Motor device

Abstract

To cool a DCDC converter while minimizing the number of cooling pipes.SOLUTION: To provide a motor device that stores, in an identical case, a motor and a power control unit on which at least a DCDC converter is mounted, the case having a partition wall between the motor and the power control unit, the motor device including a cooling pipe which is arranged on the motor, through which a cooling medium circulates, and which has a first cooling hole for discharging the cooling medium to the motor and a second cooling hole for discharging the cooling medium to the partition wall. As a result, the DCDC converter can be cooled while limiting an increase in the number of cooling pipes.SELECTED DRAWING: Figure 2

Description

Technical Field

[0004] ,

[0005] , ,

[0001] The present disclosure relates to a motor device.

Background Art

[0002] Conventionally, as this type of motor device, there has been proposed a device including a power control unit (PCU) having a drive circuit for driving a motor, and a cooling circuit for cooling the power control unit with a cooling medium (cooling water). In this device, the cooling medium for cooling the power control unit is circulated through a water jacket in the cylinder head of the engine. As a result, when there is a margin in the cooling performance of the cooling medium for cooling the power control unit, the engine is cooled with the surplus cooling performance.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a motor device including a motor housed in a case, there is a type in which a cooling pipe through which a cooling medium flows is arranged above the motor, and the cooling medium is discharged from cooling holes formed in the cooling pipe to cool the motor. When housing a power control unit in such a case, it has been recognized as an important issue to cool the DCDC converter in the power control unit. As a method for cooling the DCDC converter, it is conceivable to newly add a cooling pipe through which a cooling medium flows in the vicinity of the power control unit. However, in this method, the number of cooling pipes increases, and the entire device becomes larger. <oo00027> The motor device of this disclosure primarily aims to cool a DC-DC converter while suppressing an increase in the number of cooling pipes. [Means for solving the problem]

[0006] The motor device of this disclosure employs the following means to achieve the main objective described above.

[0007] The motor device of this disclosure is A motor device comprising a motor and a power control unit equipped with at least a DC-DC converter housed in the same case, wherein the case has a partition wall between the motor and the power control unit, A cooling pipe positioned above the motor, through which a cooling medium flows, having a first cooling hole for discharging the cooling medium to the motor, and a second cooling hole in the partition wall for discharging the cooling medium. The gist of it is that it is equipped with the following features.

[0008] In the motor device of this disclosure, a cooling pipe is positioned above the motor. This cooling pipe has a first cooling port through which a cooling medium flows and for discharging the cooling medium to the motor, and a second cooling port for discharging the cooling medium to a partition wall. As a result, using a single cooling pipe, the cooling medium discharged from the second cooling port to the partition wall can cool the power control unit, and consequently the DC-DC converter, through the partition wall. This makes it possible to cool the DC-DC converter while suppressing an increase in the number of cooling pipes. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the configuration of the motor device 20 of this embodiment. [Figure 2] Figure 1(b) is a schematic diagram showing the cross-sectional configuration along line BB. [Figure 3] This is an explanatory diagram illustrating the general configuration of the motor device 120 in another embodiment. [Modes for carrying out the invention]

[0010] Embodiments of the present disclosure will be described with reference to the drawings. Figure 1 is a schematic diagram showing the configuration of the motor device 20 of this embodiment. Figure 1(a) is a schematic diagram showing the configuration of a side view of the motor device 20 with a part of it cut out. Figure 1(b) is a schematic diagram showing the configuration of the cross section along line AA in Figure 1(a). Figure 2 is a schematic diagram showing the configuration of the cross section along line BB in Figure 1(b). In Figure 2, the thick arrow indicates an example of the direction of discharge of the cooling oil.

[0011] This is a schematic diagram showing the configuration of the motor device 20 of this embodiment. The motor device 20 is installed in a hybrid vehicle that includes an engine, motors MG1 and MG2, a planetary gear whose carrier is connected to the engine's crankshaft, a battery that exchanges power with motors MG1 and MG2, and a power control unit (hereinafter referred to as "PCU") 30. The motor device 20 comprises motors MG1 and MG2, the PCU 30, and a cooling device 40.

