JP2021151098A - Rotating electric machine and vehicle including the same - Google Patents

Abstract

To provide a rotating electric machine capable of removing heat from a magnet in a high rotation region while improving fuel efficiency in a low/medium rotation region, and a vehicle equipped with the same.SOLUTION: A rotating electric machine 100 includes: a rotor 120; a rotating shaft 110 located in the center of the rotor 120; an axial cooling path 111 inside the rotating shaft 110, extending in the axial direction and sending a refrigerant to the rotor 120 in response to refrigerant supply; a refrigerant passage 122 provided in the rotor 120 so as to allow the refrigerant to flow from the axial cooling path 111; and a storage unit 112 located between the axial cooling path 111 and the refrigerant passage 122, receiving and storing the refrigerant from the axial cooling path 111 and sending the refrigerant to the refrigerant passage 122 by centrifugal force. The storage portion 112 is formed in a tapered shape that increases in diameter toward the refrigerant passage 122.SELECTED DRAWING: Figure 2

Description

The present invention relates to a rotary electric machine and a vehicle including the rotary electric machine.

In a vehicle drive device such as a hybrid vehicle, motors / generators (rotating electric machines) are arranged side by side, and each motor / generator has a rotating shaft, and the rotating shafts are arranged so as to overlap each other in a coaxial manner. .. The motor includes a stator on the non-rotating side and a rotor on the rotating side.

Drive motors for automobiles are used from low speed to high speed. At high rotation operating points, iron loss is dominant, so magnet heat generation is a concern. It is known that in order to cool a magnet, cooling oil (for example, ATF: Automatic Transmission Fluid) (refrigerant) is flowed in a rotating shaft to remove heat from the magnet temperature.

In the motor cooling circuit, the refrigerant supplied from the shaft (rotary shaft) arranged coaxially with the rotor is supplied to the axial oil passage inside the rotor to cool the rotor, and then arranged at both ends of the rotor. A refrigerant is supplied to the annular coil end protruding axially from the stator by using the centrifugal force of the rotor from the oil holes formed in one of the pair of end plates.
In addition, the structure is such that the refrigerant always flows into the rotor through a constant orifice (cooling hole) from the shaft. The refrigerant that has passed through the rotor hits the stator and enters between the rotor and the stator to cause friction. When friction due to the refrigerant occurs, rotational loss (oil shear loss) occurs in the rotor. Further, a pump loss, which is a rotation loss caused by the discharge of the refrigerant by rotation from the rotor, is generated, and the fuel consumption (electricity cost) is deteriorated.

In Patent Document 1, an opening is provided inside the refrigerant guide member in the radial direction so as to face the refrigerant supply port in the outward direction of the rotation shaft and at a position closer to the rotation axis than the refrigerant flow path in the radial direction. Described as a rotor for a rotary electric machine having an annular groove having a dam portion as a reservoir for distributing and supplying the refrigerant to each of the refrigerant flow paths by temporarily receiving the refrigerant discharged from the refrigerant supply port and then overflowing the state. Has been done. Patent Document 1 states that the refrigerant can be supplied more evenly to a large number of refrigerant flow paths in the rotor.

Japanese Unexamined Patent Publication No. 2011-254572

However, in the rotor for rotary electric machines described in Patent Document 1, since the amount of oil in the shaft for cooling the magnet depends on the rotation speed, it can be said that the flow rate of the refrigerant is always appropriate at a low rotation speed to a high rotation speed. There is a problem that there is no such thing. That is, at low to medium rotation speeds, in-shaft refueling becomes friction in the fuel consumption mode range, which causes deterioration of fuel consumption. On the other hand, at high rotation speeds, it is necessary to actively refuel the shaft in the heat damage mode range to remove heat from the magnet.

The present invention has been made in view of such a background, and includes a rotary electric machine capable of removing heat from a magnet in a high rotation speed region while improving fuel efficiency in a low / medium rotation speed region. The purpose is to provide a vehicle.

