JP2014135859A - Electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit a temperature difference between an attachment part of a housing and an attachment part of a shaft in a bearing for connecting the shaft with the housing from becoming large without complicating a structure, such as a rotor, and providing a separate special power source etc. in an electric motor used in a device including a liquid passage where a liquid flows.SOLUTION: A rotation member body 17a is disposed on an upper end part of a storage space 11 of a housing 2 where a stator 3a, a rotor 4, and the likes are disposed. A supply passage 12a which supplies a coolant to a spiral passage 12b provided at the housing 2 extends traversing the upper end part of the storage space 11. A rotation member 17 is rotated by flow of the coolant flowing in the supply passage 12a. An upper end part of a shaft 5, which is rotatably connected to the housing 2 by a radial ball bearing 6, and a lower end part of a shaft part 17b of the rotation member 17 are connected by a thrust ball bearing 8 so that the shaft 5 and the shaft part 17b may rotate relative to each other.

Description

  The present invention relates to an electric motor used in an apparatus having a liquid flow path through which a liquid flows.

  In the electric motor described in Patent Document 1, a housing (motor case) accommodates a stator (stator), a rotor (rotor), a shaft attached to the rotor, and the like. The stator is fixed to the housing. The shaft is rotatably attached to the housing by a bearing. Further, a fan is attached to the shaft, and a hole is formed in the housing for communicating the inside and outside of the housing. When the rotor rotates, the fan attached to the shaft rotates. When the fan rotates, air is introduced from the outside into the housing through the through hole, and air in the housing is discharged to the outside through the through hole. Thereby, the rotor and stator accommodated in the housing can be efficiently cooled.

  In the electric motor described in Patent Document 2, an oil passage through which oil for cooling the rotor (rotor) flows is provided. The oil passage includes a shaft hollow portion and first to third oil passages. The shaft hollow portion extends along the axis of the shaft attached to the rotor. The first oil passage extends in the radial direction of the rotor and connects the shaft hollow portion and the outer peripheral surface of the rotor. The second and third oil passages are formed by closing grooves formed on the outer peripheral surface of the rotor with permanent magnets disposed on the outer peripheral surface of the rotor. And a rotor can be efficiently cooled with the oil which flows through such an oil path.

JP-A-5-103443 JP 2001-16826 A

  In the electric motor described in Patent Document 1, when the rotor is rotating, the inner ring of the bearing attached to the shaft rotates, and accordingly, the rolling element of the bearing also rotates. Therefore, in the bearing, heat is transferred relatively efficiently from the inner ring attached to the shaft to the outer ring attached to the housing via the rolling elements. On the other hand, when the rotation of the rotor stops, the rotation of the inner ring of the bearing attached to the shaft stops, and accordingly, the rotation of the rolling element of the bearing also stops. For this reason, the heat transfer efficiency from the inner ring to the outer ring via the rolling elements is worse than when the rotor is rotating. On the other hand, in the electric motor described in Patent Document 1, when the rotation of the rotor stops, the rotation of the fan also stops, so that the heat of the rotor is difficult to escape to the outside. From the above, in Patent Document 1, when the rotation of the rotor is stopped, the temperature difference between the inner ring and the outer ring of the bearing becomes large. If the rotation of the rotor is resumed in this state, the load on the bearing increases, and the life of the bearing may be shortened.

  Here, as described in Patent Document 2, if an oil path is formed in the rotor and oil for cooling the rotor is poured into the oil path, the rotation of the rotor is stopped. The rotor and shaft can be cooled. Therefore, even when the rotation of the rotor is stopped, an increase in the temperature difference between the inner ring and the outer ring of the bearing can be suppressed. However, when an oil passage as described in Patent Document 2 is formed in the rotor, the structure of the rotor becomes complicated. Further, when such an oil passage is provided, it is necessary to cool the oil in the oil passage where heat is transmitted from the rotor or the shaft by moving it to another place. However, if power is separately provided to the apparatus for that purpose, the energy efficiency of the entire apparatus is lowered.

