Electric motor

Abstract

An electric motor suitable for use in a washing machine includes an improved stator and / or rotor design.

Description

Technical Field

[0001] The present invention relates to a compact electric motor suitable for use in a washing machine or a drying machine or a washer-dryer or the like. Background Art

[0002] Direct drive motors are commonly used in washing machines. The motor drives the drum shaft directly without a belt or other form of motion transmission between the rotor and the shaft.

[0003] One of the requirements for a direct drive motor in a washing machine is that the motor has a minimum thickness so that the motor does not take up space from the washing machine tub (so that for a given footprint - washing machine capacity, the washing machine can accommodate a greater amount of clothes).

[0004] Another requirement is that the motor or the machine powered by the motor vibrates as little as possible and runs as quietly as possible. Vibrations in the operation of the motor are undesirable and cause noise, and in most applications, low vibration and low noise are important requirements for the motor.

[0005] It is an object of the present invention to provide an improved or at least alternative direct drive motor suitable for use in washing machines. Summary of the invention

[0006] stator

[0007] In a broad sense, in one aspect, the invention comprises a stator for an electric motor for a washing machine or dryer or a washer-dryer, comprising:

[0008] a core of magnetically conductive material, comprising an annular core ring and stator poles spaced about the core ring and extending radially outward from the core ring,

[0009] A polymer insulation structure surrounding the stator poles and comprising:

[0010] side surface, at least partially covering the axial upper surface of the core ring,

[0011] a cylindrical wall at least partially covering the radial inner surface of the core ring;

[0012] And also includes two or more fastener supports for receiving fasteners in the fastener receiving portion to fasten the stator to the non-rotating bearing hub or tub or drum or bearing shell of the washing machine or dryer or washer-dryer.

[0013] In at least some embodiments, each of the fastener supports includes a pair of axial walls and at least one axial intermediate wall located between the pair of walls, the intermediate wall protruding radially inward from the cylindrical wall to connect with the fastener receiving portion.

[0014] In at least some embodiments, each of the axial wall and the axial intermediate wall has a substantially uniform thickness in a tangential direction and a radial length that is at least twice the tangential thickness.

[0015] In at least some embodiments, each of the axial wall and the axial intermediate wall has a substantially uniform thickness in the tangential direction, and a radial length and an axial height that are at least twice the tangential thickness.

[0016] In at least some embodiments, the fastener support includes a plurality of axial intermediate walls intermediate the pair of axial walls.

[0017] In at least some embodiments, the stator includes one or more shelves located between adjacent fastener supports, wherein the shelves extend radially inward from the cylindrical wall and are spaced apart from the fastener supports to define a gap between the shelves and the fastener supports surrounding the cylindrical wall.

[0018] In at least some embodiments, the fastener support includes a surface for forming an interface with one or more corresponding surfaces on the hub or barrel or drum or bearing shell and aligning the fastener support structure with one or more corresponding surfaces on the hub or barrel or drum or bearing shell, wherein the corresponding surfaces are concentric with the bearing axis.

[0019] In at least some embodiments, the shelf includes an upper surface that is offset below the side of the insulating structure.

[0020] In at least some embodiments, one or more of the shelves carry one or more terminal mounts such that the terminal mounts are partially located below the sides of the core ring.

[0021] In at least some embodiments, the fastener support and shelf are integrally formed with the insulating structure.

[0022] Rotor

[0023] In a broad sense, in another aspect, the invention comprises a rotor for an electric motor for a washing machine or dryer or a washer-dryer, comprising a hub for connecting the rotor to a shaft, a peripheral portion for interacting with a stator of the motor to cause the rotor to rotate about an axis of rotation, and a rotor frame including a leg portion and an annular portion which together provide a structural connection between the hub and the peripheral portion, wherein

[0024] The leg portion includes a plurality of legs extending radially outwardly from the hub toward the annular portion, each leg having an inner end at the hub, the inner ends of a first plurality of legs being axially spaced from the inner ends of a second plurality of legs, and

[0025] The annular portion includes a plurality of substantially planar first wall segments, each wall segment defining an upper surface of the rotor frame, and a plurality of substantially planar second wall segments, the second wall segments being axially offset below the first wall segments, the first wall segments and the second wall segments being arranged adjacent to each other in an alternating manner around a central axis of the rotor frame.

[0026] In at least some embodiments, the first substantially planar wall segment and the second substantially planar wall segment extend through the hub at different angles relative to the axis of rotation.

