Electric motor and working machine

Abstract

To provide an electric motor and a working machine that are capable of improving cooling performance.SOLUTION: An electric motor includes a housing having a space for accommodating a rotor and a stator, and a first fluid reservoir portion that is disposed in the space of the housing and formed to guide at least a part of a fluid flowing through the space to a lower portion of a stator coil of the stator.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to electric motors and work machines. [Background technology]

[0002] Conventionally, an electric rotating shovel equipped with an electric motor for rotating an upper rotating body has been known as a construction machine. The electric motor is equipped with a cooling oil circuit for cooling the rotor, stator, etc. provided therein with cooling oil. For example, the electric motor is disposed vertically so that the axis of the rotor is vertical (vertical motor). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-68513 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration of Patent Document 1, there is a possibility that the cooling oil will not reach part of the stator coil. If the electric motor is not sufficiently cooled, loss will increase and the performance of the electric motor may deteriorate.

[0005] An object of an aspect of the present disclosure is to provide an electric motor and a work machine that can improve cooling performance. [Means for solving the problem]

[0006] An electric motor according to one embodiment of the present disclosure comprises a housing having a space for accommodating a rotor and a stator, and a first fluid reservoir portion disposed in the space of the housing and formed to guide at least a portion of a fluid flowing through the space to a lower portion of a stator coil of the stator. Effect of the Invention

[0007] According to the aspects of the present disclosure, it is possible to provide an electric motor and a work machine that can improve cooling performance. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing a work machine according to an embodiment. [Diagram 2] 1 is a diagram showing a drive system of a work machine according to an embodiment. [Diagram 3] 1 is a cross-sectional view of an electric motor according to an embodiment. [Figure 4] FIG. 2 is a perspective view of a baffle plate according to the embodiment. [Diagram 5] FIG. 2 is an enlarged perspective view of a portion of the baffle plate according to the embodiment. [Figure 6] 5 is an explanatory diagram of a flow of a cooling fluid in an electric motor according to an embodiment. FIG. [Figure 7] 5 is an explanatory diagram of a flow of a cooling fluid in an electric motor according to a comparative example. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In this embodiment, an electric motor is mounted on an electric slewing shovel (an example of a work machine) and is configured as a swing motor for swinging an upper swing body of the electric slewing shovel.

[0010] In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," do not only mean such arrangements or states strictly, but also include arrangements or states in which there is a relative displacement with an angle or distance to the extent that the same function can be obtained with a tolerance. In the drawings used in the following description, the scale of each component may be appropriately changed to show each component with a recognizable size.

[0011] <Work machinery> Fig. 1 is a schematic diagram showing a work machine according to an embodiment. The work machine 100 according to this embodiment is an electric hydraulic excavator. The work machine 100 may be a manned vehicle that is operated by a driver, or an unmanned vehicle that is operated without a driver.

[0012] The work machine 100 includes a running body 120 , an upper rotating body 140 , and a work implement 160 .

[0013] The running body 120 supports the work machine 100 so that it can run. The running body 120 is equipped with a running device 121. The running device 121 is, for example, a pair of left and right caterpillar tracks. The running device 121 is driven by a traveling motor 122. The upper rotating body 140 is supported on the running body 120 so as to be rotatable about a rotation axis. The upper rotating body 140 performs a rotating operation relative to the running body 120 by the rotation motor 114. The upper rotating body 140 has a compartment 141 that houses a drive system.

[0014] The working machine 160 is supported movably on the upper rotating body 140. The working machine 160 is hydraulically driven. The working machine 160 includes a boom 161, an arm 162, and an attachment 163. The attachment 163 is an example of a working tool. In the example shown in FIG. 1, the attachment 163 is a bucket. In the example shown in FIG. 1, the side of the upper rotating body 140 on which the working machine 160 is supported is the front, and the opposite side with respect to the front is the rear. In this embodiment, the left-right direction refers to the left and right with respect to the front, and the up-down direction refers to the direction in which the rotation axis of the upper rotating body 140 extends.

