Wound field motor

Abstract

To provide a wound field motor capable of improving cooling performance.SOLUTION: A wound field motor 1 includes a shaft 21 having a hollow portion 21a, a rotor core 22 fixed to the shaft 21, and a rotor coil 23 wound around the rotor core 22. The rotor core 22 includes a cylindrical back yoke 22a, a plurality of teeth 22b extending radially outward from the outer peripheral surface of the back yoke 22a and wound around the rotor coil, and cooling holes 22c extending axially, provided on each of the plurality of teeth 22b.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to wound field motors. [Background technology]

[0002] Patent Document 1 describes a technique for providing cooling holes near the shaft of a rotor core in a wound-field motor. In this technique, a coolant path is formed in the back yoke of the rotor core, and the coolant for axial oil cooling of the shaft passes through the coolant path to cool the rotor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-39230 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 leaves room for improvement in terms of cooling performance inside the unwound coil.

[0005] The present disclosure has been made in view of the above, and has an object to provide a wound field motor that can improve cooling performance. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the objectives, the wound field motor of the present disclosure comprises a shaft having a hollow portion, a rotor core fixed to the shaft, and a rotor coil wound around the rotor core, the rotor core comprising a cylindrical back yoke, a plurality of teeth extending radially outward from the outer peripheral surface of the back yoke and around which the rotor coil is wound, and cooling holes provided in each of the plurality of teeth and extending along the axial direction. [Effects of the Invention]

[0007] According to the present disclosure, an effect is achieved in that cooling performance can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an overall plan view including a wound field motor according to one embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is a schematic diagram of a rotor included in a wound field motor according to one embodiment. [Figure 4] FIG. 4 is a partial enlarged view of an area D1 in FIG. [Figure 5] FIG. 5 is an overall plan view illustrating the flow path of the refrigerant in the wound field motor 1. As shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line BB in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Wound-field motors according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially identical. Furthermore, the drawings referred to in the following description merely show a schematic representation of the shape, size, and positional relationship to the extent that the contents of the present disclosure can be understood. In other words, the present disclosure is not limited to the shape, size, and positional relationship exemplified in each drawing.

[0010] [Configuration of a wound field motor] Fig. 1 is an overall plan view including a wound-field motor according to one embodiment. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. Fig. 3 is a schematic configuration diagram of a rotor provided in the wound-field motor according to one embodiment. Fig. 4 is a partial enlarged view of region D1 in Fig. 3. In Figs. 1 to 4, the axial direction of the shaft direction is defined as the X direction, the circumferential direction perpendicular to the shaft direction is defined as the Y direction, and the depth direction perpendicular to the shaft direction is defined as the Z direction.

[0011] 1 to 4 includes a substantially cylindrical stator 10 fixed to a frame or the like (not shown), and a rotor 20 rotatably held on the inner periphery of the stator 10. The wound-field motor 1 further includes a stator cooling pipe 30 that cools the stator 10, an ATF temperature sensor 40 (see FIG. 2) that detects the temperature of the cooling oil, and a stator coil temperature sensor 50 (see FIG. 2) that detects the temperature of the stator 10.

[0012] The stator 10 includes a stator core 11 and a stator coil 12 wound around the stator core 11. The stator coil 12 is wound around a plurality of teeth (not shown) provided on the radially inner side of the stator core 11.

[0013] The rotor 20 includes a shaft 21, a rotor core 22 fixed to the shaft 21, a rotor coil 23 wound around the rotor core 22, and a hard portion 24.

[0014] The shaft 21 has a hollow portion 21a. Furthermore, the shaft 21 has shaft-side cooling holes 21b, 21c extending from the hollow portion 21a toward the outer circumferential surface of the shaft 21 at the upper and lower axial ends of the hollow portion 21a.

[0015] The rotor core 22 includes a cylindrical back yoke 22a, a plurality of teeth 22b (eight in FIG. 1) extending radially outward from the outer peripheral surface of the back yoke 22a, and slots (not shown) formed by the back yoke 22a and the teeth 22b.

