System for mounting motor temperature sensor

Abstract

A system for mounting a motor temperature sensor includes: an electrical lamination stator including a stator core having a plurality of slots and a plurality of electrical laminations inserted into the slots of the stator core; a motor temperature sensor including a sensor element and a sensor housing covering the sensor element; wherein the sensor housing is detachably fitted to one of the plurality of electrical laminations.

Description

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2020-0027245, filed on March 4, 2020, with the Korean Intellectual Property Office, which is incorporated herein by reference in its entirety. Technical Field

[0003] This application relates to a system for mounting a temperature sensor on an electric motor. Background Technology

[0004] The electric motor includes a stator assembly and a rotor assembly. The stator assembly is arranged in the motor housing, and the rotor assembly is rotatable relative to the stator assembly. The stator assembly has a stator core and stator coils, with the stator coils wound around the stator core.

[0005] For example, some electric motors used in drive motors for environmentally friendly vehicles employ hairpin-wound stators. A hairpin-wound stator includes a stator core with multiple slots and multiple hairpins inserted into these slots. Each hairpin acts as a conductor, and the multiple hairpins are electrically connected, allowing them to form a stator coil.

[0006] Stator coil winding structures can be categorized into distributed windings and concentrated windings. Stator coils can also be classified as circular coils with a circular cross-section and flat coils with a rectangular cross-section. Hairpin-wound stators can have a distributed winding structure.

[0007] An electric motor consists of a coil and a motor temperature sensor. The coil is the main heat source of the motor, and the motor temperature sensor measures the temperature of the terminals connected to the coil. Based on the temperature measured by the motor temperature sensor, the motor controls its output and cooling.

[0008] Electric motor temperature sensors can be classified into double-shrink type and box type, etc.

[0009] The dual-shrinkable motor temperature sensor comprises a sensor element and a heat-shrink tubing. The heat-shrink tubing, made of Teflon material, covers the sensor element by heat shrinking. Because the heat-shrink tubing of the dual-shrinkable motor temperature sensor extends in its longitudinal direction, it can sense temperature in all directions regardless of the mounting orientation (attachment direction). Since the dual-shrinkable motor temperature sensor is unaffected by the mounting orientation, it can be arranged between coils and can be advantageously applied to circular stator coils. However, when the dual-shrinkable motor temperature sensor is attached to a flat coil, the temperature measurement error may become relatively larger because it senses temperature in all directions. In particular, because the dual-shrinkable motor temperature sensor is tubular, it is difficult to attach it to a hairpin winding stator.

[0010] A box-type motor temperature sensor includes a box-shaped housing and a sensor element housed within the housing. The sensor element is fixed to the housing using epoxy resin or the like. Since the sensor element is located on the bottom surface of the housing, its mounting orientation is important. Because the bottom surface of the housing is flat, the box-type motor temperature sensor can be advantageously applied to concentrated winding configurations. However, due to its shape, it is difficult to attach the box-type motor temperature sensor to a hairpin winding stator.

[0011] Its shape makes it difficult to attach a conventional motor temperature sensor to the hairpin winding stator, so the installation position of the temperature sensor may be inaccurate, resulting in larger temperature measurement errors.

[0012] Furthermore, conventional motor temperature sensors are first fixed to the stator of the hairpin winding using a cable tie or similar method, and then secured with epoxy resin. Therefore, the disadvantages of conventional motor temperature sensors lie in the complex assembly process and increased manufacturing costs.

[0013] The information described in this background section is provided to help understand the background of the inventive concepts and may include any technical concepts. It should not be construed as an admission that the information constitutes prior art. Summary of the Invention

[0014] This application aims to solve the aforementioned problems in the prior art while maintaining the advantages of the prior art.

[0015] One aspect of this application provides a system for mounting a motor temperature sensor, which can accurately and stably mount the motor temperature sensor to the hairpin winding stator, simplifying the assembly process (installation process) and reducing manufacturing costs.

[0016] According to one aspect of this application, a system for mounting a motor temperature sensor may include: a hairpin winding stator including a stator core having a plurality of slots and a plurality of hairpins inserted into the slots of the stator core; a motor temperature sensor including a sensor element and a sensor housing covering the sensor element; wherein the sensor housing may be detachably mounted to one of the plurality of hairpins.

