Structurally reinforced rotor stack for synchronous reluctance motors

Abstract

A rotor stack is formed as a combination of axially stacked rotor laminates, each having truncated rotor sections on its outer circumference and along a quadrature axis Elongated, substantially elliptical reinforcement members are inserted through the truncated rotor sections in a form-fitting manner, extending axially to reinforce the rotor laminates against structural deformation. The rotor laminates include flux barrier groups with spaced-apart slots configured to receive substantially tubular reinforcement members. Substantially circular mounting plates are positioned at predetermined positions of the rotor stack, each having elliptical slots and spaced-apart slots symmetrically aligned with those on the rotor laminates to guide and support the elliptical and tubular reinforcement members. The elliptical and tubular reinforcement members in combination create a reinforcement structure that enhances the mechanical integrity of the rotor stack, maintains alignment of the rotor stack, and enables high-speed operation of the rotor stack with reduced structural deformation.

Description

STRUCTURALLY REINFORCED ROTOR STACK FOR SYNCHRONOUS RELUCTANCE MOTORSTECHNICAL FIELD

[0001] The present disclosure relates generally to synchronous reluctance motors and particularly to the structure of the rotors used in synchronous reluctance motors. More particularly, the present disclosure relates to a synchronous reluctance motor comprising a rotor assembly that does not get permanently deformed despite the exertion of structural forces, and is designed for high-speed operation and enhanced electromagnetic performance.BACKGROUND

[0002] Synchronous reluctance motors utilize rotors designed with strategically placed flux barriers and flux-carrying regions (flux carriers). The arrangement of flux barriers and flux carriers creates controlled flux paths for electromagnetic flux generated by stator coils, enabling an efficient motor operation. The flux barriers are typically air gaps created in the laminated rotor core by removing specific sections of the rotor laminate according to electromagnetic design requirements.

[0003] While these flux barriers are essential for proper electromagnetic function, they inherently reduce the structural integrity of the rotor core by creating discontinuities in the lamination structure, thereby compromising the rotor core's ability to withstand high-speed operations. This reduction in structural integrity is a critical limitation for high-speed motor applications.

[0004] The structural forces generated by the rotation of the rotor, combined with the electromagnetic and magnetic forces generated during the motor operation, create mechanical stresses that lead to temporary or permanent deformation of the rotor core. These forces increase proportionally with the rotational speed of the rotor core, making thestructural integrity of the rotor core a primary limiting factor for maximizing the operating speeds of the motor.

[0005] Conventional approaches to address this structural limitation include adding connecting bridges between flux carriers at locations determined by structural stress analysis. While these bridges provide additional structural strength, they create undesirable electromagnetic consequences by providing unwanted flux paths, reducing torque generation, and overall motor efficiency.

[0006] Another conventional approach involves using external sleeves made of metal, composites, or other materials positioned over the rotor outer diameter. However, when applied to synchronous reluctance motors (SynRM), external sleeves increase the effective air gap between the rotor and the stator, which negatively impacts electromagnetic performance through reduced torque and efficiency.

[0007] Therefore, there exists a need for an improved rotor reinforcement structure that provides the necessary structural support for high-speed operations of the rotor stack, while maintaining or even improving the electromagnetic performance of the rotor stack, without the design and reliability-related challenges associated with the above-identified conventional methods.OBJECTS

[0008] The primary object of the present disclosure is to provide a synchronous reluctance motor with enhanced structural integrity and high-speed operability, without compromising the electromagnetic performance.

[0009] Another object of the present disclosure is to provide a reinforcement structure that strategically removes rotor material from regions contributing minimally to electromagnetic performance and replaces the removed rotor material with structurally superior reinforcement elements.

[0010] Yet another object of the present disclosure is to provide reinforcement members within the flux barrier slots and along the quadrature axis regions to maintain theelectromagnetic flux barrier functionality while providing structural support against the structural forces.

[0011] A further object of the present disclosure is to eliminate manufacturing challenges associated with conventional bridge reinforcement approaches while enabling simplified manufacturing processes.

[0012] Another object of the present disclosure is to provide a reinforcement structure that withstands temporary deformation of the rotor core and the flux barriers during high-speed operation while maintaining structural integrity.

[0013] Yet another object of the present disclosure is to simplify the structural configuration of the rotor assembly, all the while improving the rotor assembly’s symmetry, balance, and durability during prolonged high-speed operations.

[0014] These and other objects and advantages of the present disclosure will become apparent from the following detailed description read in conjunction with the accompanying drawings.SUMMARY

[0015] The present disclosure provides a structurally reinforced synchronous reluctance motor, which, in turn, includes a rotor stack configured and designed to withstand the structural forces and mechanical stresses during high-speed operations. The rotor stack is formed by axially stacking multiple rotor laminates, each featuring truncated sections along the outer circumference and quadrature axis thereof. Elongated, substantially elliptical reinforcement members are inserted through the truncated sections in a form-fitting manner, extending axially along the rotor stack to create a reinforcement structure. The elongated, substantially elliptical reinforcement members (also referred to as “elliptical reinforcement members) provide critical structural support to prevent deformation of the rotor core and maintain the integrity of the rotor core during high-speed rotations.

[0016] In addition to the elliptical reinforcement members, each of the rotor laminates is configured with flux barrier groups comprising radially arranged flux barriers, each havingspaced-apart slots. The spaced-apart slots disposed on the flux barriers of each of the rotor laminates are collectively referred to as the “first group of spaced-apart slots”. Typically, the arrangement of the flux barriers comprised in a particular flux barrier group is in symmetry with the arrangement of the flux barriers comprised in the remaining flux barrier groups. The spaced-apart slots accommodate substantially tubular reinforcement members (also referred to as “tubular reinforcement members”) that provide structural reinforcement in a radial direction to the rotor laminates and the flux barriers arranged thereon. The combination of elliptical reinforcement members and tubular reinforcement members ensures uniform mechanical stability across the rotor stack, enhances the performance of the rotor stack, and renders the rotor stack resilient to structural failures.

[0017] To further support the reinforcement structure (i.e., the combination of elliptical reinforcement members and tubular reinforcement members), a plurality of substantially circular mounting plates are positioned at the front end of the rotor stack, rear end of the rotor stack, and between successive rotor laminates. Each circular mounting plate includes elliptical slots and a second group of spaced-apart slots aligned in symmetry with the truncated rotor sections and the first group of spaced-apart slots disposed on each of the rotor laminates, thereby ensuring axial alignment and structural continuity of the reinforcement members. Together, the rotor laminates, the reinforcement members, and circular mounting plates form the rotor stack envisaged by the present disclosure, which significantly improves the mechanical reliability and operational efficiency of the synchronous reluctance motor.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the structurally reinforced rotor stack envisaged by the present disclosure.

[0019] FIG. 1 illustrates an exploded view of the rotor stack that incorporates the substantially circular mounting plates, elliptical reinforcement members, and tubular reinforcement members, in accordance with the present disclosure.

[0020] FIG. 2 illustrates a front view of a substantially circular mounting plate with substantially elliptical slots and the second group of spaced-apart slots, in accordance with the present disclosure.

[0021] FIGs. 3A - 3C illustrate reinforcement members that provide structural support to the rotor stack, in accordance with the present disclosure.

[0022] FIG. 4A illustrates a perspective-sectional view of the rotor stack, cut off (removed) at the top portion thereof to reveal the placement of the tubular reinforcement members, in accordance with the present disclosure.

