WO2021079557A1

WO2021079557A1 - Coolant passage way structure for motor

Info

Publication number: WO2021079557A1
Application number: PCT/JP2020/024056
Authority: WO
Inventors: 泰我瀬谷
Original assignee: 株式会社明電舎
Priority date: 2019-10-23
Filing date: 2020-06-19
Publication date: 2021-04-29
Also published as: JP7053554B2; CN114586262A; CN114586262B; JP2021069179A

Abstract

A coolant passage way structure for a motor according to the present invention has a coolant passage way (7) formed so as to axially penetrate a vertically upper-side end thereof. The distance (R) from a rotation center (central axis line Z) of a rotary shaft (4) to a vertically upper-side wall surface (7a) of the coolant passage way (7) gradually increases toward one end side in the axial direction. Thus, it becomes possible to cause air included in the coolant to move to one end side in the axial direction along the vertically upper-side wall surface (7a) of the coolant passage way (7), and to be accumulated at one end of the coolant passage way (7) in the axial direction closer to a discharge port (14). Accordingly, with the air included in the coolant accumulating at one end in the axial direction where cooling water flows at a higher speed, it is possible to efficiently discharge the air included in the coolant from the discharge port (14) when the cooling water is discharged.

Description

Motor coolant passage structure

The present invention relates to a coolant passage structure of a motor.

For example, as a coolant passage structure of a conventional motor, those described in the following patent documents are known.

That is, in the conventional coolant passage structure of the motor, a coolant passage through which the coolant flows is provided inside the housing that houses the motor element. The coolant passage is formed so that the outer diameter is constant, and the wall surface on the upper side in the vertical direction opposite to the direction of gravity is formed horizontally along the rotation axis of the motor.

Japanese Patent No. 6106873

However, in the coolant passage structure of the conventional motor, the wall surface on the upper side in the vertical direction of the coolant passage is formed horizontally. Therefore, when the coolant contains air (air bubbles), the air stays along the wall surface on the upper side in the vertical direction of the coolant passage. As a result, when the discharge port of the coolant passage is formed with an opening in a direction other than the upper side in the vertical direction, it is difficult to sufficiently discharge the air from the discharge port.

The present invention has been devised focusing on such a technical problem, and an object of the present invention is to provide a coolant passage structure for a motor capable of efficiently discharging air contained in a coolant. ..

As one aspect of the present invention, a motor element for rotationally driving a rotating shaft, a tubular housing provided on the outer peripheral side of the motor element and accommodating the motor element, and a tubular housing provided inside the housing for cooling. It is a coolant passage structure of a motor provided with a coolant passage through which liquid flows, and the coolant passage is along the axial direction of the rotation axis at least at the upper end in the vertical direction of the housing. It is formed through, and the distance from the rotation center of the rotating shaft to the upper wall surface of the coolant passage in the vertical direction is gradually expanded toward one end side in the axial direction, and the coolant in the coolant passage is formed. , It is discharged from a discharge port provided on one end side in the axial direction of the coolant passage.

As described above, in the coolant passage structure of the motor according to the present invention, the coolant passage is formed through the upper end in the vertical direction along the axial direction, and is vertically above the coolant passage from the rotation center of the rotation shaft. The distance to the wall surface of the wall surface is formed so as to gradually increase toward one end side in the axial direction. As a result, the air contained in the coolant can be moved to one end side in the axial direction along the vertical upper wall surface of the coolant passage, and is provided on one end side in the axial direction of the coolant passage. It can be efficiently discharged from the outlet.

Further, as another aspect of the coolant passage structure of the motor, it is desirable that the wall surface on the upper side of the coolant passage in the vertical direction is formed so as to be inclined upward toward one end side in the axial direction.

In this way, the wall surface on the upper side in the vertical direction of the coolant passage is formed in an ascending slope toward one end side in the axial direction, so that the air contained in the coolant is formed along the ascending wall surface. Can be smoothly transported to the discharge port on one end side in the axial direction. As a result, the air contained in the coolant is efficiently discharged.

Further, as yet another aspect of the coolant passage structure of the motor, it is desirable that the coolant passage is formed in an annular shape around the rotation shaft.

