JP7447943B2 - Seal structure of coolant flow path in rotating machines - Google Patents

Description

TECHNICAL FIELD The present invention is applied to various types of rotating machines, such as motors and generators for driving electric vehicles, and relates to a sealing structure for a coolant flow path through which a coolant for cooling the rotating machines flows.

BACKGROUND ART Conventionally, as this type of sealing structure for a coolant flow path, one applied to a rotating electric machine described in Patent Document 1, for example, is known. This rotating electric machine is used as a generator mounted on a vehicle, and includes a housing formed in a substantially cylindrical shape, a stator fixed to the inner peripheral surface of the housing, and a freely rotatable part inside the stator. A rotor provided on the housing, a front bracket and a rear bracket placed on the front and rear sides in the axial direction of the housing, and a rotating shaft that is provided to rotate together with the rotor and protrudes forward from the front bracket. We are prepared.

The above-mentioned housing is provided with a cooling passage within the thick wall portion thereof, through which a cooling liquid for cooling the rotating electric machine flows. The cooling passage extends in a band shape along the circumferential direction of the housing, and is formed in an annular shape that goes around the thick wall portion of the housing. Further, in the housing, the front end of the cooling passage in the axial direction is closed, while the rear end of the cooling passage is open rearward. The annular open portion at the rear end of this cooling passage (hereinafter referred to as the “annular open portion” in this column) is sealed by a rear bracket and a sealing material.

Specifically, sealing materials are disposed on the rear end surface of the housing on the inside and outside of the annular open portion in the radial direction, and the rear bracket is in close contact with both the inside and outside sealing materials, and It can be installed with the annular opening covered. This seals the annular opening at the rear end of the cooling passage in a watertight manner.

Japanese Patent Application Publication No. 2004-364429

In the cooling passage seal structure applied to the above-mentioned rotating electric machine, seal grooves for accommodating the sealing material are formed on the rear end surface of the housing on the inside and outside of the annular opening in the radial direction. These sealing grooves are usually formed at some radial distance from the annular opening of the cooling passage. In particular, if the inner diameter of the rear end surface of the housing is the same as the diameter of the inner peripheral surface of the housing to which the stator is fixed, the seal groove formed inside the annular opening will be , are formed at a certain distance in the radial direction.

However, when seal grooves like those described above are formed on the rear end surface of the housing inside and outside the annular opening in the radial direction, the wall thickness of the housing becomes thicker, and the size and weight of the rotating electric machine increase accordingly. . In particular, when the wall thickness of the housing on the radially inner side of the cooling passage increases, the distance between the cooling passage and the stator increases, which may reduce the cooling performance.

The present invention has been made to solve the above-mentioned problems, and reduces the size and weight of the rotating machine while ensuring the sealing performance of the coolant flow path in the rotating machine and maintaining the performance of the rotating machine. It is an object of the present invention to provide a sealing structure for a coolant flow path in a rotating machine that can reduce the amount of water used and improve the cooling performance.

In order to achieve the above object, the invention according to claim 1 is provided in a thick wall part of a cylindrical outer peripheral wall of a rotating machine, is opened in at least one of the axial directions of the outer peripheral wall, and cools the rotating machine. A sealing structure for a coolant flow path that seals an open part of a coolant flow path through which a coolant flows, the coolant flow path being joined to at least one of both end surfaces in the axial direction of an outer peripheral wall, The cover member has a spigot convex portion that protrudes toward the outer peripheral wall and fits into the open portion of the coolant flow path , and the open portion of the coolant flow path is It has a ring recess formed in a ring shape with a width of a predetermined length in the radial direction of the wall, and the pilot convex part is formed in a ring shape with a width shorter than the predetermined length in the radial direction of the outer peripheral wall. , is characterized in that it fits into the ring recess while being in close contact with the radially inner circumferential surface of the ring recess .