[0015] <Work machine drive system> 2 is a diagram showing a drive system of a work machine according to an embodiment. The work machine 100 is equipped with a plurality of actuators for driving the work machine 100. The work machine 100 is equipped with an electricity storage device 111, a power supply device 112, a prime mover 113, a swing motor 114, a hydraulic pump 115, a control valve 116, a boom cylinder 117, an arm cylinder 118, an attachment cylinder 119, and a pair of travel motors 122. The electricity storage device 111, the power supply device 112, the prime mover 113, the swing motor 114, the hydraulic pump 115, and the control valve 116 are housed in a compartment 141.

[0016] The power storage device 111 supplies electric power, which is a power source for driving the work machine 100. The power storage device 111 is, for example, a battery or a capacitor. The power storage device 111 supplies electric power to the prime mover 113 and the swing motor 114 via a power supply device 112. The power supply device 112 controls the supplied electric power in accordance with the load. The power supply device 112 is, for example, an inverter device.

[0017] The prime mover 113 is an electric motor that is driven by electric power supplied from the power storage device 111. The prime mover 113 drives a hydraulic pump 115. Note that the prime mover 113 may be, for example, an internal combustion engine.

[0018] The swing motor 114 is an electric motor that is driven by power supplied from the power storage device 111. The swing motor 114 swings the upper swing body 140 relative to the traveling body 120.

[0019] The hydraulic pump 115 is driven by the prime mover 113, and supplies hydraulic oil to the boom cylinder 117, the arm cylinder 118, the attachment cylinder 119, and the traveling motor 122 via a control valve 116. The control valve 116 controls the flow rate of hydraulic oil supplied from the hydraulic pump 115 to the traveling motor 122, the boom cylinder 117, the arm cylinder 118, and the attachment cylinder 119. The traveling motor 122 is driven by the hydraulic oil supplied from the hydraulic pump 115, and operates the traveling device 121.

[0020] The boom cylinder 117 is a hydraulic cylinder for operating the boom 161 relative to the upper rotating body 140. The arm cylinder 118 is a hydraulic cylinder for operating the arm 162 relative to the boom 161. The attachment cylinder 119 is a hydraulic cylinder for operating the attachment 163 relative to the arm 162.

[0021] <Electric motor> 3 is a cross-sectional view of an electric motor according to an embodiment. The following figures include an explanation of the flow of cooling oil according to an embodiment. Hereinafter, the cooling oil may be simply referred to as "oil."

[0022] In this embodiment, the electric motor 1 is a swivel motor 114. The electric motor 1 includes a rotor 2, a stator 3, a baffle plate 90, and a housing 4 having a space 40 for accommodating the rotor 2, the stator 3, and the baffle plate 90. The electric motor 1 is an inner rotor type motor in which the stator 3 is disposed outside the cylindrical rotor 2. The electric motor 1 is placed vertically so that the rotor shaft 20 of the rotor 2 is parallel to the swivel axis.

[0023] In this embodiment, the upper side corresponds to one side parallel to the central axis CL of the rotor shaft 20, and the lower side corresponds to the other side parallel to the central axis CL of the rotor shaft 20. Hereinafter, the direction along the central axis CL of the rotor shaft 20 is referred to as the "axial direction", the direction perpendicular to the axial direction is referred to as the "radial direction", and the direction going around the central axis CL of the rotor shaft 20 is referred to as the "circumferential direction".

[0024] The rotor 2 includes a rotor shaft 20, a rotor core 21, an upper plate 22, and a lower plate 23. The rotor shaft 20 is rotatably supported with respect to the housing 4 by bearings 21A and 21B.

[0025] The rotor core 21 is formed, for example, by laminating electromagnetic steel sheets in the axial direction. The rotor core 21 is fitted onto the rotor shaft 20. The rotor core 21 rotates integrally with the rotor shaft 20. A plurality of permanent magnets (not shown) are embedded in the rotor core 21.

[0026] Each of the upper plate 22 and the lower plate 23 is annular plate members arranged coaxially with the rotor shaft 20. The upper plate 22 and the lower plate 23 are fitted to the rotor shaft 20. The upper plate 22 and the lower plate 23 hold the rotor core 21 from the outside in the axial direction. The upper plate 22 and the lower plate 23 rotate integrally with the rotor shaft 20 and the rotor core 21.