[0012] Motors MG1 and MG2 are configured, for example, as synchronous generator motors. Motors MG1 and MG2 are equipped with rotors. Details of the rotor configuration will be described in other embodiments later. The rotor of motor MG1 is connected to the sun gear of the planetary gear. The rotor of motor MG2 is connected to the ring gear of the planetary gear.

[0013] The PCU 30 is positioned above the motors MG1 and MG2 and includes a drive circuit 32 and a DC-DC converter 34. The drive circuit 32 is configured as a circuit for driving the motors MG1 and MG2 and, although not shown, includes two inverters for driving the motors MG1 and MG2, and a boost converter that boosts the voltage from the battery and supplies it to the inverters. The drive circuit 32 is positioned above the DC-DC converter 34. The DC-DC converter 34 exchanges power between the drive circuit 32 and auxiliary equipment and auxiliary batteries (not shown), involving voltage conversion.

[0014] Motors MG1, MG2, and PCU30 are housed in the same case 22. The case 22 has a partition wall 22a between motors MG1, MG2 and PCU30.

[0015] The cooling device 40 includes a strainer 42, shaft core cooling oil passages 44 and 46, and a cooling pipe 48. The strainer 42 is provided in the oil passage Pl for the cooling oil, which serves as the cooling medium, and removes foreign matter contained in the cooling oil stored at the bottom of the case 22 and sucked up by an oil pump (not shown). The shaft core cooling oil passages 44 and 46 will be described in detail in other embodiments described later. The cooling pipe 48 is located above the motor MG2. The cooling pipe 48 extends in the axial direction of the motor MG2, with one end connected to the oil passage Pl and the other end reaching the vicinity of the DC-DC converter 34. Cooling oil flows inside the cooling pipe 48. The cooling pipe 48 includes a first cooling hole 48a and a second cooling hole 48b. The first cooling hole 48a is formed to face downward so that cooling oil is discharged to the motor MG2. The second cooling hole 48b is formed to face diagonally downward so that cooling oil is discharged to the partition wall 22a separating the DC-DC converter 34 and the motor MG2 of the PCU 30. The cooling oil discharged from the first and second cooling holes 48a and 48b cools the motor MG2 and the DC-DC converter 34 and falls to the bottom of the case 22. In this way, the motor MG2 is cooled by the cooling oil discharged from the first cooling hole 48a, and the DC-DC converter 34 is cooled by the cooling oil discharged from the second cooling hole 48b. Therefore, using a single cooling pipe 48, the power control unit and, consequently, the DC-DC converter 34 can be cooled through the partition wall 22a by the cooling medium discharged from the second cooling hole 48b to the partition wall 22a. This makes it possible to cool the DC-DC converter 34 without adding a dedicated cooling pipe for the DC-DC converter 34, that is, while suppressing an increase in the number of cooling pipes. In this embodiment, cooling oil is used as the cooling medium, but cooling water may be used instead of cooling oil.

[0016] In the motor device 20 of this embodiment described above, a cooling pipe 48 is provided which is positioned above the motor MG2 and through which cooling oil flows. The cooling pipe 48 has a first cooling hole 48a for discharging cooling oil to the motor MG2 and a second cooling hole 48b for discharging cooling oil to the partition wall 22a. Therefore, the DC-DC converter 34 can be cooled while suppressing an increase in the number of cooling pipes.

[0017] In the embodiment described above, the motor MG2 and DC-DC converter 34 are cooled by providing first and second cooling holes 48a and 48b in the cooling pipe 48. However, the motor MG2 and DC-DC converter 34 may also be cooled using the axial cooling oil passage 46. Figure 3 is an explanatory diagram illustrating the schematic configuration of the motor device 120 of another embodiment. In the figure, the thick arrows indicate an example of the cooling oil discharge direction. The motor device 120 has the same configuration as the motor device 20, except that a part of the end plate Pe of the rotor R2 of the motor MG2 is bent. Therefore, a detailed explanation of the configuration identical to that of the motor device 20 will be omitted.

