Rotary machine

Abstract

The invention provides a rotating machine capable of improving torque. A rotating machine is provided with: a cylindrical stator; a rotor provided with a gap from the stator in the radial direction of the stator; and oil that impregnates a portion of the rotor and a portion of the stator. Oil is supplied in the gap. The oil contains a magnetic powder having a particle diameter smaller than the width of the gap in the radial direction of the stator.

Description

Technical Field

[0001] This invention relates to a rotary machine. Background Technology

[0002] Conventionally, the technology described in Patent Document 1 is an example of this technical field. The rotary machine described in Patent Document 1 is a radial clearance type motor comprising a cylindrical stator, a rotor disposed on the inner circumference of the stator with a gap separating it from the stator, and oil impregnating a portion of the rotor and a portion of the stator. In this rotary machine, in order to suppress foaming of the oil supplied to the gap between the rotor and the stator, a groove is formed to widen the gap at a position in the stator overlapping the oil surface.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2009-183047 Summary of the Invention

[0004] In the case of the aforementioned rotating machine, a gap needs to be set between the rotor and stator to prevent damage caused by contact between them. However, setting a gap affects the torque of the rotating machine, making it difficult to increase the torque. In particular, the impact on the torque of the rotating machine increases when the gap is large, thus hindering the increase of torque.

[0005] This invention was made to solve this technical problem, and its purpose is to provide a rotating machine that can increase torque.

[0006] The rotating machine according to the present invention comprises: a cylindrical stator; a rotor disposed radially from the stator by a gap; and oil impregnating a portion of the rotor and a portion of the stator. The rotating machine is characterized in that the oil is supplied in the gap, and the oil contains magnetic powder having a particle size smaller than the width of the gap radially from the stator.

[0007] In the rotating machine according to the present invention, oil is supplied in the gap between the rotor and the stator, and the oil contains magnetic powder having a particle size smaller than the width of the gap in the radial direction of the stator. Through this magnetic powder, the width of the gap between the rotor and the stator is approximated, thereby increasing the torque. Furthermore, since the particle size of the magnetic powder is smaller than the width of the gap, the influence of the magnetic powder on the rotation of the rotor can be suppressed.

[0008] Furthermore, in the rotary machine according to the present invention, the particle size of the magnetic powder is preferably more than 1 / 10 and less than 1 / 2 of the width of the gap in the radial direction of the stator. This suppresses the increase in the manufacturing cost of the magnetic powder and prevents the impact on rotor rotation and the obstruction of oil flow caused by the accumulation of magnetic powder particles.

[0009] In the rotary machine according to the present invention, the volume of the magnetic powder is preferably 10% to 50% of the total volume of the magnetic powder and the oil. This maintains the torque-enhancing effect of the rotary machine and suppresses any impact on oil flow.

[0010] Invention Effects

[0011] According to the present invention, the torque of the rotating machine can be increased. Attached Figure Description

[0012] Figure 1 This is a schematic top view showing the rotating machine involved in the embodiment.

[0013] Figure 2 It is a schematic top view used to illustrate the rotor, stator, and the oil supplied to the gap between the rotor and stator.

[0014] Figure 3 (a) is a schematic top view showing the rotating machine according to the embodiment (inventive product). Figure 3 (b) is a schematic top view of the rotary machine involved in the comparative example (existing product).

[0015] Figure 4 This is a graph used to illustrate the torque analysis results of the embodiments (invented products) and comparative examples (existing products). Detailed Implementation

[0016] Hereinafter, embodiments of the rotating machine according to the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are labeled with the same symbols, and repeated descriptions thereof are omitted.

[0017] Figure 1 This is a schematic top view showing the rotating machine according to the embodiment. Figure 2 This is a schematic top view used to illustrate the rotor, stator, and the oil supplied to the gap between the rotor and stator. For example... Figure 1 As shown, the rotary machine 1 involved in this embodiment is a so-called radial clearance type motor, for example, used as an electric vehicle motor. This rotary machine 1 includes: a cylindrical stator 2; a rotor 3 disposed on the inner circumference of the stator 2 and rotatable relative to the stator 2; a rotating shaft 4 embedded in the shaft hole of the rotor 3; and oil 6 (see reference). Figure 2 ), a portion of the impregnated rotor 3 and a portion of the stator 2.

