Hairpin structure temperature sensor device

Abstract

An improved temperature sensor device for determining the temperature of a stator of an electric motor includes a housing and a thermal sensor disposed in a plunger. The plunger may move relative to the housing to position the thermal sensor relative to the stator of the electric motor. The housing is configured to be coupled to the motor, the plunger is at least partially disposed in the housing and movable relative to the housing, and the thermal sensor is disposed in the plunger, where the plunger is movable relative to the housing to position the thermal sensor relative to the motor.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 404,468, filed on September 7, 2022, entitled “Hairpin Structure Temperature Sensor Device for Welding of Motor Stator Windings,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to sensor devices, and more particularly, to temperature sensor devices for electric motors. Background Art

[0004] Electric motors (motors) are increasingly being used in various systems, such as automobiles. However, motors may overheat during use, causing the motor and / or system to fail. Some conventional motor designs incorporate negative temperature coefficient (NTC) thermistors to monitor the temperature of the stator windings of the motor. NTC thermistors may be preferred due to their relatively low component cost. However, NTC thermistors may not be maintainable and may have relatively low accuracy. In addition, some applications use NTC thermistors to monitor the temperature of welded hairpin structures associated with the stator of the motor. However, the tolerances associated with the welded hairpin structures are typically very large, making it difficult to ensure accurate temperature measurements with the NTC thermistors. Therefore, there is a need in the art for an improved sensing system to prevent the motor from overheating and failing. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] In order to make it easier for ordinary technicians in the field to which the disclosed systems and technologies belong to understand how to implement and use these systems and technologies, reference may be made to the following figures.

[0006] Figure 1 is a perspective view of a temperature sensor for use with an electric motor according to aspects of the present disclosure.

[0007] Figure 2 According to various aspects of the present disclosure Figure 1 A perspective view of the temperature sensor in FIG. 1 with the cover removed.

[0008] Figure 3 According to various aspects of the present disclosure Figure 1 Exploded perspective view of the various parts of the temperature sensor.

[0009] Figure 4A According to various aspects of the present disclosure Figure 1 A perspective view of a portion of a temperature sensor in FIG.

[0010] Figure 4BAccording to various aspects of the present disclosure, Figure 4A 0 is a cross-sectional view of the temperature sensor taken along the cross-sectional line BB in FIG. DETAILED DESCRIPTION

[0011] The subject technology overcomes prior art problems associated with conventional temperature sensor devices for electric motors. For example, the systems and techniques described herein provide a temperature sensor device for measuring the temperature of a motor stator in an electric motor. In some examples, the electric motor may have a stator with one or more welded hairpin structures. The temperature of the one or more hairpin structures may be a good indicator of the proper functioning of the motor (e.g., a higher temperature may indicate poor motor health). The sensor system described herein may provide improved adjustability to ensure proper sensing of the temperature of the hairpin structure regardless of the accuracy of the position of the hairpin structure in the motor.

[0012] In some examples, a temperature sensor device according to the present disclosure may include a plunger in which a thermal sensor (such as a thermistor) is disposed. The plunger may be retained in a housing that may be fixed relative to the motor. The plunger may be movable relative to the housing (e.g., laterally and / or rotationally) such that the thermal sensor may be disposed in a position to sense the temperature of the hairpin structure regardless of the position of the hairpin structure and / or the orientation of the housing.

[0013] In some aspects of the present disclosure, the housing defines a volume portion and an opening through the bottom of the housing. For example, the plunger may include a head and a shaft extending from the head along an axis. The shaft may be sized to pass through the opening in the housing, but the head may be sized to remain in the volume portion of the housing. For example, the head may have an outer extension that is larger than the diameter of the opening in the housing. The outer diameter of the shaft may be sized smaller than the opening through the housing, such as to allow the plunger to move laterally or radially relative to the housing.