[0027] The stator 3 is fixed to the inner surface of the housing 4 so as to cover the outer periphery of the rotor 2. The stator 3 includes a cylindrical stator core 30 and a stator coil 31. Like the rotor core 21, the stator core 30 is formed by laminating electromagnetic steel sheets in the axial direction. A plurality of teeth (not shown) are provided circumferentially on the inner periphery of the stator core 30. The stator coil 31 is wound around the teeth.

[0028] In the illustrated example, the stator coil 31 is a rectangular wire coil. In the case of a rectangular wire coil, the occupancy rate can be increased compared to the case of a round wire coil, which contributes to space saving. The stator coil 31 may be other than a rectangular wire coil (for example, a round wire coil, etc.). The form of the stator coil 31 is not limited to the above and can be changed according to the design specifications.

[0029] The baffle plate 90 is configured to be disposed below the stator 3. The baffle plate 90 forms a fluid reservoir 95 (hereinafter also referred to as a “first fluid reservoir 95”) for temporarily storing at least a portion of the cooling fluid flowing through the space 40. The baffle plate 90 is configured to guide at least a portion of the cooling fluid flowing through the space 40 to the stator coil 31.

[0030] The housing 4 includes a cylindrical body 10, a ceiling portion 11 that closes an upper opening of the cylinder 10, and a bottom portion 13 that closes a lower opening of the cylinder 10. A space 40 for accommodating the rotor 2, the stator 3, and the baffle plate 90 is formed inside the housing 4 by the cylinder 10, the ceiling portion 11, and the bottom portion 13.

[0031] The ceiling portion 11 is provided with a fluid supply passage 12 for introducing cooling fluid into the space 40. The bottom portion 13 is provided with a fluid reservoir 15 (hereinafter also referred to as "second fluid reservoir 15") different from the first fluid reservoir 95 for temporarily storing the cooling fluid flowing through the space 40 via the fluid supply passage 12. The second fluid reservoir 15 is formed below the baffle plate 90. The second fluid reservoir 15 is formed below the first fluid reservoir 95. The bottom portion 13 is provided with a fluid discharge passage 16 that communicates with the second fluid reservoir 15 and discharges the cooling fluid from the space 40.

[0032] The electric motor 1 includes a cooling circuit 5 through which a cooling fluid flows. The cooling circuit 5 includes a fluid supply passage 12, a first fluid reservoir 95, a second fluid reservoir 15, and a fluid discharge passage 16.

[0033] In this embodiment, cooling oil flows as a cooling fluid in the cooling circuit 5. The cooling circuit 5 is a circuit (hereinafter also referred to as a "cooling oil circuit") for directly cooling components such as the rotor 2 and the stator 3 housed in the space 40 with cooling oil. Note that the cooling fluid may be something other than cooling oil (for example, cooling water, etc.).

[0034] As shown in FIG. 3, the electric motor 1 is configured so that the cooling fluid discharged from the cooling fluid pump 8 flows into the space 40 via the second fluid supply passage 12. The electric motor 1 is configured so that the cooling fluid flowing in from the second fluid supply passage 12 flows into the second fluid reservoir 15 via a passage 53 formed in the rotor shaft 20, a groove 54 formed in the lower plate 23, a through passage 55 formed in the rotor core 21, and an ejection hole 56 formed in the upper plate 22. The electric motor 1 is configured so that at least a part of the cooling fluid that has passed through the ejection hole 56 flows into the first fluid reservoir 95. The electric motor 1 is configured so that the cooling fluid that has flowed into the first fluid reservoir 95 flows into the second fluid reservoir 15.

[0035] <Baffle plate> Fig. 4 is a perspective view of a baffle plate 90 according to an embodiment. Fig. 5 is an enlarged perspective view of a portion of the baffle plate 90 according to an embodiment. Fig. 6 is an explanatory diagram of the flow of a cooling fluid in the electric motor 1 according to an embodiment.

[0036] The baffle plate 90 guides at least a portion of the cooling fluid flowing along the inner surface of the cylinder 10 of the housing 4 toward the second fluid reservoir 15 to the lower portion 32 (hereinafter also referred to as the "lower coil end 32") of the stator coil 31. In a cross-sectional view including the central axis CL (cross-sectional view of FIG. 6), the baffle plate 90 is formed so as to follow at least the outer shape of the lower coil end 32. The baffle plate 90 is configured to be disposed between the cylinder 10 and the rotor 2 and spaced apart from the rotor 2.

