JP6163071B2 - Cooling structure of rotary motive - Google Patents

Description

  The present invention relates to a cooling structure for a rotary motive.

  A motor used in a hybrid vehicle or an electric vehicle (EV vehicle) rises in temperature as it is driven, and is cooled by flowing a fluid such as oil. For example, in Patent Document 1 below, in an electric motor including a cylindrical case that accommodates a rotor and a stator, the motor has a cooling space through which fluid can flow, and an outer surface facing the cooling space. A configuration in which a plurality of grooves (uneven portions) is formed is described.

JP 2010-206994 A

  However, when fluid (oil) is allowed to flow in the cooling space as described in Patent Document 1, the oil contacts both of the opposing wall surfaces (outer diameter surface and inner diameter surface) that constitute the cooling space, There is a problem that uneven flow occurs in the oil flow due to the influence of surface tension. More specifically, since the oil behaves so that the oil comes into contact with the outer diameter surface and the inner diameter surface of the cooling space to minimize the surface area, a drift occurs in the oil flow. In particular, recently, due to a demand for miniaturization of the motor, the gap in the cooling space is narrowed, and the oil is more likely to come into contact with both opposing wall surfaces that constitute the cooling space. For this reason, the problem of drift due to the surface tension of the oil has become more prominent.

  If a drift occurs in the flow of oil flowing in the cooling space, the oil is not supplied uniformly to the cooling space, and it becomes difficult to cool the motor uniformly. For this reason, the temperature distribution of the motor becomes non-uniform, which may cause problems such as overheating of the motor.

  The groove (uneven portion) described in Patent Document 1 is provided in order to increase the contact area of the fluid flowing in the cooling space and improve the cooling effect. Patent Document 1 drifts due to the surface tension of the oil. Is not assumed to occur. For this reason, with the technique described in Patent Document 1, it is difficult to suppress the drift due to the surface tension of the oil.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a surface tension of a fluid when a cooling fluid is caused to flow in a space between the main body of the rotary motive and the housing. It is an object of the present invention to provide a new and improved cooling structure for a rotating motive that can reliably suppress the drift generated by the influence of the above.

In order to solve the above problems, according to an aspect of the present invention, a rotary motion machine having an outer surface of the circular columnar, the rotation same and the rotational axis of the motive center axis has the rotary motive a cylindrical covering a housing having an inner surface, said configured the outer surface of the rotational movement machine and by the said inner surface of said housing, and a fluid passage for the cooling flow body having a first width in a radial direction of the central axis, wherein At least one of the outer surface and the inner surface of the fluid passage is provided with a groove extending in a direction orthogonal to the cooling fluid flowing through the fluid passage, and the groove is wider than the first width. There is provided a cooling structure for a rotary motive, in which the fluid passage is enlarged to a second width that is larger to form an air layer on the upstream side in the flow direction of the cooling fluid.

  According to the above configuration, the enlarged portion is provided so as to extend in the direction of the rotation axis, and the width of the space of the fluid passage is enlarged upward by the enlarged portion relative to the upstream side in the fluid flow direction. As a result, an air layer is formed on the upper side of the fluid, the fluid does not stick to the upper wall surface, and the influence of the surface tension can be suppressed. Therefore, it is possible to reliably suppress the drift of the fluid in the fluid passage.

Further, the groove may also be the ash is provided on the inner surface of the housing.

Further, the groove may also be the ash is provided on the outer surface of the rotary motion machine.

Further, a supply pipe for supplying fluid to the fluid passage may be provided, and the groove may be provided below a portion where the supply pipe and the fluid passage are connected.

  As described above, according to the present invention, when a cooling fluid is allowed to flow through the space between the main body of the rotary motive and the housing, it is possible to reliably suppress the drift generated by the surface tension of the fluid.

