DESC:SEGMENTED STATOR ASSEMBLY
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority from Indian Provisional Patent Application No. 202221062148 filed on 01/11/2022, the entirety of which is incorporated herein by a reference.
TECHNICAL FIELD
The present disclosure generally relates to an electric motor. Particularly, the present disclosure relates to a segmented stator assembly of the electric motor.
BACKGROUND
Most traditional motor stators are monolithic structures, with integrated stator yoke and stator tooth. Since the integrated stator structure remains fixed during the coil winding process, the slot utilization ratio is also very low in such motors. Further, in aforesaid structures, there lies a high chance of insulation breakdown during the coil winding process because of smaller openings at stator slots. Moreover, a rigid stator structure of the stator assembly makes it more prone to mechanical failures, such as cracking or deformation. Furthermore, such stator structures are difficult to maintain. Moreover, such stator structures are prone to vibrations causing low operational smoothness and higher noise levels.
Furthermore, the cogging torque is a common undesirable phenomenon in electric motors. The cogging torque is generated due to the interaction between the magnetic flux generated by the permanent magnets of the rotor and the magnetic flux generated by the stator coils. As the rotor rotates, the permanent magnets of the rotor attract and align with the stator teeth, creating a torque. This torque varies depending on the relative position of the rotor and the stator, resulting in a jerky motion.
With the development of motor technology, the stators have evolved with different types of structures such as linear type and block type to improve the winding efficiency and winding quality. However, in certain existing block-type stator structures, the stator teeth are only buckled and hence secured structure is difficult to achieve. The management of the uncontrolled buckling behavior of stator teeth requires precise control mechanisms, that are complex and costlier to implement. Moreover, design modifications, such as slot-less motor design, higher slot count, skewing of magnets, or lamination stack have been introduced in the stator structure to reduce the cogging torque. However, the design modifications have mechanical constraints and are not suitable for all end applications of the motor. Furthermore, the existing design modifications are not effective beyond a certain extent in mitigating the cogging torque.
Therefore, there exists a need for an improved stator structure that overcomes one or more problems associated as set forth above.
SUMMARY
An object of the present disclosure is to provide a stator structure for a motor capable of providing a flexible movement of a stator tooth.
In accordance with the first aspect of the present disclosure, there is provided a stator assembly for a motor comprising a stator yoke and a plurality of stator teeth. The stator yoke comprises a plurality of first securing means along a length of radially inward surface of the stator yoke. Each of the stator tooth comprises a second securing means on a radially outward end. Each of the first securing means is secured with the second securing means making a revolute joint to form the stator assembly.
The present disclosure provides an improved stator assembly for a motor. The stator assembly, as disclosed in the present disclosure, is advantageous in terms of enabling a limited movement of the stator tooth at a radially inward end. Advantageously, such movement of the stator tooth enables ease in winding the stator assembly. Advantageously, the stator assembly, as disclosed by the present disclosure, enables a higher stator fill factor compared to conventional stator assemblies. Furthermore, the stator assembly, as disclosed by the present disclosure, is advantageous in terms of reducing cogging torque in the motor.
Additional aspects, advantages, features, and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments constructed in conjunction with the appended claims that follow.
It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
FIG. 1 illustrates an exploded view of stator assembly for a motor, in accordance with an embodiment of the present disclosure.
FIG. 2a illustrates a cross-sectional view of the stator assembly, in accordance with an embodiment of the present disclosure.
FIG. 2b illustrates a perspective view of the stator tooth along with a coil, in accordance with an embodiment of the present disclosure.
In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION
The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.
The description set forth below in connection with the appended drawings is intended as a description of certain embodiments of a segmented stator assembly and is not intended to represent the only forms that may be developed or utilized. The description sets forth the various structures and/or functions in connection with the illustrated embodiments; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
The terms “comprise”, “comprises”, “comprising”, “include(s)”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, or system that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or system. In other words, one or more elements in a system or apparatus preceded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings which are shown by way of illustration-specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
The present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the description with unnecessary detail.
As used herein, the terms “electric motor” and “motor” are used interchangeably and refer to an electromagnetic machine that converts electrical energy into mechanical motion or rotation. The motor typically comprises a housing or frame, a stator element, and a rotor element. The stator contains coils, and the rotor is positioned within the stator. When electrical energy is supplied to the coils in the stator, a magnetic field is generated in the stator that interacts with the rotor causing the rotor to rotate which in turn rotates the shaft delivering mechanical power to a load.