[0027] In at least some embodiments, the rotor frame further includes one or more ribs extending between adjacent first and second wall segments of the annular portion.

[0028] In at least some embodiments, the first substantially planar wall segment and / or the second substantially planar wall segment, or one or more portions thereof, extend at a non-zero angle to an adjacent leg portion to which the segment is connected.

[0029] In at least some embodiments, the outer ends of the first plurality of legs are axially spaced less than the inner ends of the second plurality of legs, or the outer ends of the first plurality of legs are not axially spaced from the second plurality of legs, and / or wherein the legs converge in a radially outward region to a common axial position that substantially coincides with the annular portion.

[0030] In at least some embodiments, one or more axial walls connect an edge of each first wall segment with an edge of the second wall segment.

[0031] In at least some embodiments, the radial dimension of the annular portion is between 0.5 and 1.5 times the radial dimension of the leg portion and / or the radial length of the poles and coils on an associated stator.

[0032] In a broad sense, in another aspect, the invention comprises a rotor for an electric motor of a washing machine or dryer or a washer-dryer, comprising a hub for mounting the rotor on a shaft, a peripheral portion for interacting with a stator of the motor to cause the rotor to rotate about an axis of rotation, and a frame between the hub and the peripheral portion, wherein

[0033] The frame is formed of a polymeric material and includes mounts for individual components, such as magnets, that interact with sensors on the stator to indicate the absolute angular position of the rotor relative to the stator at least once per revolution, and

[0034] The mounting comprises a flexible hook which enables the insertion of the component, and a surface and an abutment which support the component against the forces and accelerations to which it is subjected in operation without the support or assistance of any additional components, and

[0035] The mounting member is fully integrally formed with the frame.

[0036] In a broad sense, in another aspect, the invention comprises a rotor for an electric motor of a washing machine or dryer or a washer-dryer, comprising a hub for connecting the rotor to a shaft, a peripheral portion for interacting with a stator of the motor to cause the rotor to rotate about an axis of rotation, and a frame between the hub and the peripheral portion, wherein

[0037] The frame is formed of a polymeric material and includes features or mounts for components on the frame that interact with sensors on the stator to indicate the absolute angular position of the rotor relative to the stator at least once per revolution, and

[0038] The hub comprises an axially extending opening for engaging the shaft, and specific protrusions or recesses for interacting with specific corresponding recesses or protrusions on the shaft to ensure that the hub can only be mounted on the shaft in a single absolute angular position.

[0039] In a broad aspect, the invention comprises, in another aspect, an electric motor for a washing machine comprising a stator and a concentric rotor as described herein.

[0040] In a broad aspect, the invention comprises, in another aspect, an electric motor for a washing machine comprising a rotor and a stator as described herein.

[0041] In a broad aspect, the invention comprises, in another aspect, an electric motor for a washing machine comprising a stator and a rotor, both as herein described.

[0042] In a broad aspect, the invention comprises, in another aspect, a washing machine or a clothes dryer or a washer-dryer comprising a motor as described herein.

[0043] Motors and machines

[0044] The present invention also includes an electric motor comprising the stator or rotor and a washing machine or a drying machine or a washer-dryer comprising an electric motor having the stator and / or the rotor.

[0045] definition

[0046] In this instruction manual:

[0047] · "drum" and "drum" are used interchangeably and include "baskets", which are perforated drums or drums, as the case may be; and

[0048] "Comprising" means "consisting at least in part of...", and when interpreting the statement including "comprising" in the specification and claims, there may be features other than or beginning with this word. Related words such as "comprise" and "comprises" should be interpreted similarly. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Embodiments of the present invention are described with reference to the accompanying drawings, in which:

[0050] Figure 1A is a partial vertical cross-section of a front-loading horizontal axis washing machine,

[0051] Figure 1B is a full vertical cross-section of a front loading horizontal axis washing machine,

[0052] Figure 2 is a partial cross-sectional view of a top-loading vertical axis washing machine,

[0053] Figure 3 is a perspective view of a stator of a direct drive motor suitable for a washing machine according to an embodiment of the present invention,

[0054] Figure 4 yes Figure 3 The outer edge diagram of the stator,

[0055] Figure 5 yes Figure 3 and Figure 4 The stator edge Figure 3 A cross-sectional view taken along line II of

[0056] Figure 5 a is as Figure 3 , Figure 4 as well as Figure 5 A perspective view of a stator for a direct drive motor suitable for a washing machine, showing an alternative embodiment of the stator shown in FIG.