It is a perspective view which shows the structure of the rotary motive which concerns on one Embodiment of this invention, and its periphery. It is a schematic diagram which shows the cross section along the direction orthogonal to a rotating shaft in the position of arbitrary one oil distribution piping. It is a schematic diagram which shows a mode that oil flows into the surface of a main body, when a groove | channel is provided in the inner surface of the housing. It is a schematic diagram which shows the example which provided the groove | channel on the main body side. It is sectional drawing which shows the example which does not provide the groove | channel as a comparative example of FIG. It is sectional drawing which shows the example which does not provide the groove | channel as a comparative example of FIG. In the comparative example of FIG.5 and FIG.6, when oil is supplied to space from oil distribution piping, it is a schematic diagram which shows a mode that oil drifts.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

[1. Configuration example of rotating motives]
First, with reference to FIG. 1, the structure of the rotary motive 100 which concerns on one Embodiment of this invention, and its periphery is demonstrated. FIG. 1 is a perspective view showing a configuration of a rotary motive 100 and its surroundings. The rotary motive 100 is used for an electric vehicle, a hybrid vehicle, etc. as an example, and has a function as an electric motor (motor) driven by electric power. The rotating motive 100 also has a function as a generator in which the rotating shaft 112 is driven by the driving wheels of the vehicle and generates power by the driving force of the driving wheels.

  The rotary motive 100 includes a main body 110 having a columnar outer surface 114 and a housing 120 having a cylindrical inner surface 122, and the main body 110 is covered with the housing 120. The main body 110 includes a rotating shaft 112 that rotates by receiving power. The rotation shaft 112 protrudes outside the housing 120.

  The central axis of the cylindrical housing 120 and the central axis of the columnar main body 110 coincide with each other, and the radial width between the inner diameter of the housing 120 and the outer diameter of the main body 110 is about several millimeters. A narrow space 130 is provided. The space 130 constitutes an oil passage (fluid passage) inside the housing 120.

  An oil supply unit 140 that supplies oil to the space 130 is provided on the upper portion of the housing 120. The oil supply unit 140 is supplied with cooling oil from an oil pipe 150 connected upward. A plurality of oil supply pipes 160 are connected to the lower portion of the oil supply unit 140 along the direction of the rotation shaft 112 of the main body 110. The oil supply pipe 160 is connected to the space 130 inside the housing 120.

  With such a configuration, the oil supplied from the oil pipe 150 to the oil supply section 140 by free fall is distributed in the oil supply section 140 in the direction in which the rotating shaft 112 extends, and the oil supply pipe 160 in the space 130 is distributed. Supplied to. In this embodiment, oil is exemplified as the cooling fluid, but other fluids such as water may be used.

  The oil supplied into the space 130 flows downward along the space 130 and flows from the oil discharge pipe 170 connected to the lowermost part of the space 130 to the oil pan 180. Therefore, the main body 110 of the rotary motive 100 is cooled by the oil flowing on the surface, and overheating of the main body 110 is suppressed. The oil accumulated in the oil pan 180 is returned to the oil pipe 150 by driving the pump 190. In addition, although illustration is abbreviate | omitted in FIG. 1, oil is supplied also to the transmission to which the rotating shaft 112 was connected, and the transmission is lubricated with oil.

[2. Example of oil passage configuration]
FIG. 2 is a schematic diagram showing a cross section along the direction orthogonal to the rotation axis 112 at the position of any one oil supply pipe 160. FIG. 2 shows a quarter region at the upper right of the cross section. As shown in FIG. 2, the inner surface 122 of the housing 120 is a cylindrical surface, and a space 130 is formed by providing a predetermined gap with the outer surface 114 of the main body 110. Note that the radial width of the gap formed by the space 130 is, for example, about 2 to 3 mm. The oil supplied to the space 130 from the oil supply pipe 160 flows along the outer surface 114 of the main body 110 and the inner surface 122 of the housing 120 in the direction of arrow A in FIG.

  As shown in FIG. 2, a groove 124 is provided on the inner surface 122 of the housing 120 on the upper side. The width of the space 130 is expanded upward by the groove 124, and the groove 124 functions as an expansion portion that expands the width of the space 130 above the upstream side in the oil flow direction. The groove 124 is also provided at a position symmetrical with respect to the center line C in the vertical direction in FIG. The groove 124 is provided at a position relatively close to the oil supply pipe 160 and extends in the direction along the rotation shaft 112. In FIG. 2, the width of the space 130 is expanded to the upper side of the upstream side in the oil flow direction only in the groove 124, but in the entire region downstream of the position where the groove 124 is formed, The width may be increased above the upstream side in the oil flow direction.