[0023] FIG. 4B illustrates a perspective view of the rotor stack containing a rotor laminate and a substantially circular mounting plate, with the tubular reinforcement members inserted through the spaced-apart slots disposed on the substantially circular mounting plate, in accordance with the present disclosure.

[0024] FIG. 4C illustrates a perspective view of the rotor stack containing a rotor laminate, with the tubular reinforcement members inserted through the first group of spaced-apart slots disposed on the flux barriers of the rotor laminate, in accordance with the present disclosure.

[0025] FIG. 4D illustrates a front view of a rotor laminate comprising the first group of spaced- apart slots, with the tubular reinforcement members inserted through the first group of spaced-apart slots, in accordance with the present disclosure.

[0026] FIG. 5 illustrates a front view of the rotor laminate, with the quadrature axes (q-axes), in accordance with the present disclosure.

[0027] FIG. 6 illustrates a perspective view of a rotor stack that incorporates only the elliptical reinforcement members and the corresponding elliptical slots, in accordance with the present disclosure.DETAILED DESCRIPTION

[0028] The reinforced rotor stack and the reinforcement members envisaged by the present disclosure will now be described in detail with reference to the accompanying drawings. Itshould be understood that the following detailed description is provided by way of illustration and not limitation.

[0029] The present disclosure relates to a synchronous reluctance motor having a structurally reinforced rotor stack that offers improved structural integrity and resistance to deformation under high-speed rotational operations. More particularly, the present disclosure envisages a structurally enhanced rotor stack that remains axially and radially stable, remains free from substantial deformation, and incorporates a plurality of reinforcement members and a plurality of circular mounting plates for mounting the said reinforcement members.

[0030] In synchronous reluctance motor design, the rotor stack geometry (or the geometry of each of the rotor laminates that together constitute the rotor stack) is defined by two perpendicular magnetic axes, viz., the direct axis (d-axis) and the quadrature axis (q-axis). The direct axis represents the path of minimum magnetic reluctance, where flux barriers are strategically positioned to control the electromagnetic flux flow. The quadrature axis represents the path of maximum magnetic reluctance, perpendicular to the direct axis. Typically, the flux barriers are positioned on the rotor laminate radially along the q-axis.

[0031] The term “structural force” refers to any force that acts on a physical structure, in this case, a rotor stack, affecting its stability, shape, or integrity. The structural forces are both internal and external, and are critical in determining how the rotor stack behaves under various conditions. In rotating systems such as electric motors embodying a combination of rotors and stators, the structural forces include centrifugal forces, centripetal forces, Coriolis forces, electromagnetic forces, and Eddy current forces.

[0032] Typically, the centrifugal force acts outward on a rotor stack and can cause deformation or structural failure thereof if not managed properly. Typically, the centripetal force is the reactive inward force required to keep the rotor stack in circular motion. Moreover, in electromagnetic systems, radial electromagnetic forces are generated due to the interaction between the rotor and stator fields, exerting stress on the rotor laminations and reinforcement structures. Optimizing the rotor stack design to appropriately negate theeffects of the above-mentioned forces is essential to ensure high-speed durability and operational efficiency of the rotor stack.

[0033] FIG. 1 illustrates a perspective view of a rotor stack (100) that includes substantially circular mounting plates (108) positioned between successive rotor laminates (102) for enhanced structural support, according to an embodiment of the present disclosure. Referring to FIG. 1 , the rotor stack (100) includes a plurality of rotor laminates (102), a plurality of substantially tubular reinforcement members (104) (also referred to as “tubular reinforcement members” hereafter), a plurality of elongated, substantially elliptical reinforcement members (106) (also referred to as “elliptical reinforcement members” hereafter), substantially circular mounting plates (108), and a centrally-located shaft bore (110) for accommodating a rotor shaft (not shown in figures).

[0034] The rotor stack (100) is formed by axially stacking a plurality of rotor laminates (102). Each of the rotor laminates (102) is fabricated with cut-offs at its outer circumference and along its quadrature axis, thereby creating truncated rotor sections (112). The truncated rotor sections (112) are configured to receive elongated, substantially elliptical reinforcement members (106). The shape and positioning of the truncated rotor sections (112) ensure a secure, form-fitting connection between the truncated rotor sections (112) of the rotor laminates (102) and the elliptical reinforcement members (106). In accordance with the present disclosure, the quadrature axis (q-axis) of the rotor stack (100) is the same as the quadrature axis of each of the rotor laminates (102) and each of the substantially circular mounting plates (108). Since the rotor laminates (102) and the substantially circular mounting plates (108) constitute the rotor stack (100), the q-axis of the rotor stack (100) will also serve as the q-axis for each of the rotor laminates (102) and each of the substantially circular mounting plates (108). By extension, the direct axis (d-axis) of the rotor stack (100) also serves as the direct axis for each of the rotor laminates (102) and each of the substantially circular mounting plates (108).

[0035] Each rotor laminate (102) further includes a plurality of flux barrier groups (104a in FIG.4D) symmetrically disposed on each of the rotor laminates (102) along the circumferential direction thereof and aligned with the quadrature axis of the respective rotorlaminates (102). Each flux barrier group (104a) consists of a predetermined number of flux barriers (114a in FIG.4D) radially arranged at predefined intervals. Each of the flux barriers (114a) includes at least two spaced-apart slots (114). The spaced-apart slots (114) disposed on the flux barriers (114a) are collectively referred to as the first group of spaced-apart slots. The first group of spaced-apart slots (114) is configured to accommodate the substantially tubular reinforcement members (104) in a form-fitting connection.

[0036] The rotor stack (100) envisaged by the present disclosure can also be alternatively referred to as a “rotor core”. The rotor stack (100) illustrated in FIG.1 is a part of a six-pole rotor assembly. It is well-known that a six-pole rotor assembly will have six magnetic poles, and each magnetic pole would embody a corresponding quadrature axis and direct axis. Since the rotor stack (100) constitutes a part of the six-pole rotor assembly, six quadrature axes (i.e., six q-axes) and six direct axes (i.e. , six d-axes) will be formed on each of the rotor laminates (102) of the rotor stack (100), as illustrated in FIG.1 and more particularly in FIG.5. Therefore, as illustrated in FIG.5, six truncated rotor sections (112) are formed respectively along the six q-axes of each of the rotor laminates (102), and six elongated, substantially elliptical reinforcement members (106) are inserted respectively through the six truncated rotor sections (112). By extension, each of the substantially circular mounting plates (108) will also contain six substantially elliptical slots (116), arranged in symmetry with the truncated rotor sections (112), for accommodating the six elongated, substantially elliptical reinforcement members (106), as illustrated in FIG.1.

[0037] The elongated, substantially elliptical reinforcement members (106) are inserted axially through the truncated rotor sections (112) of each rotor laminate (102) along the quadrature axis. Simultaneously, the substantially tubular reinforcement members (104) are inserted axially through the first group of spaced-apart slots (114) of the flux barriers (114a). The dual-insertion of the two types of reinforcement members (i.e., substantially tubular reinforcement members (104) and substantially elliptical reinforcement members (106)) creates a reinforcement structure (120) that prevents at least a permanent deformation of the rotor laminates (102) by firmly holding each of the rotor laminates (102) together even during high speed rotations of the rotor stack (100), and at least a permanent deformation ofthe flux barriers (114a) disposed on each of the rotor laminates (102) by firmly holding each of the flux barriers (114a) through the two respective spaced apart slots (114).

