JP7675606B2 - Rotating Electric Machine - Google Patents

Description

An embodiment of the present invention relates to a rotating electric machine.

Induction motors, wound-type generators, and permanent magnet rotating electric machines are used as rotating electric machines for railway vehicles. In addition, because rotating electric machines generate heat when they are in operation, they are equipped with a cooling structure to prevent the temperature from rising. Proposed cooling structures include a totally enclosed structure that mainly dissipates heat from the rotating electric machine itself, a self-ventilation type that has a fan installed on the rotating shaft to take in outside air, and a forced air-cooling type that connects a blower to send in outside air.

For example, the electric motor described in Patent Document 1 has an axially extending ventilation hole and a first ventilation passage extending radially from the ventilation hole formed in the rotor core, and a second ventilation passage extending radially formed in the stator core. As a result, when the electric motor described in Patent Document 1 is operating, the rotor core and stator core are cooled by cooling air that flows through the ventilation hole, the first ventilation passage, and the second ventilation passage as the rotor core rotates, improving the cooling efficiency of the rotor core and stator core.

JP 2010-178532 A

The advantage of a totally enclosed rotating electric machine is that it isolates the inside of the machine from the outside, and therefore eliminates the need for maintenance work such as cleaning the inside of the machine. However, with a totally enclosed rotating electric machine, the inside of the machine is isolated from the outside, meaning that outside air cannot be taken into the machine, and so the cooling effect is lower than with self-ventilation and forced air cooling types.

In general, in rotating electric machines, the coil inside the stator core, which is placed in the stator, is one of the locations that is prone to becoming hot. For this reason, reducing the temperature of the coil inside the stator core is an effective way to increase the cooling effect, but in a totally enclosed structure type, the coil inside the stator core cannot be cooled using outside air, so there is room for improvement in the cooling structure of totally enclosed structure type rotating electric machines.

The present invention has been made in consideration of the above, and aims to provide a rotating electric machine that can improve the cooling effect in a totally enclosed structure.

The rotating electric machine of the embodiment includes a rotor attached to a rotating shaft, a stator core having a first stator core and a second stator core arranged at a distance from each other on the radial outside of the rotor and arranged at a distance from each other in the axial direction of the rotating shaft, a stator having a duct forming member arranged between the first stator core and the second stator core and connected to the first stator core and the second stator core, a first bracket arranged on the opposite side of the side where the second stator core is located relative to the first stator core in the axial direction to support the first stator core and support the rotating shaft so that it can rotate relative to the first stator core, and a stator core arranged on the opposite side of the side where the first stator core is located relative to the second stator core in the axial direction to support the first stator core and support the rotating shaft so that it can rotate relative to the first stator core. a second bracket arranged on the opposite side to the rotor and supporting the second stator core, and supporting the rotating shaft so as to be rotatable relative to the second stator core; a first fan arranged on the side of the rotor in the axial direction where the first bracket is located and rotates integrally with the rotating shaft; and a second fan arranged on the side of the rotor in the axial direction where the second bracket is located and rotates integrally with the rotating shaft, wherein a groove portion extending in the axial direction across the first stator core and the second stator core is formed on an inner peripheral surface of the stator core, and a plurality of the groove portions are arranged in the circumferential direction of the stator core, and stator coils are housed in the plurality of groove portions, and the duct forming member is an annular spacer arranged around the entire circumference of the stator core at a position of an outer end of the stator core in the radial direction, and both sides in the axial direction are connected to the first stator core and the second stator core; and a plate-like spacer formed in a plate shape and arranged with a width direction of the plate being the axial direction and a thickness direction of the plate being the circumferential direction, and both sides in the axial direction are connected to the first stator core and the second stator core, and an outer end portion in the radial direction is connected to the annular spacer, a plurality of the plate-like spacers are arranged radially between the respective groove portions, and a first ventilation hole penetrating the first stator core in the axial direction is formed in the first stator core at a position outside the groove portion in the radial direction, The second stator core has a second ventilation hole penetrating the second stator core in the axial direction at a radially outer position of the groove portion that is different in circumferential position from the groove portion in which the first ventilation hole is formed on the radially outer side of the first stator core, and the first bracket has a first ventilation duct having one end that opens from the radially outer side of the first fan to a position facing the radially outer end of the first fan and the other end that opens to a position facing the first ventilation hole, and the second bracket has a second ventilation duct having one end that opens from the radially outer side of the second fan to a position facing the radially outer end of the second fan and the other end that opens to a position facing the second ventilation hole.

FIG. 1 is a half cross-sectional view of a rotating electric machine according to an embodiment. FIG. 2 is a cross-sectional view taken along line AA of FIG. FIG. 3 is a cross-sectional view taken along line BB of FIG. FIG. 4 is a cross-sectional view taken along the line CC of FIG.

Below, exemplary embodiments of the present invention are disclosed. The configurations of the embodiments shown below, and the actions and effects brought about by said configurations, are merely examples. The present invention can also be realized with configurations other than those disclosed in the following embodiments. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derivative effects) obtained by the configurations.

Below, an example of a rotating electric machine according to this embodiment will be described with reference to the attached drawings.

[Embodiment]
1 is a half cross-sectional view of a rotating electric machine 1 according to an embodiment. The rotating electric machine 1 according to the embodiment includes a rotating shaft 70, a rotor 72 attached to the rotating shaft 70, a stator 20, and a bracket 10 supporting the stator 20. In the following description, the axial direction of the rotating shaft 70 of the rotating electric machine 1 is described as the axial direction of the rotating electric machine 1, and the radial direction of the rotating shaft 70 is described as the radial direction of the rotating electric machine 1. The outer side in the radial direction refers to the side away from the axis of the rotating shaft 70 in the radial direction, and the inner side in the radial direction refers to the side approaching the axis of the rotating shaft 70 in the radial direction. The circumferential direction refers to the direction around the rotating shaft 70.