As described above, since the coolant passage is formed in an annular shape around the rotation axis, the coolant passage can be easily formed by casting using a cylindrical core. Furthermore, since the coolant passage is formed in an annular shape around the rotation axis, the cooling performance of the motor is improved by ensuring uniform cooling around the entire circumference of the motor and ensuring a larger volume of the coolant passage. Can be done.

Further, as yet another aspect of the coolant passage structure of the motor, it is desirable that the discharge port is formed with an opening in a direction other than the upper side in the vertical direction.

When the coolant passage is formed horizontally along the axial direction as in the conventional case, the air contained in the coolant stays in the axial direction along the wall surface on the upper side in the vertical direction of the coolant passage. become. Therefore, when the discharge port is open in a direction other than the upper side in the vertical direction, it is difficult to efficiently discharge the air contained in the coolant.

On the other hand, in the present invention, as described above, the air contained in the coolant is collected at one end side in the axial direction of the coolant passage along the upper wall surface in the vertical direction. Therefore, even when the discharge port is open in a direction other than the upper side in the vertical direction, air can be efficiently discharged as the coolant is discharged.

Further, as yet another aspect of the coolant passage structure of the motor, it is desirable that a part of the passage cross-sectional area of the coolant passage is reduced at the upper end in the vertical direction.

In this way, by reducing the cross-sectional area of a part of the coolant passage, it is possible to increase the flow velocity of the coolant toward the discharge port. As a result, the air contained in the coolant can be discharged more efficiently.

Further, as yet another aspect of the coolant passage structure of the motor, a wall portion extending in the radial direction of the rotation shaft from the rotation center of the rotation shaft toward the upper wall surface in the vertical direction in the middle of the coolant passage. Is provided, and it is desirable that the wall portion of the coolant passage reduces the cross-sectional area of a part of the passage at the upper end in the vertical direction.

In this way, when the passage cross-sectional area of the coolant passage is reduced by the wall portion, the flow velocity of the coolant can be adjusted by adjusting the extension amount of the wall portion. That is, the discharge property of the air contained in the coolant can be easily adjusted, and the air can be efficiently discharged.

According to the present invention, the air contained in the coolant can be moved to one end side in the axial direction along the wall surface on the upper side in the vertical direction of the coolant passage. As a result, the air contained in the coolant can be efficiently discharged from the discharge port provided on one end side in the axial direction.

It is a perspective view of the motor provided for the description of the coolant passage structure of the motor which concerns on this invention. It is a top view of the motor seen from the A direction of FIG. It is a vertical sectional view of the motor which shows 1st Embodiment of this invention and corresponds to the cross section of line BB of FIG. The core used for forming the coolant passage shown in FIG. 3 is shown, (a) is a perspective view, and (b) is a sectional view taken along line CC of FIG. 3 (a). It is a perspective view of the motor provided to explain the operation of the coolant passage structure of the motor which concerns on this invention, and (a) is the figure which showed the state which the air contained in the coolant stayed in the coolant passage, (a). b) is a diagram showing a state in which air is discharged from the coolant passage as the coolant is discharged. It is a perspective view of a motor provided for the explanation of the coolant passage structure of a conventional motor, (a) is a view showing the state in which the air contained in the coolant stays in the coolant passage, and (b) is the cooling. It is the figure which showed the state which the air remained in the coolant passage even if the liquid was discharged. It is a vertical sectional view of the motor which shows the 2nd embodiment of this invention and corresponds to FIG.

Hereinafter, embodiments of the coolant passage structure of the motor according to the present invention will be described in detail with reference to the drawings. In the following embodiment, the coolant passage structure of the motor according to the present invention is applied to the cooling structure of the water-cooled motor as in the conventional case.