[0038] In accordance with the present disclosure, the reinforcement structure (120) is a combination of the substantially tubular reinforcement members (104) and substantially elliptical reinforcement members (106). The reinforcement structure (120) stabilizes the rotor stack (100) by firmly holding each of the rotor laminates (102) and each of the flux barriers (114a) disposed thereon, even during high speed rotations of the rotor stack (100), and thereby minimizes the deformation of the rotor laminates (102) and the flux barriers (114a) disposed thereon.

[0039] The reinforcement structure (120) thus provides mechanical and structural support to the rotor laminates (102) and the flux barriers (114a) disposed thereon, and reinforces them (i.e., the rotor laminates (102) and the flux barriers (114a) to withstand the structural forces generated, when the rotor stack (100) rotates at high operating speeds, without undergoing at least a permanent deformation.

[0040] To further improve the mechanical strength and axial alignment of the substantially tubular reinforcement members (104) and substantially elliptical reinforcement members (106), the rotor stack (100) comprises a plurality of substantially circular mounting plates (108). One circular mounting plate (108) is positioned respectively at the front end and rear end of the rotor stack (100), with at least one additional circular mounting plate (108) mounted in between successive rotor laminates (102). The use of the circular mounting plates (108) at the front end and rear end of the rotor stack (100) is optional and is often influenced by the desired structural stability of the rotor stack (100) and the desired speed of rotation of the rotor stack (100).

[0041] However, in the preferred embodiment of the present disclosure, illustrated in FIG.1 , one substantially circular mounting plate (108) is positioned at the front end of the rotor stack (100), one substantially circular mounting plate (108) is positioned at the rear end of the rotor stack (100), and one substantially circular mounting plate (108) is positioned in between two successive rotor laminates (102). The circular mounting plates (108) serve as support layersand alignment guides for the substantially tubular reinforcement members (104) and substantially elliptical reinforcement members (106).

[0042] Each substantially circular mounting plate (108) is provided with a plurality of substantially elliptical slots (116) arranged along its outer circumference and aligned along its quadrature axis. The elliptical slots (116) are in symmetry with the truncated rotor sections (112) of the rotor laminates (102) and are configured to receive the corresponding elongated, substantially elliptical reinforcement members (106) in a form-fitting connection or form-fitting manner. Additionally, each circular mounting plate (108) includes a second group of spacedapart slots (118) arranged in symmetry with the first group of spaced-apart slots (114) disposed on the flux barriers (114a). The second group of spaced-apart slots (118) is configured to receive the substantially tubular reinforcement members (104) in a form-fitting connection, thereby facilitating a secured, stabilized, and firm connection between each of the rotor laminates (102) and the substantially circular mounting plates (108).

[0043] In accordance with the present disclosure, the form-fitting connection between the substantially elliptical reinforcement members (106) and the elliptical slots (116) disposed on the substantially circular mounting plates (108), and the form-fitting connection between the substantially tubular reinforcement members (104), the first group of spaced-apart slots (114) disposed on each of the rotor laminates (102) and the second group of spaced-apart slots (118) disposed on each of the substantially circular mounting plates (108) provides for: a) the rotor laminates (102) to be firmly held with the substantially circular mounting plates (108), by the form-fitting connection between the substantially elliptical reinforcement members (106), the truncated rotor sections (112) disposed on each of the rotor laminates (102), and the elliptical slots (116) disposed on each of the substantially circular mounting plates (108); and b) the flux barriers (114a) to be firmly held in their original position and orientation on each of the rotor laminates (102), and structurally supported and reinforced against at least a permanent deformation, by the substantially tubular reinforcement members (104) inserted into the first group of spaced-apart slots (114) disposed on the rotor laminates (102) and the second group of spaced-apart slots (118) disposed on each of the substantially circular mounting plates (108), in a form-fitting connection.

[0044] The elongated, substantially elliptical reinforcement members (106) are inserted through the elliptical slots (116) disposed on the substantially circular mounting plate (108) positioned at the front end of the rotor stack (100). Further, the elongated, substantially elliptical reinforcement members (106) extend axially through the truncated rotor sections (112) of each of the rotor laminates (102), the elliptical slots (116) disposed on the circular mounting plate (108) positioned between two successive rotor laminates (102), and the elliptical slots (116) disposed on the substantially circular mounting plate (108) positioned at the rear end of the rotor stack (100). As shown in FIG.1 , the elongated, substantially elliptical reinforcement members (106) terminate at the circular mounting plate (108) positioned at the rear end of the rotor stack (100). The axial extension of the substantially elliptical reinforcement members (106) through the length of the rotor stack (100) provides continuous axial support to the entirety of the rotor stack (100), and, in turn, each of the rotor laminates (102) comprised in the rotor stack (100), and thus enables the rotor laminates (102) to withstand the structural forces created by the high speed rotation of the rotor stack (100), and prevents the rotor laminates (102) from at least a permanent deformation, despite the exertion of substantial structural forces. .

[0045] Likewise, the substantially tubular reinforcement members (104) are inserted through the second group of spaced-apart slots (118) disposed on the circular mounting plate (108) positioned at the front end of the rotor tack (100), and extend axially through the first group of spaced-apart slots (114) disposed on each of the rotor laminates (102), the second group of spaced-apart slots (118) disposed on the circular mounting plate (108) positioned in between two successive rotor laminates (102), and the second group of spaced-apart slots (118) disposed on the circular mounting plate (108) positioned at the rear end of the rotor stack (100), thereby ensuring radial stability and appropriate alignment of the flux barriers (114a) disposed on each of the rotor laminates (102) contained within the rotor stack (100). As shown in FIG.1 , the substantially tubular reinforcement members (104) and the substantially elliptical reinforcement members (106) are disposed in an axial direction and parallel to the shaft bore axis (i.e. , the central longitudinal axis of the rotor stack (100)). As shown in FIG.1 , the reinforcement structure (120) formed by the combination of the substantially tubular reinforcement members (104) and the substantially ellipticalreinforcement members (106) encases the rotor shaft (not shown in figures) inserted through the shaft bore (110). Preferably, the reinforcement structure (120) encases the rotor shaft in a structural configuration that is substantially similar to a six-sided star.

[0046] The elongated, substantially elliptical reinforcement members (106) and the substantially tubular reinforcement members (104) extend axially through the length of the rotor stack (100), creating a form-fitting connection with each of the rotor laminates (102) and the circular mounting plates (108). The substantially tubular reinforcement members (104), when inserted through each of the rotor laminates (102) and the substantially circular mounting plates (108), provide continuous and uniformly distributed structural support to the rotor laminates (102) and, in turn, the flux barriers (114a) disposed thereon, by firmly holding the flux barriers (114a) in their original positions and orientations, thereby preventing at least a permanent deformation of the said flux barriers (114a) due to the structural forces created during the rotation of the rotor stack (100). Further, the elongated, substantially elliptical reinforcement members (106) inserted in a form-fitting manner to interconnect each of the rotor laminates (102) and the substantially circular mounting plates (108) provide continuous and uniformly distributed structural support to the rotor laminates (102) by firmly holding each of the rotor laminates (102) and the substantially circular mounting plates (108) together during high speed rotation of the rotor stack (100), and thus preventing at least a permanent deformation of the rotor laminates (102) due to the structural forces created due to the high speed rotation of the rotor stack (100). Further, by taking into consideration the operating conditions of the rotor stack (100), i.e., the temperature, speed, and load, inter alia, the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106) can also be utilized to prevent or at the least substantially minimize the temporary deformation of the rotor laminates (102) and the flux barriers (114a) disposed thereon.