The rotating shaft 70 is a shaft-shaped rotating member in the rotating electric machine 1. At one end in the axial direction, the rotating shaft 70 is provided with a connecting part 71 for attaching a member for outputting the driving force generated in the rotating electric machine 1 to an external device. The rotating shaft 70 is capable of outputting the driving force generated in the rotating electric machine 1 from the connecting part 71.

The rotor 72 attached to the rotating shaft 70 is formed in a substantially circular ring shape and is configured with a permanent magnet. The rotor 72 is sandwiched from both sides in the axial direction by rotor pressing plates 73 arranged on both sides in the axial direction. This allows the rotor 72 to be arranged at a predetermined position on the rotating shaft 70. The rotor 72 arranged on the rotating shaft 70 in this manner is capable of rotating integrally with the rotating shaft 70 when the rotating shaft 70 rotates.

The stator 20 is disposed outside the rotor 72 in the radial direction. The stator 20 has a stator core 30, a stator coil 40, and a duct forming member 50. The stator core 30 is formed in a substantially annular shape with an inner diameter slightly larger than the outer diameter of the rotor 72, and is disposed outside the rotor 72 in the radial direction. That is, the stator core 30 has an axial width approximately equal to the width of the rotor 72 in the axial direction, and is disposed at a position in the axial direction approximately equal to the position of the rotor 72. In addition, since the inner diameter of the stator core 30 is slightly larger than the outer diameter of the rotor 72, a small gap G is formed between the inner peripheral surface of the stator core 30 and the outer peripheral surface of the rotor 72.

The brackets 10 are arranged on both sides of the stator core 30 in the axial direction and support the stator core 30. The brackets 10 support the stator core 30 via the stator support members 13. The stator support members 13 are arranged on both sides of the stator core 30 in the axial direction and are attached to both sides of the stator core 30. The brackets 10 arranged on both sides of the stator core 30 in the axial direction are each attached to the side of the stator support member 13 opposite the surface attached to the stator core 30 in the axial direction. In this way, the brackets 10 support the stator core 30.

The bracket 10 has an outer periphery 11 and an end surface 12. The outer periphery 11 is formed in a substantially circular ring shape, and the end surface 12 is disposed at one end of the ring in the axial direction of the outer periphery 11. The bracket 10 is connected to the stator support member 13 at an end opposite to the end of the outer periphery 11 where the end surface 12 is located.

The end surface portion 12 of the bracket 10 is formed in a generally disc-like shape, and the outer periphery of the end surface portion 12 is connected to the end of the outer periphery portion 11 of the bracket 10. As shown in FIG. 1, the outer periphery portion 11 and the end surface portion 12 of the bracket 10 are connected while being curved. The end surface portion 12 of the bracket 10 formed in this manner constitutes the end surface in the axial direction of the rotating electric machine 1.

The end surface portion 12 of the bracket 10 has a hole formed in the center of the disk, and a bearing housing 60 that supports a bearing 61 is attached to the central hole in the end surface portion 12. The bearing housing 60 is attached to both end surface portions 12 of the bracket 10 located on both sides of the stator 20 in the axial direction.

As described above, in the rotating electric machine 1 according to this embodiment, the bearing housings 60 supporting the bearings 61 are attached to the end face portions 12 formed on the bracket 10 on both sides in the axial direction, so that the interior of the rotating electric machine 1, which is the inner portion where the stator 20 and rotor 72 are arranged, is isolated from the outer portion of the rotating electric machine 1. For this reason, the rotating electric machine 1 according to this embodiment is configured as a rotating electric machine with a totally enclosed structure.

The bearing 61 supported by the bearing housing 60 is formed in a generally annular shape, with its outer peripheral surface supported by the bearing housing 60 and the rotating shaft 70 passing through its inner peripheral surface, supporting the rotating shaft 70 rotatably relative to the bearing housing 60. In addition, since the bearing housing 60 is attached to the end surface portions 12 of the bracket 10 arranged on both sides of the stator 20 in the axial direction, the bearing 61 supported by the bearing housing 60 rotatably supports the rotating shaft 70 at positions near both ends of the rotating shaft 70 in the axial direction.

Fans 75 are also arranged on the rotating shaft 70. The fans 75 are arranged on both sides of the rotor 72 in the axial direction of the rotating shaft 70, and are capable of rotating integrally with the rotating shaft 70. The base end of the fan 75 attached to the rotating shaft 70 contacts the surface opposite the surface on which the rotor 72 is located, of the rotor pressing plates 73 arranged on both sides of the rotor 72 in the axial direction. The fan 75 is formed in a roughly cone-shaped shape that inclines away from the rotor 72 in the axial direction as it moves radially outward from the position of the base end attached to the rotating shaft 70.

Rotating vanes 76 are arranged on the surface of the fan 75 near the outer periphery, on the side where the rotor 72 is located in the axial direction. The rotating vanes 76 are plate-shaped members whose thickness direction is in the circumferential direction centered on the axis of the rotating shaft 70, and are formed in a predetermined range from near the outer periphery of the fan 75 toward the inside in the radial direction. The rotating vanes 76 thus formed are arranged at multiple positions in the circumferential direction centered on the axis of the rotating shaft 70. The rotating vanes 76 are also arranged in the same form on both fans 75 arranged on both sides of the rotor 72 in the axial direction.

