MOTOR HOUSING ARRANGEMENT AND METHOD FOR MANUFACTURING THE MOTOR HOUSING ARRANGEMENT

Abstract

Motor housing assembly (12), comprising: a housing (30) designed to accommodate a stator (18); a stator (18) positioned in the housing (30), wherein a fillable gap (50) is defined by the stator (18) and an inner surface (32) of the housing (30) adjacent to the stator (18); a polymer layer (64) made of a polymer material (60) that partially fills the fillable gap (50) and is in contact with the housing (30) and the stator (18); wherein the polymer layer (64) is designed as a thermally conductive layer; wherein the housing (30) defines at least one channel (48) in conjunction with the fillable gap (50) for filling the polymer material (60) into the gap (50), characterized by the fact that a portion of the polymer material (60) remains in the channel (48) and forms a sealing plug (68) in it to seal the channel (48).

Description

TECHNICAL FIELD

[0001] The present invention relates to a motor housing assembly with a stator and a method for manufacturing the motor housing assembly according to the preamble of claim 1 and claim 7, respectively, as known for example from JP 2007-236045 A.

[0002] Similar motor housing arrangements are also described in the documents JP 2000-78797 A, US 2012 / 0011949 A and US 2009 / 0152962 A, although there the polymer material is not introduced into the gap through a housing channel. BACKGROUND

[0003] Thermal conduction away from a motor during engine operation is required to maintain an engine operating temperature that is not harmful to the motor or engine components. Heat transfer away from a motor may be limited by one or more voids or air spaces between motor components, such as between a stator and a motor housing, which reduce heat transfer away from the motor due to poor thermal conductivity, e.g., the insulating properties of the air present in the void or space.

[0004] Elevated operating temperatures can affect motor efficiency by increasing the energy input required to produce torque output, or they can affect motor performance or durability by thermally stressing the motor and increasing the likelihood of thermal fatigue of motor components such as windings. Motor control systems can be configured to monitor motor temperature and limit motor output to a maximum torque limit to prevent motor overheating in situations where heat transfer is insufficient to maintain the motor's operating temperature below a temperature limit. SUMMARY

[0005] Improving heat transfer away from the engine can lead to engine performance benefits including improved engine efficiency and durability, reduced likelihood of overheating and thermal stress, and an increase in the engine's operating torque limit.

[0006] The invention is based on the object of ensuring, based on the prior art according to JP 2007-236045 A, that no moisture, dirt or other substances can penetrate into the gap.

[0007] This object is achieved with a motor housing arrangement having the features of claim 1 and with a method having the features of claim 7.

[0008] A motor housing assembly including a stator is provided which includes a thermally conductive material configured to transfer heat from the stator to the motor housing to enhance heat transfer away from the motor, thereby improving motor efficiency.

[0009] In one example, the thermally conductive material may be configured as a thermally conductive layer disposed between the stator and the motor housing and configured to displace air from a fillable gap defined by the stator and the motor housing. As described herein, the thermally conductive layer may provide other benefits to motor performance, including stabilizing the stator position relative to the motor housing, dampening stator vibrations, and / or providing a fire-retardant layer.The thermally conductive layer may be applied or configured such that the stator can be slidably fitted into the motor housing during assembly, thereby minimizing stress on the stator core laminations that may result from undesired engagement of the stator core laminations with the housing either during motor assembly or in use due to, for example, vibrations and / or thermal expansion of the motor components comprising the stator core laminations.

[0010] A method of manufacturing the motor housing assembly is provided, including a method of forming the thermally conductive layer, wherein the thermally conductive layer is distributed in a gap between the stator and the motor housing. The thermally conductive layer is configured to transfer heat from the stator to the motor housing to cool the motor during operation. The thermally conductive layer may also be configured to stabilize the position of the stator in the motor housing, which may, for example, dampen vibrations and reduce fatigue stress on the motor components including the stator windings. The motor housing assembly may be configured for use with any type of electric motor, including traction motors. In one example, the motor may be configured as a traction motor for use in a vehicle, which may be a hybrid vehicle or an electric vehicle.