[0047] In accordance with the present disclosure, the substantially circular mounting plates (108) play a vital role in mechanically stabilizing the rotor stack (100). The substantially circular mounting plates (108) provide additional structural support to the reinforcement members, i.e., the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106), especially when they temporarilydeform during the acceleration and subsequent deceleration of the rotor stack (100). By acting as rigid retaining layers, the circular mounting plates (108) not only retain the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106) firmly in their respective slots (114, 116, 118), but also facilitate an equal distribution of the stress applied upon the rotor stack (100) by the structural forces, and a substantial reduction in the localized strain witnessed by each of the rotor laminates (102) and the flux barriers (114a) disposed thereon.

[0048] The substantially tubular reinforcement members (104) may be affixed to the circular mounting plates (108) and the rotor laminates (102) via gluing or welding methods. Such bonding techniques enhance the stability of the form-fitting connection created between the substantially tubular reinforcement members (104), the first group of spaced-apart slots (114) and the second group of spaced-apart slots (118), and thus prevent axial displacement or loosening of the substantially tubular reinforcement members (104) during high speed rotations of the rotor stack (100) and during the prolonged use of the rotor stack (100).

[0049] The combination of the rotor laminates (102), circular mounting plates (108), and the form-fitted reinforcement members (i.e., the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106)) offers a structurally optimized and reinforced rotor stack (100) for synchronous reluctance motors. The rotor stack (100) envisaged by the present disclosure ensures high-speed performance with minimized deformation, improved operational safety, and extended motor lifespan.

[0050] FIG. 2 illustrates a front view of the substantially circular mounting plate (108). The substantially circular mounting plate (108) includes the substantially elliptical slots (116) arranged thereon in symmetry with the truncated rotor sections (112) disposed on each of the rotor laminates (102), and the second group of spaced-apart slots (118) arranged thereon in symmetry with the first group of spaced-apart slots (114) disposed on the rotor laminates (102). The substantially elliptical slots (116) and the second group of spaced-apart slots (118) are configured to receive the elongated, substantially elliptical reinforcement members (106) and the substantially tubular reinforcement members (104), respectively.

[0051] The substantially elliptical slots (116) are positioned along the outer circumference of the circular mounting plate (108) and aligned with the quadrature axis, in symmetry with the positioning and alignment of the truncated rotor sections (112) on the rotor laminates (102). The substantially elliptical slots (116) are configured to receive the elongated, substantially elliptical reinforcement members (106) in a form-fitting connection.

[0052] Likewise, the second group of spaced-apart slots (118) is arranged in a pattern that is symmetrical to the arrangement of the first group of spaced-apart slots (114) on each of the rotor laminates (102). The second group of spaced-apart slots (118) accommodate the substantially tubular reinforcement members (104) and contribute to the structural integrity of the rotor laminates (102) and the flux barriers (114) disposed thereon, with the structural integrity of the rotor laminates (102) being critical for maintaining the mechanical and electromagnetic performance of the rotor stack (100), and in turn, the electric motor that accommodates the rotor stack (100).

[0053] FIGs. 3A - 3C illustrate reinforcement members (104, 106) that provide structural support to the rotor stack (100). The rotor stack (100), as shown in FIG.1 , includes two types of reinforcement members (i.e., the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106)) that, in combination, form the reinforcement structure 120. Both the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106) are essential for maintaining the structural stability of the rotor stack (100) and for preventing the deformation of the rotor laminates (102) and the flux barriers (114a) disposed thereon. Both the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106) work in combination to provide an optimal structural support and structural reinforcement to the rotor stack (100).

[0054] FIG. 3A illustrates the perspective view of the elongated, substantially elliptical reinforcement member (106). The elongated, substantially elliptical reinforcement members (106) are inserted through the truncated rotor sections (112) along the quadrature axis. The elongated, substantially elliptical reinforcement members (106) are arranged in a form-fitting connection with the truncated rotor sections (112) of each of the rotor laminates (102) and extend axially along the length of the rotor stack (100). The substantially ellipticalreinforcement members (106) are optimized to withstand the stress patterns encountered in the quadrature axis regions of the rotor laminates (102), and to provide structural support to each of the rotor laminates (102), at least along the q-axis thereof.

[0055] FIG. 3B and FIG. 3C illustrate a perspective view and a side view of the substantially tubular reinforcement member (104), respectively. The substantially tubular reinforcement members (104) are inserted through the first group of spaced-apart slots (114) arranged on the flux barriers (114a). The substantially tubular reinforcement members (104) extend axially through the rotor stack (100), passing through the corresponding spaced-apart slots (114) disposed on each of the rotor laminates (102) and the second group of spaced-apart slots (118) disposed on each of the substantially circular mounting plates (108). The substantially tubular reinforcement members (104) maintain the electromagnetic air gap function of the flux barriers (114a) while providing structural reinforcement to the flux barriers (114a) against at least permanent deformation due to the exertion of the structural forces during high-speed rotations of the rotor stack (100).

[0056] FIG. 4A illustrates a sectional perspective view of the rotor stack (100) in which the top portion of the rotor stack (100) is cut off (removed) to reveal the arrangement of the substantially tubular reinforcement members (104). The cut-off portion in FIG.4A illustrates the placement of the substantially tubular reinforcement members (104) that extend axially through the rotor stack (100). The substantially tubular reinforcement members (104) are received by the first group of spaced-apart slots (114) disposed on each of the rotor laminates (102) and the second group of spaced-apart slots (118) disposed on each of the substantially circular mounting plates (108), as illustrated previously in FIG.1. The sectional perspective view of FIG.4A emphasizes the integration of the tubular reinforcement members (104) into the first group of spaced-apart slots (114) disposed on the flux barriers (114a) of each of the rotor laminates (102) and the second group of spaced-apart slots (118) disposed on each of the circular mounting plates (108).

[0057] In accordance with the present disclosure, the insertion of the substantially tubular reinforcement members (104) through the circular mounting plates (108) positioned at the front end of the rotor stack (100) and the subsequent axial extension of the tubularreinforcement members (104) through the first group of spaced-apart slots (114) disposed on the flux barriers (114a) of each of the rotor laminates (102), the second group of spaced- apart slots (118) disposed on the circular mounting plates (108) positioned in between the successive rotor laminates (102), and the circular mounting plate (108) positioned at the rear end of the rotor stack (100) covers the rotor stack (100) in its entirety in terms of the length thereof, and structurally reinforces the flux barriers (114a) disposed on each of the rotor laminates (102) by firmly holding the flux barriers (114a) in their original orientation and alignment, thereby preventing at least a permanent deformation of the flux barriers (114a) due to the exertion of the structural forces during high speed rotations of the rotor stack (100). Further, by firmly holding the flux barriers (114a) of every rotor laminate (102) in their original orientation and alignment, the tubular reinforcement members (104) also enhance the structural stability of the rotor laminates (102) and facilitate, at least in part, the prevention of deformation of the rotor laminates (102) due to the exertion of the structural forces generated during high-speed rotations of the rotor stack (100).