[0057] Figure 6 is a perspective view of one side of a rotor of a direct drive motor applicable to a washing machine according to an embodiment of the present invention,

[0058] Figure 7 yes Figure 6 A perspective view of the opposite side of the rotor,

[0059] Figure 8 yes Figure 6 and Figure 7 The rotor edge Figure 6 A cross-sectional view taken along line II-II,

[0060] Fig. 9 yes Figure 6 and Figure 7 The rotor edge Figure 6 A cross-sectional view taken along line III-III of

[0061] Fig.10 yes Figures 6 to 9 A view of a portion of the rotor, showing the sensor magnet mounting,

[0062] Fig.11 is from Figures 6 to 9 A perspective view of the hub component of the rotor from one side.

[0063] Fig.12 is from Figures 6 to 9 A perspective view of the rotor hub from the other side.

[0064] Fig.13 is an enlarged view of the end of the matching rotor shaft,

[0065] Fig.14 It is available for Figures 6 to 9 The rotor Fig.11 and Fig.12 A perspective view of one side of an alternative hub component is shown, and

[0066] Fig.15 It is available for Figures 6 to 9 The rotor Fig.11 and Fig.12 A perspective view of the other side of an alternative hub component is shown. DETAILED DESCRIPTION

[0067] machine

[0068] refer to Figure 1A , a washing machine 1 of the front loading horizontal axis type is shown. The washing machine comprises an outer casing 2 having a front door 3 which allows access to a perforated rotatable inner drum / basket 4 for containing laundry, such as laundry, and mounted within the outer casing to rotate about a horizontal axis. A generally cylindrical fixed (non-rotating) liquid outer drum / tub 5 for containing washing liquid is mounted (suspended) within the casing 2 around the inner drum 4. Figure 1B A complete cross section of the inner and outer drums 4, 5 and the motor 7 of a horizontal axis machine is shown, in this case a front-loaded horizontal axis machine, and the outer casing is also not shown.

[0069] Figure 2is a partial cross-sectional view of a top loading vertical axis washing machine 1a. The machine comprises an outer housing 2a with a cover 3a which allows access to a perforated rotatable inner drum / basket 4a for containing laundry and mounted within the outer housing for rotation about a vertical axis. A generally cylindrical fixed (non-rotating) liquid outer drum / tub 5a for containing wash liquid is mounted (suspended) within the housing 2a around the inner drum 4a.

[0070] The stator 6 of the brushless DC (BLDC) or permanent magnet (PM) motor 7 is fixedly attached to the end 5b of the outer drum 5 / 5a directly or indirectly via the stator 6 attached to the bearing shell component 16 fixed to the end of the outer drum 5 / 5a (see Figure 1B and Figure 2 ). The rotor 8 outside the outer drum 5 / 5a is rotatably fixed to the outer end of a rotor shaft 9, which extends through a channel in the end of the outer drum 5 / 5a and carries the inner drum 4 / 4a at its other end. The rotor shaft 9 is mounted via at least one pair of spaced apart bearings, such as roller bearings carried by a bearing housing member 16. In a horizontal axis overhead or tilted access machine (not shown), the drum can be supported by bearings at both horizontal ends. The machine controller and / or motor controller (not shown) provides appropriate commutation signals to the stator windings arranged around the stator poles so that the rotational speed and direction of the rotor can be indicated during the various cycles of the washing program set by the user of the machine.

[0071] stator

[0072] Figures 3 to 5 as well as Figure 5 a shows a stator 6 of a direct drive motor suitable for a washing machine or a dryer or a washing machine and a dryer according to an embodiment of the present invention.

[0073] The stator includes an annular core ring 20 having a central opening 21, the annular core ring 20 carrying individual magnetic poles extending radially outward from the core ring 20 (transverse to the axis of rotation of the rotor) around the core ring. The core ring and the magnetic poles are formed of a magnetically conductive material. The core ring and the stator magnetic poles can be formed as a stack of thin, generally circular steel laminations, or a single spirally wound lamination. In at least some embodiments of the present invention, the stack of core rings and stator magnetic pole laminations are overmolded, encapsulated or partially encapsulated by a polymer material (also referred to herein as 'plastic') insulating structure. The stator coil is wound around the magnetic pole after the plastic encapsulation, so that the plastic encapsulation insulates the coil winding from the steel stator magnetic pole. The magnetic pole and coil are indicated together with 22.