[0011] A motor housing assembly and a method for manufacturing the motor housing assembly are provided. The motor housing assembly includes a housing configured to receive a stator, and a stator positioned within the housing to define a fillable gap defined by the stator and an interior surface of the housing adjacent to the stator. A polymer layer is formed by filling a polymer-based material into the fillable gap such that the polymer-based material, when dispersed and cured within the gap, partially fills the gap to form a polymer layer in contact with the housing and the stator.The polymer layer is configured as a thermally conductive layer having a thermal conductivity greater than the thermal conductivity of air, such that the polymer layer is configured to transfer heat from the stator to the housing to contribute to cooling the motor during operation.

[0012] The stator defines an outer surface adjacent to the inner surface of the housing. The polymer layer is formed such that the polymer layer contacts at least half of the outer surface of the stator, and preferably at least 80% of the outer surface of the stator to provide a heat transfer interface equal to or greater than 50% of the outer surface of the stator. The polymer layer is comprised of a polymer-based material having an in-plane thermal conductivity of at least 0.5 W / mK, or preferably an in-plane thermal conductivity of at least 8 W / mK. The polymer-based material may include a metallic filler configured to increase the thermal conductivity of the polymer layer and / or to improve the flow properties of the polymer-based material.The polymer layer may be configured as a fire-retardant layer, for securing the stator to the housing and / or for damping vibrations to reduce a stress load on the stator.

[0013] A method of manufacturing the motor housing assembly includes positioning a stator in a motor housing to define a gap between an outer surface of the stator and an inner surface of the motor housing, filling a flowable polymer material into the gap in contact with the outer surface of the stator and the inner surface of the housing adjacent to the outer surface of the stator, and curing the flowable polymer material to form a thermally conductive polymer layer configured to transfer heat between the stator and the housing.The stator and / or the housing may be preheated prior to filling the flowable polymer material into the gap and / or the polymer material may contain a flow-enhancing filler material or be configured as a highly flowable polymer to assist in the distribution and flow of the polymer material into the gap.

[0014] In one example, the housing defines at least one channel in communication with the gap, and the manufacturing method includes filling the gap with the flowable polymer material by injecting the flowable polymer material through the at least one channel into the gap. The channel may be configured to receive a fitting such that the flowable polymer material may be injected through the fitting into the gap to provide a polymer layer characterized by a flow pattern emanating from the channel. One or more channels may be defined through the housing to distribute the polymer material into contact with at least half of the surface area of ​​the outer surface of the rotor.The method may include controlling the amount of flowable material introduced into the gap such that the distribution of the flowable material is limited to the outer surface of the rotor.

[0015] The foregoing and other features and advantages of the present invention will be readily apparent from the following detailed description of the best modes for carrying out the invention when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic plan view of a motor assembly including a stator assembly and a motor housing defining a gap therebetween; Fig. Figure 2 is a schematic cross-sectional view of a section 2-2 of Fig. 1, which shows a thermally conductive layer between the stator assembly and the motor housing; Fig. Figure 3A is a schematic cross-sectional view of section 3A-3A of Fig. 2, which contains injection ports defined by the engine housing; Fig. Figure 3B is a schematic cross-sectional view of section 3B-3B of Fig. 3A; Fig. Figure 4A is a schematic plan view of the motor housing and stator assembly of Fig. 1 with an injector bracket; Fig. Figure 4B is a schematic cross-sectional view of section 4B-4B of Fig. 4A. DETAILED DESCRIPTION

[0016] Reference is made to the drawings, in which like reference numerals represent like components throughout the several figures. Fig. 1 - 4B are not to scale or proportional. Consequently, the specific dimensions and applications shown in the drawings provided herein should not be construed as limiting. With reference to Fig. 1 and Fig. 2, a motor, generally designated 10, is shown, also referred to herein as a motor assembly. The motor 10 may be configured as any type of electric motor. As one non-limiting example, the motor 10 may be configured as a drive motor for use in a vehicle, which may be a hybrid vehicle or an electric vehicle. The motor assembly 10 includes a motor housing assembly, generally designated 12, configured to receive a rotor assembly, generally designated 16. The motor housing assembly 12 includes a motor housing 30, also referred to herein as a housing, and a stator assembly, generally designated 14. The stator assembly 14 may be operatively secured to the housing 30. The motor housing assembly may be configured for use with any type of electric motor, including drive motors.In the example shown, without limitation, the rotor assembly 16 may include a rotor, also referred to as a rotor core 22, which is rigidly mounted to a shaft 24, for example, via a bushing 26. The rotor core 22 defines a generally cylindrical outer surface 42. For clarity of illustration, details of the rotor assembly 16, such as the rotor windings, are not provided. The rotor assembly 16 is configured to be rotatably mounted relative to the motor housing assembly 12, e.g., relative to the stator assembly 14 and the housing 30. In the example shown, a rotor bearing 28 is operatively connected to the housing 30 and configured to rotatably receive one end of the motor shaft 24 to position the rotor assembly 16 relative to the housing 30, the stator assembly 14, and / or a reference axis 66.The reference datum 66 may establish a datum from which the relative positions of the inner surface 32 of the housing 30, the rotor bearing 28, the stator assembly 14, and the rotor assembly 16 are defined, and / or it may correspond to or be defined by an operating characteristic or physical characteristic of the motor assembly 12, such as the axis of the rotor assembly 16, the axis of the stator assembly 14, etc. A second housing (not shown) may be attached to the flanged end of the motor housing 30 and may be configured to receive the other end of the motor shaft 24, to rotatably mount the rotor assembly 16 relative to the housing 30, and / or to establish the reference datum 66.

