Supercharger

Abstract

A supercharger comprising a motor including a rotor provided on a rotating shaft and a stator provided around the rotor, wherein the stator includes a stator core, an insulator, a coil, a bus bar connected to an end of the coil, and a thermistor, the temperature sensing element of the thermistor is inserted in the axial direction into a pocket provided in the insulator, and the signal cable of the thermistor is drawn out from the temperature sensing element in the opposite direction to the direction of insertion into the pocket and extends across the temperature sensing element side of the bus bar when viewed from the axial direction.

Description

turbocharger

[0001] The present disclosure relates to a supercharger.

[0002] In a conventional turbocharger equipped with a motor, when the torque of the rotating shaft generated by the turbine is insufficient, the motor applies torque to the rotating shaft to compensate for the insufficiency. The motor built into such a turbocharger requires temperature management to prevent malfunction of the coil due to heat. A thermistor mounted on the stator for such temperature management is known (see, for example, Patent Document 1 listed below).

[0003] Patent No. 5333657

[0004] In the motor of Patent Document 1, the thermistor is attached to the coil end of the stator using a specified fixture. However, since installation space for the thermistor and the fixture itself is required, space within the stator is constricted, hindering efforts to make the stator more compact. While it is also possible to adhere the thermistor to the stator using an adhesive or the like, it can be difficult to stably fix the thermistor due to variations in adhesive strength, etc.

[0005] The present disclosure describes a turbocharger in which the thermistor is stably fixed while reducing the installation space required by mounting the thermistor on the stator of the motor.

[0006] The gist of the present disclosure is as follows.

[0007] [1] A turbocharger comprising an assist motor unit having a rotor provided on a rotating shaft connecting a turbine impeller and a compressor impeller, and a stator provided around the rotor, wherein the stator has a stator core, an insulator provided around the stator core, a coil wound around the insulator, a bus bar connected to one of the coil ends located on the inner side of both ends, a temperature measurement unit having a temperature sensing element unit that detects the temperature of the coil, and a signal cable drawn out from the temperature sensing element unit, wherein the temperature sensing element unit is inserted into an element pocket provided in the insulator in the direction of the rotation axis of the assist motor unit, and the signal cable is drawn out from the temperature sensing element unit in the opposite direction to the insertion direction of the temperature sensing element unit into the element pocket and extends so as to cross the temperature sensing element unit side of the bus bar when viewed in the direction of the rotation axis.

[0008] According to the turbocharger of the present disclosure, the installation space required for mounting the thermistor on the stator of the motor is reduced, and the thermistor is stably fixed.

[0009] 5(a) to 5(c) are cross-sectional views of a turbocharger according to an embodiment. (a) to 5(c) are exploded views of the main components of a stator, continuing from FIG. 2. (a) to 5(c) are exploded views of the main components of the stator. (a) is a circuit diagram of a stator. (a) is a perspective view of an electromagnet assembly in which a thermistor is installed, and (b) is a perspective view of the electromagnet assembly with a coil removed. (b) is a cross-sectional view taken along line VI-VI in FIG. 5(b). (c) is an enlarged view of the vicinity of the thermistor in the stator immediately before being fixed by resin molding, viewed in the axial direction from the compressor side.

[0010] The gist of the present disclosure is as follows [1] to [6].

[0011] [1] A turbocharger comprising an assist motor unit having a rotor provided on a rotating shaft connecting a turbine impeller and a compressor impeller, and a stator provided around the rotor, wherein the stator has a stator core, an insulator provided around the stator core, a coil wound around the insulator, a bus bar connected to one of the coil ends located on the inner side of both ends, a temperature measurement unit having a temperature sensing element unit that detects the temperature of the coil, and a signal cable drawn out from the temperature sensing element unit, wherein the temperature sensing element unit is inserted into an element pocket provided in the insulator in the direction of the rotation axis of the assist motor unit, and the signal cable is drawn out from the temperature sensing element unit in the opposite direction to the insertion direction of the temperature sensing element unit into the element pocket and extends so as to cross the temperature sensing element unit side of the bus bar when viewed in the direction of the rotation axis.