[0074] In at least some embodiments of the invention, the insulating structure surrounding the stator poles is formed of plastic material and includes a planar side or wall 23 covering or at least partially covering the axial upper surface of the core ring 20 and a cylindrical wall 24 covering or at least partially covering the radial inner surface of the core ring.

[0075] The fastener support 25 includes a fastener receiving portion 25a defined for receiving a fastener to secure the stator to, for example, FIG. 1 and FIG. Figure 2 The non-rotating drum 5 shown in FIG. 1 and, for example, in particular the opening of the non-rotating bearing hub 16 or the like (usually each comprising a metal sleeve). Figures 3 to 5 In the embodiment shown in Figure 2a, the fastener support 25 is integrally formed with the plastic insulating structure. The fastener support 25 extends radially inward from the cylindrical wall 24, wherein the fastener receiving portion 25a is located at or near or includes the radial innermost surface 27 of the fastener support 25. The fastener support 25 also includes one or more (and preferably a pair) axial walls 26, which protrude radially inward from the cylindrical wall 24 and are connected to the fastener receiving portion. The axial wall 26 has a uniform thickness (in the tangential direction) and a radial length of at least twice the tangential thickness. The radial innermost surface 27 of the fastener support 25 can be a curved shape for forming an interface with one or more corresponding curved surfaces of the bearing hub concentric with the bearing axis and aligning the fastener support 25 with one or more corresponding curved surfaces of the bearing hub concentric with the bearing axis. As shown in the figure, the fastener support 25 also includes an intermediate wall 28, which protrudes radially inward from the cylindrical wall 24 and is connected to the fastener receiving portion. The intermediate wall 28 also has a uniform thickness (in the tangential direction) and a radial length that is at least twice the tangential thickness.

[0076] In alternative embodiments, fastener supports 25 may be integrally formed with core ring 20 rather than a plastic insulating structure, or fastener supports 25 may each comprise a metal component formed with core ring 20 that is overmolded by a plastic insulating structure. There may be at least two fastener supports, for example, two to eight, and in some exemplary embodiments, there are five fastener supports.

[0077] In at least some embodiments of the present invention, the stator also includes one or more shelves 30 located between adjacent fastener supports 25, the shelves being integrally formed as part of the overmolded insulating structure of the stator, the shelves extending radially inward from the cylindrical wall 24. One or more of the shelves 30 carry electrical terminal mountings or recesses 31 for connection to the stator coils. The shelves 30 are offset below the surface of the insulating structure so that the terminal mountings 31 are partially or entirely located below the axial upper surface of the core ring. As shown, the terminal recesses can be partially located below the surface of the lamination stack of the stator poles. This contributes to a compact and particularly low axial thickness or thin motor. Preferably, the terminal portion of the wire connected to the stator is also a low profile terminal, such as a marking terminal that is crimped directly onto the wire.

[0078] Shelf 30 may include tabs 32 on one or both sides as a strain relief feature around which the wires pass prior to terminal mountings 31, see Figure 3 .

[0079] Moreover, shelf 30 is structurally separated from fastener support 25 by a gap as shown, which extends radially inwardly from cylindrical wall 24 to the stator center opening.

[0080] To reduce noise and vibration, the structural response of the stator is optimized to attenuate internal torque oscillations and external accelerations. Reducing motor noise can be achieved by reducing the torsional stiffness of the connection between the stator and the component to which it is fixed (e.g., the bearing hub 16) so that when the torsional resonance passes through at low speeds and then at higher motor speeds, the compliance in the axial and radial walls 26, 28 reduces the transmission of torque oscillations from the motor to the drum and barrel structure. However, reducing torsional stiffness can also reduce the lateral and axial stiffness of the connection, resulting in air gap changes, distortions, and undesirable axial or lateral responses to barrel vibrations during operation. In at least some embodiments of the present invention, minimizing the torsional stiffness of the stator while maximizing the axial and radial stiffness is achieved by connecting each fastener support 25 to a laminated overmolding mold of an insulating structure having walls (26 and 28 in the illustrated embodiment) having a radial length and an axial height, but being thinner in the tangential direction (relative to the radial length and axial height). Since the bending stiffness of each portion of the wall is a function of its tangential thickness x axial height, the radial length and axial height of the series of radially protruding walls are significantly greater than their tangential thickness, resulting in a stator structure with low twisting or torsional stiffness and high axial and lateral stiffness.