Figure 2 is a cross-sectional view of A-A in Figure 1. The stator coil 40 of the stator 20 is accommodated in a plurality of grooves 32 formed in the inner peripheral surface 31 of the stator core 30. The grooves 32 are grooves formed from the inner peripheral surface 31 of the stator core 30 toward the outside in the radial direction, and are formed to extend in the axial direction. A plurality of grooves 32 are formed in the circumferential direction of the stator core 30. The stator coil 40 is accommodated in the grooves 32 thus formed, and is arranged with the coil end portions protruding on both sides of the stator core 30 in the axial direction, and the coil end portions are formed across the portions of the stator coil 40 that are accommodated in different grooves 32. As a result, the stator coils 40 accommodated in each of the plurality of grooves 32 are formed and arranged continuously.

The stator core 30 has a first stator core 30a and a second stator core 30b that are located at one end and the other end in the axial direction of the rotating shaft 70 and are spaced apart from each other. In more detail, the stator core 30 is composed of two parts that are spaced apart near the center of the stator core 30 in the axial direction, and has the first stator core 30a located at one end in the axial direction and the second stator core 30b located at the other end.

The brackets 10 that support the stator core 30 from both sides in the axial direction are arranged on both sides of the stator core 30 in the axial direction, and support the first stator core 30a and the second stator core 30b. In other words, of the brackets 10 that support the stator core 30 from both sides in the axial direction, the bracket 10 arranged on the opposite side of the side where the second stator core 30b is located relative to the first stator core 30a in the axial direction is the first bracket 10a that supports the first stator core 30a. Also, of the brackets 10 that support the stator core 30 from both sides in the axial direction, the bracket 10 arranged on the opposite side of the side where the first stator core 30a is located relative to the second stator core 30b in the axial direction is the second bracket 10b that supports the second stator core 30b.

In addition, a bearing housing 60 supporting a bearing 61 is attached to the end surface portion 12 of each of the first bracket 10a and the second bracket 10b. Therefore, the first bracket 10a supports the first stator core 30a, and also supports the rotating shaft 70 via the bearing housing 60 and the bearing 61 so that it can rotate relative to the first stator core 30a. Similarly, the second bracket 10b supports the second stator core 30b, and also supports the rotating shaft 70 via the bearing housing 60 and the bearing 61 so that it can rotate relative to the second stator core 30b.

In the following description, the driving side in the axial direction is one end side, and the anti-driving side in the axial direction is the other end side. In this case, the driving side is the side where the connecting part 71 of the rotating shaft 70 is located in the axial direction, and the anti-driving side is the side opposite the side where the connecting part 71 of the rotating shaft 70 is located in the axial direction. In other words, the stator core 30, which has two parts separated from each other in the axial direction, has a first stator core 30a located on the driving side and a second stator core 30b located on the anti-driving side.

At that time, the multiple grooves 32 formed on the inner peripheral surface 31 of the stator core 30 are divided at the portion between the first stator core 30a and the second stator core 30b, and the grooves 32 formed on the first stator core 30a and the grooves 32 formed on the second stator core 30b are continuously formed in the axial direction. That is, the grooves 32 extend in the axial direction across the first stator core 30a and the second stator core 30b. Therefore, the stator coil 40 accommodated in the grooves 32 of the stator core 30 is continuously accommodated in the portion of the groove 32 formed on the first stator core 30a and the portion formed on the second stator core 30b.

The duct forming member 50 arranged in the portion between the first stator core 30a and the second stator core 30b of the stator core 30 is connected on both sides in the axial direction to the first stator core 30a and the second stator core 30b. The duct forming member 50 has an annular spacing piece 51 and a plate-shaped spacing piece 52. The annular spacing piece 51 is arranged around the entire circumference at the outer end position of the stator core 30 in the radial direction. In other words, the annular spacing piece 51 is formed in a substantially annular shape with an outer diameter approximately the same as the outer diameter of the stator core 30 and a width approximately the same as the gap between the first stator core 30a and the second stator core 30b, and is arranged in the portion between the first stator core 30a and the second stator core 30b. The annular spacing piece 51 thus formed is connected on both sides in the width direction to the first stator core 30a and the second stator core 30b. As a result, the outer end portion in the radial direction of the portion between the first stator core 30a and the second stator core 30b is blocked by the annular spacing piece 51 of the duct forming member 50.

In addition, multiple plate-shaped spacing pieces 52 are arranged in the portion between the first stator core 30a and the second stator core 30b, and the multiple plate-shaped spacing pieces 52 are arranged radially between the grooves 32 formed in the stator core 30. In detail, the plate-shaped spacing pieces 52 are plate-shaped members arranged such that the width direction of the plate is the direction in which the first stator core 30a and the second stator core 30b are separated, i.e., the axial direction, and the thickness direction of the plate is the circumferential direction. The width of the plate-shaped spacing pieces 52 is approximately the same as the gap between the first stator core 30a and the second stator core 30b. As a result, both sides of the plate-shaped spacing pieces 52 in the width direction are connected to the first stator core 30a and the second stator core 30b.

The circumferential pitch of the plate-shaped spacing pieces 52 is the same as the circumferential pitch of the grooves 32 formed in the stator core 30, so that the plate-shaped spacing pieces 52 are arranged between the grooves 32 formed in the stator core 30. Furthermore, when the plate-shaped spacing pieces 52 are arranged in the portion between the first stator core 30a and the second stator core 30b, the position of the inner end in the radial direction is located near the inner circumferential surface 31 of the stator core 30, and the outer end in the radial direction is connected to the inner circumferential surface of the annular spacing piece 51.

As a result, in the portion between the first stator core 30a and the second stator core 30b, one space is formed by the circumferentially adjacent plate-shaped spacing pieces 52 and the annular spacing piece 51 to which these plate-shaped spacing pieces 52 are connected on the radially outer side, and multiple spaces formed in this manner are formed side by side in the circumferential direction. In other words, since the plate-shaped spacing pieces 52 are arranged between the circumferentially adjacent groove portions 32, a space formed by the circumferentially adjacent plate-shaped spacing pieces 52 and the annular spacing piece 51 is formed for each groove portion 32. In this way, the space formed by the circumferentially adjacent plate-shaped spacing pieces 52 and the annular spacing piece 51 is formed as a radial duct 55 through which air flows radially.