[0037] 6, the baffle plate 90 includes a first extension portion 91 extending radially inward from the cylinder 10 along the lower surface of the stator coil 31, and a second extension portion 92 extending upward from a radially inner portion of the first extension portion 91. A first fluid reservoir 95 is formed by at least the first extension portion 91 and the second extension portion 92. The first fluid reservoir 95 may be formed by the cylinder 10, the first extension portion 91, and the second extension portion 92, or when the third extension portion 93 is annular, the first fluid reservoir 95 may be formed by the first extension portion 91, the second extension portion 92, and the third extension portion 93.

[0038] The first extension portion 91 is annular when viewed from the top-bottom direction. The first extension portion 91 is configured to be disposed above the liquid level 15A of the cooling fluid that accumulates in the second fluid reservoir 15. The first extension portion 91 is configured to be disposed below the lower surface of the stator coil 31. The first extension portion 91 is configured to be disposed between the lower surface of the stator coil 31 and the liquid level 15A.

[0039] In the illustrated example, the first extension portion 91 is separated from each of the lower surface of the stator coil 31 and the liquid level 15A. However, the first extension portion 91 is not limited to the above, and may be in contact with the lower surface of the stator coil 31 and / or the liquid level 15A. The arrangement of the first extension portion 91 can be changed according to design specifications.

[0040] The first extension portion 91 has a through hole 91h that opens in the up-down direction (see FIG. 5). In the example shown in the figure, only one through hole 91h is formed in the first extension portion 91. The through hole 91h is circular when viewed in the up-down direction. The through hole 91h is disposed in the radial center of the first extension portion 91. Note that the number of through holes 91h is not limited to the above, and multiple through holes 91h may be formed. The aspect (number, shape, arrangement, etc.) of the through holes 91h can be changed according to design specifications.

[0041] The second extension portion 92 extends upward from the inner peripheral edge of the first extension portion 91. The second extension portion 92 is annular when viewed in the up-down direction. The second extension portion 92 is configured to be disposed between the lower coil end 32 and the rotor 2. The second extension portion 92 is configured to be disposed between the lower coil end 32 and the lower plate 23 and spaced apart from the lower plate 23.

[0042] In the illustrated example, the second extension portion 92 is spaced apart from the radial inner end of the lower coil end 32. However, the second extension portion 92 is not limited to the above, and may be in contact with the radial inner end of the lower coil end 32. The arrangement of the second extension portion 92 can be changed according to design specifications.

[0043] The upper end of the second extension portion 92 is configured to be disposed above the lower surface of the stator coil 31. In the example shown in the figure, the upper end of the second extension portion 92 is configured to be disposed above the lower surface of the stator coil 31. The upper end of the second extension portion 92 is not limited to the above, and may be disposed below the lower surface of the stator coil 31. For example, it is sufficient that the upper end of the second extension portion 92 is separated from the lower plate 23. The arrangement of the upper end of the second extension portion 92 can be changed according to design specifications.

[0044] The baffle plate 90 further includes a third extension portion 93 extending upward from the radial outer portion of the first extension portion 91, and a fourth extension portion 94 extending radially outward from an upper portion of the third extension portion 93 along the underside of the stator core 30 of the stator 3.

[0045] The third extension portion 93 extends upward from the outer circumferential edge of the first extension portion 91. The third extension portions 93 are arranged at equal intervals in the circumferential direction of the first extension portion 91. In the example shown in the figure, six third extension portions 93 are arranged at equal intervals in the circumferential direction. The third extension portions 93 may be annular when viewed from the top-bottom direction. The aspect (number, arrangement, shape, etc.) of the third extension portions 93 is not limited to the above and can be changed according to design specifications.

[0046] The fourth extension portion 94 extends radially outward from the upper end of each of the multiple third extension portions 93. Each of the multiple fourth extension portions 94 has an insertion hole 94h that opens in the up-down direction. In the example shown in the figure, six fourth extension portions 94 are arranged at equal intervals in the circumferential direction. The fourth extension portion 94 may be annular when viewed from the up-down direction. The aspect (number, arrangement, shape, etc.) of the fourth extension portion 94 is not limited to the above and can be changed according to design specifications.