[0017] The stator assembly 14 includes a stator core 18, also referred to herein as the stator, and stator windings 20. For clarity of illustration, details of the windings 20 are not provided. The stator 18 defines a generally cylindrical inner surface 44 and an outer surface 46 that extends along the axial length of the stator 18. The housing 30 defines an inner surface 32 configured to receive the stator assembly 14 so that the stator assembly 14 can be slidably fitted within the housing 30, for example, positioned within the case 30, without undesirable interference between the stator outer surface 46 and the housing inner surface 32.The stator assembly 14 is positioned within the housing 30 and rigidly attached to the housing 30 to define an empty gap 50, also referred to herein as a fillable gap, between the outer surface 46 of the stator 18 and the inner surface 32 of the housing 30, and to define an air gap 74 between the stator inner surface 44 and the outer surface 42 of the rotor such that the rotor assembly 16 is rotatable relative to the stator assembly 14 in use.

[0018] In the example shown, the stator assembly 14 may be rigidly attached to the motor housing 30 by a plurality of fasteners 40 that extend axially through a plurality of stator sections 58 and are operatively attached to the housing 30 (not shown) to retain the stator assembly 14 in the position defining the fillable gap 50 and the air gap 74. The fasteners 40 may be configured as bolts that can be rigidly attached to the housing by nuts (not shown), or they may be configured as another form of fastener suitable for operatively attaching the stator assembly 14 to the housing 30 in a rigid position.The inner surface 32 of the housing 30, in the example shown, includes recesses 70 configured to receive respective stator sections 58, such that the fillable gap 50 is partially defined by the portion of the surface 46 defined by each stator section 58 adjacent to the portion of the surface 32 defined by the respective recess 70 that receives the stator section 58. It should be understood that the example shown is not limiting, and other configurations of the stator assembly 14 and / or the housing 30 are possible to enable attachment of the stator assembly 14 to the housing 30 to define the fillable gap 50 therebetween.

[0019] The fillable gap 50, defined by the stator outer surface 46 and the portion of the housing inner surface 32 adjacent the stator outer surface 46, extends along the axial length of the stator 18. A flowable polymer material 60 is poured into the fillable gap 50 and is cured to form a polymer layer 64 disposed between the stator outer surface 46 and the housing inner surface 32, and such that the polymer layer 64 contacts the stator outer surface 46 and the housing inner surface 32, as described in further detail herein. The polymer layer 64 displaces air, which is a relatively poor thermal conductor, from the fillable gap 50 to provide a thermally conductive layer between the housing inner surface 32 and the stator outer surface 46.The polymer layer 64, which replaces the displaced air in the fillable gap 50, is characterized by a thermal conductivity greater than the thermal conductivity of air, such that the polymer layer 64 increases the heat transfer rate from the stator 18 to the housing 30 relative to the heat transfer rate in the absence of the polymer layer 64, for example, increases the heat transfer rate relative to the heat transfer rate when the fillable gap 50 is filled with air. The thermally conductive polymer layer 64 is configured to facilitate the transfer of heat generated by the stator and rotor assemblies 14, 16 during operation radially outward through the housing inner surface 32 to the housing outer surface 34 along the radial heat transfer paths, generally designated 62.