In other words, the duct forming member 50 arranged in the portion between the first stator core 30a and the second stator core 30b forms a radial duct 55 between the first stator core 30a and the second stator core 30b by means of annular spacing pieces 51 and plate-shaped spacing pieces 52. The plate-shaped spacing pieces 52 of the duct forming member 50 are arranged radially between the grooves 32 formed in the stator core 30. Therefore, the radial ducts 55 formed by the duct forming member 50 are formed for each of the grooves 32 arranged in the circumferential direction, and multiple ducts are arranged radially in the circumferential direction.

The grooves 32 formed in the first stator core 30a and the grooves 32 formed in the second stator core 30b are formed continuously in the axial direction, and the stator coil 40 is accommodated in the grooves 32 thus formed across the first stator core 30a and the second stator core 30b. Therefore, the radial duct 55 includes a portion of the stator coil 40 between the portion accommodated in the grooves 32 of the first stator core 30a and the portion accommodated in the grooves 32 of the second stator core 30b, and the stator coil 40 is arranged exposed within the radial duct 55.

In addition, the stator core 30 has ventilation holes 35 formed at a position outside the grooves 32 in the radial direction, penetrating the stator core 30 in the axial direction. The first stator core 30a has first ventilation holes 35a, which are ventilation holes 35 penetrating the first stator core 30a in the axial direction, formed at a position outside the grooves 32 in the radial direction and near the outer circumferential surface of the first stator core 30a. The first ventilation holes 35a are formed at a position in the radial direction that is radially inward of the annular spacing piece 51 and near the inner circumferential surface of the annular spacing piece 51. As a result, the end of the first ventilation hole 35a on the second stator core 30b side opens to the radial duct 55.

Figure 3 is a cross-sectional view taken along the line B-B of Figure 1. Figure 4 is a cross-sectional view taken along the line C-C of Figure 3. In Figure 3, the position of the first ventilation hole 35a in the circumferential direction is indicated by a broken line so that the difference in the positions of the first ventilation hole 35a and the second ventilation hole 35b can be easily understood. The second stator core 30b has a second ventilation hole 35b, which is a ventilation hole 35 that penetrates the second stator core 30b in the axial direction, formed at a position outside the groove portion 32 in the radial direction and near the outer circumferential surface of the second stator core 30b. The second ventilation hole 35b is formed at a position in the radial direction that is radially inward of the annular spacer 51 and near the inner circumferential surface of the annular spacer 51. As a result, the end of the second ventilation hole 35b on the first stator core 30a side opens into the radial duct 55.

The first ventilation holes 35a formed in the first stator core 30a are not formed at the radially outer positions of all of the grooves 32 formed in the stator core 30, but are formed at the radially outer positions of certain grooves 32 among the multiple grooves 32. The second ventilation holes 35b formed in the second stator core 30b are formed axially through the second stator core 30b at radially outer positions of grooves 32 that are in different circumferential positions from the grooves 32 in which the first ventilation holes 35a are formed on the radially outer side of the first stator core 30a.

More specifically, the first ventilation hole 35a formed in the first stator core 30a is formed at a radially outer position of every other groove 32 in the circumferential direction in the multiple grooves 32 formed in the stator core 30. Similarly, the second ventilation hole 35b formed in the second stator core 30b is formed at a radially outer position of every other groove 32 in the circumferential direction in the multiple grooves 32 formed in the stator core 30. In this case, the second ventilation hole 35b is formed at a radially outer position of each groove 32 that is at a different circumferential position from the groove 32 in which the first ventilation hole 35a is formed at a radially outer position in the multiple grooves 32 formed in the stator core 30.

In other words, when the grooves 32 are viewed in the circumferential direction, the first ventilation holes 35a formed in the first stator core 30a and the second ventilation holes 35b formed in the second stator core 30b are alternately formed for each groove 32 at the radially outer positions of the multiple grooves 32 formed in the stator core 30. As a result, the first ventilation holes 35a and the second ventilation holes 35b are formed at radially outer positions of the grooves 32 that are located at different circumferential positions. In other words, the first ventilation holes 35a and the second ventilation holes 35b are alternately opened for each radial duct 55 when the radial ducts 55 are viewed in the circumferential direction for the multiple radial ducts 55 that are radially arranged in the circumferential direction.

In this way, the ventilation duct 15 is formed in the bracket 10 supporting the stator core 30 in which the ventilation holes 35 are formed. The ventilation duct 15 formed in the bracket 10 has one end opening from the outside in the radial direction of the fan 75 to a position facing the outer end of the fan 75 in the radial direction, and the other end opening to a position facing the first ventilation hole 35a or the second ventilation hole 35b, and is formed as a hole that communicates between the openings at both ends. In other words, the ventilation duct 15 is a hole that is formed in the cross section of the bracket 10 shown in Figures 1 and 4, along the shape of the bracket 10 having the outer periphery 11 and the end face 12, from the position of the outer end of the fan 75 in the radial direction inside the machine to the part supporting the stator core 30.

In more detail, among the brackets 10 that support the stator core 30 from both sides in the axial direction, the first bracket 10a, which is the bracket 10 that supports the stator core 30 from the driving side in the axial direction relative to the stator core 30, has a first ventilation duct 15a formed as the ventilation duct 15. In addition, the second bracket 10b, which is the bracket 10 that supports the stator core 30 from the non-driving side in the axial direction relative to the stator core 30, has a second ventilation duct 15b formed as the ventilation duct 15.