[0014] In some examples of the present disclosure, the plunger may also include an axial opening extending through it. The thermal sensor may be arranged in the axial opening, for example, near the distal end of the axial opening opposite to the head. In some examples, the sensor device may be coupled to the motor so that the hairpin structure is arranged in the axial opening and in contact with the thermal sensor. For example, the thermal sensor may be a negative temperature coefficient thermistor. In at least some instances, the thermal sensor may include or be formed as a biasing member extending at least partially into the axial opening. When the plunger is arranged over the hairpin structure, the hairpin structure may contact the biasing member, while the biasing member applies a biasing force to the hairpin structure to improve the contact between the hairpin structure and the thermal sensor. For example, regardless of the position of the hairpin structure, the movability of the biasing member can achieve contact between the thermal sensor and the hairpin structure.

[0015] In some examples of the present disclosure, the housing may define a volume portion configured to hold the head of the plunger therein. The lateral extension of the volume portion (e.g., in a plane perpendicular to the axis of the plunger) may be at least partially defined by an inner surface of the housing. For example, the inner surface may be an inner side wall of the housing. The outer extension of the head may be smaller than the lateral extension of the volume portion. Therefore, the head may move in the volume portion (e.g., relative to the inner surface and in a plane perpendicular to the axis of the plunger). Therefore, the plunger may move laterally (or radially) relative to the housing.

[0016] In addition, in some examples of the present disclosure, the head of the plunger can rotate relative to the housing. In some examples, the head of the plunger can include a notch and the housing can include a lug extending into the volume portion. When the plunger is inserted into the housing, the lug of the housing can be retained in the notch of the plunger head. The width of the notch can be greater than the width of the lug, so that the plunger can rotate relative to the housing, for example, its rotation angle is limited by the notch width and / or the lug width. In other examples, the head of the plunger can include a lug, and the notch can be formed in the surface of the defined volume portion in the housing.

[0017] According to aspects of the present disclosure, an electrical connector can be coupled to the housing. For example, the electrical connector can be configured for coupling an external system to a temperature sensor device. Electrical leads can be provided to electrically connect the thermal sensor and the electrical connector. In some examples, the electrical leads can be arranged in one or more of a volume defined by the housing and / or an axial opening defined by the plunger. In some examples, the electrical leads can be flexible (e.g., wires) so as to maintain electrical connectivity between the thermal sensor and the electrical connector regardless of how the plunger moves relative to the housing.

[0018] According to aspects of the present disclosure, the plunger may also include one or more mounts extending from the head. In some examples, the one or more mounts may extend a distance above the head to contact the top or cover of the housing. When the cover or top is fixed to the housing, axial movement of the plunger relative to the housing is controlled or substantially eliminated. However, the relative lateral movement and / or rotational movement described herein is achievable.

[0019] In some examples, the systems and techniques described herein can overcome the shortcomings of conventional thermal sensors by enabling adjustability of the location of the thermal sensor. The systems and techniques disclosed herein can also make it easier to replace and install temperature sensors on electric motors. The systems and techniques disclosed herein can also improve the operating range of vehicles using electric motors (e.g., by ensuring that the electric motors operate properly), improve safety outcomes associated with the electric motors and / or vehicles or other systems incorporating the electric motors (e.g., by reliably sensing motor anomalies), and / or reduce assembly time.

[0020] Although aspects of the present disclosure are described in detail with reference to a temperature sensor device for an electric motor, other types of sensor devices and / or applications may benefit from the systems and techniques described herein. For example, the systems and techniques described herein can be used in other types of sensor applications, including sensor applications where the dimensional accuracy of the part to be sensed is poor. Details of exemplary aspects of the present disclosure will now be described with reference to the accompanying drawings.

[0021] Figure 1 1 is a perspective view of a temperature sensor device 100 for use with an electric motor (not shown). As shown, the temperature sensor device 100 includes a housing 102. The housing 102 is generally cylindrical and has a top surface 104, a bottom surface 106 (in Figure 1 104 and a generally cylindrical sidewall 108 extending between the top surface 104 and the bottom surface 106. As will be described in further detail below, some or all of the top surface 104 can be formed as a top or cover that can be selectively removed from the remainder of the housing 102, for example, to facilitate access to the volume inside the housing 102. In other examples, some or all of the sidewall 108 and the top surface 104 can form a removable cover.