[First Embodiment]
1 to 4 show a first embodiment of the coolant passage structure of the motor according to the present embodiment. FIG. 1 shows a perspective view of the motor M when the motor M is viewed from diagonally above. FIG. 2 shows a plan view of the motor M as viewed from the direction A shown in FIG. FIG. 3 shows a first embodiment of the present invention, and shows a vertical cross-sectional view of the motor M cut along the line BB shown in FIG. 4A and 4B show a core 8 used for forming the coolant passage 7 shown in FIG. 3, FIG. 4A is a perspective view, and FIG. 4B is a cross-sectional view taken along the line CC of FIG. 4A. Is shown. In the description of each figure, the direction parallel to the central axis Z of the rotation axis 4 of the motor M is the "axial direction", the direction orthogonal to the central axis Z is the "radial direction", and the direction around the central axis Z is "axial direction". It will be described as "circumferential direction".

(Motor configuration)
As shown in FIGS. 1 to 4, the motor M according to the present embodiment includes a tubular metal housing 1, a stator 2 housed and held inside the housing 1, and a stator 2. It includes a rotor 3 that is rotatably arranged inside a minute gap G, and a rotating shaft 4 that is press-fitted and fixed inside the rotor 3 and rotates integrally with the rotor 3. The stator 2 and the rotor 3 constitute a motor element according to the present invention.

The housing 1 is formed by casting a metal material, for example, an aluminum alloy, and has a bottomed cylindrical shape in which one end side in the axial direction is open and the other end side is closed. The bottom wall 12 and the bottom wall 12 are integrally formed. The opening on one end side of the housing 1 is closed by a disc-shaped cover plate 5. That is, the housing 1 and the cover plate 5 define a motor accommodating portion 10 for accommodating the stator 2 and the rotor 3 inside.

Further, in the central portion of the bottom wall 12 of the housing 1, a first shaft insertion hole 12a through which the tip portion 4a of the rotating shaft 4 facing the outside penetrates is formed through, and the inner peripheral side of the first shaft insertion hole 12a is formed. Is provided with a first bearing 61 that rotatably supports the tip portion 4a side of the rotating shaft 4. Similarly, a second shaft insertion hole 5a through which the base end portion 4b of the rotary shaft 4 penetrates is formed through the central portion of the cover plate 5, and the rotary shaft is formed on the inner peripheral side of the second shaft insertion hole 5a. A second bearing 62 that rotatably supports the base end portion 4b of 4 is provided.

Further, inside the housing 1, a coolant passage 7 through which a coolant (for example, cooling water) used for cooling the motor M (stator 2) passes is formed. The coolant passage 7 is formed by a so-called collapsible core 8 formed in a substantially cylindrical shape having a conical tapered surface 80a on the outer peripheral side as shown in FIG. 4 when the housing 1 is cast. To. The core 8 includes a cylindrical core body 80, an introduction port forming portion 81 projecting substantially along the tangential direction on the outer peripheral side of the axial end of the core body 80 on the small diameter side, and a core. It has a discharge port forming portion 82 projecting along the axial direction from the axial end surface of the main body 80 on the large diameter side. Further, the core body 80 has a conical tapered surface 80a on the outer peripheral side and a horizontal plane 80b along the axial direction on the inner peripheral side. Then, when the housing 1 is cast, the core body 80 forms the coolant passage 7, the introduction port forming portion 81 forms the introduction port 13, and the discharge port forming portion 82 forms the discharge port 14.

That is, the coolant passage 7 is formed with the above-mentioned core 8 in a continuous annular shape along the circumferential direction, and extends over almost the entire axial direction, so that the rotation center (central axis) of the rotation axis 4 is formed. The distance R from Z) to the outer peripheral side wall surface (for example, the upper wall surface 7a in the vertical direction) is formed so as to gradually increase toward one end side (cover plate 5 side) in the axial direction. More specifically, the coolant passage 7 is formed in a conical taper shape in which the upper wall surface 7a in the vertical direction is inclined upward toward one end side (cover plate 5 side) in the axial direction, and is formed on the inner peripheral side. The wall surface 7b of the above is formed horizontally along the axial direction.

In the present embodiment, an embodiment in which the wall surface 7a on the upper side of the coolant passage 7 in the vertical direction is formed in a substantially conical taper shape is illustrated, but the coolant passage structure of the motor according to the present invention is limited to this embodiment. It is not something that is done. That is, the coolant passage structure of the motor according to the present invention may be formed so that the distance R to the upper wall surface 7a in the vertical direction gradually increases toward one end side in the axial direction. For example, the upper wall surface in the vertical direction. Various aspects are included, such as the 7a being formed in a curved shape having a convex or concave arc shape in the vertical cross section toward one end side in the axial direction.

