11 will be described based on Figure 4. As shown in Figure 4, the partition support 11B includes, for example, a first member 115 and a second member 116. The first member 115 corresponds to, for example, a "first separation member" or a "second proximity member." The second member 116 also corresponds to, for example, a "first proximity member" or a "second separation member."

[0049] The first member 115 is the part of the partition support 11B that positions and holds the second member 116. Specifically, the first member 115 is an annular member located axially inward and radially outward of the partition support 11B. The first member 115 is close to the stator core 91 and the coil end. The first member 115 is made of, for example, an insulating synthetic resin material. This ensures the insulating performance of the coil end. Because it is close to the stator core 91 and the coil end, it can avoid the effects of magnetic flux even in locations that are susceptible to magnetic flux.

[0050] The second member 116 holds the buffer portion 12. The second member 116 is a cylindrical member extending from the axial end of the stator core 91 to the axial outer end 4A of the partition wall 4. The second member 116 is configured in an L-shape, with an L-shaped notch 116K formed in a cross-sectional view where the first member 115 fits into the axial inner end. The second member 116 has a groove portion 116M capable of housing the buffer portion 12. The groove portion 116M is located on the axial outer and radial outer sides of the second member 116. The second member 116 is made of, for example, a non-magnetic metal material. This improves the cylindrical strength of the partition wall support portion 11B and improves the positioning accuracy of the sealing position.

[0051] Next, another modification of the partition support 11 will be described based on Figure 5. As shown in Figure 5, the partition support 11C has, for example, a first member 117 and a second member 118. The first member 117 corresponds to, for example, a "first proximity member" or a "second proximity member". The second member 118 corresponds to, for example, a "first separation member" or a "second separation member".

[0052] The first member 117 is the part of the partition support 11C that positions and holds the second member 118. Specifically, the first member 117 is an annular member located axially and radially inward of the partition support 11C. Because the first member 117 is close to the stator core 91, it is susceptible to the influence of magnetic flux. The first member 117 is made of, for example, an insulating synthetic resin material.

[0053] The second member 118 holds the buffer portion 12. The second member 118 is a cylindrical member extending from the axial end of the stator core 91 to the axial outer end 4A of the partition wall 4. The second member 118 is configured in an L-shape, with an L-shaped notch 118K formed in a cross-sectional view where the first member 117 fits into the axial inner end. When the first member 117 is fitted into the second member 118, the radial inner surface of the first member 117 and the radial inner surface of the second member 118 are flush in the radial direction. The second member 118 has a groove 118M capable of housing the buffer portion 12. The groove 118M is located on the axial outer and radial outer sides of the second member 118. The second member 118 is made of, for example, a non-magnetic metal material. This improves the cylindrical strength of the partition wall support portion 11C and improves the positioning accuracy of the sealing position. Furthermore, since the second member 118 is close to the coil end, a non-conductive material is preferred.

[0054] Next, another modified example of the partition support 11 will be described based on Figure 6. As shown in Figure 6, the partition support 11D includes, for example, a first member 119 and a second member 120. The first member 119 and the second member 120 are combined radially.

[0055] The first member 119 is the part of the partition support 11D that positions and holds the second member 120, and is the part that contacts the partition wall 4. Specifically, the first member 119 is a cylindrical member that extends from the axial end of the stator core 91 to the axial outer end 4A of the partition wall 4. In the axial direction, the first member 119 is separated from the coil end but is close to the stator core 91 and is therefore susceptible to the influence of magnetic fields. By using a non-magnetic metal material, for example, a material with a higher Young's modulus than the partition wall 4 can be applied to the first member 119, thereby enabling miniaturization of the liquid-cooled motor 1. The first member 119 corresponds to, for example, the "first proximity member".

[0056] The second member 120 holds the buffer portion 12. The second member 120 is a cylindrical member extending from the axial end of the stator core 91 to the axial outer end 4A of the partition wall 4. The second member 120 has a groove portion 120M capable of housing the buffer portion 12. The groove portion 120M is located on the axial outer and radial outer sides of the second member 120.

[0057] Furthermore, the conductivity of the second member 120 is lower than that of the first member 119. This makes the second member 120 less conductive than the first member 119. In other words, because the second member 120 can be less conductive than the first member 119, insulation reliability can be improved and eddy current losses can be reduced. In addition, the second member 120 is non-conductive and non-magnetic. Examples of non-magnetic materials include stainless steel, aluminum, and titanium. Examples of non-magnetic and non-conductive materials include ceramic materials, but a zirconia material with a coefficient of thermal expansion close to that of the stator core 91 may also be used. Because the second member 120 is non-conductive and non-magnetic, leakage flux can be reduced while ensuring insulation reliability. Furthermore, if a material with a higher Young's modulus than the partition wall 4 is applied to the second member 120, for example, the liquid-cooled motor 1 can be miniaturized. The second member 120 corresponds to, for example, the "first separation member".