[0022] The sensor device 100 is configured for coupling to an electric motor (not shown). Figure 1 In the example of FIG. 1 , the sensor device 100 includes a mounting lug 110 extending outwardly from the side wall 108 of the housing 102. The mounting lug 110 is shown as including a through hole 112 formed therethrough. For example, the through hole 112 can accommodate the shaft of a fastener (not shown), such as a bolt, to secure the temperature sensor device 100 to the motor housing or other mounting structure. The arrangement of the through holes 112 can correspond to the arrangement of mounting holes on the motor. It should be understood that the through holes 112 are merely exemplary; additional or different mounting features can be used.

[0023] The housing 102 also includes a neck portion 114 extending from the bottom surface 106. Figure 4B As best shown in FIG. 1 , the neck portion 114 of the housing 102 defines an opening, such as an axial opening, to the interior volume of the housing 102. In some examples, one or more mounting features may be formed on an outer surface of the neck portion 114. For example, Figure 1The example of shows multiple annular flanges 116 offset from each other. The annular flanges 116 can be configured to cooperate with corresponding features on a motor or other mounting member to which the temperature sensor device 100 is to be connected. For example, the size of the annular flange 116 can be set to be arranged in (e.g., press-fit into) an opening in the motor housing. In other examples, the flange 116 can be replaced with threads and / or other structures. The shape and arrangement of the housing 102 are merely exemplary. In other examples, the housing 102 may not be cylindrical, there may be more than two mounting lugs 110, the mounting lugs 110 may be omitted, the neck portion 114 may be longer or shorter (or omitted), etc.

[0024] The temperature sensor device 100 also includes a plunger 118. Figure 4B As best shown in FIG. 1 and as will be described in further detail below, a plunger 118 is at least partially disposed within the housing 102 and extends through the neck portion 114 to a distal end 120 spaced from the bottom surface 106 of the housing 102. In this example, the plunger 118 includes a head portion disposed within the housing 102 (in Figure 1 1 and 12. The plunger 118 may include a plunger 118 (not visible) and a shaft 122 extending substantially along an axis 124 below the housing 102. As will be described in further detail herein, the plunger 118 may be movable relative to the housing 102, e.g., to enable reliable temperature sensing even with relatively large tolerances associated with the stator windings, as will be described in further detail herein.

[0025] Also like Figure 1 As shown in , the temperature sensor device 100 also includes a connector 126. The connector 126 can be used for connection, such as electrical connection, of the temperature sensor device 100 to one or more external systems (not shown). For example, but not limited to, the connector 126 can have one or more pins and / or one or more jacks (e.g., for receiving pins) for connection with an external system. In operation, the plunger 118 is positioned near the stator (not shown) of the motor to sense a temperature associated with the stator, such as the temperature of one or more windings (such as hairpin windings) of the stator. As will be further described in detail herein, one or more sensing elements (such as thermistors) are arranged in the plunger 118 to generate one or more signals associated with the sensed temperature. The one or more sensing elements are electrically connected to the connector 126 for transmitting the generated one or more signals to the external system via the connector 126.

[0026] Figure 2 is a top perspective view of the temperature sensor device 100, wherein a portion of the housing 102 is removed to expose the volume 202 within the housing 102. In some examples and as discussed below Figure 3 As shown in the example of FIG. 1 , the housing 102 may include a cover or top (in Figure 2 , for example, the cover or top may include a top surface 104.

[0027] like Figure 2 As shown in , lead 204 is arranged in volume 202 of housing 102. Lead 204 is electrically coupled to connector 126, for example, for transmission of a signal associated with the sensed temperature, as just discussed. In some examples, lead 204 can be flexible, for example, configured as an electrical wire, thereby maintaining electrical connection during relative movement of components of sensor device 100, as detailed herein.