[0012] [2] The turbocharger described in [1], wherein the bus bar extends radially inward from an insulating material located on the outer periphery side of the coil end and is connected to the coil end, and a portion of the signal cable between a portion crossing the bus bar and a cable end drawn out to the outside of the stator is fitted into a groove formed in the insulating material.

[0013] [3] A turbocharger described in [1] or [2], wherein a plurality of electromagnet assemblies each having the stator core, the insulator, and the coil are arranged in the circumferential direction, the bus bar extends radially at a position between two adjacent electromagnet assemblies as viewed from the axial direction, and both of the two signal cables drawn out from the temperature sensing element unit are drawn out from the temperature sensing element unit in a direction opposite to the insertion direction of the temperature sensing element unit into the element pocket, extend across the bus bar as viewed from the rotation axis direction, and pass through the temperature sensing element unit side of the bus bar.

[0014] [4] A turbocharger described in any one of [1] to [3], wherein the coil end portion extends in the axial direction and is positioned adjacent to the temperature-sensing element portion in the element pocket in the circumferential direction.

[0015] [5] The turbocharger according to any one of [1] to [4], wherein a molded resin is filled between the temperature-sensing element portion and the coil.

[0016] [6] A turbocharger described in any one of [1] to [5], wherein a gap is formed in the element pocket to expose a portion of the temperature-sensing element portion within the element pocket, and the coil and the temperature-sensing element portion are in close proximity through the gap.

[0017] A turbocharger 1 according to an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a cross-sectional view of the turbocharger 1 taken along a plane including a rotation axis H. In the following description, when simply referring to the "axial direction," "radial direction," or "circumferential direction," these refer to the axial direction, radial direction, and circumferential direction, respectively, of a rotating shaft 14, which will be described later. Furthermore, when simply referring to the "outer peripheral side" or "inner peripheral side," these refer to the outer side or inner side in the radial direction of the rotating shaft 14.

[0018] The turbocharger 1 is applied to an internal combustion engine of a vehicle or the like. As shown in Fig. 1, the turbocharger 1 includes a turbine 2 and a compressor 3. The turbine 2 includes a turbine housing 4 and a turbine wheel 6 housed in the turbine housing 4. The turbine housing 4 has a scroll passage 16 extending in the circumferential direction around the turbine wheel 6. The compressor 3 includes a compressor housing 5 and a compressor wheel 7 housed in the compressor housing 5. The compressor housing 5 has a scroll passage 17 extending in the circumferential direction around the compressor wheel 7.

[0019] The turbine wheel 6 is provided at one end of the rotary shaft 14, and the compressor wheel 7 is provided at the other end of the rotary shaft 14. A bearing housing 13 is provided between the turbine housing 4 and the compressor housing 5. The rotary shaft 14 is rotatably supported by the bearing housing 13 via bearings 15, and the rotary shaft 14, turbine wheel 6, and compressor wheel 7 rotate around the rotation axis H as an integrated rotating body 12.

[0020] The turbine housing 4 is provided with an exhaust gas inlet (not shown) and an exhaust gas outlet 10. Exhaust gas discharged from an internal combustion engine (not shown) flows into the turbine housing 4 through the exhaust gas inlet. The exhaust gas then flows into the turbine wheel 6 through a scroll passage 16, causing the turbine wheel 6 to rotate. The exhaust gas then flows out of the turbine housing 4 through the exhaust gas outlet 10.

[0021] The compressor housing 5 is provided with an inlet port 9 and a discharge port (not shown). When the turbine wheel 6 rotates as described above, the compressor wheel 7 rotates via the rotary shaft 14. The rotating compressor wheel 7 draws in external air through the inlet port 9. This air passes through the compressor wheel 7 and the scroll flow path 17, is compressed, and is discharged from the discharge port. The compressed air discharged from the discharge port is supplied to the internal combustion engine described above.