[0047] The fourth extending portion 94 is a portion that fits along the lower surface of the stator core 30. The fourth extending portion 94 is a portion that is sandwiched between a portion (seat surface) of the housing 4 to which the stator core 30 is attached and the lower surface of the stator core 30 (specifically, the lower surface of the outer periphery of the stator core 30).

[0048] A female thread is formed in the housing 4 at a portion where the stator core 30 is attached, into which a bolt is screwed. The stator core 30 has an insertion hole (not shown) through which the bolt is inserted. For example, with the fourth extension portion 94 sandwiched between the seat surface of the housing 4 and the lower surface of the stator core 30, a bolt is inserted through the insertion hole of the stator core 30 and the insertion hole 94h of the fourth extension portion 94, and screwed into the female thread of the housing 4. This allows the stator 3 and the baffle plate 90 to be fastened together to the housing 4.

[0049] <Flow of cooling fluid> 3 and 6, for example, cooling fluid supplied by cooling fluid pump 8 is sent to the inside of electric motor 1. Specifically, the cooling fluid supplied by cooling fluid pump 8 flows into fluid supply passage 12 from inlet 50. The cooling fluid that flows into fluid supply passage 12 is divided into passage 53 of rotor shaft 20 and a bearing cooling passage (not shown). The cooling fluid that flows into the bearing cooling passage flows out into the outer ring portion of upper bearing 21A to lubricate and cool bearing 21A.

[0050] Meanwhile, when the cooling fluid that has flowed into the passages 53 of the rotor shaft 20 flows to the lower end of the passages 53, it passes through the grooves 54 of the lower plate 23 and the through passages 55 of the rotor core 21 to cool the rotor 2. The cooling fluid that has passed through the through passages 55 is ejected from the ejection holes 56 of the upper plate 22 into the cylinder 10. The cooling fluid ejected into the cylinder 10 falls while cooling the stator core 30 and the stator coil 31, and lubricates and cools the lower bearing 21B.

[0051] When the electric motor 1 is a vertically mounted motor, part of the cooling fluid flows downward along the inner surface of the cylindrical body 10 of the housing 4. At least part of the cooling fluid flowing along the inner surface of the cylindrical body 10 of the housing 4 is guided by the baffle plate 90 and comes into contact with the lower coil ends 32 of the stator coil 31. The cooling fluid guided by the baffle plate 90 and / or the cooling fluid that accumulates in the first fluid reservoir 95 formed by the baffle plate 90 cools the lower coil ends 32. The cooling fluid that has passed through the baffle plate 90 flows down into the second fluid reservoir 15 (see the arrows shown in FIG. 6 ).

[0052] The cooling fluid that has flowed down into the second fluid reservoir 15 is discharged from a fluid discharge path 16. The cooling fluid discharged from the fluid discharge path 16 is sent by the cooling fluid pump 8 back into the electric motor 1.

[0053] <Action and effect> As described above, the electric motor 1 of this embodiment includes the housing 4 having the space 40 for accommodating the rotor 2 and the stator 3, and the first fluid reservoir 95 that is disposed in the space 40 of the housing 4 and is formed to guide at least a portion of the cooling fluid flowing through the space 40 to the lower coil end 32 of the stator coil 31 of the stator 3. For example, when an electric motor is placed vertically as shown in Fig. 7, part of the cooling fluid flows downward along the inner surface of the cylindrical housing. In this case, there is a high possibility that the cooling fluid flowing along the inner surface of the cylindrical housing will not reach the lower part of the stator coil (see the arrow in Fig. 7). In contrast, according to this embodiment, as shown in Fig. 6, a first fluid reservoir 95 is provided which is disposed in the space 40 and is formed to guide at least a portion of the cooling fluid flowing downward along the inner surface of the cylindrical body 10 of the housing 4 to the lower coil end 32 of the stator coil 31 of the stator 3. As a result, at least a portion of the cooling fluid flowing along the inner surface of the cylindrical body 10 of the housing 4 is guided by the first fluid reservoir 95 and hits the lower coil end 32 of the stator coil 31 (see the arrow in Fig. 6). This makes it possible to improve the cooling performance.