[0028] Also like Figure 2 As shown in , the housing 102 includes a bottom surface or bottom plate 206 that at least partially defines a lower extension or surface of the volume portion 202. For example, the bottom plate 206 can be a surface opposite to the lower surface 106 of the housing 102 discussed above. A lug 208 is also provided on the bottom plate 206. The lug 208 is formed as a protrusion extending upward from the bottom plate 206 into the volume portion 202. The lug 208 is also at least partially spaced apart from the inner surface 210 (e.g., extending radially inward from the inner surface). The inner surface 210 can define an outer extension of the volume portion 202. In the example shown, the inner surface 210 is formed by a stepped annular ring 212. The annular ring 212 defines the inner surface 210 as a cylindrical opening near the bottom plate 206. In other examples, the inner surface 210 can be the inner surface of the side wall 108 of the housing 102 discussed above. For example, the annular ring 212 can be omitted.

[0029] For example, the lug has a width W along the circumferential dimension of the housing 102. 凸耳 As also shown, the lugs 208 extend radially inwardly from the inner surface 210. Figure 2 In the embodiment, two electrical contacts 214 are arranged on the top surface of the annular ring 212, wherein the lead 204 is connected to the electrical contacts 214. In other examples, the electrical contacts 214 can be positioned in the housing 102 in other ways. The electrical contacts 214 are electrically connected to the connector 126.

[0030] Figure 2 Also shown is a top portion of the plunger 118. The plunger 118 includes a disk or head 216 having an outer diameter sized to be received within the perimeter defined by the inner surface 210. As mentioned above, the shaft 122 may extend from the bottom of the head 216.

[0031] exist Figure 2 In the example shown in FIG. 2 , a notch 218 is formed in the head 216. Specifically, the notch 218 has circumferentially spaced sides 220 that may be substantially parallel and define a notch width W.凹口 The recess 218 also has a depth, for example, measured from the outer periphery of the head 216 toward the center of the head 216 .

[0032] The plunger 118 also includes a plurality of struts or supports 222 extending upwardly from the head 216 (in Figure 2 The support 222 may be arranged to contact the housing 102 (in Figure 2 For example, the support 222 can prevent the plunger from moving upward relative to the housing 102, which will be further described herein.

[0033] To assemble, place the plunger 118 (along the Figure 1 124 is inserted axially into the opening defined by the neck portion 116, Figure 4B 1. After insertion, the bottom surface of the head 216 contacts the bottom plate 206 of the housing 102. The diameter of the head 216 is larger than the diameter of the opening through the neck portion 116, so that the plunger 118 cannot completely pass through the opening. The plunger 118 is also arranged in a rotational manner so that the lug 208 is arranged in the recess 218. Specifically, the recess width W 凹口 Greater than lug width W 凸耳 , so that when the bottom of the head 216 contacts the bottom plate 206, the lug 208 fits within the recess 218.

[0034] In the example of the present disclosure, the notch width W 凹口 Sufficiently larger than the lug width W 凸耳 , to provide a gap between the lug 208 and the recess 218. Due to the gap, the plunger 118 can rotate relative to the housing 102, while the rotation is only constrained by the contact of the lug 208 with the side 220 of the recess 218. For example, the lug 208 and the recess 218 can be formed so that the head 216 can rotate relative to the housing through a certain rotation angle. In some examples, the angle can be from about 0.5 degrees to about 10 degrees or more. As further described herein, the rotational freedom of the plunger 118 provided by the arrangement of the lug 208 and the recess 218 can be used to change the positioning of a sensing device coupled to the plunger 118. In addition, the head 216 can move laterally (or radially) relative to the lug 208, for example, due to radial clearance between the head 216 and the inner surface 210 (which can be the inner surface of the annular ring 212) and / or due to radial clearance (relative to the central axis of the head 216) between the distal end of the lug 208 (e.g., the surface farthest from the inner surface 210) and the recess 218. As a result, the plunger 118 can have a relatively large range of motion relative to the housing 102.

[0035] Although the head 216 of the plunger 118 is shown as being substantially cylindrical, such as disc-shaped, in other examples, the head 216 may be formed into other shapes. In addition, the volume portion 202 may not be substantially cylindrical. It will be appreciated from this disclosure that other shapes and configurations may be used to facilitate relative movement of the plunger 118 relative to the housing 102. For example, although the illustrated example shows that the head 216 includes a notch 218 and the lug 208 is formed in the volume portion 202, in other examples, the head 216 may be formed with a protrusion, such as a lug, and the notch may be formed in the inner surface 210, the bottom plate 206, or otherwise formed in the housing 102 to match the lug on the head 216. With the present disclosure, it will be appreciated by those of ordinary skill in the art that other arrangements may also be used to achieve a range of relative movement between the head 216 and the housing 102 (e.g., relative movement in a rotational direction and / or a lateral / radial direction).