[0016] Furthermore, rotor core 22 includes a plurality of cooling holes 22c provided in each of the plurality of teeth 22b and extending along the axial direction. Each of the plurality of cooling holes 22c is a gap (not shown) between rotor core 22 and rotor coil 23 (described later), and a refrigerant such as cooling oil from one of shaft-side cooling holes 21b and 21c flows into the gap through insulating paper (not shown). Each of the plurality of cooling holes 22c is alternately provided along the circumferential direction on the upper or lower end of each of the plurality of teeth 22b and has an ejection port 22d for ejecting (discharging) the refrigerant. Hereinafter, the side from which the refrigerant is ejected from the upper end of tooth 22b will be referred to as refrigerant ejection port 22d1, and the side from which the refrigerant is ejected from the upper end of tooth 22b will be referred to as refrigerant ejection port 22d2.

[0017] The rotor coil 23 is formed and housed in the slot by winding a coil wire around the teeth 22b.

[0018] The hard portion 24 is filled between the rotor coil 23 and the slot 23c, and is hardened in a state where the coil ends of the rotor coil 23 are exposed.

[0019] [Refrigerant flow] The flow of refrigerant in the wound-field motor 1 configured as above will now be described. Fig. 5 is an overall plan view illustrating the flow path of refrigerant in the wound-field motor 1. Fig. 6 is a cross-sectional view taken along line BB in Fig. 5. In Figs. 5 and 6, arrows schematically indicate the flow of refrigerant.

[0020] As shown in FIGS. 5 and 6, the wound field motor 1 is connected to a heat exchanger 100 and a pump 200 via a flow path such as a pipe (not shown), and is cooled by a refrigerant supplied from the pump 200.

[0021] The pump 200 supplies the refrigerant to the stator cooling pipe 30 and the hollow portion 21a of the shaft 21 through a flow path (not shown). In this case, the refrigerant injected (discharged) from the stator cooling pipe 30 cools the surfaces of the stator 10 and the rotor 20 and circulates to the pump 200.

[0022] Furthermore, the refrigerant supplied to hollow portion 21a of shaft 21 moves from hollow portion 21a of shaft 21 through each of a plurality of cooling holes 22c provided in teeth 22b of rotor core 22. Then, the refrigerant in each of the plurality of cooling holes 22c is injected (discharged) from refrigerant injection port 22d1 or refrigerant injection port 22d2 in teeth 22b of rotor core 22, and circulates to pump 200.

[0023] According to the embodiment described above, in the wound field motor 1, the teeth 22b can be directly cooled by the refrigerant, and therefore, compared to conventional cooling of the slots 23c, the teeth are cooled with a larger surface area in contact with the rotor coil 23, and the inside of the rotor coil 23 wound around them can also be cooled.

[0024] Furthermore, according to one embodiment, the wound field motor 1 has refrigerant outlets 22d1 provided on the upper end side and refrigerant outlets 22d2 provided on the lower end side of the teeth 22b of the rotor core 22, and the temperature of the refrigerant does not become high by the time it reaches the opposite side of the rotor core 22 (from the lower end side to the upper end side) as in the conventional case where the refrigerant is injected (discharged) from only one side. Therefore, sufficient cooling can be expected compared to the conventional case where the refrigerant is injected (discharged) from only one side, and the rotor 20 can be cooled uniformly.

[0025] Further advantages and modifications will readily occur to those skilled in the art. The invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0026] Although some of the embodiments of the present application have been described in detail above with reference to the drawings, these are merely examples, and the present invention can be implemented in other forms that have undergone various modifications and improvements based on the knowledge of those skilled in the art, including the aspects described in the disclosure of the present invention. [Explanation of symbols]

[0027] Single-winding field motor 2 rotors 10 Stator 11 Stator core 12 stator coil 20 rotors 21 Shaft 21a Hollow part 21b, 21c Shaft side cooling holes 22 rotor core 22a Back Yoke 22b Teeth 22c cooling hole 22d injection port 22d1,22d2 Refrigerant injection port 23 rotor coil 24 Hard part

Claims

1. a shaft having a hollow portion; a rotor core fixed to the shaft; a rotor coil wound around the rotor core; Equipped with The rotor core is A cylindrical back yoke, a plurality of teeth extending radially outward from an outer circumferential surface of the back yoke, the teeth being wound with the rotor coil; a cooling hole provided in each of the plurality of teeth and extending along the axial direction; Equipped with Wound field motor.

2. 2. The wound field motor according to claim 1, The cooling holes are an injection port for injecting the refrigerant, the injection port being alternately provided on an upper end side or a lower end side of each of the plurality of teeth along a circumferential direction; Wound field motor.

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