In order to solve the above-mentioned problems, the rotary electric machine according to claim 1 has a rotor, a rotary shaft arranged at the center of the rotor, and inside the rotary shaft, which extends in the axial direction to supply a refrigerant. Between the axial cooling passage and the refrigerant passage provided in the rotor so as to flow the refrigerant from the axial cooling passage, and the axial cooling passage for receiving and sending the refrigerant to the rotor. A storage unit that receives and stores the refrigerant from the axial cooling path and discharges the refrigerant to the refrigerant path by centrifugal force is provided, and the storage unit increases its diameter toward the refrigerant path. It is characterized by being formed in a tapered shape.

According to the present invention, it is possible to remove heat from the magnet in the high rotation speed region while improving fuel efficiency in the low / medium rotation speed region.

It is a perspective view of the rotor of the rotary electric machine which concerns on embodiment of this invention. It is sectional drawing of the upper part of the shaft center of the rotor of the rotary electric machine which concerns on embodiment of this invention. It is an enlarged view of the main part of the rotor of the rotary electric machine which concerns on embodiment of this invention. It is explanatory drawing explaining the shape of the storage part of the rotary shaft of the rotary electric machine which concerns on embodiment of this invention. It is sectional drawing of the rotor of the rotary electric machine of the comparative example 1. FIG. It is a figure explaining the structure of the refrigerant passage of the rotary shaft of the rotary electric machine of the comparative example 1, (a) shows the configuration example when the refrigerant passage is narrow, and (b) shows the configuration example when the refrigerant passage is wide. , (C) show a configuration example when the refrigerant passage is medium. It is a figure which shows the flow of the refrigerant in the rotor rotation of the rotary electric machine which concerns on embodiment of this invention in comparison with the comparative example 2, (a) shows the flow of the refrigerant in the rotor rotation of the rotary electric machine of the comparative example 2. It is a schematic diagram, (b) is a schematic diagram which shows the flow of the refrigerant during the rotor rotation of the rotary electric machine of this embodiment. It is a figure explaining the action effect of the rotary electric machine provided with the storage part having a tapered shape of the rotary electric machine and the orifice of a narrow oil passage which concerns on embodiment of this invention, (a) shows the case where the centrifugal force is small, and (b). ) Indicates a case where the centrifugal force is large. It is a figure which shows the relationship between the oil pressure and the amount of oil generated in the refrigerant passage of the rotary electric machine which concerns on embodiment of this invention, (a) shows the relationship between the required oil pressure and the amount of oil at a low rotation speed, and (b) is Shows the required oil pressure and oil amount at high rpm. It is a figure which shows the efficiency MAP of the rotary electric machine which concerns on embodiment of this invention. It is a figure which shows the fuel consumption mode and the heat damage range of the rotary electric machine which concerns on embodiment of this invention, and the rotary electric machine of the conventional example.

Next, the rotary electric machine and the vehicle provided with the rotary electric machine according to the embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In each figure, the same reference numerals are given to common parts, and duplicate description will be omitted.
(Embodiment)
FIG. 1 is a perspective view of a rotor of a rotary electric machine according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the upper part of the shaft center of the rotor of the rotary electric machine of FIG. FIG. 3 is an enlarged view of a main part of the rotor of FIG. FIG. 4 is an explanatory diagram illustrating the shape of the storage portion 112 of the rotating shaft 110 of FIG.
The rotary electric machine 100 according to the present embodiment is provided so as to be mounted on various vehicles 1 including, for example, a hybrid vehicle, an electric vehicle, a fuel cell vehicle, and the like.
As shown in FIGS. 1 and 2, the rotary electric machine 100 includes a rotor 120 and a rotary shaft 110 arranged at the center of the rotor 120.
A stator (not shown) fixed to a case (not shown) of the rotary electric machine 100 is arranged so as to surround the rotor 120.