[0017] Each hairpin may include a crown and two legs extending from the crown. The crown may include a apex and a first inclined portion and a second inclined portion extending obliquely from the apex. The apex may be bent such that the axis of the second inclined portion may be offset relative to the axis of the first inclined portion in the radial direction of the stator core.

[0018] The sensor housing may include two mounting ribs that are attached to the vertex of the hairpin by means of surface contact, each mounting rib being bent into the same shape as the vertex.

[0019] The two mounting ribs can be spaced apart from each other along the width direction of the sensor housing, and a mounting recess can be defined between the two mounting ribs, and the vertex of the hairpin can be fitted into the mounting recess.

[0020] Each mounting rib may have a contact surface that directly contacts the corresponding side of the apex of the hairpin.

[0021] The sensor element can be located above the mounting rib.

[0022] The sensor housing may further include a support protrusion spaced apart from the mounting rib, the support protrusion supporting the apex of another hairpin arranged adjacent to the hairpin to which the mounting rib is attached.

[0023] The support protrusion may have a support surface that contacts the apex of the adjacent hairpin.

[0024] The sensor housing may have two gripping recesses, which may be located above the mounting rib.

[0025] The sensor element can be located between the two grip recesses. Attached Figure Description

[0026] The above and other objects, features and advantages of this application will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings:

[0027] Figure 1 A front view of a hairpin winding stator according to an exemplary embodiment of this application is shown;

[0028] Figure 2 Showing from Figure 1 The view being observed is in the direction indicated by arrow A in the image;

[0029] Figure 3 Showing Figure 1 The image shows a 3D view of the hairpin winding stator.

[0030] Figure 4 A schematic winding diagram of a hairpin winding stator according to an exemplary embodiment of this application is shown;

[0031] Figure 5 Showing Figure 2 A magnified view of part B in the image;

[0032] Figure 6 Showing Figure 5A magnified view of part C in the image;

[0033] Figure 7 A top perspective view of an electric motor temperature sensor according to an exemplary embodiment of this application is shown;

[0034] Figure 8 A plan view of an electric motor temperature sensor according to an exemplary embodiment of this application is shown;

[0035] Figure 9 Showing from Figure 8 The view being observed is in the direction indicated by arrow D in the image;

[0036] Figure 10 A bottom perspective view of an electric motor temperature sensor according to an exemplary embodiment of this application is shown;

[0037] Figure 11 Showing from Figure 10 The view being observed is in the direction indicated by arrow E in the image;

[0038] Figure 12 Showing from Figure 11 The view being observed is in the direction indicated by the arrow F in the image;

[0039] Figure 13 Showing for Figure 11 Alternative implementations of the construction shown in the figure.

[0040] Figure label:

[0041] 10: Hairpin winding stator

[0042] 11: Hairpin stator

[0043] 12,12a: Hairpin

[0044] 13: Slot

[0045] 20,20a: Crown

[0046] 21,21a: First leg

[0047] 22,22a: Second leg

[0048] 23,23a: First extension

[0049] 24, 24a: Second extension

[0050] 31, 31a: First inclined portion

[0051] 32, 32a: Second inclined section

[0052] 33,33a: Vertex

[0053] 50: Motor temperature sensor

[0054] 51: Sensor Components

[0055] 52: Sensor housing

[0056] 53,54: Grip recess

[0057] 55, 56: Mounting ribs

[0058] 57: Installation recess

[0059] 58: Supporting protrusion

[0060] 58a: Support surface. Detailed Implementation

[0061] Exemplary embodiments of this application will now be described in detail with reference to the accompanying drawings. For reference, the dimensions of elements and the thickness of lines shown in the drawings mentioned in the description of the exemplary embodiments of this application may be exaggerated for ease of understanding. The terminology used to describe the concepts of the invention is defined in consideration of the function of the elements, and the terminology may be adjusted according to the intention of the user or operator, practice, etc. Therefore, the terminology should be defined based on the entire description.

[0062] Exemplary embodiments of this application may be described using terms such as first, second, A, B, (a), and (b). These terms are used only to distinguish one element from another and do not limit the inherent characteristics, order, or sequence of the corresponding elements. Unless otherwise stated, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. Terms defined in general dictionaries should be interpreted as having the same meaning as in the context of the relevant technical field, and should not be interpreted as having an idealized or overly literal meaning, unless expressly defined in this application.