According to this configuration, a coolant flow path through which a coolant for cooling the rotary machine flows is provided in the thick wall portion of the cylindrical outer peripheral wall of the rotary machine. Further, this coolant flow path is open in at least one of the axial directions of the outer circumferential wall, and the open portion is covered with a cover member joined to the end surface of the outer circumferential wall in the axial direction. Furthermore, this cover member has a spigot convex portion that protrudes toward the outer peripheral wall, and this spigot convex portion fits into the open portion of the coolant flow path. In this way, the cover member is joined to the end face of the outer peripheral wall with the spigot convex part of the cover member fitted into the open part of the coolant flow path, so when joining, the cover member and the outer peripheral wall It can be easily assembled while centering the parts, and the sealing performance of the open part of the coolant flow path can be improved compared to, for example, a case where the open part of the coolant flow path is covered with a flat surface. In addition, it is possible to reduce the thickness of the wall thickness section of the outer peripheral wall while ensuring the sealing performance of the open part of the coolant flow path and maintaining the performance of the rotating machine. The cooling performance can be improved as well as the weight and weight can be reduced.

Further, according to the above configuration, the open portion of the coolant flow path has a ring recess having a width of a predetermined length in the radial direction, and the spigot convex portion of the cover member has a ring recess having a width of a predetermined length. It is formed into a ring shape with a width shorter than that of the ring. Thereby, compared to the case where the pilot protrusion has the same width as the ring recess, the weight of the pilot protrusion can be reduced, and the weight of the rotating machine can be reduced accordingly. In addition, since the spigot convex part fits into the ring recess while being in close contact with the radial inner circumferential surface of the ring recess, it improves the sealing performance of the radially inner side of the ring recess in the coolant flow path. be able to.

The invention according to claim 2 provides a sealing structure for a coolant flow path in a rotating machine according to claim 1 , in which a first predetermined area is provided on the radially inner side of the ring recess on the joint surface between the cover member and the outer peripheral wall. A liquid gasket is applied to the cover member, and the liquid gasket is applied to the first predetermined region on the joint surface of the cover member, outside the first predetermined region in the radial direction and immediately inside the spigot convex portion. It is characterized by having a first seal reservoir groove for preventing the ring from entering the ring recess.

According to this configuration, since the liquid gasket is applied to the first predetermined area inside the ring recess in the radial direction on the joint surface between the cover member and the outer peripheral wall, the cooling The sealing performance of the radially inner side of the ring recess of the liquid flow path can be further improved. In addition, since the first seal reservoir groove is provided on the joint surface of the cover member outside the first predetermined region in the radial direction, when the cover member is joined to the outer peripheral wall, the sealing groove is applied to the first predetermined region. Even if the liquid gasket leaks into the ring recess, it will flow into the first seal reservoir groove and will be prevented from entering the ring recess. Thereby, it is possible to reliably prevent the liquid gasket applied to the first predetermined area from entering the ring recess. Furthermore, since the first seal reservoir groove is provided immediately inside the spigot convex portion, the diameter of the coolant flow path is smaller than that in the case where the first seal reservoir groove is provided at a position away from the spigot convex portion, for example. It is possible to reduce the thickness of the wall thickness section of the outer circumferential wall on the inside of the direction. Thereby, good cooling performance in the rotating machine can be ensured.

The invention according to claim 3 is a sealing structure for a coolant flow path in a rotating machine according to claim 2 , in which a second predetermined area on the outside in the radial direction of the ring recess is provided on the joint surface between the cover member and the outer peripheral wall. A liquid gasket is applied to the outer circumferential wall, and the liquid gasket applied to the second predetermined area is applied to the outer circumferential wall outside the ring recess in the radial direction and inside the second predetermined area on the joint surface of the outer circumferential wall. It is characterized by having a second seal reservoir groove for preventing entry into the recess.

According to this configuration, the liquid gasket is further applied to the joint surface of the cover member and the outer circumferential wall in the second predetermined area on the outside in the radial direction of the ring recess, so that the liquid gasket It is possible to improve the sealing performance on the outside of the direction. Therefore, the liquid gasket applied to the first predetermined area and the liquid gasket applied to the second predetermined area work together to further improve the radial sealing performance in the ring recess of the coolant flow path. be able to. In addition, since the second seal reservoir groove is provided on the joint surface of the outer peripheral wall outside the ring recess in the radial direction and inside the second predetermined area, when joining the cover member to the outer peripheral wall, Even if the liquid gasket applied to the second predetermined area leaks toward the ring recess, it flows into the second seal reservoir groove and is prevented from entering the ring recess. Thereby, it is possible to reliably prevent the liquid gasket applied to the second predetermined area from entering the ring recess.