[0018] The stator 2, for example, includes: a stator core 21, formed by stacking multiple annular electromagnetic steel plates along the axial direction of the rotation shaft 4; and multiple coils 22 wound around the stator core 21. The stator core 21 is not limited to electromagnetic steel plates, and may also be formed of magnetic materials such as powder-coated magnetic cores. The coils 22 are arranged at equal intervals along the circumference of the stator core 21. Furthermore, when the coils 22 are energized, a rotating magnetic field is generated to rotate the rotor 3.

[0019] The rotor 3 is positioned opposite the stator 2 in the radial direction (i.e., the radial direction of the rotating machine 1) of the stator 2, separated by a gap S. The rotor 3 has a cylindrical rotor core 31 with a centrally located shaft hole 32. The rotor core 31 is formed, for example, by stacking multiple circular electromagnetic steel plates along the axial direction of the rotating shaft 4, and functions as a magnetic circuit for the reluctance torque of the stator 2 or the magnetic torque of the magnet 34 (described later). The rotating shaft 4 is made of metal, is inserted into the shaft hole 32 of the rotor core 31, and is fixed to the rotor core 31.

[0020] Furthermore, a plurality of slots 33 (16 in this embodiment) are provided on the rotor core 31 along the circumference of the rotor core 31. These slots 33 are arranged at predetermined intervals along the circumference of the rotor core 31. Moreover, adjacent slots 33 are arranged in a V-shape or an inverted V-shape with each other.

[0021] Magnets 34 are embedded in each groove 33. The magnets 34 are rectangular permanent magnets, inserted into the grooves 33 with their length direction parallel to the axis of rotation 4, and fixed to the grooves 33 by resin. Examples of resins include epoxy resins, polyimide resins, and other thermosetting resins.

[0022] Oil 6 is an oil used for cooling and / or lubrication of the rotating machine 1, which circulates within the rotating machine 1, for example, by an oil pump, to impregnate a portion of the rotor 3 and a portion of the stator 2. Furthermore, oil 6 contains a width t (referring to a distance t) having a radial clearance S greater than that of the stator 2. Figure 2 5. Small-particle-size magnetic powder. Magnetic powder 5 is composed, for example, of iron powder and is distributed substantially uniformly in oil 6.

[0023] In this embodiment, oil 6 containing magnetic powder 5 is supplied into the gap S between the stator 2 and the rotor 3. Figure 2 As shown, the gap S between the stator 2 and the rotor 3 is the space between the outer circumferential surface of the rotor 3 and the inner circumferential surface of the stator 2 opposite to the rotor 3, and is an annular shape extending circumferentially along the rotating machine 1 with the rotating shaft 4 as the center.

[0024] exist Figure 2In the image, the oil 6 is depicted as a ring shape biased towards the rotor 3 side in the gap S, but in reality, it becomes a wavy shape that does not bias towards the rotor 3 side, causing the gap S to serpentine. Furthermore, the magnetic powder 5 contained in the oil 6 is attracted to the rotor 3 side by the magnetic force of the magnet 34, but flows approximately uniformly in the gap S that does not bias towards the rotor 3 side through the circulation of the oil pump.

[0025] In the rotating machine 1 according to this embodiment, a gap S is provided between the rotor 3 and the stator 2, thus preventing contact between the rotor 3 and the stator 2 and preventing damage caused by contact. Furthermore, oil 6 is supplied into the gap S, and this oil 6 contains magnetic powder 5 having a particle size smaller than the width t of the gap S in the radial direction of the stator 2. Through this magnetic powder 5, the width t of the gap S is approximatedly reduced, thus increasing the torque of the rotating machine 1. Moreover, since the particle size of the magnetic powder 5 is smaller than the width t of the gap S, the obstruction of the magnetic powder 5 to the rotation of the rotor 3 can be suppressed. As a result, damage caused by contact between the rotor 3 and the stator 2 can be prevented, and the torque of the rotating machine 1 can be increased.

[0026] At this time, the particle size of the magnetic powder 5 is preferably more than 1 / 10 and less than 1 / 2 of the width of the radial gap S of the stator 2. That is, when the width of the gap S is set to t, the particle size of the magnetic powder 5 is 0.1t to 0.5t. This range is determined as follows.

[0027] For example, if the particle size of the magnetic powder 5 is less than 0.1t, it needs to be pulverized even finer. This increases the time required for pulverizing the magnetic powder 5, leading to increased manufacturing costs. On the other hand, if the particle size of the magnetic powder 5 exceeds 0.5t, for example, if two or more magnetic powder particles 5 accumulate radially in the gap S, the gap S will be blocked, affecting not only the rotation of the rotor 3 but also hindering the flow of oil 6.