<Rotating shaft 110>
As shown in FIGS. 1 to 3, the rotating shaft 110 is a hollow cylindrical member having an axial cooling path 111. The rotating shaft 110 is arranged at the center of the rotor core 121 of the rotor 120, and is pivotally supported by a case (not shown) via a pair of bearings (not shown).
The axial cooling path 111 is an internal space of the rotating shaft 110, extends in the axial direction, receives the supply of the refrigerant, and sends the refrigerant to the rotor core 121.

As shown in FIGS. 1 to 3, the rotating shaft 110 is located between the axial cooling passage 111 and the refrigerant passage 122 on the peripheral wall portion 110a, and receives and stores the refrigerant from the axial cooling passage 111 while storing the centrifugal force. The storage unit 112 is provided between the storage unit 112 and the refrigerant passage 122, and an orifice 113 which is formed to have a diameter smaller than that of the refrigerant passage 122 and has a predetermined orifice diameter. ..

As shown in FIGS. 3 and 4, the storage portion 112 is formed in a tapered shape in which the diameter thereof increases toward the refrigerant passage 122. Specifically, the storage unit 112 has a tapered surface 112a that forms a tapered shape that increases its diameter toward the refrigerant passage 122. The tapered shape (tapered surface 112a) of the storage portion 112 is created based on FIG. 8 and the like described later. The shape of the tapered surface 112a is not limited to a straight tapered shape when viewed in cross section, and may be a curved surface (that is, a curved surface) when viewed in cross section.

As shown by the arrow in FIG. 4, the refrigerant from the axial cooling passage 111 (see the arrow a in FIG. 4) is stored in the storage unit 112 and centrifugally is applied along the tapered surface 112a of the storage unit 112 (FIG. 4). (See arrow b) Move to the orifice port 113a. Then, it is throttled by the orifice 113 communicating with the refrigerant passage 122 of the rotor core 121 (see the arrow c in FIG. 4) and discharged to the refrigerant passage 122 of the rotor core 121 (see FIGS. 1 and 2) by centrifugal force.

<Rotor 120>
As shown in FIGS. 1 and 2, the rotor 120 is a rotor that is rotated by a magnetic force generated by a stator (not shown). The rotor 120 is formed in parallel with the cylindrical rotor core 121, the refrigerant passage 122 provided in the rotor core 121 so as to flow the refrigerant from the axial cooling path 111, and the axis O direction of the rotor core 121, and is a permanent magnet 130. The rotor core 121 is one end of the rotating shaft 110, the magnet insertion hole 123 for burying and fixing the refrigerant, the refrigerant flow path 124 for flowing the refrigerant (for example, ATF) from the refrigerant passage 122 along the permanent magnet 130 and recovering the heat of the permanent magnet 130. It is provided with an end face plate 125 (FIG. 1 shows only one) so as not to be displaced in the direction.
As shown in FIG. 1, the permanent magnets 130 are arranged at equal intervals in the circumferential direction on the outer peripheral surface side (diameter outside, stator side) of the rotor core 121.

As shown in FIG. 1, in the rotor core 121, thin ring plate-shaped electromagnetic steel sheets for the rotor core are laminated in the axis O direction and caulked. By press working, each electromagnetic steel sheet is provided with punching holes at equal intervals in the circumferential direction, so that a plurality of refrigerant flow paths 124 are formed at equal intervals in the circumferential direction of the rotor 120. The refrigerant introduced from the refrigerant passage 122 is supplied to the refrigerant flow path 124. The permanent magnets 130 are adhesively fixed to the outside of each refrigerant flow path 124 in the radial direction.

The introduced refrigerant (ATF) flows in contact with the permanent magnet 130, and the permanent magnet 130 is efficiently cooled. That is, while the refrigerant flows through the refrigerant flow path 124 and is discharged from the discharge port 124a (see the arrow d in FIG. 2), the heat of the permanent magnet 130 is recovered by the refrigerant, so that the permanent magnet 130 is reduced by the high temperature. Magnetism is suppressed.
As shown in FIGS. 1 and 2, the end face plate 125 is formed of a non-magnetic metal such as stainless steel or aluminum.