1 is an external perspective view showing a motor to which a sealing structure for a coolant flow path according to an embodiment of the present invention is applied; FIG. (a) is a longitudinal cross-sectional view of the motor cut vertically with the shaft protruding upward, and (b) is the area surrounded by the dashed line in (a) (the spigot convex part of the bracket and its surroundings) FIG. (a) and (b) are respectively the bracket and frame shown in FIG. 2(b), and are three-dimensional views showing these separated from each other in the vertical direction. FIG. 4 is a diagram for explaining a state when the bracket shown in FIG. 3 is joined to the upper end surface of the frame.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the appearance of a motor to which a sealing structure for a coolant flow path according to an embodiment of the present invention is applied. Note that this motor 1 (rotating machine) is used, for example, as a drive motor for an electric vehicle.

As shown in FIGS. 1 and 2(a), the motor 1 includes a cylindrical frame 2 (outer peripheral wall) and an axial direction of this frame 2 (vertical direction in FIGS. 1 and 2(a)). two brackets 3 and 4 (cover members) joined to both ends of the rotor 8, which rotates integrally with a shaft 5 rotatably supported by both brackets 3 and 4 via bearings 3a and 4a; The rotor 8 is provided with a stator 9 and the like fixed to the inner circumferential surface of the frame 2, facing the rotor 8 with a gap therebetween. In the motor 1 shown in both figures, the shaft 5 protrudes outward (upward) from the bracket 3.

In the following description, the protruding side of the shaft 5 in FIGS. 1 and 2(a) will be referred to as the upper side, while the opposite side will be referred to as the lower side, and the above brackets 3 and 4 will be referred to as "upper bracket 3", respectively. and "lower bracket 4".

The frame 2 is manufactured, for example, by aluminum die-casting, and most of the frame 2 is formed into a cylindrical shape having predetermined inner and outer diameters and a relatively thick wall thickness section 2a. Furthermore, an upper flange 6 and a lower flange 7 that protrude a predetermined length in the radial direction are provided at the upper and lower ends of the frame 2 in the axial direction, respectively. The upper flange 6 is formed with a plurality of (only four are shown in FIG. 1) mounting holes 6a for bolting the upper bracket 3. Similarly, the lower flange 7 is also formed with a plurality of (only three are shown in FIG. 1) mounting holes 7a for bolting the lower bracket 4.

Further, a flow path 10 (coolant flow path) through which a predetermined cooling water (coolant) for cooling the motor 1 flows is formed in the thick wall portion 2a of the frame 2 . The flow path 10 has a predetermined depth (a predetermined thickness in the radial direction of the frame 2), extends along the circumferential direction of the frame 2, and is open above and below the frame 2. It is formed within the thick portion 2a.

Further, as shown in FIG. 1, at a predetermined position on the outer peripheral surface of the frame 2 having the flow path 10, there is a cooling water introduction part 17 for introducing cooling water into the flow path 10, and a cooling water introduction part 17 for introducing cooling water from the flow path 10. A cooling water discharge section 18 is provided for discharging the cooling water. Therefore, when cooling the motor 1, the cooling water is introduced into the flow path 10 via the cooling water introduction section 17, cools the stator 9 and rotor 8 by flowing through the flow path 10, and is discharged from the cooling water discharge section 18. It is discharged to the outside.

Next, with reference to FIGS. 2 to 4, a sealing structure at the upper and lower ends of the flow path 10 by joining the frame 2 and the upper and lower brackets 3 and 4 will be described. In the flow path 10 formed in the thick wall portion 2a of the frame 2, the entire upper end portion is open upward, and the lower end portion is entirely or partially open downward.