As used herein, the terms “stator” and “stator assembly” are used interchangeably and refer to the stationary part of the electric motor that generates a magnetic field for driving the rotating armature. The stator acts as a field magnet. The design of the stator is an important factor in deciding the performance of the motor such as efficiency, power output, and torque generated in the motor.
As used herein, the terms “stator yoke” and “yoke” are used interchangeably and refer to a component of the stator assembly that provides structural support for stator teeth and completes the magnetic circuit of the stator. The stator yoke generally forms the outermost portion of the stator assembly. The stator yoke is typically constructed from a magnetic material such as steel, laminated iron, and/or soft magnetic composite material and may enhance the motor's magnetic circuit, influencing its overall performance, efficiency, and electromagnetic characteristics.
As used herein, the term “first securing means” refers to a design element of the stator yoke extending longitudinally along the inner circumferential area to enable assembly of the stator yoke with the stator teeth. The first securing means may be spaced on a radially inward surface of the stator yoke according to the dimensions of the stator teeth. Optionally, the first securing means may be evenly spaced on the radially inward surface of the stator yoke.
As used herein, the term “radially inward surface” of the rotor refers to the innermost or inner-circumferential area of the stator yoke facing the rotor.
As used herein, the terms “stator tooth”, and “plurality of stator teeth” are used interchangeably and refer to a stator slot wedge that holds the conductive windings in the slot for producing an electromagnetic field in the stator. The stator tooth directs the magnetic field toward the rotor assembly to rotate the rotor assembly.
As used herein, the term “second securing means” refers to a design element of stator tooth at extreme radial end extending longitudinally for securely connecting the stator teeth with the stator yoke while allowing rotational movement of the stator teeth with reference to the stator yoke. The second securing means is hinged with the first securing means to connect the stator teeth with the stator yoke.
As used herein, the term “radially outward end” of the stator tooth refers to the outermost extremity of the stator tooth facing the stator yoke.
As used herein, the term “revolute joint” refers to joint that offers a one degree-of-freedom between connected components. The first securing means and the second securing means are connected to form revolute joint, enabling the relative rotational motion of the second securing means with respect to first securing means.
As used herein, the term “radially inward end” refers to the innermost extremity of the stator tooth facing the rotor.
As used herein, the term “magnetic wedges”, “securing wedges” and “wedges” are used interchangeably and refer to wedges made up of magnetically permeable material such as iron or mild steel. The magnetic wedges are designed to restrict the rotational movement of the radially inward end of the stator teeth beyond a certain threshold. The magnetic wedges are designed, shaped, and sized in conformation with side gaps in between the stator yoke and the stator teeth.
Figure 1, in accordance with an embodiment, describes a stator assembly 100 for a motor comprising a stator yoke 102 and a plurality of stator teeth 106. The stator yoke 102 comprises a plurality of first securing means 104 along a length of radially inward surface 102a of the stator yoke 102. Each of the stator tooth 106 comprises a second securing means 108 on a radially outward end 106a. Each of the first securing means 104 is secured with the second securing means 108 making a revolute joint to form the stator assembly 100.
The present disclosure provides an improved stator assembly 100 for a motor. The stator assembly 100 is advantageous in terms of enabling a limited movement of the stator tooth 106 at a radially inward end 106b. Advantageously, such movement of the stator tooth 106 enables ease in winding the stator assembly 100. Beneficially, during the winding process, a slot opening formed by the adjacent stator teeth 106 may be widened to enable ease of winding. Advantageously, the stator assembly 100 enables a higher stator fill factor compared to conventional stator assemblies. Furthermore, the stator assembly 100 is advantageous in terms of reducing cogging torque in the motor. The stator assembly 100 is provided with movement of the stator tooth 106 at a radially inward end 106b, thus, during the operation of the motor, the plurality of stator teeth 106 are able to exhibit oscillatory rotational movement due to the knuckle joint formed at junction of the stator tooth 106 stator yoke 102 resulting in reduction of the cogging torque as permanent magnets of rotor does not completely align with the stator tooth 106. Beneficially, the oscillatory rotational movement of the plurality of stator teeth 106 is controlled to prevent physical contact of adjacent stator tooth 106.