[0081] In a preferred embodiment, each wall 26, 28 has an axial height that is significantly greater (e.g., at least twice) than its tangential thickness, and a radial length that is at least twice (e.g., three or four times longer) than its tangential thickness. In a preferred embodiment, each wall has a constant tangential thickness along its radial length, and optionally also has a constant axial height. In some embodiments, the radial length of the walls 26, 28 may be between approximately 1 / 5 and 1 / 15 of the inner diameter of the core ring 20. For example, the radial length of the walls 26, 28 may be approximately 1 / 8 of the inner diameter of the core ring 20, such as Figures 3 to 5 shown.

[0082] In alternative embodiments, the number of intermediate walls 28 of fastener support 25 may be varied to adjust the overall stiffness of the connection between the stator and the component to which it is secured, such as bearing hub 16. Adjusting the fastener support stiffness can fine-tune the stator structure to, to some extent, avoid resonant peaks and noise that coincide with or cause particular user dissatisfaction with the rotational speeds / frequencies encountered during sustained operation of a washing machine or dryer or washer-dryer over a period of time (although the machine may pass through these frequencies as the rotation speeds are accelerated and decelerated during the wash cycle). Figure 5A Shows Figures 3 to 5 An alternative embodiment of the stator is shown in which the fastener mounting member 25 includes three intermediate walls 28 located between a pair of walls 26, rather than a single intermediate wall 28. In a preferred embodiment, the fastener mounting member 25 includes one to three intermediate walls 28, and most preferably includes three intermediate walls 28. In a preferred embodiment, the tangential thickness of the intermediate wall 28 can be substantially equal to the tangential thickness of the wall 26.

[0083] Rotor

[0084] Figures 6 to 13 , especially Figures 6 to 9 , shows a rotor of a direct drive motor suitable for a washing machine or a dryer or a washer dryer according to an embodiment of the present invention. Figures 6 to 9 The rotor is designed to Figures 3 to 5 stator and vice versa.

[0085] The rotor 8 preferably includes a relatively lightweight but rigid and low-cost polymer or plastic frame 40 formed, for example, by injection molding. The rotor frame 40 includes: Fig.11 and Fig.12 , Fig.14 and Fig.15 The central rotor hub 41 is shown separately in FIG. 1 and has a splined aperture 42 that fits to the splines on the end of the drive shaft (see, for example, Figure 1B and Figure 2 9 of , and Fig.13, showing the end of the matching rotor shaft 9); and a peripheral portion 43 of a circumferential ring carrying a permanent magnetic pole or multiple magnetic pole elements 44. The rotor frame 40 can be formed of a plastic material and a metal hub 41 (e.g., the hub 41 is insert molded into the center of the plastic rotor frame 40, such as Fig. 9 ), or, the rotor frame 40 may be formed as a single component from a single material, such as a polymeric material or a metal.

[0086] Fig.14 and Fig.15 An alternative rotor hub 41 is shown in FIG.

[0087] Between the hub 41 and the peripheral portion 43, the rotor includes a leg portion 45 and an annular portion, which together provide a structural connection between the hub 41 and the peripheral portion 43 of the rotor. The leg portion 45 includes a plurality of legs 45a and 45b extending radially outward from the hub 41 toward the annular portion 46. The alternating legs 45a and 45b are axially spaced apart at least toward the inner end of the hub or the leg. That is, each leg has an inner end at the hub, and the inner ends of the first plurality of legs 45a are axially spaced apart from the inner ends of the second plurality of legs 45b, such that an axial gap exists between the first plurality of legs 45a and the second plurality of legs 45b. Therefore, the first plurality of legs 45a and the second plurality of legs 45b extend through the hub at different angles relative to the axis of rotation. In the illustrated embodiment, the first plurality of legs 45a are maximally spaced apart from the outer ends of the second plurality of legs 45b at their inner ends, and are less axially spaced apart or not axially spaced apart from the outer ends of the second plurality of legs 45b at their outer regions where they engage the annular portion 46. As a further example, the legs may be arranged substantially as described in U.S. Pat. No. 9,325,210, the entire contents of which are incorporated herein. In a region radially outward of the hub, the legs (axially spaced apart at their inner ends) may converge to a common axial position that substantially coincides with the annular portion 46.