  The oil supplied from the plurality of oil supply pipes 160 to the space 130 is dispersed along the direction of the rotation shaft 112 and flows from the top to the bottom along the outer surface 114 of the main body 110 by gravity. As shown in FIG. 2, the oil is in contact with both the outer surface 114 of the main body 110 and the inner surface 122 of the housing 120 until the oil reaches the groove 124. For this reason, the oil flow is affected by the surface tension.

  On the other hand, when the oil reaches the position of the groove 124, the diameter of the inner surface 122 is expanded by the groove 124, and the radial width of the space 130 is expanded, so that an air layer is formed so that the oil does not contact the housing 120. become. Thereby, the influence of the surface tension of the oil is alleviated, and the oil contacts only the outer surface 114 of the main body 110 downstream of the groove 124. Accordingly, since the oil is separated from the inner surface 122 of the housing 120, the influence of the surface tension is eliminated, and the oil flows smoothly. Thus, by providing the groove 124 on the inner surface 122 of the housing 120, the surface tension of the oil can be controlled, and it is possible to reliably prevent the oil from drifting in the space 130. The oil can flow uniformly over the entire outer surface 114 of the main body 110.

[3. Oil flow in oil passage]
FIG. 3 is a schematic diagram illustrating a state (simulation result) that oil flows on the outer surface 114 of the main body 110 when the groove 124 is provided on the inner surface 122 of the housing 120. In FIG. 3, the housing 120 is not shown for convenience of explanation. Moreover, in FIG. 3, the black-painted part has shown the area | region where the oil is flowing. As shown in FIG. 3, since the influence of the surface tension of the oil can be suppressed by providing the groove 124, the oil spreads in the direction of the rotating shaft 112, and the oil flows uniformly over the entire outer surface 114 of the main body 110. It becomes possible. Thereby, it becomes possible to make the temperature distribution of the main body 110 uniform, and it can suppress reliably that the main body 110 overheats locally.

  Further, by eliminating the influence of the surface tension, it is possible to control the oil flow with higher accuracy, such as partially cooling the high temperature region of the main body 110. Therefore, it is possible to flow oil to a desired site by appropriately setting the flow path.

  As shown in FIG. 3, ribs 116 are provided at both ends in the axial direction of the main body 110, and the oil is supplied in the axial direction of the main body 110 by contacting the outer periphery of the rib 116 and the inner surface 122 of the housing 120. It is configured not to reach the end face 118.

  As described above, by providing the groove 124 above the oil in the gravity direction, an air layer can be formed between the oil and the housing 120, so that the oil does not contact the inner surface 122 of the housing 120. can do. When the oil drifts near the oil discharge pipe 170, a groove is provided on the main body 110 side which is the upper side in the gravity direction with respect to the oil. FIG. 4 is a schematic view showing an example in which the groove 119 is provided on the main body 110 side, and shows a cross section along the direction orthogonal to the rotation shaft 112 at the position of the oil discharge pipe 170. As shown in FIG. 4, by providing a groove 119 on the main body 110 side, an air layer can be formed between the oil and the main body 110, so that the oil does not contact the outer surface 114 of the main body 110. it can. Thereby, even in the vicinity of the oil discharge pipe 170, it is possible to suppress the influence of the surface tension and suppress the occurrence of drift.

  5 and 6 are cross-sectional views showing an example in which the groove 124 is not provided as a comparative example of FIG. FIG. 5 shows a relatively early stage in which oil has started to flow from the oil supply pipe 160, and FIG. 6 shows a state where the oil has flowed to the lower part of the main body 110. As shown in FIGS. 5 and 6, when the groove 124 is not provided, the oil contacts both the outer surface 114 of the main body 110 and the inner surface 122 of the housing 120, and the influence of the surface tension becomes large. For this reason, the oil is stuck to both the outer surface 114 of the main body 110 and the inner surface 122 of the housing 120, and the oil behaves so that the surface area is minimized by the surface tension. In particular, the narrower the width in the radial direction of the space 130, the more easily the oil sticks to both the outer surface 114 and the inner surface 122, and the influence of surface tension increases.