In an embodiment, each of the stator tooth 106 is rotationally moveable at a radially inward end 106b along an axis of the first securing means 104. It is to be understood that the formed revolute joint between the first securing means 104 and the second securing means 108 enables rotational movement of the stator tooth 106. Beneficially, such rotational movement facilitates the easier winding of the stator assembly 100, as the stator tooth 106 may be moved to widen the slot opening during the winding of the stator assembly 100.
In an embodiment, the second securing means 108 extend along a length of the radially outward end 106a of each of the stator tooth 106. Beneficially, the second securing means 108 ensures that the stator tooth 106 is securely hinged with the stator yoke 102. Beneficially, the extension of the second securing means 108 along the length of the radially outward end 106a of each of the stator tooth 106 prevents longitudinal movement and vibrations of the stator teeth 106 during the operation of the motor.
In an embodiment, each of the stator tooth 106 are in physical contact with the stator yoke 102 via the first securing means 104 and the second securing means 108. Beneficially, the hinging of the first securing means 104 and the second securing means 108 securely connects the stator teeth 106 with the stator yoke 102. It is to be understood that the physical contact of each of the stator tooth 106 with the stator yoke 102 creates and completes a magnetic flux path for a magnetic flux produced in the stator assembly 100 during the operation of the motor. Beneficially, the physical contact of each of the stator tooth 106 with the stator yoke 102 is in the form of the revolute joint allowing movement of the stator teeth 106.
In an embodiment, the stator assembly 100 comprises a plurality of magnetic wedges 110, inserted mutually opposite along each of the second securing means 108. It is to be understood that magnetic wedges 110 are provided along each physical contact of the stator tooth 106 with the stator yoke 102 to restrict rotational movement of the stator tooth 106 beyond a threshold degree. Beneficially, the plurality of magnetic wedges 110 are inserted along the gap between the second securing means 108 and stator yoke 102.
In an embodiment, the plurality of magnetic wedges 110 extend along the length of the radially outward end 106a of each of the stator tooth 106. Beneficially, the extension of the magnetic wedges 110 along the length of the radially outward end 106a of each of the stator tooth 106 prevents longitudinal movement and vibrations of the magnetic wedges 110 during the operation of the motor.
In an embodiment, the plurality of magnetic wedges 110 are fixed on the radially inward surface 102a of the stator yoke 102. Beneficially, the plurality of magnetic wedges 110 are fixed on the radially inward surface 102a of the stator yoke 102 using a suitable fixing means that securely fix the plurality of magnetic wedges 110 and prevents dislocation of the plurality of magnetic wedges 110 during the operation of the motor.

In an embodiment, the plurality of magnetic wedges 110 are configured to restrict the rotational movement of each of the stator tooth 106 beyond a predefined degrees to avoid physical contact between the radially inward ends 106b of two adjacent stator teeth 106. Beneficially, the plurality of magnetic wedges 110 are designed, shaped, and sized accordingly.
It is to be understood that during the operation of the motor, the combination of the revolute joint formed between the first securing means 104 and the second securing means 108, and the plurality of magnetic wedges 110 allows oscillating rotational movement of each of the stator tooth 106 at the radially inward end 106b along the axis of the first securing means 104 that reduces alignment of the permanent magnets of the rotor with the stator tooth 106 resulting in reduction of cogging torque. Beneficially, the plurality of magnetic wedges 110 ensures that the stator tooth 106 does not move beyond a certain limit, maintaining the structural and operational integrity of the motor.
In an embodiment, the first securing means 104 is secured inside the second securing means 108 making the revolute joint. It is to be understood that the second securing means is designed to accommodate the first securing means in itself. Beneficially, the first securing means 104 securely fits inside the second securing means 108 to form the revolute joint that allows movement of the stator tooth 106.
In an alternative embodiment, the second securing means 108 is secured inside the first securing means 104 making the revolute joint. It is to be understood that first securing means is designed to accommodate the second securing means in itself. Beneficially, the second securing means 108 securely fits inside the first securing means 104 to form the revolute joint that allows movement of the stator tooth 106.