[0018] Here, the rotor R2 and the shaft core cooling oil passages 44 and 46 of the motor MG2 will be described. The rotor R2 comprises a rotor core Rcore having multiple stacked hollow disc-shaped electromagnetic steel sheets and end plates Pe positioned at both ends in the stacking direction of the electromagnetic steel sheets (the axial direction of the motor MG2), and a rotor shaft Raxl that penetrates the hollow of the rotor core Rcore. The shaft core cooling oil passage 46 is formed so that one end is connected to the oil passage Pl, passes through the rotor shaft Raxl and rotor core Rco of the rotor R2 of the motor MG2, and the other end reaches the end plate Pe and opens. Note that the rotor of the motor MG1 has the same configuration as the rotor R2 of the motor MG2 except for the dimensions, so a detailed explanation will be omitted. Cooling oil is supplied to the shaft core cooling oil passages 44 and 46 from the oil passage Pl. The cooling oil supplied to the shaft core cooling oil passage 46 flows through the shaft core cooling oil passage 46 and is discharged from the other end of the shaft core cooling oil passage 46. Since the shaft core cooling oil passage 44 has the same configuration as the shaft core cooling oil passage 46, except that it is provided in the motor MG1, a detailed explanation will be omitted.

[0019] In the motor device 120, a bent portion Pef that bends outward is formed around an opening where the axial center cooling oil passage 46 of the end plate Pe opens. Due to such a bent portion Pef, the cooling oil is discharged in directions toward the stator and toward the partition wall 22a from the opening of the axial center cooling oil passage 46. Thereby, the DCDC converter 34 can be cooled without adding a cooling pipe dedicated to cooling the DCDC converter 34, that is, while suppressing an increase in the number of cooling pipes.

[0020] In the above-described embodiment, the vehicle on which the motor devices 20 and 120 are mounted is in the form of a hybrid vehicle including an engine, motors MG1 and MG2, and a planetary gear. However, it may be in the form of a hybrid vehicle in which the engine and the motor MG2 are connected via a clutch without including the motor MG1 or the planetary gear, or in the form of an electric vehicle including only the motor MG2 without including the engine, the motor MG1, or the planetary gear.

[0021] The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the motor MG2 corresponds to the "motor", the PCU 30 corresponds to the "power control unit", the DCDC converter 34 corresponds to the "DCDC converter", the cooling pipe 48 corresponds to the "cooling pipe", the first cooling hole 48a corresponds to the "first cooling hole", and the second cooling hole 48b corresponds to the "second cooling hole".

[0022] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems is an example for specifically explaining the form for implementing the invention described in the column of means for solving the problems in the embodiment, and does not limit the elements of the invention described in the column of means for solving the problems. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the column of means for solving the problems.

[0023] The embodiments for implementing the present disclosure have been described above. However, the present disclosure is not limited to such embodiments, and it is needless to say that it can be implemented in various forms without departing from the gist of the present disclosure.

Industrial Applicability

[0024] The present disclosure can be used in the manufacturing industry of motor devices and the like.

Explanation of Signs

[0025] 20, 120 Motor device, 22a Partition wall, 30 Power control unit (PCU), 32 Drive circuit, 34 DCDC converter, 40 Cooling device, 42 Strainer, 44, 46 Axial core cooling oil passage, MG1, MG2 Motor, Pe End plate, Pef Bent portion, Pl Oil passage, R2 Rotor, Rcore Rotor core, Raxl Rotor shaft.

Claims

[Claim 1] A motor device comprising a motor and a power control unit equipped with at least a DC-DC converter housed in the same case, wherein the case has a partition wall between the motor and the power control unit, A cooling pipe positioned above the motor, through which a cooling medium flows, having a first cooling hole for discharging the cooling medium to the motor, and a second cooling hole in the partition wall for discharging the cooling medium. A motor device equipped with the following features.

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