[0058] FIG. 4B illustrates a perspective view of the rotor stack (100), in which at least one rotor laminate (102) and at least one substantially circular mounting plate (108) are axially stacked. As shown in FIG.4B, the substantially circular mounting plate (108) is positioned at the front end of the rotor stack (100) and the at least one rotor laminate (102) is coupled to the substantially circular mounting plate (108) via elongated, substantially elliptical reinforcement members (106) and the substantially tubular reinforcement members (104). Further, FIG.4B illustrates the axial extension of the elongated, substantially elliptical reinforcement members (106) and the substantially tubular reinforcement members (104) from the substantially circular mounting plate (108) positioned at the front end of the rotor stack (100) to the rotor laminate (102), and the consequential firm coupling of the substantially circular mounting plate (108) and the rotor laminate (102). The elongated, substantially elliptical reinforcement members (106) and the substantially tubular reinforcement members (104) maintain the structural integrity and balance of the rotor stack (100) during high-speed rotations of the rotor stack (100), and enable the rotor stack (100) to withstand the structural forces generated during such high-speed rotations.

[0059] FIG. 4C illustrates a perspective view of the rotor stack (100), in which the substantially circular mounting plate (108) positioned at the front end of the rotor stack (100) is removed to reveal the structure of the underlying rotor laminate (102). As shown in FIG.4C, the elongated, substantially elliptical reinforcement members (106) have been inserted, in a form-fitting manner, through the truncated rotor sections (112) of the rotor laminate (102), and the substantially tubular reinforcement members (104) have been inserted, in a formfitting manner, through the spaced-apart slots (114) disposed on the flux barriers (114a) of the rotor laminate (102). As shown in FIG.4C, the elongated, substantially elliptical reinforcement members (106) and the substantially tubular reinforcement members (104) are inserted, in a form-fitting manner, through the truncated rotor sections (112) and the first group of spaced-apart slots (114) disposed on the rotor laminate (102), respectively, thereby structurally supporting and reinforcing the rotor stack (100). The form-fitting connection formed between the pair of elongated, substantially elliptical reinforcement members (106) and the truncated rotor sections (112), and the pair of substantially tubular reinforcement members (104) and the spaced-apart slots (114) provides structural support to the rotor laminate (102) of the rotor stack (100), and prevents the rotor laminates (102) and the flux barriers (114a) disposed thereon from getting at least permanently deformed due to the structural forces exerted on the rotor stack (100) during high-speed rotations.

[0060] FIG. 4D illustrates a front view of the rotor laminate (102), in accordance with the present disclosure. FIG.4D also illustrates the circumferential arrangement of the flux barrier groups (104a) along the outer face of the rotor laminate (102). Each of the flux barrier groups (104a) contains a plurality of flux barriers (114a) symmetrically arranged in a radial direction with reference to the shaft bore (110). As shown in FIG.4D, the flux barriers (114a) of a group of flux barriers (104a) are in symmetry with the flux barriers (114a) of the remaining flux barrier groups (104a). FIG.4D also illustrates the truncated rotor sections (112) created along the outer periphery of the rotor laminate (102) and along the q-axis of the rotor laminate (102) for receiving the respective elongated, substantially elliptical reinforcement members (106). FIG.4D also illustrates the positioning of two-spaced apart slots (114) on each of the flux barriers (114a) for receiving the respective substantially tubular reinforcement members (104).

[0061] FIG. 5 illustrates a front view of the rotor stack (100) comprising a rotor laminate (102) in a stacked relationship with the substantially circular mounting plate (108) positioned at the front end of the rotor stack (100). FIG.5 also shows the positioning of quadrature axes (q- axes) on the rotor stack (100). In FIG.5, the quadrature axes (q-axes) are shown by respective horizontal lines extending radially outwards with reference to the centralized position of the shaft bore (110). As described previously with reference to FIG.1 , the rotor stack (100) and the rotor laminate (102) are a part of a six-pole rotor assembly. It is well- known that a six-pole rotor assembly will have six magnetic poles, and each magnetic pole would embody a corresponding quadrature axis and direct axis. Since the rotor stack (100) constitutes a part of the six-pole rotor assembly, six quadrature axes (i.e. , six q-axes) are formed on the rotor laminate (102) of the rotor stack (100), as illustrated previously in FIG.1.

[0062] However, in FIG.5, the six truncated rotor sections (112) disposed on the rotor laminate (102) are overlapped by the substantially elliptical slots (116) disposed on the substantially circular mounting plate (108), for the substantially circular mounting plate (108) is stacked above the rotor laminate (102). Further, FIG.5 specifically illustrates the orientation of each of the six q-axes formed along the outer periphery of the rotor laminate (102) underlying the substantially circular mounting plate (108).

[0063] Along each of the quadrature axes, near the outer circumference of the rotor laminate (102), are the truncated rotor sections (112) that are cut-out regions configured to receive the elongated, substantially elliptical reinforcement members (106) in a form-fitting connection. The truncated rotor sections (112) are symmetrically arranged along the respective quadrature axes (as shown in both FIG.1 and FIG.5) so as to receive the elongated, substantially elliptical reinforcement members (106), which, in turn, structurally reinforce each of the rotor laminates (102) along the respective q-axes. As shown in FIG.5, the six elongated, substantially elliptical reinforcement members (106) are inserted respectively into the six substantially elliptical slots (116) disposed on the circular mounting plate (108) and along the q-axes thereof. Subsequently, the six elongated, substantially elliptical reinforcement members (106) extend axially from the six substantially elliptical slots (116) and into the six truncated rotor sections (112) disposed on the rotor laminate (102), along the six q-axes thereof.

[0064] Correspondingly, the substantially circular mounting plate (108) positioned adjacent and in an axial relationship to the rotor laminate (102) is shown with a plurality of substantially elliptical slots (116) disposed along its outer circumference and aligned precisely along the quadrature axes. The elliptical slots (116) are configured to align with the truncated rotor sections (112) of each of the rotor laminates (102) to receive the elongated, substantially elliptical reinforcement members (106) in a form-fitting connection.

[0065] FIG. 6 illustrates a perspective view of the rotor stack (600) with an alternative configuration, in accordance with an alternative embodiment of the present disclosure, in which the rotor stack (600) is reinforced only by the elongated, substantially elliptical reinforcement members (106). The rotor stack (600) envisaged by the alternative embodiment is different from the rotor stack (100) in that it is not reinforced by the substantially tubular reinforcement members (104), and the rotor laminates (102) of the rotor stack (600) do not incorporate the first group of spaced-apart slots (114), and the substantially circular mounting plates (108) used in the rotor stack (600) do not incorporate the second group of spaced-apart slots (118).

[0066] Referring to FIG. 6, the rotor stack (600) includes a plurality of rotor laminates 102, a plurality of elongated, substantially elliptical reinforcement members (106), at least one substantially circular mounting plate (108) located at the front end and rear end of the rotor stack (600), and substantially circular mounting plates (108) located in between successive rotor laminates (102).

[0067] The rotor stack (100) illustrated in FIG.1 is substantially similar to the rotor stack (600) illustrated in FIG.6, except that the rotor stack (600) is reinforced only by the elongated, substantially elliptical reinforcement members (106). The explanation provided in respect of rotor stack (100) applies equally to the rotor stack (600), except for the explanation of the substantially tubular reinforcement members (104), the first group of spaced-apart slots (114) and the second group of spaced-apart slots (118) that receive the substantially tubular reinforcement members (104).

[0068] The substantially tubular reinforcement members (104) are not a part of the rotor stack (600). As shown in FIG.6 the rotor stack (600) is reinforced only by the elongated, substantially elliptical reinforcement members (106) that are inserted through the substantially elliptical slots (116) disposed on the substantially circular mounting plate (108) positioned at the front end of the rotor stack (600), and made to radially extend through the truncated rotor sections (112) disposed on each of the rotor laminates (102), the substantially elliptical slots (116) disposed on the substantially circular mounting plate (108) positioned in between two successive rotor laminates (102), and the substantially elliptical slots (116) disposed on the substantially circular mounting plate (108) positioned at the rear end of rotor stack (600), in a form-fitting connection.