[0022] Furthermore, the turbocharger 1 is equipped with a motor 21 (assist motor section). For example, when the torque of the rotating shaft 14 is insufficient, such as during vehicle acceleration, the motor 21 applies torque to the rotating shaft 14 to compensate for the insufficiency. The motor 21 is, for example, a brushless AC motor, and includes a rotor 25 which is a rotor and a stator 27 which is a fixed part. The vehicle battery can be used as a driving source for the motor 21. Furthermore, when the vehicle is decelerating, the motor 21 may generate power regeneratively using the rotational energy of the rotating body 12. The motor 21 has characteristics that allow it to handle high-speed rotation of the rotating shaft 14 (for example, 100,000 to 200,000 rpm).

[0023] The rotor 25 is disposed axially between the bearing 15 and the compressor impeller 7. The rotor 25 is fixed to the rotary shaft 14 and is rotatable together with the rotary shaft 14. The stator 27 is housed in the bearing housing 13 and disposed so as to surround the rotor 25 in the circumferential direction. The stator 27 includes a plurality of coils and an iron core (not shown). When a current is supplied to the coils and the stator 27 generates a magnetic field, a circumferential force acts on the permanent magnets 29 of the rotor 25 by the magnetic field, and as a result, a torque is applied to the rotary shaft 14.

[0024] The stator 27 will be described in more detail. FIGS. 2( a) to 2(c) and FIGS. 3(a) to 3(c) are exploded views showing the main components of the stator 27. The direction perpendicular to the plane of the paper in FIGS. 2 and 3 is the axial direction, with the turbine 2 side facing the paper and the compressor 3 side facing the paper. In the stator 27, the components shown in FIG. 2(b) are arranged in a stacked manner on the front side of the components shown in FIG. 2(c), and the components shown in FIG. 2(a) are arranged in a stacked manner on the front side of that. Furthermore, the components shown in FIG. 3(a) are arranged in a stacked manner on the back side of the components shown in FIG. 2(c), and the components shown in FIG. 3(b) are arranged in a stacked manner on the back side of that, and the components shown in FIG. 3(c) are arranged in a stacked manner on the back side of that.

[0025] FIG. 2C shows the main body 30 of the stator 27. The main body 30 includes six electromagnet assemblies 31 arranged to surround the rotor 25 ( FIG. 1 ). These electromagnet assemblies 31 are housed, for example, in a circular metal casing (not shown) and are arranged at equal circumferential intervals at 60° intervals. Each electromagnet assembly 31 includes core teeth 33 extending radially inward and coils 35 wound around the core teeth 33. The coils 35 are made of pairs of round wires, and are wound in a concentrated manner with 5.5 turns. Of the coil ends of the coil 35, a radially inner coil end 36 extends from the core teeth 33 toward the compressor side (the front side of the paper in FIG. 2 ), while a radially outer coil end 37 extends from the core teeth 33 toward the turbine side (the back side of the paper in FIG. 2 ).

[0026] Stator 27 is a three-phase, six-slot stator, and the six coils 35 are composed of a first U-phase coil 35u1, a second U-phase coil 35u2, a first V-phase coil 35v1, a second V-phase coil 35v2, a first W-phase coil 35w1, and a second W-phase coil 35w2. In main body 30, these coils are arranged clockwise in Figure 2 in the following order: first V-phase coil 35v1, second W-phase coil 35w2, first U-phase coil 35u1, second V-phase coil 35v2, first W-phase coil 35w1, and second U-phase coil 35u2. Note that an SPM single-pole-pair motor rotor is used as rotor 25 for such stator 27.