As shown in FIG. 2, the refrigerant flowing out from the axial cooling path 111 of the rotating shaft 110 passes through the disc-shaped refrigerant path 122 between the end face of the rotor core 121 and the end face plate 125 due to centrifugal force, and enters the refrigerant flow path 124. Be supplied.

Hereinafter, the cooling operation of the rotating shaft of the rotating electric machine configured as described above will be described.
First, Comparative Example 1 will be described.
<Comparative example 1>
FIG. 5 is a cross-sectional view of the rotor of the rotary electric machine of Comparative Example 1. The same components as those in FIG. 2 are designated by the same reference numerals.
As shown in FIG. 5, the rotary electric machine 1000 of Comparative Example 1 includes a rotary shaft 1110 and a rotor 120 fixed to the rotary shaft 1110.
The rotating shaft 1110 is provided with a refrigerant passage (oil passage) 1112 in the peripheral wall portion 1110a, which allows the refrigerant from the axial cooling passage 1111 to flow to the rotor core on the outer side in the radial direction by centrifugal force.
As shown in FIG. 5, the refrigerant (ATF) flows into the axial cooling passage 111. The refrigerant that has flowed into the axial cooling passage 111 is sent out from the refrigerant passage 1112 to the rotor core side by centrifugal force. The width of the refrigerant passage 1112 is determined as follows.

FIG. 6 is a diagram for explaining the structure of the refrigerant passage of the rotating shaft of the rotating electric machine of Comparative Example 1. FIG. 6A shows a configuration example when the refrigerant path is narrow (refrigerant path 1112a), FIG. 6B shows a configuration example when the refrigerant path is wide (refrigerant path 1112b), and FIG. 6C shows a configuration example. A configuration example is shown when the refrigerant passage is medium (refrigerant passage 1112c).
As a premise, inertia (friction) increases due to the flow of the refrigerant (ATF) through the rotor core 121. Therefore, there is a demand to suppress the flow rate of the refrigerant to the rotor core 121 to an appropriate amount. On the other hand, if the flow rate of the refrigerant to the rotor core 121 is not an appropriate amount, the suppression of magnet heat generation becomes insufficient.

Further, the requirements for the inertia (friction) and the flow rate are different depending on the rotation speed of the rotary electric machine. That is, the above requirements are as follows according to the rotation speed of the rotary electric machine.
(1) Low rotation speed (fuel efficiency range)
At low rotation speeds (fuel economy range), in-shaft refueling becomes inertia (friction), and the lower the inertia, the better the fuel economy. There is no problem even if the flow rate is low. Therefore, at low rotation speeds, it is necessary to consider the magnitude of inertia. When applied to the structure of the refrigerant passage of the rotating shaft of FIG. 6, FIG. 6A shows a case where the refrigerant passage is narrow (refrigerant passage 1112a), and the inflow of the refrigerant into the refrigerant passage 122 of the rotor core 121 is small. The inertia is small and preferable. FIG. 6B shows a case where the refrigerant path is wide (refrigerant path 1112b), and since a large amount of refrigerant flows into the rotor core 121, inertia is large and is not preferable in terms of improving fuel efficiency.

(2) High rotation speed (heat damage area)
As with the case of low rotation speed, the lower the inertia, the better the fuel efficiency. However, heat cannot be removed unless the flow rate is high. That is, the deterioration of fuel efficiency is tolerated, and heat removal is prioritized. When applied to the structure of the refrigerant passage of the rotating shaft of FIG. 6, FIG. 6A shows a case where the refrigerant passage is narrow (refrigerant passage 1112a), and the flow of the refrigerant into the refrigerant passage 122 of the rotor core 121 is small. Although the inertia is small, the flow rate is small and the heat removal is not sufficient. If this condition continues, there is concern about damage to the magnet.
Further, in FIG. 6B, when the refrigerant passage is wide (refrigerant passage 1112b), there is a large amount of refrigerant flowing into the rotor core 121 and the flow rate is large, so that there is no problem with heat removal.