[0069] According to the rotor stack (600) envisaged by the alternative embodiment, each of the flux barriers (114a), disposed on each of the rotor laminates (102), does not incorporate the spaced-apart slots (114) that received the substantially tubular reinforcement members (104) in the case of the rotor stack (100). By extension, the substantially circular mounting plates (108) of the rotor stack (600) do not incorporate the second group of spaced-apart slots (118) that received the substantially tubular reinforcement members (104) in the case of the rotor stack (100).

[0070] Instead, each of the rotor laminates (102) of the rotor stack (600) incorporates only the truncated rotor sections (112) that are configured to receive corresponding elongated, substantially elliptical reinforcement members (106) in a form-fitting connection. Further, in line with the construction of each of the rotor laminates (102), each of the substantially circular mounting plates (108) contains only the elliptical slots (116) that are configured to receive the elongated, substantially elliptical reinforcement members (106).

[0071] In the case of rotor stack (600), the elongated, substantially elliptical reinforcement members (106) are inserted axially through the truncated rotor sections (112) of each of the rotor laminates (102). The truncated rotor sections (112) are positioned along the outer circumference of each of the rotor laminates (102) and along the quadrature axis of each of the rotor laminates (102). Upon insertion, the elongated, substantially elliptical reinforcement members (106) reinforce the rotor stack (600) by firmly coupling each of the rotor laminates (102) with the substantially circular mounting plates (108), and thereby mitigate the prospectof rotor laminates (102) deforming, at least permanently, due to the structural forces exhibited thereon during high-speed rotations of the rotor stack (600).

[0072] In accordance with the alternative embodiment, the rotor stack (600) comprises a plurality of substantially circular mounting plates (108). At least one circular mounting plate (108) is positioned at the front end of the rotor stack (600) and the rear end of the rotor stack (600), respectively, as was the case with the rotor stack (100). Further, a substantially circular mounting plate (108) is placed in between successive rotor laminates (102), as was the case with the rotor stack (100).

[0073] Each of the substantially circular mounting plates (108) incorporates only the substantially elliptical slots (116), arranged along the outer circumference thereof and aligned with the quadrature axis thereof. The substantially circular mounting plates (108), in the case of the rotor stack (600), do not incorporate the second group of spaced-apart slots (118). The elliptical slots (116) are in symmetry with the truncated rotor sections (112) of the rotor laminates (102) and are configured to receive the elongated, substantially elliptical reinforcement members (106) in a form-fitting manner.

[0074] The elongated, substantially elliptical reinforcement members (106) are inserted through the substantially elliptical slots (116) disposed on the circular mounting plate (108) positioned at the front end of the rotor stack (600). Subsequently, the elongated, substantially elliptical reinforcement members (106) pass through the substantially elliptical slots (116) disposed on the circular mounting plate (108) positioned at the front end of the rotor stack (600), and extend axially through the truncated rotor sections (112) of each of the rotor laminates (102), the elliptical slots (116) disposed on the circular mounting plate (108) positioned in between successive rotor laminates (102), and the elliptical slots (116) disposed on the circular mounting plate (108) positioned at the rear end of the rotor stack (600). The elongated, substantially elliptical reinforcement members (106) terminate at the substantially elliptical slots (116) disposed on the circular mounting plate (108) positioned at the rear end of the rotor stack (600).

[0075] The elongated, substantially elliptical reinforcement members (106), arranged on the outer circumference and along the quadrature axis of each of the rotor laminates (102) andthe circular mounting plates (108), extend axially through the entirety of the rotor stack (600) in terms of the length of the rotor stack (600). The form-fitting connection of the elliptical reinforcement members (106) with the truncated rotor sections (112) disposed on the outer periphery of each of the rotor laminates (102) and the substantially elliptical slots (116) disposed on each of the circular mounting plates (108) provides for a firm coupling between each of the rotor laminates (102) and the circular mounting plates (108), thereby reinforcing each of the rotor laminates (102) and adding additional structural strength to each of the rotor laminates (102), and, in turn, the entire rotor stack (600). In this manner, elongated, substantially elliptical reinforcement members (106) prevent at least a permanent deformation of the rotor laminates (102) due to the exertion of the structural forces during high-speed rotations of the rotor stack (600).

[0076] As illustrated in FIG.6, the rotor stack (600) is reinforced only by the insertion of the elongated, substantially elliptical reinforcement members (106) into each of the substantially elliptical slots (116) disposed on each of the substantially circular mounting plates (108) and the substantially elliptical slots (116) disposed on each of the rotor laminates (102). The substantially tubular reinforcement members (104) are not used for reinforcing the rotor stack (600), for the operating speed of the rotor stack (600) and the desired structural rigidity of the rotor stack (600) requires reinforcement only along the q-axis and the outer periphery of each of the rotor laminates (102). Therefore, in such a case, only the elongated, substantially elliptical reinforcement members (106) are used to reinforce each of the rotor laminates (102) along the q-axis and outer periphery thereof.

[0077] Further, the form-fitting connection of the elliptical reinforcement members (106) with the truncated rotor sections (112) and the substantially elliptical slots (116) supports and structurally reinforces the entire rotor stack (600), for the elliptical reinforcement members (106) extend axially through the length of the entire rotor stack (600), thereby firmly coupling each of the rotor laminates (102), comprised within the rotor stack (600), to the corresponding substantially circular mounting plates (108).

[0078] The form-fitting connection described herein above with reference to the rotor stack (100) and the rotor stack (600) is preferably achieved through precise dimensional controlduring machining and laser marking of the substantially elliptical reinforcement members (106), the substantially tubular reinforcement members (104), the truncated rotor sections (112), the substantially elliptical slots (116), the first group of spaced apart slots (114), and the second group of spaced-apart slots (118). For instance, the elongated, substantially elliptical reinforcement members (106) are manufactured with dimensions that closely match the truncated rotor sections (112) and the substantially elliptical slots (116) with minimal clearance. Alternative methods for ensuring a form-fitting connection typically include thermal expansion fitting during rotor stack assembly, where the temperature differential is used to achieve a proper fit, or elastic deformation fitting, where the reinforcement members are slightly oversized relative to the receiving sections and made to deform elastically during the insertion phase to create a secured and form-fitting mechanical connection.

[0079] In accordance with the present disclosure, the plurality of substantially tubular reinforcement members (104) and the plurality of elongated, substantially elliptical reinforcement members (106) are inserted into the second group of spaced-apart slots (118) and the substantially elliptical slots (116), respectively, in a form-fitting connection. The formfitting connection is achieved through various attachment methods, including threaded connections, interference fits, welding, gluing, and brazing, inter alia. The number and the positioning of substantially circular mounting plates (108) typically depend upon the length of the rotor stack (100, 600), the operating speed of the rotor stack, properties of the materials used for creating the rotor laminates, and the desired structural rigidity of the rotor stack (100, 600).

[0080] The substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106) envisaged by the present disclosure can be used to reinforce the rotor stacks (100, 600) of synchronous reluctance motors (SynRM), permanent magnet assisted synchronous reluctance motors, ferrite assisted synchronous reluctance motors, permanent magnet synchronous motors (PMSM), and interior permanent magnet (IPM) motors.