[0020] The fillable gap can be filled by a gap width of 76 (see Fig. 3C). The gap width 76 may vary circumferentially within a housing assembly 12 due to variability in the housing interior surface 32, in the positioning of the stator 18 relative to the housing interior surface 32, and / or in the reference datum 66, and / or in the positioning of the stator 18 relative to the rotor assembly 16 to establish the air gap 74 between the rotor assembly 16 and the stator assembly 14. Since the polymer layer 64 contacts the stator exterior surface 46 and the housing interior surface 32, it will be understood that the thickness of the polymer layer 64 at any radial location corresponds to and / or is determined by the gap width 76 at that radial location, such that the thickness of the polymer layer 64 is equivalent to the gap width 76.

[0021] Preferred or required minimum and maximum tolerances or values ​​for the gap width 76 may be influenced by or correspond to a number of factors, including, for example, the configuration of the motor and the assembly process for the motor, the materials comprising the housing 30 and / or the stator 18, the heat transfer targets for or maximum operating temperature limits of the motor 10 during operation, etc.For example, a preferred minimum value of the gap width 76 may correspond to the minimum clearance required to insert the stator assembly 14 into the housing 30 such that the stator assembly 14 can be slidably fitted relative to the housing inner surface 32, for example, such that there is clearance and / or no interaction between the housing inner surface 32 and the outer surface 46 of the stator 18, thereby minimizing stress on the stator core laminations (not shown in detail) that the stator 18 includes, including minimizing stress that may result from undesired engagement of the stator 18 with the housing 30, either during assembly of the motor 10 or in operation, for example, due to vibration and / or thermal expansion of the motor components that comprise the stator 18.The preferred gap width 76 may correspond to a thickness and compressibility of the polymer layer 64 needed to absorb vibrations and / or thermal expansion of the stator 18 during operation to reduce stress on the stator 18 and / or the windings 20, so that the reduction in stress may improve the durability of the motor 10.

[0022] The minimum and maximum tolerances, e.g., values ​​provided for the gap width 76, may be determined by the flow and curing properties of a polymer material 60 that is poured into the fillable gap 50 to form the polymer layer 64. For example, the minimum necessary gap width 76 may correspond to a gap width value through which the polymer material 60 can flow into the fillable gap 50 during formation of the polymer layer 64, so that the polymer material 60 can flow in a specified distribution pattern on the outer surface 46 of the stator, or to provide minimal coverage of the outer surface 46 of the stator.The maximum desirable gap width 76 may correspond to a gap width value which, if exceeded, may affect the formation of the polymer layer 64, for example, by affecting the curing cycle or the bonding or adhesion of the polymer layer 64 to at least one of the surfaces 32, 46.

[0023] The engine assembly 10, in use, e.g., during operation of the engine assembly 10, may generate heat that must be transferred away from the engine assembly 10 to maintain the engine assembly 10 within an acceptable operating temperature range. The minimum and / or maximum tolerances or preferred values ​​for the gap width 76 may be determined by the thermal conductivity properties of the polymer material 60 in combination with the heat transfer goals established for the engine 10 during operation, such that the thickness of the polymer layer 64, determined by the gap width 76, corresponds to or provides the level of heat transfer required by the engine 10 during operation. In one example, the gap width 76 may have a typical value ranging from 1.5 mm to 2.0 mm; however, this example is not limiting, and configurations resulting in other gap widths are possible.

[0024] In the example shown, the housing 30 may include one or more coolant passages 36 through which a coolant (not shown) may be circulated during operation of the engine assembly 10 to facilitate heat transfer to and / or from the engine assembly 10. As shown in Fig. 1-2, each of the coolant passages 36 may be formed in the housing 30 between the outer surface 34 of the housing and the housing inner surface 32 to facilitate heat transfer from the stator and rotor assemblies 14, 16 radially outward through the inner surface 32 via the coolant passages 36 to the outer surface 34 along the radial heat transfer paths 62. The polymer material 60 may be distributed within the fillable gap 50 such that the polymer layer 64 is formed adjacent to each of the coolant passages 36 to increase heat transfer through the coolant passages 36 during engine operation.