The fans 75 are arranged on both sides of the rotor 72 in the axial direction, and include a first fan 75a arranged on the side where the first stator core 30a is located in the axial direction, and a second fan 75b arranged on the side where the second stator core 30b is located in the axial direction. That is, the first fan 75a is arranged on the drive side, which is the side where the first bracket 10a is located relative to the rotor 72 in the axial direction, and is a fan 75 that rotates integrally with the rotating shaft 70. The second fan 75b is arranged on the non-drive side, which is the side where the second bracket 10b is located relative to the rotor 72 in the axial direction, and is a fan 75 that rotates integrally with the rotating shaft 70.

Of the ventilation ducts 15 formed in the bracket 10, the first ventilation duct 15a has one end opening from the radial outside of the first fan 75a to a position facing the radial outer end of the first fan 75a, and the other end opening to a portion of the first bracket 10a that supports the first stator core 30a. The second ventilation duct 15b has one end opening from the radial outside of the second fan 75b to a position facing the radial outer end of the second fan 75b, and the other end opening to a portion of the second bracket 10b that supports the second stator core 30b.

Here, the bracket 10 supports the stator core 30 via the stator support member 13, and the stator support member 13 located between the first bracket 10a and the first stator core 30a is the first stator support member 13a, and the stator support member 13 located between the second bracket 10b and the second stator core 30b is the second stator support member 13b. The first stator support member 13a has a hole that communicates from the first ventilation duct 15a formed in the first bracket 10a to the first stator core 30a, and the hole formed in the first stator support member 13a is also treated as the first ventilation duct 15a. Similarly, a hole is formed in the second stator support member 13b that connects from the second ventilation duct 15b formed in the second bracket 10b to the second stator core 30b, and this hole formed in the second stator support member 13b is also treated as the second ventilation duct 15b.

The first ventilation hole 35a formed in the first stator core 30a has an end opposite to the side where the second stator core 30b is located in the axial direction that opens into the first stator support member 13a, but the first ventilation duct 15a opens into the portion of the first ventilation hole 35a that opens into the first stator support member 13a. In other words, the portion of the first ventilation duct 15a that opens into the first ventilation hole 35a is in the same position in the radial direction and in the circumferential direction as the first ventilation hole 35a. As a result, the first ventilation duct 15a is in communication with the first ventilation hole 35a.

In addition, the portion of the first ventilation duct 15a that opens toward the position of the outer end of the first fan 75a in the radial direction opens into the portion of the first bracket 10a that covers the first fan 75a from the outside in the radial direction. In other words, the shape of the inside of the first bracket 10a is formed in a shape that covers the first fan 75a from the outside in the radial direction near the outer periphery of the first fan 75a, and the first ventilation duct 15a opens in the portion that covers the first fan 75a from the outside in the radial direction. Therefore, the first ventilation duct 15a opens in a position that faces the first fan 75a from the outside in the radial direction near the outer periphery of the first fan 75a in the radial direction. As a result, the first ventilation duct 15a opens into a position that faces the rotary vanes 76 formed on the first fan 75a from the outside position in the radial direction.

The first ventilation ducts 15a thus formed are formed in multiple numbers on the first bracket 10a and the first stator support member 13a, and the multiple first ventilation ducts 15a are formed in the same circumferential positions as the multiple first ventilation holes 35a formed in the first stator core 30a. In other words, multiple first ventilation ducts 15a are formed on the first bracket 10a and the first stator support member 13a in correspondence with the multiple first ventilation holes 35a formed in the first stator core 30a.

The second ventilation hole 35b formed in the second stator core 30b has an end opposite to the side where the first stator core 30a is located in the axial direction that opens to the second stator support member 13b, but the second ventilation duct 15b opens to the part of the second ventilation hole 35b that opens to the second stator support member 13b. In other words, the part of the second ventilation duct 15b that opens to the second ventilation hole 35b has the same radial and circumferential positions as the second ventilation hole 35b. As a result, the second ventilation duct 15b is in communication with the second ventilation hole 35b.

In addition, the portion of the second ventilation duct 15b that opens toward the position of the outer end of the second fan 75b in the radial direction opens into the portion of the second bracket 10b that covers the second fan 75b from the outside in the radial direction. In other words, the shape of the second bracket 10b on the inside side is formed in a shape that covers the second fan 75b from the outside in the radial direction near the outer periphery of the second fan 75b, and the second ventilation duct 15b opens in the portion that covers the second fan 75b from the outside in the radial direction. Therefore, the second ventilation duct 15b opens in a position that faces the second fan 75b from the outside in the radial direction near the outer periphery of the second fan 75b in the radial direction. As a result, the second ventilation duct 15b opens into a position that faces the rotary vanes 76 formed on the second fan 75b from the outer position in the radial direction.

The second ventilation ducts 15b thus formed are formed in multiple locations on the second bracket 10b and the second stator support member 13b, and the multiple second ventilation ducts 15b are formed at the same circumferential positions as the multiple second ventilation holes 35b formed in the second stator core 30b. In other words, multiple second ventilation ducts 15b are formed on the second bracket 10b and the second stator support member 13b in correspondence with the multiple second ventilation holes 35b formed in the second stator core 30b.

The rotating electric machine 1 according to this embodiment includes the above-mentioned configuration, and an example of its operation will be described below. When the rotating electric machine 1 is in operation, power is supplied to the stator coil 40 of the stator 20. The stator 20 generates magnetic force by the power supplied to the stator coil 40. The magnetic force generated in the stator 20 generates an attractive force and a repulsive force between the permanent magnet of the rotor 72 and the stator 20, and the rotor 72 rotates integrally with the rotating shaft 70. The rotational driving force generated by the rotation of the rotating shaft 70 is output to an external device from a connecting member (not shown) attached to a connecting portion 71 located at the drive side end of the rotating shaft 70.