The upper and lower brackets 3 and 4 are manufactured by aluminum die-casting similarly to the frame 2 described above, and have a disk-like planar shape. As shown in FIG. 2(a), the lower surface of the upper bracket 3 has a spigot convex portion 21 that protrudes a predetermined length toward the frame 2, that is, downward, and fits into the upper end (open portion) of the flow path 10. It is provided. On the other hand, as shown in FIG. 2(a), on the upper surface of the lower bracket 4, there is a spigot convex portion 22 that protrudes a predetermined length toward the frame 2 side, that is, upward, and fits into the open portion of the lower end of the flow path 10. is provided.

Note that the sealing structure of the upper and lower ends of the flow path 10 by the pilot convex portions 21 and 22 of the upper and lower brackets 3 and 4 is basically the same, so in the following explanation, the connection between the frame 2 and the upper bracket 3 will be The seal structure at the upper end of the flow path 10 will be mainly described.

FIG. 2(b) shows an enlarged view of the portion surrounded by the dashed line in FIG. 2(a), specifically, the spigot convex portion 21 of the upper bracket 3 and its surroundings. Moreover, FIGS. 3(a) and 3(b) respectively show the upper bracket 3 and frame 2 shown in FIG. 2(b), which are shown three-dimensionally in a state where they are separated from each other in the vertical direction.

As shown in FIGS. 2(b) and 3(a), the spigot convex portion 21 of the upper bracket 3 protrudes downward by a predetermined length and extends by a predetermined width in the radial direction (horizontal direction in FIGS. 2 and 3). The planar shape is formed into a ring shape having a predetermined diameter. In addition, in this pilot convex part 21, the inner corner part in the radial direction of the lower end part is chamfered.

Furthermore, an inner seal reservoir groove 23 (first seal reservoir groove) that opens downward is formed in the upper bracket 3 immediately inside the spigot convex portion 21 in the radial direction. The inner seal reservoir groove 23 has a predetermined width and depth, and is formed into a ring shape in plan view that is concentric with the spigot convex portion 21 .

On the other hand, as shown in FIGS. 2(b) and 3(b), at the upper end of the flow path 10 in the frame 2, a ring recess 20 (open portion ) is configured. The ring recess 20 has a radial width set larger than that of the pilot protrusion 21 and an inner diameter in the radial direction equal to that of the pilot protrusion 21 . Note that in the ring recess 20, the inner corner in the radial direction of the upper end thereof is chamfered.

Further, on the upper end surface of the frame 2, an outer seal reservoir groove 24 (second seal reservoir groove) that opens upward is formed outside the ring recess 20 in the radial direction. Like the inner seal reservoir groove 23 described above, the outer seal reservoir groove 24 has a predetermined width and depth, and is formed into a ring shape whose planar shape is concentric with the ring recess 20 and larger than the ring recess 20. ing.

A liquid gasket (not shown) formed into a thin layer by coating is provided on the joint surface between the upper bracket 3 and the frame 2, that is, on the lower surface 25 of the upper bracket 3 and the upper end surface 26 of the frame 2. .

Specifically, as shown in FIG. 3(a), the lower surface 25 of the upper bracket 3 has a radially inner surface (hereinafter referred to as "inner lower surface 25a") of the inner seal reservoir groove 23 and a spigot convex portion. 21 (hereinafter referred to as the "outer lower surface 25b"), and when joining the upper bracket 3 to the frame 2, the inner lower surface 25a (first predetermined area) of the upper bracket 3 is A liquid gasket is applied.

On the other hand, as shown in FIG. 3(b), the upper end surface 26 of the frame 2 has a surface inside the ring recess 20 in the radial direction (hereinafter referred to as "inner upper end surface 26a") and a surface outside the ring recess 20. (hereinafter referred to as "outer upper end surface 26b"), and when joining the upper bracket 3 to the frame 2, the outer upper end surface 26b of the frame 2, more specifically, the outer upper end surface 26b. A liquid gasket is applied to a region outside the outer seal reservoir groove 24 (second predetermined region).

Note that the above-mentioned liquid gasket has fluidity at room temperature, hardens by drying after a certain period of time, and exhibits elasticity and adhesiveness.