  The object of the present invention is to install the shaft of the bearing that connects the shaft to the housing when the rotor is not rotating, without complicating the structure of the rotor or the like, or providing a separate dedicated power. It is providing the electric motor which can suppress that the temperature difference of a part and the attachment part of a housing | casing becomes large.

  An electric motor according to the present invention is an electric motor used in an apparatus provided with a liquid flow path through which a liquid flows, and includes a housing, a stator housed in the housing, and fixed to the housing, A rotor housed in the housing; a shaft disposed in the housing and attached to the rotor; a housing mounting portion disposed in the housing and attached to the housing; and the shaft A first shaft attaching portion attached to the housing, and a plurality of first rolling elements sandwiched between the housing attaching portion and the shaft attaching portion, and the shaft is rotatably coupled to the housing. One bearing, a rotating member arranged coaxially with the shaft and rotating by the flow of the liquid, a second shaft attaching portion arranged in the housing and attached to the shaft, and attached to the rotating member Rotating member removal And a second bearing that has a plurality of second rolling elements sandwiched between the second shaft mounting portion and the rotating member mounting portion, and rotatably connects the shaft and the rotating member to each other, It has.

  According to the present invention, the heat of the rotor is transmitted to the rotating member via the shaft and the second bearing. In the second bearing, heat is transmitted from the second shaft mounting portion to the rotating member mounting portion via the second rolling element. At this time, since the rotating member is rotated by the flow of the liquid flowing through the liquid flow path, the rotating member attaching portion also rotates. Thereby, a 2nd rolling element also rotates. Therefore, in the second bearing, heat is more efficiently transmitted from the shaft attachment portion to the rotation member attachment portion via the second rolling element than when the rotation member attachment portion is not rotating. Furthermore, in the present invention, since the rotating member is rotatable with respect to the shaft and is rotated by the flow of the liquid flowing through the apparatus, the rotating member mounting portion of the second bearing and the second rolling element have the rotor rotated. Rotates even when not. From the above, even when the rotor is not rotating, the rotor and the shaft are efficiently cooled, and the temperature of the housing mounting portion and the first shaft mounting portion of the first bearing is reduced. As a result, the load on the first bearing is reduced when the rotation of the rotor is resumed after the rotation of the rotor is stopped. Thereby, the lifetime of a 1st bearing can be lengthened. Further, since the rotating member is rotatable with respect to the shaft and is rotated by the flow of the liquid, no additional power or the like is required to rotate the rotating member.

It is an axial sectional view of the electric motor concerning an embodiment of the invention. It is the II-II sectional view taken on the line of FIG. FIG. 10 is a view corresponding to FIG. FIG. 10 is a view corresponding to FIG. FIG. 10 is a view corresponding to FIG. FIG. 10 is a diagram corresponding to FIG.

  Hereinafter, preferred embodiments of the present invention will be described.

  An electric motor 1 according to the present embodiment is an electric motor used in an apparatus such as a construction machine, and as shown in FIGS. 1 and 2, a housing 2, a stator 3, a rotor 4, a shaft 5, and a radial ball. A bearing 6, a rotating unit 7, and a thrust ball bearing 8 are provided. In FIG. 1, only the casing 2, the stator 3, the rotor 4, the radial ball bearing 6, a casing 16 described later of the rotation unit 7, and the thrust ball bearing 8 are shown in cross-sectional shape. Further, in FIG. 2, only a storage space 11 and a cooling flow path 12 to be described later are illustrated in the configuration to be illustrated by a broken line inside the housing 2.

  The housing | casing 2 is a substantially cylindrical member which consists of metal materials etc., and the accommodation space 11 is formed in the inside. In the accommodation space 11, the stator 3, the rotor 4, the shaft 5, the radial ball bearing 6, the rotation unit 7, the thrust ball bearing 8, and the like are accommodated.