[0063] Figure 1 and Figure 2 An example of a hairpin winding stator is shown. The hairpin winding stator 10 may include a stator core 11 having a plurality of slots 13 and a plurality of hairpins 12 and 12a respectively inserted into the plurality of slots 13.

[0064] Multiple slots 13 may be spaced apart from each other in the circumferential direction of the stator core 11. Each slot 13 may extend in the longitudinal or axial direction of the stator core 11. Hairpins 12 and 12a may be inserted into slots 13 respectively.

[0065] refer to Figure 3Hairpins 12 and 12a may include crowns 20 and 20a, first legs 21 and 21a, and second legs 22 and 22a, the first legs 21 and 21a and the second legs 22 and 22a extending from the crowns 20 and 20a, respectively. One leg of hairpin 12 (12a) may be coupled to one of a plurality of slots 13.

[0066] Crowns 20 and 20a may protrude upward from the top of the stator core 11. Crowns 20 and 20a may include apexes 33 and 33a (e.g., the highest point of each hairpin), and first inclined portions 31 and 31a and second inclined portions 32 and 32a extend obliquely from apexes 33 and 33a, respectively. (See reference) Figure 5 and Figure 6 Vertices 33 and 33a can be bent into an S-shape, such that the axis X2 of the second inclined portions 32 and 32a can be offset relative to the axis X1 of the first inclined portions 31 and 31a in the radial direction of the stator core 11.

[0067] The first legs 21 and 21a and the second legs 22 and 22a can extend substantially linearly along the longitudinal direction of the stator core 11, and the first legs 21 and 21a and the second legs 22 and 22a can be parallel to each other. The first legs 21 and 21a and the second legs 22 and 22a can be inserted into the slots 13 respectively.

[0068] Hairpins 12 and 12a may include first extensions 23 and 23a and second extensions 24 and 24a, the first extensions 23 and 23a extending obliquely from the bottom ends of the first legs 21 and 21a, and the second extensions 24 and 24a extending obliquely from the bottom ends of the second legs 22 and 22a. The first extensions 23 and 23a and the second extensions 24 and 24a may protrude downward from the bottom end (not shown) of the stator core 11, such that the top and bottom ends of each hairpin 12 are arranged outside the top and bottom ends of the stator core 11. (See reference) Figure 4 Multiple hairpins 12 and 12a can be configured as multiple layers 14 and 14a. The multiple layers 14 and 14a are arranged along the radial direction of the stator core 11, thus multiple hairpins 12 and 12a can form a stator coil. For example, two layers 14 and 14a can be adjacent to each other along the radial direction of the stator core 11, with hairpins 12 electrically connected to form one layer 14, and hairpins 12a electrically connected to form another layer 14a.

[0069] refer to Figure 5 and Figure 6 According to an exemplary embodiment of this application, the motor temperature sensor 50 can be detachably mounted to the hairpins 12 and 12a of the hairpin winding stator 10. In one embodiment, the motor temperature sensor 50 can be a negative temperature coefficient (NTC) thermistor, but the type of sensor 50 is not limited to this.

[0070] refer to Figures 7 to 12 The electric motor temperature sensor 50 according to an exemplary embodiment of this application may include a sensor element 51 and a sensor housing 52 covering the sensor element 51.

[0071] The sensor element 51 and the wires connected to the sensor element 51 can be embedded in the sensor housing 52, which may comprise a resin material. In one embodiment, the sensor element 51 and the wires can be integrally connected to the sensor housing 52, for example, by injection molding. Thus, the sensor element 51 and the sensor housing 52 can form a single, integrated structure.

[0072] refer to Figures 7 to 9 The sensor housing 52 may have a cuboid shape. The sensor housing 52 may have two opposing gripping recesses 53 and 54, through which an operator can easily grip the sensor housing 52. The sensor housing 52 can be easily mounted to the hairpins 12 and 12a of the hairpin winding stator 10 via the two gripping recesses 53 and 54. The two gripping recesses 53 and 54 may be located on opposite sides of the sensor housing 52.

[0073] refer to Figures 10 to 12 The sensor housing 52 may have two opposing mounting ribs 55 and 56, which may be spaced apart from each other along the width direction of the sensor housing 52. A mounting recess 57 may be defined between the mounting ribs 55 and 56. The mounting ribs 55 and 56 may protrude from the bottom surface of the sensor housing 52 toward the hairpin winding stator 10. At least a portion of the hairpins 12 and 12a of the hairpin winding stator 10 may be fitted into the mounting recess 57, thereby allowing the motor temperature sensor 50 to be securely mounted to at least one hairpin 12 of the hairpin winding stator 10.

