Patent ID: 12191724

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION OF THE DISCLOSURE

Specific structural or functional descriptions of embodiments of the present disclosure disclosed in the present specification or application are only exemplified for the purpose of describing the embodiments according to the present disclosure. The embodiments according to the present disclosure may be carried out in various forms and should not be interpreted as being limited to the embodiments described in the present specification or application.

Since the embodiment according to the present disclosure may have various changes and various forms, specific embodiments are shown in the accompanying drawings and described in detail in the present specification or application. However, this is not intended to limit the embodiments according to the concept of the present disclosure to a specific disclosed form. The present disclosure should be understood to include all changes, equivalents, or substitutes included in the spirit and technical scope of the present disclosure.

The terms first, second, and so on may be used to describe various components, but components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from other components. For example, a first component may be referred to as a second component without departing from the scope according to the concept of the present disclosure. Similarly, the second component may also be referred to as the first component without departing from the scope according to the concept of the present disclosure.

When a certain component is said to be “connected” or “coupled” to another component, it should be understood that the certain component may be directly connected or coupled to another component. However, other components may also be present therebetween. On the other hand, when a certain component is said to be “directly connected to” or “directly coupled to” another component, it should be understood that other components are not present therebetween. Other expressions for describing the relationship between components, i.e., expressions such as “between” and “directly between” or “adjacent to” and “directly adjacent to” should also be interpreted in the same manner.

The terms used in the present specification are only used to describe the specific embodiments and are not intended to limit the present disclosure. The singular expression also includes the plural expression unless otherwise specified in the context. It should be understood that terms such as “comprises” or “has” used in the present specification specify the presence of the practiced feature, number, step, operation, component, part, or a combination thereof. However, these terms do not exclude the presence or addition possibility of one or more other features, numbers, steps, operations, components, parts, or a combination thereof in advance.

When a component, device, element, or the like of the present disclosure is described as having a purpose or performing an operation, function, or the like, the component, device, or element should be considered herein as being “configured to” meet that purpose or to perform that operation or function.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those having ordinary skill in the art to which the present disclosure pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with the meanings in the context of the related art and should not interpreted as an ideal or excessively formal meaning unless explicitly defined in the present specification.

Hereinafter, the present disclosure is described in detail by describing embodiments of the present disclosure with reference to the accompanying drawings. The same reference numerals presented in each drawing indicate the same or equivalent member.

Referring toFIGS.1-6, a dual rotor motor according to embodiments of the present disclosure includes: an inner rotor IR and an outer rotor OR; a stator ST disposed between the inner rotor IR and the outer rotor OR; a stator variable unit SV provided in the stator ST to intermit a magnetic path between outside and the inside of the stator ST according to a pressure in an axial direction; and a pressing mechanism provided to provide the pressure in the axial direction to the stator variable unit SV.

In other words, the dual rotor motor according to the present disclosure is configured to vary a magnetic path connection state between the inside and the outside of the stator through the stator variable unit SV and the pressing mechanism. Therefore, when the inner rotor IR and the outer rotor OR rotate independently of each other, as shown inFIG.1, a magnetic path formed by the stator ST and the outer rotor OR outside the stator ST and a magnetic path formed by the stator ST and the inner rotor IR inside the stator ST are blocked from each other and formed independently of each other.

When the inner rotor IR and the outer rotor OR rotate at the same speed, as shown inFIG.2, the inside and the outside of the stator ST are connected to form an integrated magnetic path. Accordingly, the overall length of a magnetic path formed among the stator ST, the inner rotor IR, and the outer rotor OR is decreased and the reluctance is reduced to increase the torque density of a motor.

For reference, a permanent magnet is disposed on each of the inner rotor IR and the outer rotor OR, and N and S, which mean two poles of the permanent magnet, are displayed on the drawing.

In one embodiment, the stator ST includes the inner teeth IT facing the inner rotor IR and the outer teeth OT facing the outer rotor OR. In particular, the inner teeth IT and outer teeth OT are arranged in a radial direction, and the stator variable unit SV is deformed by the pressure in an axial direction provided by the pressing mechanism. Thus the stator variable unit SV is configured to intermit a magnetic path between the inner teeth IT and the outer teeth.

In addition, an inner slot IS is provided between the inner teeth IT, an outer slot OS is provided between the outer teeth OT, and coils CL wound around the inner teeth IT and the outer teeth OT are positioned in each of the inner slot IS and the outer slot OS.

For reference, the axial direction is a rotational axis direction of a motor, and a radial direction is a radial direction from the rotational axis of the motor.

In embodiments of the present disclosure, the stator variable unit SV is configured by stacking a plurality of wave silicon steel plates1, and the pressing mechanism is installed to vary a curvature of the wave silicon steel plate1.

In a first embodiment illustrated inFIGS.1-4, the wave silicon steel plate1constituting the stator variable unit SV is formed in a ring shape in which a wave portion3having a curvature is configured only at a portion positioned between the inner teeth IT and the outer teeth OT in a circumferential direction of the stator ST.

In the present embodiment, as shown inFIG.3, the wave portion3of the wave silicon steel plate1is mainly formed outside a ring shape in a radial direction, and a wave of the wave portion3is formed in an arc shape in a cross-sectional view in an axial direction. The arc shape is unfolded in a straight line by the pressure in the axial direction provided by the pressing mechanism. Thus, a gap AG between the inner teeth IT and the outer teeth OT may be removed.

The pressing mechanism is installed on one side of the stacked wave silicon steel plates1inside the stator ST to be slid in the axial direction. The pressing mechanism may include a piston5capable of pressing one side of the stacked wave silicon steel plates1and include a return spring7for providing an elastic force so that the piston5returns when the piston5releases the pressure applied to the wave silicon steel plate1.