[0036] Further details of the temperature sensor device 100 are given in Figure 3 shown in . Specifically, Figure 3 FIG. 1 shows an exploded view of the temperature sensor device 100, including the housing 102, the plunger 118, and the cover 302. For ease of explanation, the cover 302 is Figure 2 was removed. Figure 3 Also shown is a thermal sensor 304, which may be, for example, an NTC thermistor. In other implementations, the thermal sensor 304 may not be an NTC thermistor. One or more leads 306 are electrically connected to the thermal sensor 304. The one or more leads 306 are electrically coupled to the leads 204 discussed above. The thermal sensor 304 is disposed in an axial opening (at the end) extending through the plunger 118. Figure 4B The thermal sensor 304 may be arranged, for example, near the bottom of the plunger 118 to couple to the plunger 118. In some examples, the thermal sensor 304 may be coupled to the plunger 118 via a clip (also in FIG. Figure 4B ) is fixed in the plunger 118. In some examples, the thermal sensor 304 may include a spring or other biasing member that is at least partially elastic, deformable and / or deflectable. For example, the spring or biasing member can reliably and accurately contact a stator winding hairpin structure or other feature to be monitored by the thermal sensor 304, for example, the contact is achieved by pressing against the feature to be sensed. In other examples, the clip can be a spring clip or other mounting device that is at least partially elastic, deformable and / or deflectable and holds the sensing element. In some examples, the clip can reliably and accurately contact a stator winding hairpin structure or other feature to be monitored by the thermal sensor 304.

[0037] Also like Figure 3As shown in FIG. 1 , the plunger 118 is generally cylindrical and includes a head 216 at a first end and a shaft 122 extending from the head 216 at a first (top) end 308 to a second (bottom) end 310. As mentioned above, the thermal sensor 304 may be disposed proximate the second end 310 of the plunger 118. Figure 3 As shown in , the outer surface of the shaft 122 may include a reduced diameter portion 312. As will be further described herein, the reduced diameter portion 312 is sized to provide a gap between the outer surface of the reduced diameter portion 312 and the inner surface of the neck portion 116 of the housing 102. As mentioned above, this gap can allow the plunger 118 and the housing 102 to move relative to each other (e.g., lateral movement). In other examples, the entire length of the shaft 122 of the plunger 118 can have a single diameter, such as a reduced diameter.

[0038] Figure 4A is a perspective view of the temperature sensor device 100 , wherein the housing 102 is shown with dashed lines. Figure 4A The interconnection of leads 306 and leads 204 to pins 402 in connector 126 is shown.

[0039] Figure 4B It is along Figure 4A A cross-sectional view taken along line BB in FIG. Figure 4B An axial opening 404 is shown extending through and at least partially defined by the neck portion 116 of the housing 102. The reduced diameter portion 312 of the plunger is generally disposed in the axial opening 404 of the neck portion 116. The outer surface of the reduced diameter portion 312 is spaced apart from the inner surface of the axial opening 404 by a radial spacing r. Due to the radial spacing r, the plunger 118 can move radially relative to the housing 102. As described in detail above, the lugs 208 and the recesses 218 are used to allow a certain relative rotational movement between the plunger 118 and the housing 102. Therefore, the temperature sensor device 100 allows the plunger 118 to perform relative translational and rotational movement relative to the sensor device housing 102.

[0040] Figure 4B Also shown is the plunger 118 partially located in the housing 102, e.g., the head 216 of the plunger 118 contacts the bottom plate 206 of the housing 102, and the shaft 122 extends below the housing 102 through the axial opening 404 in the housing and neck portion 116. Also as shown, the standoff 222 extends above the head 216 to a position proximate to (or in contact with) the cover 302. In this example, the cover 302 and the bottom plate 206 sandwich the head 216 and the standoff 222 therebetween, e.g., to limit (or inhibit) axial movement of the plunger 118 relative to the housing 102.