  The stator 3 is fixed to the side wall surface of the accommodation space 11. The rotor 4 is disposed in a region inside the housing space 11 where the stator 3 is disposed. Here, since the structure and arrangement of the stator 3 and the rotor 4 are the same as those in the prior art, a detailed description thereof will be omitted.

  The shaft 5 is attached to the rotor 4 so as to be coaxial with the rotation axis of the rotor 4 and extends in the vertical direction. A drive target of the electric motor 1 is attached to the lower end portion of the shaft 5. Further, in the central portion including the central axis of the shaft 5, a portion 5 a extending from the portion attached to the rotor 4 to the upper end thereof is made of a material having higher thermal conductivity than the other portions. For example, parts other than the part 5a of the shaft 5 are made of iron or the like, whereas the part 5a of the shaft 5 is made of aluminum, copper or the like.

  The radial ball bearing 6 (first bearing) is made of a metal material or the like, and has a substantially annular outer ring 6a (housing mounting portion) and a substantially annular inner ring 6b (first shaft mounting portion) having a smaller diameter than the outer ring 6a. ), A plurality of balls 6c (first rolling elements) arranged along the circumferential direction of the outer ring 6a and the inner ring 6b are sandwiched. And thereby, the outer ring | wheel 6a and the inner ring | wheel 6b are mutually rotatable. Since the structure of the radial ball bearing 6 is the same as that of the conventional bearing, further detailed description thereof is omitted. The outer ring 6 a is attached to the wall of the housing space 11 of the housing 2. The inner ring 6 b is attached to the shaft 5. Thereby, the shaft 5 is rotatably connected to the housing 2.

  The rotation unit 7 is disposed at the upper end portion of the accommodation space 11 that is located almost directly above the rotor 4 and the shaft 5. The rotating unit 7 has a structure in which a rotating member 17 is accommodated in a casing 16. The rotating member 17 includes a rotating member main body 17a and a shaft portion 17b. The rotating member main body 17 a is a water wheel, a propeller, or the like, and is disposed coaxially with the rotor 4 and the shaft 5. The shaft portion 17 b is fixed to the central axis of the rotating member main body 17 a and extends through the casing 16 to a position below the casing 16. Here, the clearance between the outer peripheral portion of the casing 16 and the wall of the housing space 11 and the clearance between the shaft portion 17b of the casing 16 and the shaft portion 17b are sealed. Thereby, as will be described later, it is possible to prevent the coolant flowing in the area where the rotation member main body 17a of the accommodation space 11 is arranged from flowing into the area below the casing 16 of the accommodation space 11.

  The thrust ball bearing 8 (second bearing) is made of a metal material or the like, and is disposed to face each other in the vertical direction, and has a substantially annular mounting portion 8a (second shaft mounting portion) having a substantially annular shape in plan view. A plurality of balls 8c (second rolling elements) arranged along the circumferential direction of the mounting portions 8a and 8b are sandwiched between the mounting portion 8b (rotating member mounting portion). In the thrust ball bearing 8, the mounting portion 8a and the mounting portion 8b are rotatable with respect to each other. In addition, since the structure of the thrust ball bearing 8 is the same as that of the prior art, further detailed description is omitted. The lower attachment portion 8 a is attached to the upper end portion of the shaft 5. The upper attachment portion 8 b is attached to the lower end portion of the shaft portion 17 b of the rotating member 17. Thereby, the shaft 5 and the rotating member 17 are rotatably connected to each other.

  The housing 2 is provided with a cooling flow path 12. The cooling channel 12 has a supply channel 12a and a spiral channel 12b. The supply flow path 12a extends in the horizontal direction so as to cross the upper end portion of the accommodation space 11 in which the rotating member main body 17a is disposed, and one end thereof (the left end in FIG. 1) is The liquid supply port 12c is opened on the side wall surface. The spiral flow path 12 b is provided on the side wall of the housing 2 and extends spirally along the outer periphery of the accommodation space 11. Further, the upper end portion of the spiral flow path 12b is connected to the end of the supply flow path 12a opposite to the liquid supply port 12c (the right side in FIG. 1). Further, the lower end portion of the spiral flow path 12 b is connected to a liquid outlet 12 d that is open on the side wall surface of the housing 2.