(3) Summary In the low rotation speed (fuel consumption region), the configuration that must be avoided from the viewpoint of the inertia is the case where the refrigerant passage shown in FIG. 6B is wide (refrigerant passage 1112b). On the other hand, in the high rotation speed (fuel consumption region), the configuration that must be avoided from the viewpoint of the flow rate is the case where the refrigerant passage shown in FIG. 6A is narrow (refrigerant passage 1112a). As described above, the low rotation speed (fuel consumption region) and the high rotation speed (fuel consumption region) have conflicting demands regarding the width of the refrigerant path. Therefore, in Comparative Example 1, the width of the refrigerant passage is intermediate between the two, and the configuration in which the refrigerant passage shown in FIG. 6 (c) is medium (refrigerant passage 1112c), that is, the inertia and the flow rate are both. It had a medium configuration.
However, since heat removal at high rotation speed is prioritized, as shown in the conventional example of FIG. 11 below, the flow rate (friction) at low to medium rotation speed is large, and fuel consumption is sacrificed.

<Flow of refrigerant (ATF) during rotor rotation>
The basic concept of the present invention will be described with reference to FIGS. 4, 7 and 8.
FIG. 4 is a schematic view showing the flow of the refrigerant during rotor rotation.
As shown by the arrow a in FIG. 4, the refrigerant (ATF) (see the shaded area in FIG. 4) flows into the axial cooling passage 111 and is stored in the storage unit 112.
Due to the rotation of the rotating shaft 110, the centrifugal force F represented by the equation (1) is applied to the refrigerant.

F = mv ² / r ... (1)

F: Centrifugal force [N]
m: Mass [g]
v: Speed (rotational speed)
r: Diameter (distance from the central axis of the rotating shaft to the inlet of the refrigerant passage 122)

The refrigerant stored in the storage unit 112 moves by centrifugal force F along the tapered surface 112a of the storage unit 112 to the orifice port 113a communicating with the refrigerant passage 122 (see arrow b in FIG. 4).
The refrigerant that has moved to the orifice port 113a is throttled by the orifice 113 (see arrow c in FIG. 4) and discharged to the rotor core 121 (see FIGS. 1 and 2) by centrifugal force.

<Structure of rotating shaft storage>
FIG. 7 is a diagram showing the flow of the refrigerant during rotor rotation in comparison with Comparative Example 2 in the present embodiment. FIG. 7A is a schematic view showing the flow of the refrigerant during the rotor rotation of the rotary electric machine of Comparative Example 2 of FIG. FIG. 7B is a schematic view showing the flow of the refrigerant during the rotation of the rotor of the rotary electric machine of the present embodiment of FIG.

As shown in FIG. 7A, the rotating shaft 1110 of Comparative Example 2 contains a rectangular storage portion 1113 for storing the refrigerant from the axial cooling passage 1111 and a refrigerant held by the rectangular storage portion 1113. It is provided with a refrigerant passage 1112 that flows through the rotor core on the outer side in the radial direction by centrifugal force.
In Comparative Example 2 of FIG. 7A, the diameter of the axial cooling passage 1111 (axial core oil passage) of the rotating shaft 1110 is Φ10, and the diameter of the refrigerant passage 1112 (oil passage) is Φ1.
As shown in FIG. 7A, the refrigerant (ATF) flows into the axial cooling path 1111. The inflowing refrigerant is temporarily held in a circular shape by the rectangular storage unit 1113, and the refrigerant stored in the rectangular storage unit 1113 is sent out from the refrigerant passage 1112 to the rotor core side by centrifugal force.