[0025] The polymer material 60 is comprised of a flowable, polymer-based material configured to be poured into the fillable gap 50 and curable to form the thermally conductive polymer layer 64. The term thermal conductivity, as used herein, refers to the thermal conductivity, measured in-plane, in watts per meter Kelvin (W / mK). The polymer material 60 may be characterized by a thermal conductivity greater than the thermal conductivity of air. As a reference, the thermal conductivity of air is 0.024 W / mK. The polymer material 60 may have a thermal conductivity of at least 0.25 W / mK, preferably a thermal conductivity of at least 1.0 W / mK, and more preferably a thermal conductivity of at least 8 W / mK.For example, the polymer material 60 may include a nylon-based or polyamide-based material having a thermal conductivity of 0.25 W / mK. For example, the polymer material 60 may be a thermally conductive material such as TC154A, TC153, TC501, or TC551, each from Stanyl. ® which have a thermal conductivity of 1 W / mK, 8 W / mK, 14 W / mK and 14 W / mK respectively.

[0026] The polymer material 60 may be a polymer-based material that includes a filler material with a thermal conductivity greater than that of the base polymer, e.g., the polymer or polymers used to provide the polymer base for the polymer-based material, such that the filler material increases the thermal conductivity of the polymer material 60 relative to the base polymer. The filler material may include a metal-based material and / or be configured to enhance the flow of the polymer material 60 during filling of the polymer material 60 into the fillable gap 50. In one example, the filler material may include an aluminum-based material, a titanium-based material, and / or a magnesium-based material. For example, the filler material may be a metallic filler material such as INTEC SB 94. ®having a thermal conductivity of 20 W / mK. By providing the thermally conductive layer 64 in contact with the stator outer surface 46 and the housing inner surface 32, heat transfer away from the motor is improved, which may provide motor performance benefits including improved motor efficiency and durability, a reduced likelihood of overheating and temperature stresses, and / or an increase in the operating torque limit of the motor.

[0027] The polymer material 60 may be configured as a flowable material that may contain substances to improve flowability and / or substances to modify the cure cycle, such that the polymer material 60 is a high-flow material with a cure cycle that enables the injection, flow, and distribution of the polymer material 60 into the fillable gap 50 such that the polymer layer 64 is formed in contact with at least one half of the outer surface of the stator, for example, at least 50% of the fillable gap is filled by the polymer layer 64 in contact with the housing 30 and the stator 18 to provide a heat transfer interface equal to or greater than 50% of the outer surface 46 of the stator 18. The polymer layer 64 is preferably in contact with and / or distributed over at least 80% of the outer surface 46 of the stator 18.

[0028] The polymer material 60 may be configured to provide other benefits for motor performance, including fire retardancy, stabilizing the stator position relative to the motor housing, and / or dampening stator vibrations. For example, the polymer material 60 may be configured as a fire-retardant material, or it may include a fire-retardant filler material. The polymer material 60 may be configured to adhere and / or adhere to the housing inner surface 32 and the outer surface of the stator, such that the polymer layer 64 forms an adhesive layer to adhere the stator 18 to the housing 32. The polymer layer 64 may be characterized as a damping layer to absorb or dampen vibrations of the motor 10 during operation, which may increase the durability of the motor, reduce fatigue loads on motor components including the windings 20, and / or reduce motor noise during operation.The polymer layer 64 may be configured to be compressible so that thermal expansion of the stator 18 and / or the housing 30 may compress the polymer layer 64 and prevent or minimize unwanted contact of the stator 18 and the housing 30 during vibration or thermal expansion of the motor 10, thereby minimizing stress on motor components including the stator assembly 14 during operation.

[0029] A method is provided herein for manufacturing the housing assembly 12 of the motor assembly, including forming the polymer layer 64. The method includes positioning the stator assembly 14 within the motor housing 30 to define the fillable gap 50 between the outer surface 46 of the stator 18 and the inner surface 32 of the motor housing 30, which, as described above, may include operatively attaching the stator assembly 14 to the motor housing 30 by a plurality of fasteners 40 or other suitable means. The flowable polymer material 60 is poured into the fillable gap 50 such that the flowable polymer material 60 is distributed within the fillable gap 50 over the outer surface 46 of the stator to form the polymer layer 64 in contact with the outer surface 46 of the stator and the housing inner surface 32 adjacent the outer surface 46 of the stator.