[0074] Specifically, mounting ribs 55 and 56 can be bent into the same shape as the vertex 33 of the hairpin 12, and mounting ribs 55 and 56 can have contact surfaces 55a and 56a that directly contact the opposite sides of the vertex 33 of the hairpin 12, respectively. The shape and size of the mounting recess 57 can correspond to the shape and size of the vertex 33 of the hairpin 12. Therefore, the two mounting ribs 55 and 56 can receive the opposite sides of the vertex 33 through direct surface contact, and the vertex 33 of the hairpin 12 can be securely fitted to the mounting recess 57 of the sensor housing 52, as shown. Figure 2 and Figure 3As shown. That is, the sensor housing 52 can be easily and securely mounted to the apex 33 of the hairpin 12 via mounting ribs 55 and 56 and mounting recess 57, thus eliminating the need for adhesive or bonding methods such as epoxy resin and cable ties. Specifically, the two mounting ribs 55 and 56 can be bent into the same shape as the apex 33 of the hairpin 12, and the contact surfaces 55a and 56a of the mounting ribs 55 and 56 can be supported to the hairpin 12 through surface contact. Therefore, compared with the prior art, the contact area between the sensor housing 52 and the hairpin 12 is significantly increased. This increases the heat transfer area, improves the temperature sensing (response) of the sensor element 51, and reduces temperature measurement errors.

[0075] Furthermore, according to an exemplary embodiment of this application, the sensor housing 52 can be securely and easily mounted to the apex 33 of the hairpin 12 via a mounting recess 57 defined by two mounting ribs 55 and 56, thereby improving the assembly (mounting) and attachment of the motor temperature sensor 50 and reducing errors in the mounting position of the motor temperature sensor 50.

[0076] refer to Figure 13 The thickness of each mounting rib 55 and 56 can be slightly greater than or equal to the thickness of the apex 33 of the hairpin 12, so that the mounting ribs 55 and 56 can obtain sufficient rigidity to support the apex 33 of the hairpin 12.

[0077] Because the two mounting ribs 55 and 56 are bent into the same shape as the apex 33 of the hairpin 12, the mounting position of the motor temperature sensor 50 can be accurately adjusted. Therefore, the error in the mounting position of the motor temperature sensor 50 can be reduced, and the temperature sensing accuracy of the motor temperature sensor 50 can be improved. Furthermore, because the mounting ribs 55 and 56 and the mounting recess 57 of the sensor housing 52 are securely mounted to the apex 33 of the hairpin 12, the sensor housing 52 will not easily separate from the apex 33 of the hairpin 12, or even when an unexpected force is applied to the sensor housing 52, movement along the width and / or longitudinal direction of the sensor housing 52 can be prevented.

[0078] Mounting ribs 55 and 56 and mounting recess 57 can be located directly below holding recesses 53 and 54, and sensor element 51 can be located between the two holding recesses 53 and 54. When sensor housing 52 is mounted to the apex 33 of hairpin 12 via mounting recess 57 and mounting ribs 55 and 56, sensor element 51 can be located directly above mounting recess 57 and mounting ribs 55 and 56, thus allowing motor temperature sensor 50 to measure the temperature of hairpin 12 more accurately. In other words, the performance (response) of motor temperature sensor 50 can be significantly improved.

[0079] The sensor housing 52 may have a support protrusion 58, which may be spaced apart from the mounting ribs 55 and 56 along the longitudinal direction of the sensor housing 52 (or along the circumferential direction of the stator core 11). The support protrusion 58 may protrude from the bottom surface of the sensor housing 52 toward the hairpins 12 and 12a. The support protrusion 58 may have a support surface 58a.