In Comparative Example 2, unlike the tapered storage portion 112 (see FIGS. 1 to 4) of the present embodiment, the refrigerant stored in the rectangular storage portion 1113 is subjected to the refrigerant passage 1112 side even when subjected to centrifugal force. (Refer to arrow d in FIG. 7A). In other words, in Comparative Example 2, the refrigerant is statically held in the rectangular storage portion 1113 even when it receives centrifugal force. Therefore, in the rotary electric machine of Comparative Example 2, the flow rate of the refrigerant sent from the refrigerant passage 1112 to the rotor core side does not change so much even if the rotation speed changes (see arrow e in FIG. 7A). Therefore, it is difficult to control the flow rate of the refrigerant according to the rotation speed.

On the other hand, in the present embodiment, as shown in FIG. 7B, the storage unit 112 has a tapered shape, so that when centrifugal force is applied, the refrigerant flows along the tapered surface 112a of the storage unit 112. Move to the 122 side. That is, since the storage portion 112 has a tapered shape, the refrigerant positively flows into the refrigerant passage 122 (oil passage) when centrifugal force is applied.

<Action and effect of storage unit 112 and refrigerant passage 122>
Next, the operation and effect of the rotary electric machine 100 (see FIGS. 1 to 3) including the storage portion 112 having a tapered shape and the orifice 113 of the narrow oil passage will be described.
FIG. 8 is a diagram illustrating the operation and effect of the rotary electric machine 100 including the storage portion 112 having a tapered shape and the orifice 113 of a narrow oil passage. FIG. 8A shows a case where the centrifugal force is small, and FIG. 8B shows a case where the centrifugal force is large.

・ Low rotation speed (fuel consumption range) (see Fig. 8 (a))
As described above, in the low rotation speed (fuel consumption region), the lower (smaller) the inertia (friction), the better the fuel consumption. Moreover, there is no problem even if the flow rate is low.
As shown by the thin arrow in FIG. 8A, the rotary shaft 110 of the present embodiment has a small centrifugal force at a low rotation speed, so that the refrigerant is sent to the refrigerant passage 122 side on the tapered surface 112a of the storage portion 112. The force to move is small. However, since the orifice 113 is a narrow oil passage, the required amount of oil is secured. Therefore, the flow rate is low.

・ High rotation speed (heat damage area) (see Fig. 8 (b))
As described above, at a high rotation speed (heat damage region), the fuel efficiency is improved when the inertia (friction) is low (small), as in the case of the low rotation speed (fuel efficiency region). However, heat cannot be removed unless the flow rate is high. In addition, heat removal is prioritized over fuel efficiency.
As shown by the thick arrow in FIG. 8B, the rotary shaft 110 of the present embodiment has a large centrifugal force at a high rotation speed, so that the refrigerant stored in the storage unit 112 is along the tapered surface 112a. It actively moves to the orifice 113 side. Therefore, the flow rate becomes large.

<Relationship between oil pressure and oil amount generated in the oil passage>
Next, the relationship between the oil pressure and the amount of oil generated in the refrigerant passage 122 (oil passage) will be described.
FIG. 9 is a diagram showing the relationship between the oil pressure and the amount of oil generated in the refrigerant passage 122 (oil passage). FIG. 9 (a) shows the relationship between the required oil pressure and the amount of oil at a low rotation speed (up to 8,000 rpm), and FIG. 9 (b) shows the required oil pressure and the amount of oil at a high rotation speed (from 10,000 rpm). show. The horizontal axis of FIG. 9 is the oil pressure [kpa] generated in the oil passage, and the vertical axis is the amount of oil [L / min] generated in the oil passage.

As shown in FIG. 9A, the structures of the refrigerant passage 122 (oil passage) and the storage portion 112 are set so that the oil pressure and the amount of oil are on this curve at a low rotation speed (~ 8,000 rpm). .. Specifically, it is as follows.
As shown in FIG. 6C, in Comparative Example 1, the refrigerant passage 1112c of the rotating shaft had to have a medium size. The broken line in FIG. 9A shows the required oil pressure and the amount of oil at a low rotation speed (up to 8,000 rpm) when the refrigerant passage 1112c in Comparative Example 1 is used.