[0027] A neutral point bus bar 39 shown in FIG. 2B is provided on the compressor side of main body 30. Neutral point bus bar 39 includes an annular portion 41 provided on the peripheral edge of main body 30 and three connection bus bars 43u2, 43v2, and 43w2 extending inward in a cantilevered manner from annular portion 41. Connection bus bar 43u2 is connected to coil end 36 of second U-phase coil 35u2, connection bus bar 43v2 is connected to coil end 36 of second V-phase coil 35v2, and connection bus bar 43w2 is connected to coil end 36 of second W-phase coil 35w2. Connection bus bars 43u2, 43v2, and 43w2 are equally spaced circumferentially at 120° intervals. Connection bus bar 43u2 extends radially between second U-phase coil 35u2 and first W-phase coil 35w1 as viewed axially. Connection bus bar 43v2 extends radially at a position between second V-phase coil 35v2 and first U-phase coil 35u1 when viewed axially. Connection bus bar 43w2 extends radially at a position between second W-phase coil 35w2 and first V-phase coil 35v1 when viewed axially.

[0028] 2A are provided on the compressor side of neutral point bus bar 39. One end of lead bus bar 45u1 is connected to coil end 36 of first U-phase coil 35u1, one end of lead bus bar 45v1 is connected to coil end 36 of first V-phase coil 35v1, and one end of lead bus bar 45w1 is connected to coil end 36 of first W-phase coil 35w1. The other ends of the three lead bus bars 45u1, 45v1, 45w1 form input terminals 47u, 47v, 47w that accept external current input, and each protrudes radially outward beyond main body 30 and is exposed to the outside of stator 27.

[0029] Lead-wire bus bar 45u1 connects input terminal 47u and coil end 36 of first U-phase coil 35u1 via an arc portion that follows the peripheral edge of main body 30. The portion of lead-wire bus bar 45u1 on the coil end 36 side extends radially at a position between first U-phase coil 35u1 and second W-phase coil 35w2 when viewed in the axial direction. Lead-wire bus bar 45v1 connects input terminal 47v and coil end 36 of first V-phase coil 35v1 in a generally linear manner. The portion of lead-wire bus bar 45v1 on the coil end 36 side extends radially at a position between first V-phase coil 35v1 and second U-phase coil 35u2 when viewed in the axial direction. Lead-wire bus bar 45w1 connects input terminal 47w and coil end 36 of first W-phase coil 35w1 via an arc portion that follows the peripheral edge of main body 30. The portion of lead bus bar 45w1 on the coil end 36 side extends radially at a position between first W-phase coil 35w1 and second V-phase coil 35v2 when viewed in the axial direction.

[0030] 3(a) to 3(c), three crossover bus bars 49u, 49v, 49w are installed in a stacked manner on the turbine side of main body 30. Crossover bus bar 49u connects coil end 37 of first U-phase coil 35u1 to coil end 37 of second U-phase coil 35u2 via a semicircular arc portion that follows the peripheral edge of main body 30. Crossover bus bar 49v connects coil end 37 of first V-phase coil 35v1 to coil end 37 of second V-phase coil 35v2 via a semicircular arc portion that follows the peripheral edge of main body 30. Crossover bus bar 49w connects coil end 37 of first W-phase coil 35w1 to coil end 37 of second W-phase coil 35w2 via a semicircular arc portion that follows the peripheral edge of main body 30.

[0031] The neutral bus bar 39, the lead bus bars 45u1, 45v1, 45w1, and the crossover bus bars 49u, 49v, 49w are each made of integrally formed copper sheet material and extend in a plane generally perpendicular to the axial direction. When these bus bars are stacked axially on the main body 30, electrical insulation layers are interposed between each bus bar and the electromagnet assembly 31 and between each bus bar. For example, in this embodiment, the neutral bus bar 39, the lead bus bars 45u1, 45v1, 45w1, and the ring-shaped insulating resin portion 42 (see FIG. 7) that embeds these bus bars are integrally molded. A portion of this insulating resin portion 42 penetrates between the bus bars and functions as the electrical insulation layer. The components shown in FIGS. 2 and 3 constitute the Y-connected two-series stator 27 as shown in the circuit diagram of FIG. 4.