[0081] The elongated, substantially elliptical reinforcement members (106) are preferably fabricated from high-strength materials optimized for specific stress patterns encountered along the quadrature axes of each of the rotor laminates (102). The elliptical design of theelongated, substantially elliptical reinforcement members (106) provides directional strength characteristics that are aligned with the principal stress directions exhibited by rotor operations in synchronous reluctance motors. The substantially tubular reinforcement members (104) are preferably fabricated from non-magnetic materials to preserve flux barrier (114a) functionality. The tubular configuration of the substantially tubular reinforcement members (104) provides optimized strength-to-weight ratios while maintaining the electromagnetic air gap necessary for optimized rotor operations.

[0082] In accordance with the present disclosure, the substantially circular mounting plates (108), especially the circular mounting plates (108) positioned between successive rotor laminates (102), divide the rotor stack (100, 600) into a plurality of sub-stacks. In accordance with the present disclosure, dividing the rotor stack (100, 600) into a plurality of sub-stacks creates multiple shorter rotor spans instead of a single long rotor span and consequentially reduces the maximum bending stress applied upon the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106), during high-speed rotations of the rotor stack (100, 600). Further, the division of a longer rotor stack (100, 600) into multiple sub-stacks also provides for improved management of thermal expansion, with the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106) functioning to firmly hold the rotor laminates (102) and the circular mounting plates (108) together, albeit facilitating a temporary, limited, controlled thermal expansion / deformation of the rotor laminates (102) and the flux barriers (114a) disposed thereon.

[0083] The substantially tubular reinforcement members (104) and elongated, substantially elliptical reinforcement members (106) envisaged by the present disclosure provide structural support to the rotor laminates (102) and the flux barriers (114a) disposed thereon while minimizing the electromagnetic impact created by electromagnetic forces generated by rotor operations. The creation of truncated rotor sections (112) on the outer circumference and along the q-axis of each of the rotor laminates (102) helps remove those sections of each of the rotor laminates (102) that do not contribute significantly to the performance of the rotor stack (100). Additionally, the truncated rotor sections (112) disposed on the outer circumference of each of the rotor laminates (102) also brings about a reduction in fluxsaturation on the outer circumference of each of the rotor laminates (102) and also reduces the amount of heat generated on the outer circumference of each of the rotor laminates (102), thereby enhancing the operational efficiency of the rotor stack (100). Further, the insertion of elongated, substantially elliptical reinforcement members (106) into the truncated rotor sections (112) enhances the structural stability and integrity of the rotor stack (100).

[0084] The insertion of the elongated, substantially elliptical reinforcement members (106) into the truncated rotor sections (112) of each of the rotor laminates (102) structurally reinforces the rotor laminates (102), thereby providing for a controlled and calculated reduction in the thickness of the outer periphery of each of the rotor laminates (102), which, in turn, prevents or at the least minimizes flux saturation at the outer circumference of each of the rotor laminates (102) and consequentially improves the electromagnetic efficiency of each of the rotor laminates (102), and in turn the rotor stack (100, 600). Further, the positioning of the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106) within the flux barriers (114a) of each of the rotor laminates (102) and the truncated rotor sections (112) created along the q-axis of each of the rotor laminates (102), respectively, exhibits minimal impact on the electromagnetic flux paths created by the flux barriers (114a) while structurally reinforcing each of the rotor laminates (102) and the flux barriers (114a) disposed thereon against at least a permanent deformation due to the exertion of the structural forces created during the rotation of the rotor stack (100).

[0085] Unlike conventional rotor reinforcement approaches that include positioning connecting bridges between flux carriers at predetermined locations, the positioning of the reinforcement structure (120), i.e., the combination of substantially tubular reinforcement members (104) and elongated, substantially elliptical reinforcement members (106), does not create redundant and ineffective electromagnetic flux paths, but structurally reinforces the rotor laminates (102) and the flux barriers (114a) disposed thereon to facilitate high speed operations of the rotor stack (100) with enhanced electromagnetic efficiency. Further, the combined use of the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106) provides superior structural support and reinforcement to the rotor stack (100) in comparison to the use of thin connecting bridges or outer sleeves in isolation as reinforcement members. Further, the insertion of thesubstantially tubular reinforcement members (104) into the rotor stack (100) is separate from the insertion of the elongated, substantially elliptical reinforcement members (106) into the rotor stack (100). The separate installation of the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106) provides for simplified replacement of the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106) in case of wear and tear or failure. Since the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106) are not mechanically coupled to one another, replacing any of the substantially tubular reinforcement members (104) and the elongated, substantially elliptical reinforcement members (106), in case of a failure or wear and tear is straight forward, simpler, and less time consuming.

Claims

WE CLAIM:

1. A synchronous reluctance motor, said synchronous reluctance motor (100) comprising: a rotor stack, said rotor stack formed by arranging a plurality of rotor laminates (102) in a stacked axial relationship, and wherein each of said rotor laminates (102) is cut-off at an outer circumference thereof and along a quadrature axis thereof to form truncated rotor sections (112) configured to receive respective elongated, substantially elliptical reinforcement members (106); a plurality of flux barrier groups symmetrically disposed in a circumferential direction and along said quadrature axis of each of said rotor laminates (102), each of said flux barrier groups comprising a plurality of flux barriers symmetrically arranged at predetermined intervals along a radial direction and a first group of spaced-apart slots (114) symmetrically disposed on each of said plurality of flux barriers, and wherein each of said plurality of flux barriers comprises at least two spaced-apart slots (114), belonging to said first group of spaced-apart slots (114), arranged along said radial direction, and wherein each of said first group of spaced-apart slots (114) is configured to receive respective substantially tubular reinforcement members (104) in a form-fitting connection; and wherein said elongated, substantially elliptical reinforcement members (106) are inserted through said truncated rotor sections (112) of each of the rotor laminates (102) in said form-fitting connection, and wherein said elongated, substantially elliptical reinforcement members (106) extend axially along the quadrature axis of each of said rotor laminates (102), and wherein said substantially tubular reinforcement members (104) are inserted through respective spaced-apart slots belonging to said first group of spaced-apart slots (114), arranged on each of said flux barriers, in said form-fitting connection; and wherein said elongated, substantially elliptical reinforcement members (106) and said substantially tubular reinforcement members (104), when inserted through said truncated rotor sections (112) and said spaced-apart slots (114) respectively in said form-fitting connection, form a reinforcement structure that reinforces said rotor stack by preventing substantial deformation of each of said rotor laminates (102) and saidflux barrier groups disposed thereon, during rotation of said rotor stack, by providing structural support to each of said rotor laminates (102) and said flux barrier groups to withstand structural forces generated by said rotation of said rotor stack.

2. The synchronous reluctance motor as claimed in claim 1 , wherein said synchronous reluctance motor (100) further comprises a plurality of substantially circular mounting plates (108), and wherein at least one substantially circular mounting plate (108) is positioned at a front end and a rear end of said rotor stack respectively, and at least one substantially circular mounting plate (108) is positioned in between successive rotor laminates (102) of said rotor stack, and wherein each of said substantially circular mounting plates (108) comprise: a plurality of substantially elliptical slots (116) arranged on said outer circumference of each of said substantially circular mounting plates (108) and on said quadrature axis of each of said substantially circular mounting plates (108), and wherein said plurality of substantially elliptical slots (116) are in symmetry with said truncated rotor sections (112) disposed on each of said rotor laminates (102), said plurality of substantially elliptical slots (116) configured to receive said elongated, substantially elliptical reinforcement members (106) in said form-fitting connection; and a second group of spaced-apart slots (118) arranged on each of said substantially circular mounting plates (108), said second group of spaced-apart slots (118) arranged in symmetry with said first group of spaced-apart slots (114), each of said second group of spaced-apart slots (118) configured to receive said respective substantially tubular reinforcement members (104) in said form-fitting connection.