Further, the peripheral wall 11 on the other end side (bottom wall 12 side) in the axial direction of the housing 1 extends tangentially along the vertical direction and is aligned with the rotation center (central axis Z) of the rotation shaft 4 in the vertical direction. Cylindrical introduction ports 13 connected to the coolant passage 7 at overlapping positions are formed so as to project. That is, the coolant is introduced into the coolant passage 7 from the outside of the housing 1 through the introduction port 13. In the present embodiment, the introduction port 13 is opened in the tangential direction with respect to the peripheral wall of the housing 1, but the opening direction of the introduction port 13 is, for example, the axial direction in addition to the tangential direction. Alternatively, it can be freely changed according to the layout of the coolant passage 7 such as the radial direction.

On the other hand, the cover plate 5 has a cylindrical discharge port 14 connected to the coolant passage 7 at a position overlapping the rotation center (center axis Z) of the rotation shaft 4 in the vertical direction and extending along the axial direction. , Protruding is formed. That is, the coolant flowing through the coolant passage 7 is discharged to the outside of the housing 1 through the discharge port 14. In the present embodiment, the discharge port 14 is opened in the axial direction in the cover plate 5 corresponding to the axial end portion of the housing 1, but in the coolant passage structure of the motor according to the present invention, the discharge port 14 is discharged. The outlet 14 may be opened in a direction other than the upper side in the vertical direction, and the opening direction of the discharge port 14 can be freely changed according to the layout of the coolant passage 7, such as the axial direction or the radial direction. is there.

(Action and effect of this embodiment)
FIG. 5 is a perspective view of the motor M used to explain the operation of the coolant passage structure of the motor M according to the present embodiment, and FIG. 5A is a perspective view of the motor M in which air contained in the coolant stays in the coolant passage. A diagram showing the state, (b) shows a diagram showing a state in which air is discharged from the coolant passage as the coolant is discharged. FIG. 6 is a perspective view of the motor used to explain the coolant passage structure of the conventional motor, and FIG. 6A is a view showing a state in which air contained in the coolant stays in the coolant passage. (B) shows a diagram showing a state in which air remains in the coolant passage even when the coolant is discharged. For convenience of explanation, in each figure, the coolant passage 7, the introduction port 13, and the discharge port 14 are shown by solid lines, and the housing 1, the rotating shaft 4, and the cover plate 5 are shown by virtual lines of two-dot chain lines. Further, in the description of each figure, the direction parallel to the central axis Z of the rotation axis 4 of the motor M is the "axial direction", the direction orthogonal to the central axis Z is the "diameter direction", and the direction around the central axis Z is the "circumferential direction". It will be explained as "direction".

As shown in FIG. 6, in the coolant passage structure of the conventional motor, the wall surface 7a on the upper side of the coolant passage 7 in the vertical direction is formed horizontally along the axial direction. Therefore, as shown in FIG. 6A, the air A contained in the coolant stays so as to extend in the axial direction along the wall surface 7a on the upper side in the vertical direction of the coolant passage 7. In this case, when the coolant is discharged from the discharge port 14, as shown in FIG. 6B, the coolant on the side closer to the discharge port 14 indicated by the arrow N has a high flow velocity, and the discharge port 14 indicated by the arrow F has a high flow velocity. As a result of the slow flow of the coolant on the side far from the air A, the air A gathers along the arrow X on the other end side (bottom wall 12 side) in the axial direction where the flow rate of the cooling water is slow, and is not discharged from the discharge port 14. There was a problem that it remained in the coolant. Then, the portion where the air A remains cannot contribute to the cooling of the motor M, and there is a possibility that the cooling efficiency of the motor M may decrease.