[0030] The method may include curing the flowable polymer material 60 to form the polymer layer 64. The polymer layer 64 may adhere to the outer surface 46 of the stator and the housing inner surface 32 during the filling and / or curing process. The polymer layer 64 may be distributed and / or patterned within the fillable gap 50, as described in detail hereinabove, to transfer heat between the stator 18 and the housing 30, to dampen vibrations, as a fire retardant, and / or to adhere the stator outer surface 46 to the housing inner surface 32. The stator assembly 14 and / or the housing 30 may be preheated prior to filling the flowable polymer material 60 into the fillable gap 50 to enable the flow and / or distribution of the polymer material 60 within the fillable gap and / or on or relative to the outer surface 46 of the stator 18.The polymer material 60 may contain a filler to improve flowability or may be configured as a high-flow polymer to assist in the distribution and flow of the polymer material 60 in the fillable gap 50.

[0031] With reference now to Fig. 3A-3C, in the non-limiting example shown, the housing 32 defines one or more channels 48 extending from the outer surface 34 of the housing to the inner surface 32 of the housing and communicating with the fillable gap 50. In the example shown, the channel 48 may be configured to receive a manifold nozzle 52, wherein the manifold nozzle 52 is configured to inject the flowable polymer material 60 into the fillable gap 50. The temperature, pressure, flow rate, and / or amount of the polymer material 60 injected through the nozzle 52 may be controlled within predefined parameters corresponding to the desired distribution pattern of the polymer layer 64 to be formed therefrom and / or as required by the flow, curing, and / or material properties or other characteristics of the polymer material 60.The channel 48 and / or the nozzle 52 and / or the method for filling the polymer material 60 may be configured such that the polymer material 60 seals the channel 48 or forms a gasket therefor during the formation of the polymer layer 64, for example such that the one or more channels 48 seal themselves as a result of the process of filling and / or curing the polymer material 60.

[0032] The method for forming the polymer layer 64 may include filling the flowable polymer material 60 into the fillable gap 50 by injecting the flowable polymer material 60 through at least one channel 48 and into the fillable gap 50 such that the injected polymer material 60 flows through the fillable gap 50 and is distributed over the outer surface 46 of the stator in contact with the housing interior surface 32 adjacent to the outer surface 46 of the stator. The number and configuration of the one or more channels 48 may be varied such that the polymer material 60 is filled into the fillable gap 50 in a distribution pattern configured to achieve coverage of at least 50% of the outer surface 46 of the stator and / or filling of at least 50% of the volume of the fillable gap 50.The polymer layer 64 formed by filling the polymer material 60 through the one or more channels 48 may be characterized by a flow pattern emanating from the one or more channels 48.

[0033] To prevent the flowable polymer material 60 from migrating to other areas of the motor assembly 10, the number and / or location of the one or more channels 48 may be varied to provide a distribution pattern of the polymer material 60 such that the polymer layer 64 formed therefrom is contained within the vicinity of the stator outer surface 46, for example, such that the polymer layer 64 does not extend beyond the axial ends of the stator outer surface 46. For example, the one or more channels 48 may be arranged such that each channel 48 is in fluid communication with a central portion of the stator outer surface 46 via an opening 56.

[0034] For an example without limitation, which is Fig. 2 and Fig. 3B, the housing 30 may include a restriction feature 38 that may be configured to restrict flow of the polymer material 60 within the fillable gap to prevent migration or flow of the polymer material 60, for example, to the stator windings 20 and / or other areas of the motor assembly 10, including migration into the air gap 74 and / or onto portions of the motor 10, including the shaft 24 and the rotor assembly 16, that are movable during operation. The restriction feature 38 may be defined by the housing 30, for example, integrally formed as part of the housing 30, or it may be an insert operatively attached to or positioned within the housing 30.

[0035] The amount of polymer material 60 poured into the fillable gap 50 may be metered or otherwise controlled such that the distribution of the polymer material 60 and the distribution pattern of the polymer layer 64 formed therefrom are limited to the outer surface 46 of the stator and provide coverage of at least 50% of the outer surface 46 of the stator without extending beyond the perimeter of the outer surface 46 of the stator. The amount of polymer material 60 and / or the number and arrangement of the one or more channels 48 may be configured such that the flowable polymer material 60 flows into the portion of the fillable gap 50 adjacent to the coolant passage 36 and / or flows into the portion of the fillable gap 50 defined by the stator sections 58 and the housing recess 70 to provide a thermally conductive polymer layer 64 in those areas.The amount of polymer material 60 introduced through the channel 48 may be metered or otherwise controlled such that an amount of the flowable polymer material 60 is retained and / or remains in the channel 48 to form a sealing plug 68, as shown in FIG. Fig. 3A, to prevent the ingress of moisture, contaminants, or other substances into the interior of the housing 30. The sealing plug 68 may be integral with the polymer layer 64, for example, formed continuously with the polymer layer 64, so that the sealing plug 68 can effectively connect or attach the polymer layer 64 to the housing 30.