[0058] Next, another modification of the partition support 11 will be described based on Figure 7. As shown in Figure 7, the partition support 11E includes, for example, a first member 121 and a second member 122. The first member 121 and the second member 122 are combined in the axial direction.

[0059] The first member 121 is the part of the partition wall support 11E that positions and holds the second member 122, and contacts the partition wall 4. Specifically, the first member 121 is a cylindrical member that extends from the axial end of the stator core 91 to an intermediate position between the axial outer end 4A of the partition wall 4. The first member 121 has weaker magnetism than the second member 122. Therefore, because the first member 121 has weaker magnetism than the second member 122, its magnetic resistance is greater, and magnetic flux leakage can be reduced. In other words, because magnetic resistance is greater and magnetic flux leakage can be reduced, eddy current loss can be reduced. Furthermore, it is preferable that the material of the first member 121 is non-magnetic and non-conductive. This prevents eddy currents from flowing. Therefore, eddy current loss does not occur in the first member 121 during motor operation. The first member 121 corresponds to, for example, the "second proximity member".

[0060] The second member 122 holds the buffer portion 12. The second member 122 is in contact with the partition wall 4. Specifically, the second member 122 is a cylindrical member connected to the axial outer end of the first member 121 and extending from the axial outer end of the first member 121 to the axial outer end 4A of the partition wall 4. The second member 122 has a groove portion 122M capable of housing the buffer portion 12. The groove portion 122M is located in the axial middle portion of the second member 122 and radially outward. Furthermore, the second member 122 has a higher Young's modulus than the first member 121. Because the second member 122 has a higher Young's modulus than the first member 121, it can have higher rigidity compared to a configuration where the partition wall support portion 11E is made up of the first member 121 alone. In other words, the rigidity of the partition wall 4 and the partition wall support portion 11E can be increased, thus reducing the deflection of the partition wall 4 and the partition wall support portion 11E. In other words, the support rigidity on the open end side is increased, which suppresses the deflection of the entire structure, including the bulkhead support section 11E. The second member 122 corresponds to, for example, a "second separation member".

[0061] Embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention. The drawings sometimes schematically show the components in order to facilitate understanding. The number of each component shown in the drawings may differ from the actual number due to the convenience of drawing creation. Furthermore, the components shown in the above embodiments are examples and are not particularly limiting, and various modifications are possible without substantially departing from the effects of the present invention.

[0062] In this embodiment, an inner rotor type motor is used, but an outer rotor type motor may also be used. In the case of an outer rotor type motor, the inner and outer relationship of the rotor and stator in the radial direction is reversed compared to the above embodiment.

[0063] Furthermore, in this embodiment, by configuring the buffer portion 12 with an O-ring, it is possible to mitigate the force generated on the partition wall 4 and partition wall support portion 11 due to forced displacement caused by the difference in linear expansion between the housing 3 and the stator core 91, as well as to function as a sealing member that seals the gap S2 between the flange portion 31C or 31D and the partition wall support portion 11 or partition wall support portion 11. However, it is also possible to implement this by providing two separate members: a force-relieving member that mitigates the force generated on the partition wall 4 and partition wall support portion 11 due to forced displacement caused by the difference in linear expansion between the housing 3 and the stator core 91, and a sealing member that seals the gap S2 between the flange portion 31C or 31D and the partition wall support portion 11 or partition wall support portion 11. If the sealing member is not used, the force-relieving member can also be provided intermittently in the circumferential direction.

[0064] Furthermore, in this embodiment, the cushioning portion 12 is configured to mitigate force radially, but it may also be configured to mitigate force axially.

[0065] Furthermore, in this embodiment, the partition wall 4 and the partition wall support parts 11, 11 are constructed from separate components. However, by integrally forming the partition wall 4 and the partition wall support parts 11, 11, the number of components can be reduced. In this case, by making the coil end portion of the partition wall 4 protrude outwards or inwards, the thickness of the coil end portion of the partition wall 4 is made thicker than other parts. This increases the rigidity of the partition wall 4 itself, allowing the partition wall 4 to maintain a perfect circular shape on its own, thus improving ease of assembly.

[0066] Furthermore, although the partition support portion 11 is configured in a cylindrical shape in this embodiment, the partition support portion 11 may have any shape as long as it can be positioned between the partition 4 and the coil end portion.

[0067] Furthermore, although the housing 3 is made of a single metal material in this embodiment, the parts of the housing 3 that are positioned in such a positional relationship with respect to the stator core 91 that a force due to the difference in linear expansion may be generated, i.e., the flange portion 31C or 31D, and a part of the housing 3 including the flange portion 31C or 31D, may be made of a material with a different coefficient of linear expansion from the material constituting the stator core 91, and the other parts of the housing 3 may be made of a different material, or in some cases, a synthetic resin. Also, although the stator core 91 is made of a single metal material, the parts of the housing 3 that are positioned in such a positional relationship with respect to the housing 3 that a force due to the difference in linear expansion may be generated, i.e., both axial ends of the stator core 91, may be made of a material with a different coefficient of linear expansion from the material constituting the housing 3, and the other parts of the stator core 91 excluding both axial ends may be made of a different material.