[0028] Therefore, in this embodiment, by setting the width of the gap S in the radial direction of the stator 2 to more than 1 / 10 and less than 1 / 2 of the particle size of the magnetic powder 5, it is possible to suppress the increase in the manufacturing cost of the magnetic powder 5, and to prevent the influence on the rotation of the rotor 3 and the obstruction of the flow of oil 6 caused by the accumulation of magnetic powder 5 on each other.

[0029] Furthermore, the volume of the magnetic powder 5 relative to the total volume of the magnetic powder 5 and the oil 6 is preferably 10% to 50%. That is, the volume ratio of the magnetic powder 5 relative to the total volume of the magnetic powder 5 and the oil 6 is in the range of 10% to 50%. This range is determined as follows.

[0030] For example, when the volume ratio of magnetic powder 5 is less than 10%, the effect of magnetic powder 5 in increasing torque is reduced. On the other hand, when the volume ratio of magnetic powder 5 exceeds 50%, the effect of magnetic powder 5 in increasing torque is increased, but the magnetic powder 5 tends to accumulate between itself. Due to this accumulation, the magnetic powder 5 piles up, causing problems that affect the flow of oil 6.

[0031] Therefore, in this embodiment, by setting the volume of the magnetic powder 5 to the total volume of the magnetic powder 5 and the oil 6 to 10% to 50%, the torque enhancement effect can be maintained and the influence on the flow of the oil 6 can be suppressed.

[0032] In this embodiment, an example of a rotating machine 1 being a motor has been described, but the present invention can also be applied to rotating machines such as generators.

[0033] The present invention will now be described through embodiments, but the present invention is not limited to the scope of the embodiments. Furthermore, in the following embodiments and comparative examples, the width of the gap S and the width of the clearance are both radial distances of the sub-sub2.

[0034] [Example]

[0035] In this embodiment, an analytical model was created based on the rotating machine 1 (inventive product) described in the above embodiments, and a magnetic field analysis was performed using the created model. Furthermore, in the oil 6 used in this embodiment, the volume of the magnetic powder 5 was set to 50% of the total volume of the magnetic powder 5 and the oil 6.

[0036] [Comparative Example]

[0037] Furthermore, as a comparative example, an analytical model was constructed based on an existing rotary machine (a prior art product) that does not contain oil 6 containing magnetic powder 5, and a magnetic field analysis was performed using the constructed model under the same conditions as in the example. Figure 3 As shown in (b), the existing product's rotary machine 1A includes: a stator 2; a rotor 3 disposed radially from the stator 2 with a gap S; and a rotating shaft 4 embedded in the rotor 3.

[0038] Furthermore, in the embodiments and comparative examples, the width t2 relative to the gap S of the existing product (refer to...) Figure 3 (b)), the width t1 of the clear space excluding oil 6 in the gap S of the invented product (refer to) Figure 3 (a) is set as t1 / t2=0.5. The width t1 of the clearance S in the invention product, excluding oil 6, is the shortest distance from the inner circumferential surface of stator 2 to the liquid surface of oil 6.

[0039] Furthermore, in the embodiments and comparative examples, the materials used in the stator 2, rotor 3, and rotating shaft 4, as well as the various conditions related to magnetic field analysis, are the same.

[0040] Figure 4 This is a graph used to illustrate the torque analysis results of the embodiments (invented products) and comparative examples (existing products). For example... Figure 4 As shown, compared with existing products, the result of the invention is that the torque can be increased by 5%. Therefore, the rotary machine according to the invention demonstrates the ability to achieve the effect of increasing torque.

[0041] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments. Various design changes can be made without departing from the spirit of the present invention as set forth in the claims.

[0042] Symbol Explanation

[0043] 1-Rotating machine, 2-Stator, 3-Rotor, 4-Rotating shaft, 5-Magnetic powder, 6-Oil, 21-Stator core, 22-Coil, 31-Rotor core, 32-Shaft hole, 33-Slot, 34-Magnet, S-Gap.

Claims

1. A rotating machine comprising: a cylindrical stator; a rotor disposed radially from the stator by a gap; and oil impregnating a portion of the rotor and a portion of the stator, characterized in that... The oil is supplied in the gap. The oil contains magnetic powder with a particle size smaller than the width of the gap in the radial direction of the stator.

2. The rotating machine according to claim 1, characterized in that, The particle size of the magnetic powder is more than 1 / 10 and less than 1 / 2 of the width of the gap in the radial direction of the stator.

3. The rotating machine according to claim 1, characterized in that, The volume of the magnetic powder is 10% to 50% of the total volume of the magnetic powder and the oil.

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