When the rotating electric machine 1 is in operation, heat is generated by the supply of power to the stator coil 40, but since the rotating electric machine 1 has a totally enclosed structure, air does not flow between the inside and outside of the machine, so the heat generated inside the machine is difficult to dissipate to the outside. In contrast, the rotating electric machine 1 according to this embodiment has ventilation holes 35 and radial ducts 55 formed in the stator 20, ventilation ducts 15 formed in the bracket 10 supporting the stator 20, and fans 75 arranged on both sides of the rotor 72 in the axial direction, making it easier to dissipate heat generated inside the machine to the outside.

In more detail, when the rotating shaft 70 rotates during operation of the rotating electric machine 1, the fans 75 arranged on both sides of the rotor 72 in the axial direction also rotate together with the rotating shaft 70. Since the fan 75 is provided with a rotating blade 76, when the fan 75 rotates, the rotating blade 76 also rotates in the circumferential direction, and the fan 75 rotates the air around the rotating blade 76 together with the rotating blade 76. As a result, a centrifugal force is generated in the air around the rotating blade 76, and the air located on the surface side where the rotating blade 76 is located in the axial direction of the fan 75 flows outward in the radial direction as shown by the arrows in Figures 1 and 4. In other words, when the fan 75 rotates, an airflow is generated in the air located on the surface side where the rotating blade 76 is located in the axial direction, flowing from the inside to the outside in the radial direction.

At a position near the outer periphery of the fan 75 in the radial direction, on the radial outside of the fan 75, is the opening of the ventilation duct 15 formed in the bracket 10. As a result, when the fan 75 rotates, air flowing from the inside to the outside in the radial direction near the fan 75 enters the ventilation duct 15 through the opening portion of the ventilation duct 15 formed in the bracket 10 that faces the fan 75.

When the rotating shaft 70 rotates, the fan 75 rotates with the rotation of the rotating shaft 70, and the air in the ventilation duct 15 flows from the end that opens to the fan 75 along the ventilation duct 15 toward the opposite end in the extension direction of the ventilation duct 15. The end of the ventilation duct 15 opposite the end that opens to the fan 75 faces the ventilation hole 35 formed in the stator core 30. Therefore, the air that enters the ventilation duct 15 from the end of the ventilation duct 15 that opens to the fan 75 and flows through the ventilation duct 15 flows out toward the ventilation hole 35 from the end of the ventilation duct 15 that faces the ventilation hole 35 of the stator core 30.

Specifically, the first ventilation duct 15a, which is the ventilation duct 15 formed in the first bracket 10a and the first stator support member 13a, faces the first ventilation hole 35a formed in the first stator core 30a, so that the air flowing through the first ventilation duct 15a from the portion that opens facing the first fan 75a flows toward the first ventilation hole 35a. As a result, in the first ventilation hole 35a formed in the first stator core 30a, as shown by the arrow in FIG. 1, the air that has flowed in from the first ventilation duct 15a flows from the end of the first ventilation hole 35a on the first ventilation duct 15a side toward the end on the side where the second stator core 30b is located.

The second ventilation duct 15b, which is the ventilation duct 15 formed in the second bracket 10b and the second stator support member 13b, faces the second ventilation hole 35b formed in the second stator core 30b, so that the air flowing through the second ventilation duct 15b from the portion that opens facing the second fan 75b flows toward the second ventilation hole 35b. As a result, in the second ventilation hole 35b formed in the second stator core 30b, as shown by the arrow in FIG. 4, the air that has flowed in from the second ventilation duct 15b flows from the end of the second ventilation hole 35b on the second ventilation duct 15b side toward the end on the side where the first stator core 30a is located.

Air flowing from inside the first ventilation hole 35a toward the second stator core 30b side, or air flowing from inside the second ventilation hole 35b toward the first stator core 30a side, flows from inside the first ventilation hole 35a or the second ventilation hole 35b toward the radial duct 55 formed between the first stator core 30a and the second stator core 30b.

Here, the first ventilation hole 35a and the second ventilation hole 35b are alternately opened for each radial duct 55 when the radial ducts 55 are viewed in the circumferential direction in order with respect to the multiple radial ducts 55 that are radially arranged in the circumferential direction. Therefore, the air flowing from the first ventilation hole 35a or the second ventilation hole 35b toward the radial duct 55 flows independently from the first ventilation hole 35a or the second ventilation hole 35b without interference between the air flowing from the first ventilation hole 35a to the radial duct 55 and the air flowing from the second ventilation hole 35b to the radial duct 55.

The first ventilation hole 35a and the second ventilation hole 35b open to the radial duct 55 at a position near the annular spacing piece 51. That is, the first ventilation hole 35a and the second ventilation hole 35b open to the radial duct 55 near the outer end of the radial duct 55 in the radial direction. The outer end of the radial duct 55 in the radial direction is blocked by the annular spacing piece 51 in the radial outward direction. Therefore, the radial outward air flow of the radial duct 55 is blocked by the annular spacing piece 51, and the air flowing into the radial duct 55 does not flow outward in the radial direction.

Air is sent sequentially from the first ventilation hole 35a and the second ventilation hole 35b to the radial duct 55, so that the air that flows into the radial duct 55 from the first ventilation hole 35a and the second ventilation hole 35b flows radially inward along each radial duct 55.

The air flowing radially inward inside the radial duct 55 flows around the portion of the stator coil 40 exposed inside the radial duct 55. At that time, the air flowing inside the radial duct 55 exchanges heat with the stator coil 40, which has generated heat as a result of the supply of power. In other words, the heat generated when current flows through the stator coil 40 is dissipated to the air flowing inside the radial duct 55.