On the other hand, in the coolant passage structure of the motor according to the present embodiment, as shown in FIG. 5, the coolant passage 7 is formed through the upper end in the vertical direction along the axial direction, and the rotating shaft 4 is formed. The distance R from the center of rotation (central axis Z) to the wall surface 7a on the upper side in the vertical direction of the coolant passage 7 is gradually expanded toward one end side in the axial direction. Therefore, the air A contained in the coolant is moved to one end side in the axial direction along the vertical upper wall surface 7a of the coolant passage 7, and is in the axial direction of the coolant passage 7 close to the discharge port 14. It becomes possible to collect at one end. In this way, the air A contained in the coolant is concentrated at one end in the axial direction in which the flow velocity of the cooling water is high, and the air A is included in the coolant along the arrow E with the discharge of the cooling water with this high flow velocity. The exhausted air A can be efficiently discharged from the discharge port 14. As a result, the retention of air A in the coolant in the coolant passage 7 is suppressed, and the cooling efficiency of the motor M can be improved.

Further, in the present embodiment, the wall surface 7a on the upper side in the vertical direction of the coolant passage 7 is formed so as to be inclined upward toward one end side in the axial direction.

As a result, the air A contained in the coolant can be smoothly carried to the discharge port 14 on one end side in the axial direction along the wall surface 7a on the upper side in the vertical direction formed in the upward inclination, and the cooling can be performed. It is used for efficient discharge of air A contained in the liquid.

Further, in the present embodiment, the coolant passage 7 is formed in an annular shape around the rotating shaft 4.

This has the advantage that the coolant passage 7 can be easily formed by casting using the cylindrical core 8. Further, since the coolant passage 7 is formed in an annular shape around the rotating shaft 4, uniform cooling can be achieved over the entire circumference of the motor M, and a larger volume of the coolant passage 7 is secured, so that the motor M can be cooled more uniformly. Cooling performance can be improved.

Further, in the present embodiment, the discharge port 14 is formed with an opening in a direction other than the upper side in the vertical direction. Specifically, the discharge port 14 is formed with an opening in the cover plate 5 along the axial direction.

When the coolant passage 7 is formed horizontally along the axial direction as in the conventional case, the air A contained in the coolant is axially along the vertical upper wall surface 7a of the coolant passage 7. Will stay in. Therefore, when the discharge port 14 is open in a direction other than the upper side in the vertical direction, it is difficult to efficiently discharge the air A contained in the coolant.

On the other hand, in the present embodiment, as described above, the air A contained in the coolant is collected at one end side in the axial direction of the coolant passage 7 along the wall surface 7a on the upper side in the vertical direction. Therefore, when the discharge port 14 is opened in a direction other than the upper side in the vertical direction, for example, even when the cover plate 5 is formed along the axial direction as in the present embodiment, air is discharged as the coolant is discharged. A can be discharged efficiently.

[Second Embodiment]
FIG. 7 shows a second embodiment of the coolant passage structure of the motor according to the present invention, and this embodiment is a modification of the configuration of the coolant passage 7 in the first embodiment. The basic configuration other than such changes is the same as that of the first embodiment. Therefore, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Further, in the description of FIG. 7, the direction parallel to the central axis Z of the rotation axis 4 of the motor M is the "axial direction", the direction orthogonal to the central axis Z is the "diameter direction", and the direction around the central axis Z is "axial direction". It will be described as "circumferential direction".

As shown in FIG. 7, in the coolant passage structure of the motor according to the present embodiment, a plurality of motor coolant passage structures extending along the radial direction on the inner peripheral wall surface 7b of the coolant passage 7 in the housing 1 (three in the present embodiment). ) Are integrally formed at substantially equal intervals in the axial direction. That is, in the present embodiment, at the upper end of the coolant passage 7 in the vertical direction, the space between the wall surface 7a and the wall portion 7c on the upper side in the vertical direction is narrowed, so that the passage is cut at the axial position where the wall portion 7c is provided. The area S2 is configured to be smaller than the passage cross-sectional area S1 at another axial position where the wall portion 7c is not provided.

In the present embodiment, the wall portion 7c is integrally formed on the inner peripheral side wall surface 7b of the coolant passage 7, so that a part of the passage cross-sectional area S2 at the upper end of the coolant passage 7 in the vertical direction is formed. However, the means for reducing a part of the passage cross-sectional area S2 at the upper end of the coolant passage 7 in the vertical direction according to the present invention is not limited to the mode in which the wall portion 7c is provided. However, it can be freely changed according to the specifications of the motor M and the like.