Of course, when an elastic force of the wave silicon steel plate1is at a level sufficient for smoothly returning from the state shown inFIG.4to the state shown inFIG.3, the return spring7can be omitted.

In addition, in the present embodiment, a stopper9is provided to restrict an axial movement of the wave silicon steel plates1stacked on a side opposite to the piston5with respect to the stacked wave silicon steel plates1inside the stator ST.

Accordingly, when the piston5presses the stator variable unit SV, the wave silicon steel plate1of the stator variable unit SV is compressed between the stopper9and the piston5, and an arc-shaped cross section is changed into a straight line-shaped cross section. Thus, the gap AG between the inner teeth IT and the outer teeth OT and connecting the magnetic path may be removed.

Referring toFIGS.3and4, the outer teeth OT and the inner teeth IT of the stator ST are connected and fixed to a motor housing17.

Meanwhile, as shown inFIGS.5and6, in a second embodiment of the present disclosure, all components are the same as those in the first embodiment except for the stator variable unit SV that is different from that in the first embodiment. The wave silicon steel plate1constituting the stator variable unit SV is disposed only at a portion positioned between the inner teeth IT and the outer teeth OT in a circumferential direction of the stator ST, and a blocking block11for restricting a position in a circumferential direction of the wave silicon steel plates1is provided between the wave silicon steel plates1in a circumferential direction of the stator ST.

Accordingly, the blocking block11may be integrally formed in a protruding shape on the inner slot IS or the outer slot OS of the stator ST. In this case, it is desirable that the blocking block11protrudes only to a height at which gaps AG of a predetermined level or higher are formed between the inner slot IS and the outer slot OS and always blocks the magnetic path between the inner slot IS and the outer slot OS.

In addition, the blocking block11may be formed of a non-magnetic material positioned between the inner slot IS and the outer slot OS of the stator ST.

In this case, the blocking block11may protrude only to a height at which a gap AG between the inner slot IS and the outer slot OS is formed, but since the blocking block11itself is a non-magnetic material and blocks a magnetic path, the inner slot IS and the outer slot OS may be mechanically connected to each other without a separate gap AG. Thus, it is advantageous to secure the mechanical strength of the stator ST.

In the embodiments of the present disclosure as described above, the pressing mechanism is connected to the pressure providing device13that provides pressure to the piston5so that the piston5slides in an axial direction, and the pressure providing device13may be installed to be controlled by a controller15for controlling the motor.

Herein, the pressure providing device13may include a pneumatic pump, a hydraulic pump, a valve, a linear motor, or the like.

In the controller15, when the inner rotor IR and the outer rotor OR are rotated independently of each other, the piston5may not press the stator variable unit SV so that a gap AG between the inner teeth IT and the outer teeth OT is formed. When the inner rotor IR and the outer rotor OR rotate at the same speed, the piston5may press the stator variable unit SV, and thus the controller15controls the pressure providing device13to remove the gap AG between the inner teeth IT and the outer teeth OT.

Accordingly, when the inner rotor IR and the outer rotor OR are independently rotated, the inner and outer magnetic paths of the stator ST are independently formed due to a gap AG between the inner teeth IT and the outer teeth OT, and thus independent driving of the inner rotor IR and the outer rotor OR can be stably performed.

In addition, when the inner rotor IR and the outer rotor OR rotate at the same speed, the gap AG between the inner teeth IT and the outer teeth OT is removed, and the magnetic paths inside and outside the stator ST are connected as one path, and thus the overall length of the magnetic paths is decreased compared to the magnetic paths formed independently inside and outside the stator ST. Thus, the reluctance is reduced, and ultimately, the torque density of a motor can be increased.

The embodiments of the present disclosure as described above may be expressed as follows.

In other words, a dual rotor motor of the present disclosure includes: an inner rotor IR and an outer rotor OR; a stator ST disposed between the inner rotor IR and the outer rotor OR; a stator variable unit SV provided inside the stator ST to vary the size of a gap AG between the outside and the inside of the stator ST according to the pressure in the axial direction; and a pressing mechanism provided to provide the pressure in the axial direction to the stator variable unit SV.

The stator ST is disposed so that the inner teeth IT facing the inner rotor IR and the outer teeth OT facing the outer rotor OR are arranged in a radial direction; and the stator variable unit SV is deformed by the pressure in the axial direction provided by the pressing mechanism and configured to continuously vary the size of a gap AG between the inner teeth IT and the outer teeth OT.

The stator variable unit SV is configured by stacking a plurality of wave silicon steel plates1; and the pressing mechanism may be configured to continuously vary the size of a gap AG between the inner teeth IT and the outer teeth OT by varying a curvature of the wave silicon steel plate1.

The pressing mechanism may include a piston5installed in the stator ST to press one side of the stacked wave silicon steel plates1by sliding in the axial direction; and a return spring7for providing an elastic force so that the piston5returns when the piston5releases the pressure applied to the wave silicon steel plate1.

In addition, the pressing mechanism is connected to the pressure providing device13that provides pressure to the piston5so that the piston5slides in the axial direction. The pressure providing device13is installed to be controlled by a controller15for controlling the motor. In the controller15, when the inner rotor IR and the outer rotor OR are rotated independently of each other, the piston5may not press the stator variable unit SV so that a gap AG between the inner teeth IT and the outer teeth OT is formed. When the inner rotor IR and the outer rotor OR rotate at the same speed, the piston5may press the stator variable unit SV, and thus the controller15controls the pressure providing device13to remove the gap AG between the inner teeth IT and the outer teeth OT.

Although specific embodiments of the present disclosure have been shown and described, it should be apparent to those having ordinary skill in the art that the present disclosure may be variously modified and changed without departing from the technical spirit of the present disclosure.