In this way, while exchanging heat with the stator coil 40, the air flowing in the radial duct 55 flows radially inward, and when it reaches the position of the rotor 72 located on the radial inside of the radial duct 55, it flows through the gap G between the stator core 30 and the rotor 72. In other words, when the air flowing in the radial duct 55 reaches the position of the rotor 72 located on the radial inside of the stator core 30, it flows along the gap G between the stator core 30 and the rotor 72.

When the rotating electric machine 1 is driven, the fans 75 arranged on both sides of the rotor 72 in the axial direction cause the air around the fans 75 to flow toward the ventilation duct 15 located radially outside the fans 75. For this reason, air is more likely to flow toward the fan 75 in the parts of the machine other than the radial outside of the fan 75, i.e., the part on the face side where the rotating blades 76 of the fan 75 are arranged in the axial direction. For this reason, air that flows from inside the radial duct 55 toward the gap G between the stator core 30 and the rotor 72 flows through the gap G toward the fan 75.

For example, air flowing from the radial duct 55 into the gap G between the first stator core 30a and the rotor 72 flows toward the first fan 75a, which is closer to the first stator core 30a. Air flowing from the radial duct 55 into the gap G between the second stator core 30b and the rotor 72 flows toward the second fan 75b, which is closer to the second stator core 30b.

The air that flows through the gap G toward the fan 75 in this way leaves the gap G and reaches the position of the fan 75, then flows radially outward of the fan 75 as the fan 75 rotates, and flows into the ventilation duct 15. The air that flows into the ventilation duct 15 flows through the ventilation duct 15 and the ventilation holes 35, which are formed in positions close to the outer surface of the rotating electric machine 1.

In other words, the ventilation duct 15 is formed in the bracket 10 that separates the inside and outside of the rotating electric machine 1, and the ventilation holes 35 are formed near the outer peripheral surface of the stator core 30, so that the ventilation duct 15 and the ventilation holes 35 are formed near the outer surface of the rotating electric machine 1. Therefore, the air flowing through the ventilation duct 15 and the ventilation holes 35 can easily exchange heat with the air outside the machine.

Air flowing from the gap G between the stator core 30 and the rotor 72 toward the fan 75 exchanges heat with the stator coil 40, and the temperature of the air increases. Therefore, when the air with a high temperature flows from the fan 75 to the ventilation duct 15 and from the ventilation duct 15 to the ventilation hole 35, heat exchange occurs between the air in the ventilation duct 15 or the ventilation hole 35 and the air outside the machine, and the air in the ventilation duct 15 or the ventilation hole 35 dissipates heat to the air outside the machine.

By dissipating heat to the air outside the machine, the air, whose temperature has been reduced, flows from the ventilation holes 35 into the radial duct 55 and exchanges heat with the stator coil 40 exposed inside the radial duct 55. As a result, the stator coil 40 dissipates heat to the air flowing inside the radial duct 55.

When the rotating electric machine 1 is in operation, the fan 75 rotates in conjunction with the rotation of the rotating shaft 70, and the air inside the machine circulates from the fan 75 to the ventilation duct 15, the ventilation holes 35, the radial duct 55, the gap G between the stator core 30 and the rotor 72, and back to the fan 75. At that time, the heat generated in the stator coil 40 by the power being supplied to the stator coil 40 is dissipated to the air flowing through the radial duct 55, and the air whose temperature has increased due to the heat from the stator coil 40 dissipates heat to the air outside the machine as it flows through the ventilation duct 15 and the ventilation holes 35. As a result, the heat generated in the stator coil 40 is dissipated to the air outside the machine via the air circulating inside the machine, and the stator coil 40 is cooled.

The stator coil 40 is thus cooled by the air circulating inside the machine, but the first ventilation hole 35a formed in the first stator core 30a and the second ventilation hole 35b formed in the second stator core 30b are formed at radially outer positions of the groove portion 32, which are at different circumferential positions. In other words, the first ventilation hole 35a and the second ventilation hole 35b open to the radial duct 55, which are at different circumferential positions. Therefore, the air flowing from the first ventilation hole 35a to the radial duct 55 and the air flowing from the second ventilation hole 35b to the radial duct 55 do not collide, and the air flowing on the first ventilation hole 35a side and the air flowing on the second ventilation hole 35b side can each flow in one direction.

As a result, when the stator coil 40 is cooled by the circulating air, the air can be circulated efficiently, and therefore cooling can be performed efficiently. As a result, the cooling effect can be improved in the rotating electric machine 1 with a totally enclosed structure.

The first ventilation hole 35a and the second ventilation hole 35b are formed at the radially outer positions of every other groove portion 32 in the circumferential direction in the plurality of groove portions 32, and at the radially outer positions of the groove portions 32 whose circumferential positions are different from each other. This allows the air flow circulating through the first ventilation hole 35a and the air flow circulating through the second ventilation hole 35b to be uniform in the circumferential direction. Therefore, heat dissipation from the stator coil 40 to the air flowing through the radial duct 55, and heat dissipation from the air flowing through the ventilation duct 15 and the ventilation hole 35 to the air outside the machine can be distributed between the driving side and the non-driving side in the circumferential position and the axial direction. As a result, the cooling effect can be improved more reliably in the fully enclosed structure type rotating electric machine 1.

In addition, since the cooling effect can be improved in a totally enclosed rotating electric machine 1, the cooling effect can be improved while maintaining the totally enclosed structure, which has the advantage of eliminating the need for maintenance work such as cleaning inside the machine.

In addition, because fans 75 for circulating air inside the machine are arranged on both the driving side and the non-driving side, the amount of air blown by the fans 75 can be increased. This improves the cooling performance when cooling the stator coil 40 with the air blown by the fans 75. Furthermore, by improving the cooling performance in this way, it is possible to increase the capacity compared to a conventional rotating electric machine 1 with a totally enclosed structure.