As described above, according to the present embodiment, the passage cross-sectional area S2 of a part of the coolant passage 7 is reduced at the upper end of the coolant passage 7 in the vertical direction.

In this way, a part of the passage cross-sectional area S2 in the middle is reduced and formed at the upper end of the coolant passage 7 in the vertical direction, so that the flow velocity of the coolant toward the discharge port 14 can be increased. .. Thereby, the air A contained in the coolant can be discharged more efficiently with the increased flow velocity of the coolant.

Further, in particular, in the present embodiment, a wall portion 7c extending in the radial direction from the rotation center (central axis Z) of the rotation shaft 4 toward the wall surface 7a on the upper side in the vertical direction is provided in the middle of the coolant passage 7 for cooling. The wall portion 7c of the liquid passage 7 reduces a part of the passage cross-sectional area S2 at the upper end in the vertical direction.

In this way, when the passage cross-sectional area S2 of the coolant passage 7 is reduced by the wall portion 7c, the flow velocity of the coolant can be adjusted by adjusting the extension amount of the wall portion 7c. As a result, the discharge property of the air A contained in the coolant can be easily adjusted, and the air A can be discharged more efficiently.

The present invention is not limited to the configuration exemplified in the above embodiment, and can be freely changed according to the specifications and the like to be applied within a range not deviating from the gist of the present invention.

In particular, the form of the coolant passage 7 disclosed in the above embodiment is only an example of the coolant passage structure of the motor according to the present invention. In other words, in the coolant passage structure of the motor according to the present invention, the coolant passage 7 is formed through the upper end in the vertical direction along the axial direction, and is formed from the rotation center (central axis Z) of the rotation shaft 4. It suffices that the distance R to the vertical upper wall surface 7a of the coolant passage 7 is gradually expanded toward one end side in the axial direction, and in the circumferential direction, in addition to the annular shape, the spiral shape or the cross section is circular. Various forms such as an arc-shaped semi-annular shape can be adopted depending on the specifications of the motor M, the layout of the coolant passage 7, and the like.

1 ... Housing 2 ... Stator (motor element)
3 ... Rotor (motor element)
4 ... Rotating shaft 5 ... Cover plate (housing)
7 ... Coolant passage 7a ... Wall surface on the upper side in the vertical direction M ... Motor Z ... Central axis (center of rotation)

Claims

A motor element that rotates and drives the rotating shaft,
A tubular housing provided on the outer peripheral side of the motor element and accommodating the motor element,
A coolant passage provided inside the housing through which the coolant flows,
It is a coolant passage structure of a motor equipped with
The coolant passage is formed through at least at the upper end of the housing in the vertical direction along the axial direction of the rotation axis.
The distance from the center of rotation of the rotating shaft to the upper wall surface of the coolant passage in the vertical direction is gradually expanded toward one end side in the axial direction.
The coolant passage structure of a motor, characterized in that the coolant in the coolant passage is discharged from a discharge port provided on one end side of the coolant passage in the axial direction.
In the coolant passage structure of the motor according to claim 1,
A coolant passage structure for a motor, wherein a wall surface on the upper side of the coolant passage in the vertical direction is formed so as to be inclined upward toward one end side in the axial direction.
In the coolant passage structure of the motor according to claim 1,
The coolant passage structure of the motor, wherein the coolant passage is formed in an annular shape around the rotation shaft.
In the coolant passage structure of the motor according to claim 1,
A coolant passage structure for a motor, wherein the discharge port is formed with an opening in a direction other than the upper side in the vertical direction.
In the coolant passage structure of the motor according to claim 1,
The coolant passage structure of the motor is characterized in that a part of the passage cross-sectional area is reduced at the upper end portion in the vertical direction.
In the coolant passage structure of the motor according to claim 5.
A wall portion extending in the radial direction of the rotating shaft from the rotation center of the rotating shaft toward the upper wall surface in the vertical direction is provided in the middle of the coolant passage.
The coolant passage structure of the motor is characterized in that the wall portion reduces the cross-sectional area of a part of the passage at the upper end portion in the vertical direction.