[0088] The annular portion 46 is between the leg portion 45 and the peripheral portion 43. It includes a plurality of substantially planar first wall segments 46a and a plurality of substantially planar second wall segments 46b axially offset below the first wall segments 46a, each of the first wall segments 46a defining an upper surface of the rotor frame 40. The first wall segments 46a and the second wall segments 46b of the annular portion 46 are arranged adjacent to each other in an alternating manner around the central axis of the rotor frame 40, each wall segment being connected to its adjacent wall segment by an axial wall portion 47. Also in the illustrated embodiment, an annular wall portion or rib 49 extends between adjacent wall segments 46a and 46b. In the illustrated embodiment, the annular portion 46 includes two radially spaced annular wall portions or ribs 49 between each pair of adjacent wall segments 46a and 46b.

[0089] In some embodiments, the first substantially planar wall segment 46a and the second substantially planar wall segment 46b extend through the hub at different angles relative to the axis of rotation—that is, they lie on planes that are angularly offset from one another. The wall segments 46a and 46b may be integral with or connected to radially outer regions of the legs 45a and 45b. In this way, the planar wall segments 46a, 46b cooperate with the legs 45a and 45b to increase the stiffness and strength of the rotor frame 40 (compared to a rotor frame 40 having only the legs 45a, 45b without an offset planar wall segment connecting the legs to the periphery) without significantly increasing the mass of the rotor frame.

[0090] Typically, the radial dimension of the annular portion 46 is substantially equal to the radial dimension of the leg portion 45 and / or substantially equal to the radial length of the salient poles and coils on the stator. For example, the radial dimension of the annular portion 46 may be between 0.5 and 1.5 times the radial dimension of the leg portion 45 and / or the radial length of the poles and coils on the stator.

[0091] refer to Fig.10 In a preferred embodiment, the rotor frame 40 is formed of a polymeric material and includes mountings integrally formed with the frame for separate components, such as magnets (not shown), which interact with sensors on the stator to indicate the absolute angular position of the rotor relative to the stator at least once per revolution. The mountings may include flexible hooks 50. Surrounding surfaces and abutments 51 define recesses 52 in the frame below the hooks 50, which also support the components against forces and accelerations experienced in operation with the support or assistance of any additional components.

[0092] In the preferred embodiment, the hub 41 includes an axially extending opening 42 for engaging the rotor shaft, and a corresponding keying projection 55 (see FIG. Fig.13 ) or recesses interact to ensure that the rotor can only be mounted on the shaft in a single absolute angular position 43. Essentially, the hub lacks spline teeth for angular alignment.

[0093] Although in the figures the rotor comprises a plastic frame 40 and the rotor hub 41 is formed as a separate metal component, alternatively the frame and hub may be formed from a single material, for example made by metal pressing or casting, or from a plastic material.

[0094] Motor Type

[0095] As described above, the electric motor of the present invention preferably includes the rotor and stator described above.

[0096] The motors used in direct drive washing machines are typically of the radial flux – permanent magnet synchronous motor type (RF-PMSM) with an external rotor, and the rotor and stator shown in the figure and described above are RF-PMSM motors. Alternatively, the motor can be an axial flux permanent magnet synchronous motor (AF-PMSM) motor. An AF-PMSM motor is a motor with an axial orientation of the flux gap.

[0097] The motor can be any form of motor with permanent magnets. For example, the motor can be a permanent magnet synchronous motor (PMSM), a radial flux permanent magnet synchronous motor (RF-PMSM motor) with a radial orientation of the flux path, or an axial flux permanent magnet synchronous motor (AF-PMSM motor) with an axial orientation of the flux path. Alternatively, the motor can be a DC brushless or brushless motor (DCBM) with permanent magnets. The motor can have an external rotor or an internal rotor that carries the permanent magnets. The motor can be a direct drive motor, i.e., a motor in which the motor directly drives the output drive shaft or drum or bucket or basket of the machine without a belt or other form of motion transmission between the rotor and the shaft, or an indirect drive motor.

[0098] So far, the present invention has been described with reference to multi-pole pairs of permanent magnets on a rotor of an electric motor. However, the multi-pole pairs of permanent magnets may alternatively be on a stator, such as on a stator of a DC brushed motor. Thus, the present invention includes an electric motor including a stator including multi-pole pairs of permanent magnets, and all of the foregoing descriptions of embodiments of the present invention apply equally to replacing the stator with a rotor, and vice versa.