[0041] Also like Figure 4BAs shown in FIG. 4 , the axial opening 406 extends through the plunger 118. Although the axial opening 406 is shown as extending through the entire axial length of the plunger 118, in other examples, the axial opening 406 may include a hole or other blind opening proximate the lower end 310 of the plunger 118 (only).

[0042] The thermal sensor 304 is disposed in an axial opening 406 extending through the plunger 118. More specifically, the thermal sensor is disposed proximate the second end 310 of the plunger 118. Figure 4B The thermal sensor 304 is also shown integrated with a biasing member 408 that partially extends into the axial opening 406. The biasing member 408 can be coupled to the shaft 122 of the plunger 118 by a clip 410 or other fastener. In some examples, the biasing member 408 can be a sensing element of the thermal sensor 304. In other examples, the biasing member 408 can carry or otherwise provide a mounting for a sensing element associated with the thermal sensor 304. In yet other examples, the biasing member 408 can be coupled (e.g., thermally coupled) to the sensing element of the thermal sensor 304. The biasing member 408 can be integrally formed with the clip 410.

[0043] The biasing member 408 is positioned in the axial opening 406 to contact a stator winding hairpin structure 412 that extends at least partially into the axial opening 406. In the example shown, the biasing member 408 includes a substantially arcuate leg that extends away from the inner surface of the axial opening 406 and generally away from the end 310 of the plunger 118. When the sensor device 100 is positioned over the hairpin structure 412, the hairpin structure 412 contacts and presses against the biasing member 408. The biasing member 408 can be repositioned or deflected under the action of the hairpin structure 412. In this example, the hairpin structure 412 is positioned between the inner surface of the axial opening 406 and the biasing member 408. The internal force of the biasing member 408 keeps the biasing member in direct contact with the hairpin structure 412. It should be understood that, since the biasing member 408 extends across the axial opening 406, the exact position of the hairpin structure 412 relative to the plunger 118 is not critical to achieving good contact between the biasing member 408 and the hairpin structure 412. In addition, since the plunger 118 can move relative to the housing 102 and the housing 102 can be fixed relative to the hairpin structure 412, the sensor device 100 also has a self-adjusting ability to ensure reliable and accurate contact between the biasing member 408 and the hairpin structure 412. It should also be understood that, since the biasing member 408 can include the thermal sensor 304 or can be in thermal contact with the thermal sensor 304, the direct contact of the biasing member 408 ensures that the thermal sensor 304 is properly contacted for sensing. In some examples, the biasing member 408 can include spring steel or any material that facilitates biasing as described in detail herein. The biasing member 408 can provide a relatively low resistance and spring-loaded radially pressed plunger contact, thereby reliably and accurately measuring the temperature of the stator winding and meeting the required step response.

[0044] Figure 4BAlso shown is a tapered surface 414 that forms a portion of the axial opening 406 through the shaft 122 of the plunger 118. The tapered surface 414 is proximate the second end 310 of the axial opening 406. In some examples, the tapered surface 414 can be configured to guide the plunger 118 over the hairpin structure, for example, when the sensor device 100 is installed on the motor. For example, during the process of installing the sensor device 100 on the motor, the hairpin structure 412 can contact the tapered surface 414, and at the same time, for example, when the plunger is further (axially) pressed over the hairpin structure 412, the tapered surface 414 guides the hairpin structure into the axial opening 406. When the hairpin structure 412 contacts the tapered surface 414, the continued axial compression of the plunger generates a force at the tapered surface 414. This force causes the plunger 118 to move relative to the housing 102, thereby allowing the hairpin structure 412 to extend further into the axial opening 406 and ultimately contact the biasing member 408. When the hairpin structure is disposed in the axial opening 404, the plunger 118 can also move (in a rotational and translational manner as detailed above) to achieve contact between the thermal sensor 304 and the hairpin structure.