FIG. 4 shows a state in which the upper bracket 3 of FIG. 3 described above is joined to the upper end surface 26 of the frame 2. As shown in FIG. In addition, in FIG. 4, the upper bracket 3 is shown by a chain double-dashed line for convenience of illustration.

As shown in FIG. 4, when the upper bracket 3 is joined to the upper end surface 26 of the frame 2, the spigot convex portion 21 of the upper bracket 3 fits into the ring recess 20 at the upper end of the flow path 10. More specifically, the spigot convex portion 21 fits into the ring recess 20 with its inner peripheral surface 21 a in close contact with the inner peripheral surface 20 a of the ring recess 20 . As mentioned above, the inner corner of the lower end of the spigot convex part 21 is chamfered, while the inner corner of the upper end of the ring recess 20 is chamfered, so that the spigot convex part 21 has a chamfered inner corner of its upper end. When fitting the convex portion 21 into the ring recess 20, the fitting operation can be easily performed while bringing both chamfered corners into contact with each other.

In addition, in the above case, as described above, since the liquid gasket is applied to the inner lower surface 25a of the upper bracket 3 and the outer upper end surface 26b of the frame 2, the inner side of the upper bracket 3 is coated via the liquid gasket. The lower surface 25a and the inner upper end surface 26a of the frame 2 are in close contact with each other, and the outer lower surface 25b of the upper bracket 3 and the outer upper end surface 26b of the frame 2 are in close contact with each other. Thereby, the sealing performance of the radially inner and outer sides of the ring recess 20 of the flow path 10 can be further improved.

In the motor 1 configured as described above, the cooling water flows through the flow path 10, thereby cooling the stator 9 and rotor 8 of the motor 1 during operation, and suppressing the heat generation thereof. As a result, good performance of the motor 1 can be maintained.

As described in detail above, according to the present embodiment, the upper bracket 3 is attached to the upper end surface 26 of the frame 2 while the spigot convex portion 21 of the upper bracket 3 is fitted into the ring recess 20 at the upper end of the flow path 10. Since the lower surface 25 of 3 is joined, it is possible to easily assemble the upper bracket 3 and the frame 2 while centering them at the time of joining. Compared to this, the sealing performance of the ring recess 20 in the flow path 10 can be improved.

In addition, since the width of the spigot convex part 21 of the upper bracket 3 is formed shorter than that of the ring recess 20, the spigot convex part 21 The weight of the motor 1 can be reduced accordingly. In addition, since the spigot convex portion 21 fits into the ring recess 20 while being in close contact with the radially inner circumferential surface 20a of the ring recess 20, it is possible to improve the sealing performance of the radially inner side of the ring recess 20. .

Furthermore, the upper bracket 3 is provided with an inner seal reservoir groove 23 just inside the pilot convex portion 21, while the frame 2 is provided with an outer seal reservoir groove 24 outside the ring recess 20. When the bracket 3 is joined to the frame 2, even if the liquid gasket applied to the inner lower surface 25a of the upper bracket 3 and the outer upper end surface 26b of the frame 2 leaks to the ring recess 20 side, the inner seal reservoir groove 23 or the outer side By flowing into the seal reservoir groove 24, entry into the ring recess 20 is prevented. Thereby, the liquid gasket can be reliably prevented from entering the ring recess 20.

Furthermore, since the inner seal reservoir groove 23 is provided immediately inside the pilot convex portion 21, it is possible to reduce the thickness of the thick wall portion 2a of the frame 2, thereby reducing the physique and weight of the motor 1. It is possible to reduce the amount of water and improve the cooling performance. Note that the configuration in which the inner seal reservoir groove 23 is provided immediately inside the spigot convex portion 21 is such that the spigot convex portion 21 functions as an outer wall portion of the inner seal reservoir groove 23, thereby preventing accumulation in the inner seal reservoir groove 23. This can be achieved because it prevents the liquid gasket from entering the flow path 10. Therefore, for example, if the upper bracket 3 without the spigot convex portion 21 is provided with the inner seal reservoir groove 23 just inside the inner circumferential surface of the flow path 10, there is a risk that the liquid gasket that has flowed into the groove may mix into the flow path 10. There is.