[Modification]
In the above-described embodiment, the rotating motor 1 is a so-called frameless type rotating motor 1 in which the stator 20 is supported by brackets 10 from both sides in the axial direction and does not have a frame formed across the driving side and the anti-driving side, but the rotating motor 1 may also have a frame formed across the driving side and the anti-driving side.

In the above-described embodiment, the first ventilation holes 35a formed in the first stator core 30a and the second ventilation holes 35b formed in the second stator core 30b are both formed at positions radially outside every other groove portion 32 in the circumferential direction in the multiple groove portions 32, but the first ventilation holes 35a and the second ventilation holes 35b may be formed at positions radially outside the groove portions 32 other than every other groove portion 32. In other words, the first ventilation holes 35a and the second ventilation holes 35b may open in a manner other than alternating with the multiple radial ducts 55 formed side by side in the circumferential direction.

For example, two first ventilation holes 35a adjacent in the circumferential direction may open to two radial ducts 55 adjacent in the circumferential direction, and two second ventilation holes 35b adjacent in the circumferential direction may open to two radial ducts 55 adjacent in the circumferential direction, and these first ventilation holes 35a and radial ducts 55, and the second ventilation holes 35b and radial ducts 55 may be formed alternately in the circumferential direction.

In addition, if the first fan 75a and the second fan 75b have different sizes, shapes, etc., and therefore have different air volumes during rotation, the number of first ventilation holes 35a and the number of second ventilation holes 35b may be made different according to the difference in air volume between the first fan 75a and the second fan 75b. For example, the balance between the amount of air circulating on the driving side and the amount of air circulating on the anti-driving side may be adjusted by making the number of ventilation holes 35 through which air sent from the fan 75 on the side with a low air volume flow greater than the number of ventilation holes 35 through which air sent from the fan 75 on the side with a high air volume flow. The first ventilation holes 35a and the second ventilation holes 35b may be arranged in any manner as long as they open into different radial ducts 55.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

LIST OF SYMBOLS 1 Rotating electric machine 10 Bracket 10a First bracket 10b Second bracket 11 Outer periphery 12 End face 13 Stator support member 13a First stator support member 13b Second stator support member 15 Ventilation duct 15a First ventilation duct 15b Second ventilation duct 20 Stator 30 Stator core 30a First stator core 30b Second stator core 31 Inner periphery 32 Groove 35 Ventilation hole 35a First ventilation hole 35b Second ventilation hole 40 Stator coil 50 Duct forming member 51 Annular spacer 52 Plate-shaped spacer 55 Radial duct 60 Bearing housing 61 Bearing 70 Rotor 71 Connection 72 Rotor 73 Rotor retainer plate 75 Fan 75a First fan 75b Second fan 76 Rotating blade

Claims (2)

A rotor attached to a rotating shaft;
a stator having a first stator core and a second stator core that are arranged apart from each other on the radially outer side of the rotor and are arranged apart from each other in the axial direction of the rotating shaft, and a duct forming member that is arranged in a portion between the first stator core and the second stator core and is connected to the first stator core and the second stator core;
a first bracket disposed on an opposite side of the first stator core in the axial direction from a side where the second stator core is located, the first bracket supporting the first stator core and supporting the rotating shaft so as to be rotatable relative to the first stator core;
a second bracket that is disposed on an opposite side of the second stator core in the axial direction from a side where the first stator core is located, supports the second stator core, supports the rotating shaft relatively rotatably with respect to the second stator core, and
a first fan that is disposed on a side of the rotor where the first bracket is located in the axial direction and rotates integrally with the rotating shaft;
a second fan that is disposed on a side of the rotor where the second bracket is located in the axial direction and rotates integrally with the rotating shaft;
Equipped with
a groove portion is formed on an inner peripheral surface of the stator core, the groove portion extending in the axial direction across the first stator core and the second stator core, and a plurality of the groove portions are arranged in a circumferential direction of the stator core,
A stator coil is housed in the plurality of grooves,
The duct forming member is
an annular spacer disposed around the entire circumference of the stator core at an outer end of the stator core in the radial direction, and having both ends in the axial direction connected to the first stator core and the second stator core;
a plate-like spacer that is formed in a plate-like shape and is arranged such that the width direction of the plate is the axial direction and the thickness direction of the plate is the circumferential direction, both sides in the axial direction are connected to the first stator core and the second stator core, and an outer end in the radial direction is connected to the annular spacer;
having
A plurality of the plate-shaped spacing pieces are radially arranged between the respective groove portions,
A first ventilation hole penetrating the first stator core in the axial direction is formed in the first stator core at a position outside the groove portion in the radial direction,
In the second stator core, a second ventilation hole is formed at a radially outer position of the groove portion different from a circumferential position of the groove portion in which the first ventilation hole is formed on the radially outer side in the first stator core, the second ventilation hole penetrating the second stator core in the axial direction,
a first ventilation duct is formed in the first bracket, the first ventilation duct having one end that opens from an outer side of the first fan in the radial direction to a position facing an outer end of the first fan in the radial direction and the other end that opens to a position facing the first ventilation hole;
A rotating electric machine characterized in that a second ventilation duct is formed in the second bracket, one end of which opens from the outside of the radial direction of the second fan to a position opposite the radial outer end of the second fan, and the other end of which opens to a position opposite the second ventilation hole. The first ventilation holes are formed at radially outer positions of every other one of the groove portions in the circumferential direction,
The rotating electric machine according to claim 1 , wherein the second ventilation hole is formed at a radially outer position of each of the groove portions that is at a different circumferential position from the groove portions in which the first ventilation hole is formed at a radially outer position.

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