3. The synchronous reluctance motor as claimed in claim 2, wherein each of said elongated, substantially elliptical reinforcement members (106) is inserted, in said form-fitting connection, through respective substantially elliptical slots (116) arranged on said outer circumference of said substantially circular mounting plate (108) positioned at said front end, and wherein each of said elongated, substantially elliptical reinforcement members (106) axially extend along said quadrature axis from said substantially circular mounting plate (108) positioned at said front end, andwherein each of said elongated, substantially elliptical reinforcement members (106) is inserted, in said form-fitting connection, respectively through: each of said substantially elliptical slots disposed on each of said rotor laminates (102); each of said substantially elliptical slots (116) disposed on said at least one substantially circular mounting plate (108) positioned in between said successive rotor laminates (102); and each of said substantially elliptical slots (116) disposed on said at least one substantially circular mounting plate (108) positioned at said rear end of said rotor stack; and wherein each of said substantially tubular reinforcement members (104) is inserted through said second group of spaced-apart slots (118) disposed on said substantially circular mounting plate (108) positioned at said front end, and wherein each of said substantially tubular reinforcement members (104) extend axially from said substantially circular mounting plate (108) positioned at said front end, and wherein each of said substantially tubular reinforcement members (104) are inserted, in said form-fitting connection, respectively into: each of said spaced-apart slots belonging to said first group of spaced-apart slots (114), and disposed on each of said rotor laminates (102); each of said second group of spaced-apart slots (118) disposed on at least one substantially circular mounting plate (108) positioned in between said successive rotor laminates (102); and each of said spaced-apart slots belonging to said first group of spaced-apart slots (114), and disposed on said at least one substantially circular mounting plate (108) positioned at said rear end of said rotor stack.

4. The synchronous reluctance motor as claimed in claim 1 or 2, wherein said rotor stack further comprises a shaft bore (110) for accommodating a rotor shaft, and wherein: said elongated, substantially elliptical reinforcement members (106) are arranged in said form-fitting connection with said truncated rotor sections (112) and said substantially elliptical slots, on said outer circumference and along said quadratureaxis of each of said rotor laminates (102) and each of said substantially circular mounting plates (108); said substantially tubular reinforcement members (104), when inserted through said second group of spaced-apart slots (118) and each of said spaced-apart slots belonging to said first group of spaced-apart slots (114), extend axially along a shaft bore (110) axis, and are disposed in parallel to said rotor shaft; and said elongated, substantially elliptical reinforcement members (106) and said substantially tubular reinforcement members (104) axially extend along a length of said rotor stack, forming said form-fitting connection with each of said rotor laminates (102) and each of said substantially circular mounting plates (108), thereby providing said structural support to each of said rotor laminates (102) and said flux barrier groups disposed thereon to withstand said structural forces generated by said rotation of said rotor stack.

5. The synchronous reluctance motor as claimed in claim 1 , wherein said plurality of substantially circular mounting plates (108) provide an additional structural support to said elongated, substantially elliptical reinforcement members (106) and said substantially tubular reinforcement members (104) inserted therethrough in said formfitting connection, when said elongated, substantially elliptical reinforcement members (106) and said substantially tubular reinforcement members (104) temporarily deform during said rotation of said rotor stack.

6. The synchronous reluctance motor as claimed in claim 2, wherein said substantially tubular reinforcement members (104) are at least one of glued onto each of said plurality of substantially circular mounting plates (108) and welded onto each of said plurality of substantially circular mounting plates (108).

7. A synchronous reluctance motor, said synchronous reluctance motor (600) comprising: a rotor stack, said rotor stack formed by arranging a plurality of rotor laminates (102) in a stacked axial relationship, and wherein each of said rotor laminates (102) is cut-off at an outer circumference thereof and along a quadrature axisthereof to form truncated rotor sections (112) configured to receive respective elongated, substantially elliptical reinforcement members (106); and wherein said elongated, substantially elliptical reinforcement members (106) are inserted through said truncated rotor sections (112) of each of the rotor laminates (102) in a form-fitting connection, and wherein said elongated, substantially elliptical reinforcement members (106) are disposed on said outer circumference of each of said rotor laminates (102), and wherein said elongated, substantially elliptical reinforcement members (106) extend axially along said quadrature axis of each of said rotor laminates (102); and wherein said elongated, substantially elliptical reinforcement members (106) when inserted through said truncated rotor sections (112) in said form-fitting connection, form a reinforcement structure that reinforces said rotor stack by preventing substantial deformation of each of said rotor laminates (102) during rotation of said rotor stack, by providing structural support to each of said rotor laminates (102) to withstand structural forces generated by said rotation of said rotor stack.

8. The synchronous reluctance motor as claimed in claim 7, wherein said synchronous reluctance motor (600) further comprises a plurality of substantially circular mounting plates (108), and wherein at least one substantially circular mounting plate (108) is positioned at a front end and a rear end of said rotor stack respectively, and at least one substantially circular mounting plate (108) is positioned in between successive rotor laminates (102) of said rotor stack, and wherein each of said substantially circular mounting plates (108) comprise: a plurality of substantially elliptical slots (116) arranged on said outer circumference of each of said substantially circular mounting plates (108) and on said quadrature axis of each of said substantially circular mounting plates (108), and wherein said plurality of substantially elliptical slots (116) are in symmetry with said truncated rotor sections (112) disposed on each of said rotor laminates (102), said plurality of substantially elliptical slots configured to receive said elongated, substantially elliptical reinforcement members (106) in said form-fitting connection; andwherein each of said elongated, substantially elliptical reinforcement members (106) is inserted, in said form-fitting connection, through respective substantially elliptical slots (116) arranged on said outer circumference of said substantially circular mounting plate (108) positioned at said front end, and wherein each of said elongated, substantially elliptical reinforcement members (106) axially extend along said quadrature axis from said substantially circular mounting plate (108) positioned at said front end, and wherein each of said elongated, substantially elliptical reinforcement members (106) is inserted, in said form-fitting connection, respectively into: each of said substantially elliptical slots disposed on each of said rotor laminates (102); each of said substantially elliptical slots (116) disposed on said at least one substantially circular mounting plate (108) positioned in between said successive rotor laminates (102); and each of said substantially elliptical slots (116) disposed on said at least one substantially circular mounting plate (108) positioned at said rear end of said rotor stack.

9. The synchronous reluctance motor as claimed in claim 7 or 8, wherein: said elongated, substantially elliptical reinforcement members (106) are arranged in said form-fitting connection with said truncated rotor sections (112) and said substantially elliptical slots, on said outer circumference and along said quadrature axis of each of said rotor laminates (102) and each of said substantially circular mounting plates (108); said elongated, substantially elliptical reinforcement members (106) axially extend along a length of said rotor stack, forming said form-fitting connection with each of said rotor laminates (102) and each of said substantially circular mounting plates (108), thereby providing said structural support to each of said rotor laminates (102) to withstand said structural forces generated by said rotation of said rotor stack; andwherein said plurality of substantially circular mounting plates (108) provide an additional structural support to said elongated, substantially elliptical reinforcement members (106) inserted therethrough in said form-fitting connection, when said elongated, substantially elliptical reinforcement members (106) temporarily deform during said rotation of said rotor stack.

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