[0068] Furthermore, although the partition support section 11 is composed of two members in this embodiment, it can also be composed of three members, or any number of members (four or more). By composing the partition support section 11 from multiple members in this way, it is possible to create a partition support section 11 using materials suitable for the required function, depending on its relationship with other components in the motor. Specifically, since each member can be composed of the optimal material according to the magnitude of the force generated on each member, the force generated on each member can be effectively mitigated.

[0069] When the partition wall support portion 11 is divided into a first region that is spaced away from the partition wall 4 and close to the stator core 91, a second region that is spaced away from the partition wall 4 and close to the stator core 91, a third region that is close to the partition wall 4 and close to the stator core 91, and a fourth region that is close to the partition wall 4 and spaced away from the stator core 91, it is preferable to allocate the following materials. First area: Non-magnetic, non-conductive material Second area: Magnetism and conductivity are not considered. Third area: Non-magnetic material Area 4: Magnetism and conductivity are not considered. Furthermore, when combining each region to form a single part, it is preferable that the priority of material selection be such that the material of the second region and the material of the fourth region are equal, the priority of the material of the third region is higher than that of the material of the second region, and the priority of the material of the first region is higher than that of the material of the third region.

[0070] The material forming the first region is preferably, for example, a ceramic material or a zirconia material. The material forming the third region is preferably, for example, stainless steel, aluminum, or titanium. The materials forming the second and fourth regions are, for example, materials that are dense, easy to keep airtight, have high smoothness and workability, and have a high Young's modulus, although magnetism and conductivity are not required. For example, metallic materials (aluminum, iron, stainless steel, titanium, magnesium) or dense ceramics are preferred. Furthermore, these regions do not necessarily need to be separated, and may be composites formed by combining each of these materials. [Explanation of Symbols]

[0071] 1...Motor, 3...Housing, 4...Bulkhead, 8...Rotor, 9...Stator, 11,11A~11E...Bulkhead support section, 12...Buffing section, 111...First member, 112...Second member, 113...First member, 114...Second member, 115...First member, 116...Second member, 117...First member, 118...Second member, 119...First member, 120...Second member, 121...First member, 122...Second member, X...Axis

Claims

1. The casing and A rotor that rotates around an axis relative to the housing, A stator fixed to the housing and generating a magnetic force for rotation to the rotor, the stator being formed of a material having a different coefficient of thermal expansion from the housing, In order to partition the passage through which the cooling liquid passes within the housing, a partition wall is provided between the rotor and the stator so as to be aligned with the direction of the axis, A partition wall support section is provided along the partition wall to support the portion of the partition wall that does not overlap with the stator in the direction of the axis, and is composed of a plurality of members, wherein at least one of the plurality of members is made of a different material from the other members. A buffer portion interposed between the housing and the partition support portion, the buffer portion being formed from a material with a lower modulus of elasticity than the housing and the partition support portion, A liquid-cooled motor equipped with [a specific feature / feature].

2. At least two of the aforementioned plurality of members are combined in the radial direction, The liquid-cooled motor according to claim 1, wherein the first separating member, which is radially separated from the partition wall, has lower conductivity than the first proximity member, which is radially close to the partition wall.

3. The liquid-cooled motor according to claim 2, wherein at least one of the first proximity member and the first separation member has a higher Young's modulus than the partition wall, and the first separation member is non-conductive and non-magnetic.

4. At least two of the aforementioned plurality of members are combined in the axial direction, The liquid-cooled motor according to claim 1, wherein the second proximity member, of the two members, that is closer to the stator core of the stator, has weaker magnetism than the second separation member that is separated from the stator core.

5. The liquid-cooled motor according to claim 4, wherein the second separating member has a higher Young's modulus than the second proximity member.

6. The casing and A rotor that rotates around an axis relative to the housing, A stator fixed to the housing and generating a magnetic force for rotation to the rotor, the stator being formed of a material having a different coefficient of thermal expansion from the housing, In order to partition the passage through which the cooling liquid passes within the housing, a partition wall is provided between the rotor and the stator so as to be aligned with the direction of the axis, A partition wall support portion is provided along the partition wall to support the portion of the partition wall that does not overlap with the stator in the direction of the axis, A buffer portion interposed between the housing and the partition support portion, the buffer portion being formed from a material with a lower modulus of elasticity than the housing and the partition support portion, Equipped with, The aforementioned partition wall support portion is A first region that is radially separated from the partition wall and axially close to the stator core of the stator, A second region is radially separated from the partition wall and axially separated from the stator core of the stator than the first region, A third region is located radially closer to the partition wall than the first region, and axially closer to the stator core of the stator than the second region, A fourth region is provided that is radially closer to the partition wall than the first region and axially further away from the stator core of the stator than the third region, It has, The first region is formed of a non-magnetic and non-conductive material. The third region is formed of a non-magnetic material, A liquid-cooled motor in which the second and fourth regions are formed of a material not limited by magnetism and conductivity.

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