[0036] The channel 48 may be configured to receive a fitting 72 configured such that the flowable polymer material 60 can be injected into the fillable gap 50 through the fitting 72. The fitting 72 may be configured to couple to the manifold nozzle 52 such that the nozzle 52 can be placed in selective fluid communication with the fitting 72 to fill the polymer material 60 into the fillable gap 50. In one example, the fitting 72 may be a nipple fitting, commonly referred to as a nipple, configured to receive the manifold nozzle 52. The fitting 72 and channel 48 may be configured, as desired, to effectively retain the fitting 72 to the channel 48 during filling of the flowable polymer material 60.For example, both the channel 48 and the fitting 72 may each be threaded to provide a screw connection. The channel 48 and the fitting 72 may be configured through tolerances, knurling, etc., to provide an interference fit therebetween during installation to retain the fitting 72 to the channel 48. The fitting 72 may include a method of sealing after the polymer material 60 is filled through the fitting 72 and the channel 48. For example, the fitting 72 may include a check valve ball of the type used in nipple fittings. As discussed above, the polymer material 60 may form a sealing plug 68 to seal the fitting 72 and / or the channel 48 during formation of the polymer layer 64.

[0037] The polymer material 60 may include a flow-enhancing agent to facilitate flow of the polymer material 60 through the channel 48, the nozzle 52, and / or the fitting 72. In a support (not shown), a plurality of nozzles 52 and / or the motor housing assembly 12 may be configured such that the polymer material 60 may be simultaneously flowed through the plurality of nozzles 52 into the plurality of channels 48 and / or through the plurality of fittings 72. In one example, each of the plurality of nozzles 52 may be in fluid communication with a common source (not shown) of the polymer material 60 such that the properties of the polymer material 60 flowing through the plurality of nozzles 52, such as material composition, flow rate, fill temperature, thermal conductivity, etc.is substantially the same to provide uniformity in the properties of the polymer layer 64 formed therefrom.

[0038] Additional constraint features (not shown) may be provided for and / or included in the motor assembly 10 and / or defined by the housing 30 or the stator assembly 14 and configured to confine the polymer material 60 within the fillable gap 50. The additional constraint features may be in addition to or as an alternative to the constraint feature 38 and / or they may be selectively removable from the motor assembly 10 after the polymer layer 64 is formed. In a non-limiting example shown in Fig. 4A-4B, a tray 54 may be positioned at one end of the stator 18 to at least partially enclose the fillable gap 50 during filling of the polymeric material 60. As shown, the tray 54 may be configured to generally conform to the outermost surface of the windings 20 and the housing interior surface 32 such that the tray closes one end of the fillable gap 50. A mounting clearance (not shown) may be provided between the radially innermost edge of the tray 54 and the windings 20 such that the tray 54 may be placed in direct contact with, for example, directly on, the end surface of the stator core 18. In another example, the stator core 18 is configured from a plurality of stacked core sheets (not shown), wherein the end core sheet of the stator core 18 may be configured as the insert 54 such that the insert 54 is integral with the stator core 18.In this configuration, it is understood that the insert 54 may, for example, include openings to receive the fasteners 40 to secure the stator core 18 including the insert 54 in a position relative to the housing interior surface 32.