  In the present embodiment, a coolant such as water or oil is supplied from the liquid supply port 12c to the supply channel 12a. The supplied coolant flows in the supply flow path 12a in the horizontal direction so as to cross the region where the rotation member 17 of the accommodation space 11 is disposed, and flows into the spiral flow path 12b. At this time, the rotating member 17 is rotated by the flow of the coolant flowing through the supply flow path 12a. The coolant that has flowed into the spiral flow path 12b flows spirally through the side wall of the housing 2, and finally flows out from the liquid outlet 12d.

  In the electric motor 1 as described above, when the electric motor 1 is driven to rotate the rotor 4, heat is usually generated in the stator 3 and the rotor 4. At this time, the heat of the stator 3 is transmitted to the housing 2 and further transferred to the cooling liquid flowing through the spiral flow path 12b formed in the housing 2, so that the heat is released to the outside. On the other hand, the heat of the rotor 4 is transmitted to the housing 2 via the shaft 5 and the radial ball bearing 6 and further transmitted to the coolant flowing through the spiral flow path 12b formed in the housing 2. Escaped to the outside. Here, while the rotor 4 is rotating, the inner ring 6b to which the shaft 5 is attached is rotating. Thereby, the several ball | bowl 6c arrange | positioned between the outer ring | wheel 6a and the inner ring | wheel 6b is rotating in the circumferential direction of the outer ring | wheel 6a and the inner ring | wheel 6b. Therefore, in the radial ball bearing 6, the heat of the inner ring 6b is relatively efficiently transmitted to the outer ring 6a via the plurality of balls 6c. Therefore, a large temperature difference does not occur between the outer ring 6a and the inner ring 6b.

  On the other hand, when the rotation of the rotor 4 is stopped, the rotation of the inner ring 6b is stopped, so that the rotation of the plurality of balls 6c is also stopped. Therefore, compared to when the rotor 4 is rotating, heat transfer efficiency from the inner ring 6b to the outer ring 6a via the plurality of balls 6c is deteriorated, and heat is not easily transferred from the shaft 5 to the housing 2. As a result, unlike the present embodiment, if there is no rotating member 17 or thrust ball bearing 8, the temperature difference between the housing 2 and the shaft 5 increases. Thereby, the temperature difference between the outer ring 6a attached to the housing 2 and the inner ring 6b attached to the shaft 5 also increases, and the difference in the degree of thermal expansion between the outer ring 6a and the inner ring 6b increases. If the rotation of the rotor 4 is resumed in this state, the load on the radial ball bearing 6 increases, and the life of the radial ball bearing 6 may be shortened.

  On the other hand, in the present embodiment, the heat of the shaft 5 is transmitted to the rotating member 17 via the thrust ball bearing 8 in addition to being transmitted to the housing 2 via the radial ball bearing 6. It is transmitted from the rotating member 17 to the coolant flowing through the housing 2 and the supply channel 12a. At this time, since the mounting portion 8b of the thrust ball bearing 8 is rotated by the rotation of the rotating member 17, the plurality of balls 8c are rotating in the circumferential direction of the mounting portions 8a and 8b. Thereby, heat is efficiently transmitted from the attachment portion 8a to the attachment portion 8b via the plurality of balls 8c. That is, heat is efficiently transferred from the shaft 5 to the shaft portion 17 b of the rotating member 17.

  In the present embodiment, since the rotating member 17 and the attachment portion 8b are rotated by the flow of the coolant flowing through the supply flow path 12a, it is determined whether or not the rotor 4 and the shaft 5 are rotating. Regardless, the mounting portion 8b and the plurality of balls 8c rotate. Therefore, even when the rotor 4 is not rotating, the plurality of balls 8c are rotating.