[0080] The support protrusion 58 of the sensor housing 52 can support the vertex 33a of the hairpin 12a, which is arranged adjacent to the hairpin 12 (mounting ribs 55 and 56 and mounting recess 57 are attached to the hairpin 12). The support surface 58a can be bent into the same shape as the adjacent hairpin 12a, so the structure and shape of the support surface 58a allow direct contact with the vertex 33a of the hairpin 12a. Specifically, the support surface 58a of the support protrusion 58 can support the hairpin 12a relative to the vertex 33a through direct surface contact, thereby enabling the sensor housing 52 to be securely mounted between two adjacent hairpins 12 and 12a. Therefore, the sensor housing 52 can be more securely and stably mounted between two adjacent hairpins 12 and 12a. Specifically, when the mounting ribs 55 and 56 of the sensor housing 52 are attached to a hairpin 12, the support surface 58a of the support protrusion 58 can be supported up to the apex 33a of the adjacent hairpin 12a, thus preventing accidental force from causing the sensor housing 52 to rotate.

[0081] According to an exemplary embodiment, the hairpin winding stator 10 may have multiple hairpins arranged in multiple layers (e.g., eight layers) along the radial direction of the stator core 11. The highest heat may be generated in the innermost layer (the first layer), while the motor temperature sensor 50 may be mounted in the third or fourth layer to facilitate rotor assembly.

[0082] As described above, according to the exemplary embodiment of this application, since the motor temperature sensor 50 is mounted to the apex 33 of the hairpin 12 via the mounting ribs 55 and 56 of the sensor housing 52 and the mounting recess 57, bonding or joining methods such as cable ties and epoxy resin can be eliminated. Therefore, the assembly process (mounting process) can be simplified and manufacturing costs can be reduced.

[0083] According to an exemplary embodiment of this application, the two mounting ribs 55 and 56 can be bent into the same shape as the apex 33 of the hairpin 12. The contact surfaces 55a and 56a of the mounting ribs 55 and 56 can be supported to the hairpin 12 through surface contact. Therefore, compared with the prior art, the contact area between the sensor housing 52 and the hairpin 12 is significantly increased. In this way, the heat transfer area between the sensor element 51 and the hairpin 12 can be increased, which can improve the temperature sensing (response) of the sensor element 51 and reduce the error of temperature measurement.

[0084] Furthermore, according to an exemplary embodiment of this application, the sensor housing 52 can be easily and securely mounted to the apex 33 of the hairpin 12 via a mounting recess 57 defined by two mounting ribs 55 and 56. Therefore, the assembly and attachment of the motor temperature sensor 50 can be improved, and errors in the mounting position of the motor temperature sensor 50 can be reduced.

[0085] While this application has been described above with reference to exemplary embodiments and accompanying drawings, it is not limited thereto and various modifications and variations can be made by those skilled in the art without departing from the spirit and scope of this application as defined in the appended claims.

Claims

1. A system for installing a motor temperature sensor, the system comprising: a hairpin winding stator comprising a stator core having a plurality of slots and a plurality of hairpins inserted into the slots of the stator core; a motor temperature sensor comprising a sensor element and a sensor housing covering the sensor element; wherein the sensor housing is detachably fitted to one of the plurality of hairpins; wherein each hairpin comprises a crown and two legs extending from the crown, the crown comprises an apex and a first inclined portion and a second inclined portion obliquely extending from the apex, the apex is curved in an S-shape such that an axis of the second inclined portion is offset from an axis of the first inclined portion in a radial direction of the stator core, the axis of the second inclined portion being parallel to the axis of the first inclined portion as projected in a plane perpendicular to an axis of the stator core; wherein the sensor housing comprises two mounting ribs joined to the apex of the hairpin by surface contact, each mounting rib is curved in the same shape as the apex; the mounting rib has contact surfaces in direct contact with opposite sides of the apex of the hairpin respectively, the contact surfaces supporting the hairpin by surface contact; wherein the two mounting ribs are spaced apart from each other in a width direction of the sensor housing, a mounting recess is defined between the two mounting ribs, the apex of the hairpin is fitted into the mounting recess; the sensor housing further comprises a support protrusion spaced apart from the mounting ribs, the support protrusion supports an apex of another hairpin arranged adjacent to the hairpin joined by the mounting ribs.

2. The system for installing a motor temperature sensor of claim 1, wherein, the sensor element is located above the mounting ribs.

3. The system for mounting a motor temperature sensor of claim 1, wherein, the support protrusion has a support surface in contact with the apex of the adjacent hairpin.

4. The system for mounting a motor temperature sensor of claim 1, wherein, the sensor housing has two holding recesses, the two holding recesses are located above the mounting ribs.

5. The system for mounting a motor temperature sensor of claim 4, wherein, the sensor element is located between the two holding recesses.

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