On the other hand, in the present embodiment, as shown in FIG. 8A, the storage portion 112 in which the rotating shaft 110 receives and stores the refrigerant and sends it to the refrigerant passage 122 by centrifugal force, and the diameter of the storage portion 112 is larger than that of the refrigerant passage 122. Since the structure is provided with an orifice 113 formed in a small size, the amount of in-shaft oil for cooling the magnet is reduced by the refrigerant passage 122, which is a narrowed oil passage, at a low rotation speed, that is, when the centrifugal force is small. (See arrow g in FIG. 9A). Further, the oil pressure can be lowered (see the arrow f in FIG. 9A), whereby the inertia (friction) can be reduced as compared with Comparative Example 1.

As shown in FIG. 9B, at high rpm (10,000 rpm ~), as at low rpm (~ 8,000 rpm), the orifice 113 and the refrigerant path are arranged so that the oil pressure and the amount of oil are on this curve. The structure of 122 (oil channel) and the storage unit 112 is set.
The broken line in FIG. 9B shows the required oil pressure and the amount of oil at a high rotation speed (10,000 rpm or more) when the refrigerant passage 1112c in Comparative Example 1 is used. At the high rotation speed (10,000 rpm or more), the required oil pressure and the amount of oil are originally larger than those at the low rotation speed (up to 8,000 rpm) shown in FIG. 9 (b).

On the other hand, in the present embodiment, at a high rotation speed, the refrigerant stored in the storage unit 112 is transferred to the tapered surface 112a by using a large centrifugal force in addition to the refrigerant passage 122 which is a narrowed oil passage. The amount of oil can be secured by actively moving the refrigerant passage along the line to the side of the refrigerant passage 122. That is, as shown by the arrow h in FIG. 9B, the oil pressure can be increased as compared with Comparative Example 1, the in-shaft flow rate for cooling the magnet can be increased, and heat removal can be achieved.

As described above, in the present embodiment, at a high rotation speed, the storage unit 112 uses a large centrifugal force to secure the amount of oil in the shaft for cooling the magnet, and at a low rotation speed, the orifice 113 narrows the oil passage to reduce the oil pressure. To reduce the amount of oil.

<Effect>
FIG. 10 is a diagram showing the efficiency MAP of the rotary electric machine. The horizontal axis of FIG. 10 represents the rotation speed [rpm], and the vertical axis represents the torque [Nm].
When the rotary electric machine 100 (see FIG. 1) is mounted on a vehicle, for example, it is desirable to operate the rotary electric machine 100 (see FIG. 1) at a low to medium rotation speed within the fuel consumption mode range shown by reference numeral i in FIG. On the other hand, at a high rotation speed, it is required to operate within the heat damage range shown by reference numeral j in FIG.

The rotary electric machine 100 (see FIG. 1) of the present embodiment lowers the oil pressure in the low to medium rotation speed fuel mode range to reduce friction due to in-shaft refueling, and is positive in the high rotation speed heat damage mode range. The permanent magnet 130 can be deheated by lubrication in the shaft.

FIG. 11 is a diagram showing a comparison between the fuel consumption mode and the heat damage range of the rotary electric machine of the present embodiment and the conventional example. The horizontal axis of FIG. 11 represents the rotation speed [rpm], and the vertical axis represents the flow rate (friction) [Nm].
When the rotary electric machine 100 (see FIG. 1) is mounted on a vehicle, for example, it is desirable to operate the rotary electric machine 100 (see FIG. 1) within the “fuel consumption mode range” shown by reference numeral i in FIG. 10 at low to medium rotation speeds. On the other hand, at a high rotation speed, it is required to operate within the "heat damage range" shown by reference numeral j in FIG.
The rotary electric machine 100 (see FIG. 1) of the present embodiment can reduce the friction due to the in-shaft refueling by lowering the oil pressure in the fuel consumption mode of low to medium rotation speed. In the heat damage range of high rotation speed, it is possible to positively refuel in the shaft to achieve magnet heat removal almost the same as in the conventional example.