  And from these things, in this Embodiment, the temperature of the inner ring | wheel 6b of the shaft 5 or the radial ball bearing 6 tends to fall. As a result, the temperature difference between the housing 2 and the shaft 5 is reduced. Thereby, the temperature difference between the outer ring 6 a attached to the housing 2 and the inner ring 6 b attached to the shaft 5 is also reduced. Therefore, the load applied to the radial ball bearing 6 when the rotation of the rotor 4 is resumed is reduced, and the life of the radial ball bearing 6 can be extended.

  Further, in the present embodiment, the rotating member 17 and the attachment portion 8b are provided by the flow of the coolant flowing through the supply flow channel 12a provided in the housing 2 for supplying the coolant to the spiral flow channel 12b. Rotate. Therefore, in order to rotate the rotating member 17 and the attachment portion 8b, no dedicated power or the like is required.

  At this time, a portion 5 a extending from the portion where the rotor 4 is mounted to the upper end portion where the mounting portion 8 a of the thrust ball bearing 8 is mounted in the central portion including the axis of the shaft 5 is the other portion of the shaft 5. It is comprised with the material whose heat conductivity is higher than a part. Therefore, the heat at the center portion of the shaft 5 that is particularly difficult to escape heat can be efficiently released. Furthermore, the shaft 5 has a portion 5a made of a relatively soft material having high thermal conductivity such as aluminum or copper, whereas the portion other than the portion 5a has a thermal conductivity higher than that of the portion 5a such as iron. Although it is low, since it is comprised with the material harder than the part 5a, the intensity | strength of the shaft 5 is securable.

  Next, modified examples in which various changes are made to the present embodiment will be described. However, the description of the same configuration as the present embodiment will be omitted as appropriate.

  In the above-described embodiment, the supply flow path 12a for supplying the coolant to the spiral flow path 12b is provided so as to cross the upper end portion of the accommodation space 11 in which the rotating member main body 17a is disposed in the horizontal direction, The rotating member 17 is rotated by the flow of the coolant flowing through the supply flow path 12a, but is not limited thereto.

  In one modified example (Modified Example 1), as shown in FIG. 3, the side wall surface of the housing 2 is connected to the spiral channel 12 b at a portion located at the same height as the upper end of the spiral channel 12 b. A liquid supply port 12e is provided. And a cooling fluid is supplied to the spiral flow path 12b from the liquid supply port 12e. On the other hand, a rotation flow path 36 is provided at the upper end of the housing 2 so as to cross the housing space 11 in which the rotation member main body 17a is disposed in the horizontal direction. One end (the left end in FIG. 3) of the rotation flow path 31 is a liquid inflow port 31 a that opens to the side wall surface of the housing 2. The other end (the right end in FIG. 3) of the rotation flow path 31 is a liquid outlet port 36 b opened in the side wall surface of the housing 2. The liquid inflow port 31a is, for example, a liquid flow path provided in a device including the electric motor 1, such as a flow path through which cooling water or cooling oil of an engine of the construction machine flows when the electric motor 1 is provided in the construction machine. It is connected. The liquid outlet 31b is connected to a portion on the downstream side of the portion where the liquid inlet 31a is connected in the liquid channel. Then, the liquid flowing through the liquid channel flows from the liquid inlet 31a into the rotation channel 31, flows through the rotation channel 31, and then flows out from the liquid outlet 31b and returns to the liquid channel.

  In this case, since the rotating member main body 17a is rotated by the flow of the liquid flowing from the liquid channel of the apparatus into the rotating channel 31, no special power or the like is required to rotate the rotating member 17.

  Further, in the above-described embodiment, the entire rotating member 17 is disposed in the housing space 11 of the housing 2 so that the rotating member 17 is rotated by the flow of liquid flowing through the liquid flow path formed in the housing 2. However, it is not limited to this. In another modification (Modification 2), as shown in FIG. 4, a portion of the rotating member 17 excluding the lower end portion of the shaft portion 17 b is disposed outside the housing 2. The rotating member main body 17a is provided outside the casing 2 of the apparatus including the electric motor 1, such as a flow path through which cooling water or cooling oil flows through the engine of the construction machine when the electric motor 1 is provided in the construction machine. The liquid channel 101 is disposed. The shaft portion 17 b passes through the upper end portion of the housing 2 and extends into the accommodation space 11, and the lower end portion thereof is attached to the attachment portion 8 b of the thrust ball bearing 8. In the second modification, as in the first modification, the liquid is supplied from the liquid supply port 12e to the spiral flow path 12b.