[0045] As can be appreciated from the foregoing, aspects of the present disclosure provide a temperature sensing mechanism that enables accurate temperature sensing of a motor even when the tolerances associated with the feature to be measured (such as a hairpin structure) are relatively large. In some examples, the present disclosure achieves consistent and reliable temperature readings between the sensing element and the stator winding hairpin structure, which not only simplifies the motor control scheme, but also achieves a significant reduction in system-level costs (maintainability, ease of assembly, and reliability of the motor).

[0046] All directions and arrangements of the parts shown herein are used as examples only. In addition, it will be appreciated by those of ordinary skill in the art that, in alternative embodiments, the functions of several elements may be performed by fewer elements or by a single element. Similarly, in some embodiments, any functional element may perform fewer or different operations compared to the operations described with respect to the illustrated embodiments. In addition, the functional elements shown as different for the purpose of illustration may be integrated in other functional elements in a particular implementation.

[0047] Although the subject technology has been described with respect to preferred embodiments, it is readily understood by those skilled in the art that various changes and / or modifications may be made to the subject technology without departing from the spirit or scope of the subject technology. For example, each claim may be subordinate to any or all claims in a multiple reference manner, even if these claims were not originally claimed for protection.

Claims

1. A sensor device, comprising: a housing configured to be coupled to the electric motor; a plunger at least partially disposed within the housing and movable relative to the housing; as well as A thermal sensor is disposed in the plunger, wherein the plunger is movable relative to the housing to position the thermal sensor relative to the motor.

2. The sensor device according to claim 1, wherein: The plunger is movable relative to the housing to position the thermal sensor relative to a hairpin structure of a stator of the electric motor.

3. The sensor device according to claim 2, wherein: The plunger includes a shaft extending below the housing, the plunger defining an axial opening configured to receive the hairpin structure of the stator of the motor therein.

4. The sensor device according to claim 3, wherein: The thermal sensor includes a biasing contact extending into the axial opening to contact the hairpin structure of the stator of the electric motor received in the axial opening.

5. The sensor device according to claim 3, wherein: The plunger includes a tapered wall proximate a distal end of the axial opening, the tapered wall being configured to guide the hairpin structure of the stator of the motor into the axial opening to a position proximate the thermal sensor.

6. The sensor device according to claim 1, wherein: The housing defines an interior volume; and The plunger includes a head located in the interior volume and a shaft extending along an axis from the head to a position below the housing, the head being sized to provide a gap between an inner surface of the housing and the head.

7. The sensor device according to claim 6, wherein: A recess is formed in the head, The housing includes a lug extending into the interior volume, and The plunger is arranged in the housing such that the recess receives at least a portion of the lug.

8. The sensor device according to claim 7, wherein: The notch has a notch width greater than a lug width of the lug to allow the plunger to rotate relative to the housing about the axis.

9. The sensor device according to claim 1, wherein: The housing includes a neck portion extending from a bottom surface of the housing, the neck portion defining an axial opening having an axial opening diameter, The outer diameter of the portion of the plunger disposed in the neck portion is smaller than the axial opening diameter, and The difference between the outer diameter of the portion of the plunger and the axial opening diameter enables the plunger to move laterally relative to the housing.

10. The sensor device according to claim 9, wherein: The portion of the plunger is a reduced diameter portion of the shaft of the plunger.

11. The sensor device according to claim 9, wherein: The housing includes an inner side wall, The plunger head has an outer surface spaced from the inner side wall of the housing, and The spacing between the outer surface of the head of the plunger and the inner sidewall of the housing enables the plunger to move laterally relative to the housing.

12. The sensor device according to claim 11, wherein: The inner sidewall is a cylindrical sidewall defining a sidewall diameter, and The head of the plunger has a cylindrical outer surface defining a head diameter that is smaller than a diameter of the sidewall.

13. The sensor device according to claim 1, wherein: The plunger also includes one or more standoffs extending from the head of the plunger, the one or more standoffs being configured to contact a cover of the housing.

14. The sensor device according to claim 1, wherein: The housing further comprises an electrical connector, and the sensor device further comprises: The thermal sensor is electrically coupled to one or more electrical leads of the electrical connector.

15. The sensor device according to claim 1, wherein: The thermal sensor includes a negative temperature coefficient thermistor.

Images