  FIG. 7 shows a state in which oil drifts when the oil is supplied from the oil supply pipe 160 to the space 130 (simulation result) in the comparative example of FIGS. 5 and 6 until 2.0 seconds after the start of oil supply. It is the schematic diagram shown in time series. Also in FIG. 7, illustration of the housing 120 is omitted as in FIG. Further, as in FIG. 3, in FIG. 7, the black portions indicate the regions where oil flows. When the oil flows in contact with both the outer surface 114 of the main body 110 and the inner surface 122 of the housing 120, as shown in FIG. 7, the oil behaves so as to minimize the surface area. It becomes difficult to flow oil uniformly over the entire outer surface 114 of 110. For this reason, the temperature distribution of the main body 110 becomes uneven, and the main body 110 cannot be efficiently cooled with oil.

  In the example shown in FIG. 7, after 1.0 seconds from the start of oil supply, the oil flows in a biased region in a region on the right side of the alternate long and short dash line I-I ′ shown in the drawing. For this reason, in particular, the region on the left side of the main body 110 with respect to the dashed line I-I ′ cannot be sufficiently cooled.

  As described above, it can be seen that when oil flows in a state where the oil is in contact with both the outer surface 114 of the main body 110 and the inner surface 122 of the housing 120, a drift occurs due to the influence of the surface tension. For this reason, by providing the groove 124 in the housing 120 so that the oil does not contact the inner surface 122 of the housing 120, the influence of the surface tension can be minimized. Therefore, as shown in FIG. 3, the oil can be made to flow uniformly over the entire outer surface 114 of the main body 110. Thereby, the temperature distribution of the main body 110 becomes uniform, and the cooling effect of the main body 110 by oil can be greatly improved.

  As described above, according to the present embodiment, the space 130 between the outer surface 114 of the main body 110 and the inner surface 122 of the housing 120 is provided with the groove 124 that expands the width of the space 130 upward. The inner surface 122 of the housing 120 can be prevented from contacting. Thereby, the influence of the surface tension of oil can be suppressed and it can suppress reliably that oil drifts. Therefore, the temperature distribution of the main body 110 can be made uniform, and the cooling effect by the oil can be greatly enhanced.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above embodiment, the groove 124 that increases the width of the space 130 upward is provided in the space 130 between the outer surface 114 of the main body 110 and the inner surface 122 of the housing 120. However, the present invention is not limited to such an example. . For example, in FIG. 2, a groove that expands the width of the space 130 may be provided in the downward direction by providing a groove on the main body 110 side, and an air layer may be formed between the oil and the inner surface 122 of the housing 120.

DESCRIPTION OF SYMBOLS 100 Rotation motive 110 Main body 112 Rotating shaft 114 Outer surface 119 Groove 120 Housing 122 Inner surface 124 Groove 130 Space

Claims (4)

A rotational movement machine having a circular columnar outer surface,
A housing having a cylindrical inner surface the same central axis and rotation axis covering has the rotational movement machine of the rotary motive,
The constructed the outer surface of the rotational movement machine and by the said inner surface of said housing, and a fluid passage for the cooling flow body radially having a first width of said central axis,
At least one of the outer surface and the inner surface of the fluid passage is provided with a groove extending in a direction orthogonal to the cooling fluid flowing through the fluid passage, and the groove has the first width. A structure for cooling a rotary motive , wherein the fluid passage is enlarged to a second width larger than the air passage to form an air layer on the upstream side in the flow direction of the cooling fluid.   The cooling structure for a rotary motive according to claim 1, wherein the groove is provided in the inner surface of the housing.   The cooling structure for a rotary motive according to claim 1, wherein the groove is provided on the outer surface of the rotary motive.   A supply pipe for supplying fluid to the fluid passage;
  2. The cooling structure for a rotary motive according to claim 1, wherein the groove is provided below a portion where the supply pipe and the fluid passage are connected.