Note that the present invention is not limited to the above-described embodiments, and can be implemented in various forms. For example, in the embodiment, the width of the pilot protrusion 21 of the upper bracket 3 is made smaller than the width of the ring recess 20 in the flow path 10 of the frame 2, but the present invention is not limited to this. It is also possible to make the width of the spigot convex portion 21 and the ring concave portion 20 the same.

Further, in the embodiment, the sealing structure of the flow path 10 in the motor 1 as a rotating machine has been described, but the present invention can be applied to various types of rotating machines (for example, generators) that generate heat during operation. . Further, in the embodiment, the motor 1 is cooled by flowing cooling water through the flow path 10 extending along the circumferential direction of the frame 2, but instead of the above-mentioned cooling water, other suitable cooling fluid (for example, cooling oil) may be used instead of the cooling water described above. etc.), or it is also possible to use a flow path having an appropriate configuration, such as one extending meanderingly along the circumferential direction of the frame 2, as the flow path 10.

In addition, the detailed configurations of the motor 1, frame 2, brackets 3 and 4, flow path 10, ring recess 20, pilot protrusion 21 and 22, and inner and outer seal reservoir grooves 23 and 24 shown in the embodiment are as follows. This is merely an example and can be modified as appropriate within the spirit of the present invention.

1 Motor (rotating machine)
2 Frame (outer wall)
2a Thick wall part of frame 3 Upper bracket (cover member)
4 Lower bracket (cover member)
5 Shaft 10 Flow path (coolant flow path)
20 Ring recess (open part)
20a Inner circumferential surface of ring recess 21 Upper bracket spigot convex portion 21a Inner circumferential surface of spigot convex portion 22 Lower bracket spigot convex portion 23 Inner seal reservoir groove (first seal reservoir groove)
24 Outer seal reservoir groove (second seal reservoir groove)
25 Lower surface 25a of upper bracket Inner lower surface (first predetermined area)
25b Outer lower surface 26 Frame upper end surface 26a Inner upper end surface 26b Outer upper end surface (second predetermined area)

Claims (3)

A portion that is provided in a thick wall portion of a cylindrical outer circumferential wall of a rotating machine, is open in at least one direction of the axis of the outer circumferential wall, and is open to a coolant flow path through which a coolant for cooling the rotating machine flows. A sealing structure of a coolant flow path that seals a
A cover member is provided that is joined to at least one of both end faces in the axial direction of the outer peripheral wall and covers an open portion of the coolant flow path,
The cover member has a spigot convex portion that protrudes toward the outer peripheral wall and fits into an open portion of the coolant flow path ,
The open portion of the coolant flow path has a ring recess formed in a ring shape having a width of a predetermined length in the radial direction of the outer peripheral wall,
The spigot convex portion is formed in a ring shape having a width shorter than the predetermined length in the radial direction of the outer peripheral wall, and is fitted into the ring recess while being in close contact with the radial inner peripheral surface of the ring recess. A sealing structure for a coolant flow path in a rotating machine, characterized by : A liquid gasket is applied to the joint surface of the cover member and the outer peripheral wall in a first predetermined area inside the ring recess in the radial direction,
The cover member is arranged such that, on the joint surface of the cover member, a liquid gasket applied to the first predetermined region is applied to the ring recess, outside the first predetermined region in the radial direction and immediately inside the spigot convex portion. 2. The seal structure for a coolant flow path in a rotating machine according to claim 1 , further comprising a first seal reservoir groove for preventing the coolant from entering. A liquid gasket is applied to a second predetermined area on the radially outer side of the ring recess on the joint surface of the cover member and the outer peripheral wall,
The outer circumferential wall is configured such that, on the joint surface of the outer circumferential wall, a liquid gasket applied to the second predetermined area infiltrates the ring recess outside the ring recess in the radial direction and inside the second predetermined area. 3. The sealing structure for a coolant flow path in a rotating machine according to claim 2 , further comprising a second seal reservoir groove for preventing the coolant from being damaged.

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