[0099] The present invention includes a washing machine or dryer or washer-dryer incorporating a motor according to the present invention, such as a top-loading vertical axis washing machine, a front-loading or top-loading or tilt-access horizontal axis washing machine, or a top-loading vertical axis washing machine, and a dryer or washer-dryer, which are typically horizontally accessed. Typically, a washing machine includes an outer housing with a top or front door, an outer drum / tub, and a rotating inner drum / basket that contains the clothes in use. Typically, the stator of the motor of the machine is fixed to one end of the outer drum / tub, and a rotor external to the outer drum is rotationally fixed to the outer end of a rotor / basket shaft extending through a channel in the end of the outer drum / tub and carries the inner drum / basket at its other end. The machine controller and / or motor controller (not shown) provides appropriate commutation signals to the stator windings arranged around the stator poles so that the rotation speed and direction of the rotor can be indicated during various cycles of the washing program set by the user of the machine.

[0100] The foregoing describes the invention, including preferred forms thereof. Modifications and variations, which will be apparent to those skilled in the art, may be made without departing from the scope of the invention.

Claims

1. A stator for an electric motor of a washing machine or a drying machine or a washer-dryer, include: a core of magnetically conductive material, comprising an annular core ring and stator poles spaced about the core ring and extending radially outward from the core ring, A polymer insulation structure surrounding the stator poles and comprising: side surface, at least partially covering the axial upper surface of the core ring, a cylindrical wall at least partially covering the radial inner surface of the core ring, and further comprising two or more fastener supports for receiving fasteners in the fastener receiving portions to fasten the stator to a non-rotating bearing hub or tub or drum or bearing housing of the washing machine or dryer or washer-dryer; and wherein each of the fastener supports includes a pair of axial walls and at least one axial intermediate wall located between the pair of walls, the intermediate wall protruding radially inwardly from the cylindrical wall to connect with the fastener receiving portion; Each of the axial wall and the axial intermediate wall has a substantially uniform thickness in the tangential direction, and a radial length and an axial height of at least twice the tangential thickness.

2. The stator according to claim 1, in, The fastener support includes a plurality of axial intermediate walls intermediate the pair of axial walls.

3. The stator according to claim 1 or claim 2, in, The fastener support includes a surface for forming an interface with one or more corresponding surfaces on the hub or barrel or drum or bearing shell and aligning the fastener support structure with one or more corresponding surfaces on the hub or barrel or drum or bearing shell, wherein the corresponding surfaces are concentric with the bearing axis.

4. The stator according to any one of claims 1 to 3, in, The stator includes one or more shelves located between adjacent fastener supports, wherein the shelves extend radially inwardly from the cylindrical wall and are spaced apart from the fastener supports to define gaps between the shelves and the fastener supports surrounding the cylindrical wall.

5. The stator according to claim 4, in, The shelf includes an upper surface that is offset below the side of the insulating structure.

6. The stator according to claim 4 or claim 5, in, One or more of the shelves carry one or more terminal mounts such that the terminal mounts are partially located below the sides of the core ring.

7. A stator according to any one of claims 4 to 6, in, The fastener support and shelf are integrally formed with the insulating structure.

8. A rotor for an electric motor of a washing machine or a drying machine or a washer-dryer, include: a hub for connecting the rotor to a shaft, a peripheral portion for interacting with the stator of the motor to cause the rotor to rotate about an axis of rotation, and a rotor frame including a leg portion and an annular portion which together provide a structural connection between the hub and the peripheral portion, wherein the leg portion includes a plurality of legs extending radially outward from the hub toward the annular portion, each leg having an inner end at the hub, the inner ends of the first plurality of legs being axially spaced from the inner ends of the second plurality of legs, and The annular portion includes: a plurality of substantially planar first wall segments, each wall segment defining an upper surface of the rotor frame; and a plurality of substantially planar second wall segments, the second wall segments being axially offset below the first wall segments, the first wall segments and the second wall segments being arranged adjacent to each other in an alternating manner around a central axis of the rotor frame.

9. The rotor according to claim 8, in, The first substantially planar wall segment and the second substantially planar wall segment extend through the hub at different angles relative to the axis of rotation.

10. A rotor according to claim 8 or claim 9, in, The rotor frame also includes one or more ribs extending between adjacent first and second wall segments of the annular portion.

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