In this way, the flow rate becomes low in the low to medium rotation range, and fuel efficiency can be improved. In addition, the function of the rotary electric machine 100 can be protected by setting the same flow rate for heat damage at high rotation.

As described above, the rotary electric machine 100 is inside the rotor 120, the rotary shaft 110 arranged at the center of the rotor 120, and the rotary shaft 110, and extends in the axial direction to receive the supply of the refrigerant. A shaft located between the axial cooling path 111 that sends the refrigerant to the 120, the refrigerant path 122 provided in the rotor 120 so that the refrigerant from the axial cooling path 111 flows, and the axial cooling path 111 and the refrigerant path 122. A storage unit 112 that receives and stores the refrigerant from the core cooling passage 111 and sends the refrigerant to the refrigerant passage 122 by centrifugal force is provided, and the storage unit 112 has a tapered shape that increases its diameter toward the refrigerant passage 122. Is formed in.

The conventional technique is a simple oil channel width change as in Comparative Example 2 (see FIG. 6). Further, since the amount of oil in the shaft for cooling the magnet depends on the rotation speed, it cannot always be said that the flow rate of the refrigerant is appropriate at low rotation speed to high rotation speed.
On the other hand, in the present embodiment, the rotary electric machine 100 includes a storage unit 112 having a tapered shape and an orifice 113 of a narrow oil passage, and by utilizing centrifugal force, the action of the storage unit 112 on the refrigerant is changed. .. That is, in the low to medium rotation speed fuel mode range, the oil pressure is lowered to reduce friction due to in-shaft lubrication, and in the high rotation speed heat damage mode range, in-shaft lubrication is actively performed to remove the permanent magnet 130. Can be heated.

In the rotary electric machine 100, the rotary shaft 110 includes an orifice 113 having a predetermined orifice diameter formed between the storage unit 112 and the refrigerant passage 122 and having a diameter smaller than that of the refrigerant passage 122.

With this configuration, it is possible to improve fuel efficiency in the low / medium rotation speed region while securing the required amount of oil, and it is possible to remove heat from the magnet in the high rotation speed region.

It should be noted that the present invention is not limited to each of the above embodiments, and it goes without saying that various configurations can be adopted based on the contents described in this specification.

The hybrid vehicle 1 is mentioned as the cooling structure, but the present invention is not limited to this as long as it is a structure provided with a rotating electric machine (motor and generator) and which needs to be cooled. For example, the hybrid vehicle 1 may be an electric vehicle or a fuel cell vehicle that does not have an engine and uses only a motor as a drive source.

1 Hybrid vehicle (vehicle)
100 Rotating electric machine 110 Rotating shaft 111 Axis cooling path 112 Reservoir 112a Tapered surface 113 orifice 113a orifice port 120 Rotor 121 Rotor core 122 Refrigerant path 123 Magnet insertion hole 124 Refrigerant flow path 125 End face plate 130 Permanent magnet

Claims (3)

With the rotor
A rotation shaft arranged in the center of the rotor and
An axial cooling path inside the rotating shaft that extends in the axial direction, receives the supply of the refrigerant, and sends the refrigerant to the rotor.
A refrigerant passage provided in the rotor so as to allow the refrigerant to flow from the axial cooling passage, and a refrigerant passage provided in the rotor.
A storage unit located between the axial cooling passage and the refrigerant passage, which receives and stores the refrigerant from the axial cooling passage and discharges the refrigerant to the refrigerant passage by centrifugal force, is provided.
The rotating electric machine is characterized in that the storage portion is formed in a tapered shape whose diameter is increased toward the refrigerant passage. The rotary electric machine according to claim 1, wherein the rotating shaft includes an orifice between the storage portion and the refrigerant passage and having a predetermined orifice diameter formed to be smaller than the refrigerant passage. .. A vehicle equipped with the rotary electric machine according to claim 1 or 2.

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