  In this case, the heat of the rotor 4 and the shaft 5 is transmitted to the shaft portion 17 b via the thrust ball bearing 8. The heat transmitted to the shaft portion 17b is transmitted to the housing 2 and the rotating member main body 17a. The heat transferred to the housing 2 is transferred to the liquid flowing through the spiral flow path 12b and released to the outside. The heat transmitted to the rotating member main body 17a is transmitted to the liquid flowing through the liquid channel 101 and is released to the outside. Thereby, the temperature difference of the outer ring | wheel 6a and the inner ring | wheel 6b of the radial ball bearing 6 can be made small like the above-mentioned embodiment. Further, in this case, since the rotating member main body 17a is rotated by the flow of the liquid flowing through the liquid flow path 101 of the apparatus, no special power or the like is required for rotating the rotating member 17. Further, in this case, since the rotating member main body 17a is disposed in the liquid flow path 101 outside the housing 2, the liquid used for rotating the rotating member 17 flows into the storage space 11. It can be surely prevented.

  Further, in the above-described embodiment, the portion 5a extending from the portion where the rotor 4 is attached to the upper end portion where the attachment portion 8a of the thrust ball bearing 8 is attached, out of the central portion including the central axis of the shaft 5, Although it was made of a material having a higher thermal conductivity than the other parts of the shaft 5, it is not limited to this. For example, the entire shaft 5 may be made of the same material.

  In the above-described embodiment, the radial ball bearing is used as the first bearing for rotatably connecting the shaft 5 to the housing 2, but is not limited thereto. For the connection between the shaft 5 and the housing 2, a bearing other than a radial ball bearing such as a radial roller bearing may be used as the first bearing. In the above-described embodiment, the thrust ball bearing 8 is used as the second bearing for rotatably connecting the shaft 5 and the rotating member 17 to each other. However, the present invention is not limited to this. For the connection between the shaft 5 and the shaft portion 17b, a bearing other than a thrust ball bearing such as a thrust roller bearing may be used as the second bearing.

  As another modification (Modification 3), an example in which a thrust roller bearing is used as the second bearing will be described. As shown in FIG. 5, a thrust roller bearing 36 is provided instead of the thrust ball bearing 8. Yes. The thrust roller bearing 36 is made of a metal material or the like, and has two substantially annular mounting portions 36a (second shaft mounting portions), which are opposed to each other in the vertical direction, and a mounting portion 36b (rotating member mounting portion). A plurality of rollers 36c (second rolling elements) arranged along the circumferential direction of the attachment portions 36a and 36b are sandwiched between the two. Here, the roller 36c is a member having a substantially cylindrical shape or a truncated cone shape, and FIG. 5 illustrates a case where the roller 36c has a trapezoidal cone shape. Since the structure of the thrust roller bearing 36 is the same as that of the prior art, further detailed description will be omitted. The attachment portion 36 a is attached to the shaft 5, and the attachment portion 36 b is attached to the shaft portion 17 b of the rotating member 17.

  In this case, in the thrust roller bearing 36, heat is transferred from the mounting portion 36a to which the shaft 5 is mounted to the mounting portion 36b to which the shaft portion 17b of the rotating member 17 is mounted via the plurality of rollers 36c. On the other hand, when the rotating member 17 is rotated by the flow of the coolant flowing through the supply flow path 12a, the attachment portion 36b is rotated, and the plurality of rollers 36c are rotated accordingly. Accordingly, as in the case of the above-described embodiment, even when the rotor 4 is not rotating, heat is efficiently transferred from the mounting portion 36a to the mounting portion 36b via the plurality of rollers 36c. That is, heat is efficiently transferred from the shaft 5 to the shaft portion 17 b of the rotating member 17.