[0054] In this embodiment, a second fluid reservoir 15 different from the first fluid reservoir 95 is formed in the bottom 13 of the housing 4. The first fluid reservoir 95 is formed to guide at least a portion of the cooling fluid flowing toward the second fluid reservoir 15 to the lower coil end 32. With this configuration, at least a portion of the cooling fluid flowing toward the second fluid reservoir 15 is guided by the first fluid reservoir 95 and hits the lower coil end 32. This improves cooling performance.

[0055] In this embodiment, the electric motor 1 further includes a baffle plate 90. The baffle plate 90 forms a first fluid reservoir 95. According to this configuration, the first fluid reservoir 95 can be easily formed.

[0056] In this embodiment, the baffle plate 90 is formed so as to follow at least the outer shape of the lower coil end 32 in a cross-sectional view including the central axis CL of the housing 4. According to this configuration, at least a portion of the cooling fluid guided by the baffle plate 90 can be directed to hit at least the lower coil ends 32. Therefore, the cooling performance can be further improved.

[0057] In this embodiment, the housing 4 includes a cylindrical body 10. The baffle plate 90 is configured to be disposed between the cylindrical body 10 and the rotor 2 and spaced apart from the rotor 2. According to this configuration, it is possible to prevent the rotation of the rotor 2 from being hindered by the arrangement of the baffle plate 90.

[0058] In this embodiment, in cross-sectional view, the baffle plate 90 has a first extension portion 91 extending from the cylinder 10 radially inwardly perpendicular to the central axis CL along the underside of the stator coil 31, and a second extension portion 92 extending upwardly from the radially inner portion of the first extension portion 91. With this configuration, at least a portion of the cooling fluid flowing downward along the inner surface of the cylinder 10 of the housing 4 accumulates in the space formed by the cylinder 10, the first extension portion 91, and the second extension portion 92, and the accumulated cooling fluid can cool the lower coil end 32. This makes it possible to further improve cooling performance.

[0059] In the present embodiment, the upper end of the second extending portion 92 is configured to be disposed above the lower surface of the stator coil 31 . With this configuration, at least a portion of the lower coil end 32 can be immersed in the cooling fluid stored in the first fluid reservoir 95 formed by the cylindrical body 10, the first extension portion 91, and the second extension portion 92. This makes it possible to further improve cooling performance.

[0060] In this embodiment, the first extension portion 91 is configured to be disposed above the liquid level 15A of the cooling fluid that accumulates in the second fluid reservoir 15. For example, if the first extension portion 91 is disposed below the liquid level 15A of the cooling fluid that accumulates in the second fluid reservoir 15, there is a high possibility that the agitation loss of the cooling fluid will increase. In contrast, according to this embodiment, the first extension portion 91 is disposed above the liquid level 15A of the cooling fluid that accumulates in the second fluid reservoir 15, thereby making it possible to reduce the churning loss of the cooling fluid.

[0061] In this embodiment, the first extending portion 91 has a through hole 91h that opens in the up-down direction. According to this configuration, the cooling fluid can be discharged through the through-hole 91h formed in the first extending portion 91. For example, when the cooling fluid accumulates in the first fluid reservoir 95, the accumulated cooling fluid can be discarded through the through-hole 91h, thereby reducing the agitation loss of the cooling fluid.

[0062] In this embodiment, the baffle plate 90 further includes a third extension portion 93 extending upward from the radially outer portion of the first extension portion 91, and a fourth extension portion 94 extending radially outward from an upper portion of the third extension portion 93 along the underside of the stator core 30 of the stator 3. According to this configuration, the fourth extension portion 94 can be supported by the lower surface of the stator core 30, so that the baffle plate 90 can be stably held.

[0063] In this embodiment, the first extension portion 91 is annular when viewed in the up-down direction. The second extension portion 92 extends upward from the inner peripheral edge of the first extension portion 91. The third extension portion 93 extends upward from the outer peripheral edge of the first extension portion 91. The fourth extension portion 94 extends radially outward from the upper end of the third extension portion 93. The fourth extension portion 94 has an insertion hole 94h that opens in the up-down direction. According to this configuration, since the baffle plate 90 can be fixed with a fastening member such as a bolt through the insertion hole 94h of the fourth extension portion 94, the baffle plate 90 can be held more stably.