Figure 2a, in accordance with an embodiment, describes a cross-sectional view of stator assembly 100. The stator assembly 100 comprises a stator yoke 102 and a plurality of stator teeth 106. The stator yoke 102 comprises a plurality of first securing means 104 along a length of radially inward surface 102a of the stator yoke 102. Each of the stator tooth 106 comprises a second securing means 108 on a radially outward end 106a. Each of the first securing means 104 is secured with the second securing means 108 making a revolute joint to form the stator assembly 100. Furthermore, each of the stator tooth 106 is rotationally moveable at a radially inward end 106b along an axis of the first securing means 104. Furthermore, the second securing means 108 extend along a length of the radially outward end 106a of each of the stator tooth 106. Furthermore, each of the stator tooth 106 are in physical contact with the stator yoke 102 via the first securing means 104 and the second securing means 108. Furthermore, the stator assembly 100 comprises a plurality of magnetic wedges 110, inserted mutually opposite along each of the second securing means 108. Furthermore, the plurality of magnetic wedges 110 extend along the length of the radially outward end 106a of each of the stator tooth 106. Furthermore, the plurality of magnetic wedges 110 are fixed on the radially inward surface 102a of the stator yoke 102. Furthermore, the plurality of magnetic wedges 110 are configured to restrict the rotational movement of each of the stator tooth 106 beyond a predefined degrees to avoid physical contact between the radially inward ends 106b of two adjacent stator teeth 106. Furthermore, the first securing means 104 is secured inside the second securing means 108 making the revolute joint. Alternatively, the second securing means 108 is secured inside the first securing means 104 making the revolute joint.
Figure 2b, in accordance with an embodiment, describes a stator tooth 106 along with coil. The stator tooth 106 comprises a coil wound around the stator tooth 106. The coil generates a magnetic flux in the stator tooth 106 when a current passes through the coil. The generated magnetic flux is guided by the stator tooth 106 towards the rotor assembly to rotate the rotor. It is to be understood the coil may be wound around the stator tooth 106 with a bobbin. Alternatively, the coil may be wound around the stator tooth 106 without the bobbin using any other suitable form of insulation.
In the description of the present invention, it is also to be noted that, unless otherwise explicitly specified or limited, the terms “disposed,” “mounted,” and “connected” are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected, either mechanically or electrically. They may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Modifications to embodiments and combinations of different embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “have”, and “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural where appropriate.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the present disclosure, the drawings, and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
,CLAIMS:We Claim:
1. A stator assembly (100) for a motor, the stator assembly (100) comprises:
- a stator yoke (102) comprising a plurality of first securing means (104) along a length of radially inward surface (102a) of the stator yoke (102); and
- a plurality of stator teeth (106), wherein each of the stator tooth (106) comprises a second securing means (108) on a radially outward end (106a),
wherein each of the first securing means (104) is secured with the second securing means (108) making a revolute joint to form the stator assembly (100).
2. The stator assembly (100) as claimed in claim 1, wherein each of the stator tooth (106) is rotationally moveable at a radially inward end (106b) along an axis of the first securing means (104).
3. The stator assembly (100) as claimed in claim 1, wherein the second securing means (108) extend along a length of the radially outward end (106a) of each of the stator tooth (106).
4. The stator assembly (100) as claimed in claim 1, wherein each of the stator tooth (106) is in physical contact with the stator yoke (102) via the first securing means (104) and the second securing means (108).
5. The stator assembly (100) as claimed in claim 1, wherein the stator assembly (100) comprises a plurality of magnetic wedges (110), inserted mutually opposite along each of the second securing means (108).
6. The stator assembly (100) as claimed in claim 5, wherein the plurality of magnetic wedges (110) extend along the length of the radially outward end (106a) of each of the stator tooth (106).
7. The stator assembly (100) as claimed in claim 5, wherein the plurality of magnetic wedges (110) are fixed on the radially inward surface (102a) of the stator yoke (102).
8. The stator assembly (100) as claimed in claim 5, wherein the plurality of magnetic wedges (110) are configured to restrict the rotational movement of each of the stator tooth (106) beyond a predefined degrees to avoid physical contact between the radially inward ends (106b) of two adjacent stator teeth (106).
9. The stator assembly (100) as claimed in claim 1, wherein the first securing means (104) is secured inside the second securing means (108) making the revolute joint.
10. The stator assembly (100) as claimed in claim 1, wherein the second securing means (108) is secured inside the first securing means (104) making the revolute joint.