  The present invention can also be applied to an electric motor provided with an angle sensor for detecting the rotation angle of the rotor 4 and the shaft 5. For example, in a modification (Modification 4), as shown in FIG. 6, the housing space 11 of the housing 2 extends further upward than the area where the rotation unit 7 is disposed. In addition, a through hole 17c that penetrates the rotating member main body 17a and the shaft portion 17b in the vertical direction is formed at the substantially central portion, and the upper end portion of the shaft 5 passes above the rotating hole 7 through the through hole 17c. It extends to. An angle sensor 41 (angle detection means) is provided in the upper end portion of the shaft 5 located above the rotation unit 7 and the region above the rotation unit 7 in the accommodation space 11. Here, although simplified in FIG. 6, the angle sensor 41 is, for example, a resolver. In this case, the gap between the outer peripheral portion of the casing 16 and the wall of the housing space 11 is also sealed. This prevents the liquid that has flowed from the supply flow path 12a into the area where the rotation member main body 17a of the accommodation space 11 is arranged, from flowing into the area where the angle sensor 41 of the accommodation space 11 is arranged. .

  Some electric motors require an angle sensor for detecting the rotation angle of the shaft. In the modified example 4, as described above, the through hole 17c extending vertically is formed in the rotating member 17, and the shaft 5 is placed above the rotating unit 7 through the through hole 17c (opposite to the rotor 4 sandwiching the rotating member 17). Side). And the angle sensor 41 is provided in the part above the rotation unit 7 of the shaft 5 and the accommodation space 11. FIG. Thereby, even when the rotary unit 7 and the thrust ball bearing 8 are provided in the electric motor, the angle sensor can be arranged.

DESCRIPTION OF SYMBOLS 1 Electric motor 2 Case 3 Stator 4 Rotor 5 Shaft 5a Part 6 Radial ball bearing 6a Outer ring 6b Inner ring 6c Ball 8 Thrust ball bearing 8a, 8b Mounting part 8c Ball 12 Cooling channel 17 Rotating member 31 Rotating channel 36 Thrust roller bearing 36a, 36b Mounting portion 36c Roller 101 Liquid flow path

Claims (4)

An electric motor used in an apparatus having a liquid flow path through which a liquid flows,
A housing,
A stator housed in the housing and fixed to the housing;
A rotor housed in the housing;
A shaft disposed within the housing and attached to the rotor;
A plurality of housings disposed between the housing, the housing mounting portion attached to the housing, the first shaft mounting portion attached to the shaft, and the housing mounting portion and the shaft mounting portion. A first bearing having a first rolling element and rotatably connecting the shaft to the housing;
A rotating member disposed coaxially with the shaft and rotated by the flow of the liquid;
The second shaft mounting portion that is disposed in the housing and is mounted on the shaft, the rotating member mounting portion that is mounted on the rotating member, and the second shaft mounting portion and the rotating member mounting portion. An electric motor comprising: a plurality of second rolling elements; and a second bearing that rotatably connects the shaft and the rotating member to each other. In the casing, as the liquid channel, a cooling channel through which a coolant for cooling the casing flows is formed,
2. The electric motor according to claim 1, wherein the rotating member is disposed in the cooling flow path and is rotated by the flow of the coolant flowing through the cooling flow path.   Of the portion including the shaft axis, at least a portion extending from the portion where the rotor is attached to the portion where the second shaft attachment portion is attached is made of a material having higher thermal conductivity than the other portion of the shaft. The electric motor according to claim 1, wherein the electric motor is configured. The rotating member is formed with a through hole penetrating the central axis portion in the axial direction,
The shaft extends through the through hole to the opposite side of the rotor sandwiching the rotating member,
The electric motor according to any one of claims 1 to 3, wherein angle detection means for detecting a rotation angle of the shaft is disposed on the opposite side of the rotor with the rotation member interposed therebetween.

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