[0064] <Modification> In the above embodiment, an example has been described in which a first fluid reservoir constituting a cooling circuit is formed in the bottom of the housing, and the baffle plate guides at least a portion of the cooling fluid flowing toward the first fluid reservoir to the coil end, but this is not limited thereto. For example, the bottom of the housing may not have a fluid reservoir, and the work machine may be provided with an oil tank. For example, the baffle plate may guide at least a portion of the cooling fluid returning to the oil tank to the lower coil end. The manner in which the fluid reservoir is formed may be changed according to design specifications.

[0065] In the above embodiment, an example has been described in which the cooling circuit has a passage through which the cooling oil flows as a fluid, but this is not limited thereto. For example, the cooling circuit may include a passage through which a fluid other than the cooling oil flows. For example, the second fluid reservoir may include a portion in which a fluid other than the cooling oil accumulates. The configuration of the cooling circuit and the second fluid reservoir may be changed according to design specifications.

[0066] In the above embodiment, an example has been described in which the baffle plate is formed to follow at least the outer shape of the lower part of the stator coil in a cross section including the central axis of the housing, but this is not limited thereto. For example, the baffle plate may be formed to follow the outer shape of the outer part of the coil end in a cross section including the central axis of the housing. The form of the baffle plate can be changed according to design specifications.

[0067] In the above embodiment, the housing includes a cylindrical body, and the baffle plate is disposed between the cylinder and the rotor and spaced apart from the rotor, but the present invention is not limited to this. For example, the baffle plate may be configured to be disposed between the cylinder and the stator. For example, the baffle plate may be configured to be disposed near a lower coil end of the stator. For example, the baffle plate may extend from a part of the housing. The arrangement of the baffle plate may be changed according to design specifications.

[0068] In the above embodiment, an example has been described in which the baffle plate includes a first extension portion that extends from the cylinder toward the inside in the radial direction perpendicular to the central axis so as to follow the lower surface of the stator coil, and a second extension portion that extends upward from the inside part of the first extension portion in the radial direction, but this is not limited thereto. For example, the baffle plate may not include the second extension portion. For example, the baffle plate may extend radially inward from a part of the cylinder. The configuration of the baffle plate may be changed according to design specifications.

[0069] In the above embodiment, the upper end of the second extension portion is disposed above the lower surface of the stator coil, but this is not limited thereto. For example, the upper end of the second extension portion may be configured to be disposed below the lower surface of the stator coil. The arrangement of the upper end of the second extension portion can be changed according to the design specifications.

[0070] In the above embodiment, the first extension portion is disposed above the liquid level of the cooling fluid stored in the fluid reservoir, but the present invention is not limited to this. For example, the first extension portion may be configured to be disposed below the liquid level of the cooling fluid stored in the fluid reservoir. The arrangement of the first extension portion can be changed according to design specifications.

[0071] In the above embodiment, the first extension portion has a through hole that opens in the vertical direction, but this is not limited to the above. For example, the first extension portion may not have a through hole. The formation mode of the through hole can be changed according to the design specifications.

[0072] In the above embodiment, the baffle plate further includes a third extension portion extending upward from a radially outer portion of the first extension portion, and a fourth extension portion extending radially outward from an upper portion of the third extension portion so as to follow the lower surface of the stator core of the stator. However, the present invention is not limited to this. For example, the baffle plate may not include the third extension portion and / or the fourth extension portion. For example, the baffle plate may be supported by the cylindrical body by connecting the first extension portion and / or the third extension portion to the cylindrical body. The installation manner of the third extension portion and / or the fourth extension portion may be changed according to the design specifications.

[0073] In the above embodiment, the first extension portion is annular when viewed from the top-bottom direction, the second extension portion extends upward from the inner peripheral edge of the first extension portion, the third extension portion extends upward from the outer peripheral edge of the first extension portion and is arranged at equal intervals in the circumferential direction of the first extension portion, the fourth extension portion extends radially outward from the upper end of each of the third extension portions, and each of the fourth extension portions has an insertion hole that opens in the top-bottom direction. However, this is not limited to the above. For example, each of the fourth extension portions may not have an insertion hole. For example, the baffle plate may be fixed by a fastening member such as a bolt through an insertion hole formed in a part of the fourth extension portions. The formation mode of the insertion hole can be changed according to the design specifications.