[0039] The insert 54 may include one or more openings 56. The one or more openings 56 may each be configured to receive a manifold nozzle 52 configured to couple with the respective opening 56 to fill the polymer material 60 into the fillable gap 50. As shown in Fig. 4A, the configuration, number, and / or location of the openings 56 may be varied, as discussed above with respect to the channels 48, to provide a distribution pattern of the flowable polymer material 60 within the fillable gap 50, to fill the fillable gap 50 at least 50% with the polymer material 60, and to form a polymer layer 64 covering and / or in contact with at least 50% of the stator outer surface 46 and the housing interior surface 32 adjacent to the stator outer surface 46.The configuration, number, and / or location of the openings 56 may be varied, as discussed above with respect to the channels 48, to provide a distribution pattern of the polymer material 60 that is confined to the perimeter of the stator outer surface 46 and / or to provide a polymer layer 64 that may be characterized by a flow pattern corresponding to the pattern of the openings 56. Various sizes and configurations of nozzles 52, including, for example, round and / or blade nozzles 52, may be used in combination with the insert 54 to fill the flowable polymer material 60 into the fillable gap 50. One or more of the nozzles 52 may be configured to extend into the fillable gap 50, as shown in FIG. Fig.4B, such that the filling end of the nozzle 52 is disposed within the perimeter of the stator outer surface 46 before the polymer material 60 is filled to direct the flow of the polymer material 60 to a central portion of the outer surface 46 and / or to confine the distribution pattern of the polymer layer 64 within the perimeter of the stator outer surface 46.

[0040] A plurality of nozzles 52 and / or the motor housing assembly 12 may be configured in a holder (not shown) so that the polymer material 60 can be simultaneously flowed through the plurality of nozzles 52 into the fillable gap 50. In one example, each of the plurality of nozzles 52 may be in fluid communication with a common source of the polymer material 60 (not shown) such that the properties of the polymer material 60 flowing through the plurality of nozzles 52, such as material composition, flow properties, fill temperature, thermal conductivity, etc., are the same to provide uniformity in the properties of the polymer layer 64 formed therefrom.

Claims

[1] Motor housing assembly (12) comprising: a housing (30) configured to receive a stator (18); a stator (18) positioned in the housing (30), wherein a fillable gap (50) is defined by the stator (18) and an inner surface (32) of the housing (30) adjacent to the stator (18); a polymer layer (64) made of a polymer material (60) partially filling the fillable gap (50) and in contact with the housing (30) and the stator (18); wherein the polymer layer (64) is configured as a thermally conductive layer; wherein the housing (30) defines at least one channel (48) in communication with the fillable gap (50) for filling the polymer material (60) into the gap (50), characterized by , that a portion of the polymer material (60) remains in the channel (48) and forms a sealing plug (68) therein to seal the channel (48). [2] Motor housing assembly according to claim 1, wherein: the stator (18) defines an outer surface (46) adjacent to the inner surface (32) of the housing (30); and the polymer layer (64) is in contact with at least half of the outer surface (46). [3] The motor housing assembly of claim 1, wherein the polymer layer (64) is made of a polymer-based material having an in-plane thermal conductivity of at least 0.25 W / mK. [4] The motor housing assembly of claim 1, wherein the polymer layer (64) is made of a polymer-based material containing a metallic filler material. [5] The motor housing assembly of claim 1, wherein the polymer layer (64) is configured as a fire-retardant layer. [6] The motor housing assembly of claim 1, wherein the polymer layer (64) is configured to dampen vibrations of the stator (18). [7] A method of manufacturing a motor housing assembly (12), the method comprising: a stator (18) is positioned in a motor housing (30) to define a fillable gap (50) between an outer surface (46) of the stator (18) and an inner surface (32) of the motor housing (30); a flowable polymer material (60) is poured into the fillable gap (50) in contact with the outer surface (46) of the stator (18) and the inner surface (32) of the housing (30) adjacent to the outer surface (46) of the stator (18); and the flowable polymer material (60) is cured to form a polymer layer (64); wherein the polymer layer (64) is characterized by a thermal conductivity greater than the thermal conductivity of air; wherein the housing (30) defines at least one channel (48) in communication with the fillable gap (50); and the flowable polymer material (60) is filled into the fillable gap (50) by injecting the flowable polymer material (60) through the at least one channel (48) into the fillable gap (50); characterized by , that a portion of the polymer material (60) is retained in the channel (48) and cured therein to form a sealing plug (68) that seals the channel (48). [8] The method of claim 7, wherein the at least one channel (48) is configured to receive a nipple fitting (72); the method further comprising: the nipple connector (72) is fitted into the at least one channel (48); the flowable polymer material (60) is filled through the nipple connector (72) into the fillable gap (50). [9] The method of claim 7, further comprising: the stator (18) and / or the housing (30) are heated before the flowable polymer material (60) is filled into the fillable gap (50).

Images