[0074] In the above-described embodiment, the electric motor is mounted on an electric slewing shovel, and an electric slewing motor for rotating an upper rotating body of the electric slewing shovel has been described as an example, but the present invention is not limited thereto. For example, the electric motor may be mounted on other work vehicles such as a wheel loader, a bulldozer, or a dump truck. For example, the electric motor may be configured as a drive motor for driving a work machine or a drive motor for driving a traveling device. The aspect of the work machine on which the electric motor is mounted and the target driven by the electric motor can be changed according to the design specifications.

[0075] Although one embodiment has been described above with reference to the drawings, the specific configuration is not limited to the above, and addition, omission, substitution, and other modifications of the configuration are possible without departing from the spirit of this disclosure, and the above-mentioned embodiments can also be combined as appropriate. [Explanation of symbols]

[0076] REFERENCE SIGNS LIST 1...electric motor, 2...rotor, 3...stator, 4...housing, 5...cooling circuit (cooling oil circuit), 10...cylinder, 13...bottom, 15...second fluid reservoir, 15A...liquid level, 20...rotor shaft, 31...stator coil, 32...lower coil end, 40...space, 90...baffle plate, 91...first extension, 91h...through hole, 92...second extension, 93...third extension, 94...fourth extension, 94h...insertion hole, 95...first fluid reservoir, CL...central axis

Claims

1. a housing having a space for accommodating a rotor and a stator; a first fluid reservoir portion disposed in the space of the housing and formed to guide at least a portion of the fluid flowing through the space to a lower portion of a stator coil of the stator; Electric motor.

2. A second fluid reservoir different from the first fluid reservoir is formed in a bottom portion of the housing, The first fluid reservoir is formed to guide at least a portion of the fluid flowing toward the second fluid reservoir to a lower portion of the stator coil.

2. The electric motor of claim 1.

3. Further comprising a baffle plate, The baffle plate forms the first fluid reservoir.

2. The electric motor of claim 1.

4. In a cross-sectional view including a central axis of the housing, the baffle plate is formed to follow an outer shape of at least a lower portion of the stator coil.

4. The electric motor according to claim 3.

5. The housing comprises a cylindrical body, The baffle plate is configured to be disposed between the cylindrical body and the rotor and spaced apart from the rotor.

5. An electric motor according to claim 4.

6. In the cross-sectional view, the baffle plate has a first extension portion extending from the cylindrical body toward the inside in a radial direction perpendicular to the central axis so as to follow a lower surface of the stator coil; A second extension portion extending upward from the radially inner portion of the first extension portion.

6. An electric motor according to claim 5.

7. An upper end of the second extension portion is configured to be disposed above the lower surface of the stator coil.

7. An electric motor according to claim 6.

8. A second fluid reservoir different from the first fluid reservoir is formed in a bottom portion of the housing, The first extension portion is configured to be disposed above a liquid level of the fluid stored in the second fluid reservoir.

7. An electric motor according to claim 6.

9. The first extension portion has a through hole that opens in the vertical direction.

7. An electric motor according to claim 6.

10. The baffle plate is a third extension portion extending upward from the radially outer portion of the first extension portion; and a fourth extension portion extending from an upper portion of the third extension portion toward the outside in the radial direction so as to follow a lower surface of the stator core of the stator.

7. An electric motor according to claim 6.

11. The first extension portion is annular when viewed from the top-bottom direction, The second extension portion extends upward from an inner circumferential edge of the first extension portion, The third extension portion extends upward from an outer circumferential edge of the first extension portion, The fourth extension portion extends from an upper end of the third extension portion toward an outer side in the radial direction, The fourth extension portion has an insertion hole that opens in the vertical direction.

11. An electric motor according to claim 10.

12. A running body, An upper rotating body supported on the traveling body so as to be rotatable about a rotating shaft; an electric motor configured as a rotation motor for rotating the upper rotating body relative to the traveling body, The electric motor is a housing having a space for accommodating a rotor and a stator; a first fluid reservoir portion disposed in the space of the housing and formed to guide at least a portion of the fluid flowing through the space to a lower portion of a stator coil of the stator; Working machinery.

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