[0032] When the coil 35 of the stator 27 is in operation, if the temperature of the coil 35 becomes too high, the insulating coating will be damaged, causing problems such as a short circuit, and therefore it is necessary to control the temperature of the coil 35. To achieve this temperature control, the stator 27 is equipped with a thermistor 51. The thermistor 51 is attached to the core teeth portion 33 of one electromagnet assembly 31. The thermistor 51 (see FIG. 5(b)) includes a temperature sensing element portion 51a having an elongated rectangular parallelepiped shape, two signal cables 51b extending from one longitudinal end face of the temperature sensing element portion 51a, and crimp terminals 51c provided at the end of each signal cable 51b for connection to the outside.

[0033] 2 and 3 are assembled together and then the entire assembly is resin-molded and fixed, with the input terminals 47u, 47v, 47w and the two crimp terminals 51c exposed to the outside from the molded resin 50. The resin molding process can be performed by, for example, transfer molding or potting.

[0034] The structure in which the thermistor 51 is installed inside the stator 27 will be described below.

[0035] Fig. 5(a) is a perspective view showing one of the six electromagnet assemblies 31 described above, in which a thermistor 51 is installed. Fig. 5(b) is a perspective view showing a state in which the coil 35 has been removed from this electromagnet assembly 31. Fig. 6 is a cross-sectional view taken along the line VI-VI in Fig. 5(b).

[0036] 5(b) and 6, the electromagnet assembly 31 includes a stator core 53, which is an iron core, and a resin insulator 55 provided to cover the surface of the stator core 53. The stator core 53 and the insulator 55 are integrally formed by, for example, insert molding. The insulator 55 functions as a guide for winding the coil 35 and also functions as an electrical insulator between the stator core 53 and the coil 35. In the core teeth portion 33, the periphery of the stator core 53 is completely covered by the insulator 55, and the coil 35 is wound around the insulator 55.

[0037] A pocket 57 for installing the thermistor 51 is provided in the insulator 55 at the tip end (inner peripheral end) of the core teeth portion 33. The pocket 57 is formed by cutting out a part of the inner peripheral end of the insulator 55. A temperature sensing element 51a is inserted into the pocket 57 in the axial direction from the compressor side toward the turbine side. The temperature sensing element 51a abuts against the pocket bottom surface 57a on the turbine side and is stored in an orientation with its longitudinal direction facing the axial direction.

[0038] Before the resin molding process described above, the pocket bottom surface 57a restricts the displacement of the temperature sensor unit 51a toward the turbine. However, the pocket 57 does not have any portion restricting the movement of the temperature sensor unit 51a toward the compressor, allowing the temperature sensor unit 51a to be removed from the pocket 57 toward the compressor. The pocket 57 also has wall-like portions 57b and 57c that restrict the radial displacement of the temperature sensor unit 51a, and a wall surface 57d and restricting portion 57e that restrict the circumferential displacement of the temperature sensor unit 51a. Therefore, before the resin molding process, the radial and circumferential displacements of the temperature sensor unit 51a are restricted. A radial gap 57f is formed between the restricting portion 57e and the wall-like portion 57b, and the temperature sensor unit 51a is exposed circumferentially throughout its entire length within the width of the gap 57f.

[0039] As shown in FIG. 5A, the coil end 35a of the coil 35 on the coil end 36 side passes through the turbine side of the pocket bottom surface 57a, bends toward the compressor side, and extends axially along the gap 57f. This coil end 35a is circumferentially adjacent to the temperature sensing element portion 51a through the gap 57f. That is, the coil end 35a is close to the temperature sensing element portion 51a through the gap 57f. The coil end 35a may also be in contact with the temperature sensing element portion 51a. The restricting portion 57e may also function as a guide for the coil end 35a.

[0040] The above describes the configuration of the electromagnet assembly 31 (FIGS. 5 and 6) in which the thermistor 51 is installed. In contrast, the other electromagnet assemblies 31 in which the thermistor 51 is not installed differ only in that they do not have a pocket 57 formed therein, and have the same configuration in other respects, so a duplicated description will be omitted. However, the pocket 57 may be formed in all six electromagnet assemblies 31, including the other electromagnet assemblies 31 in which the thermistor 51 is not installed. In this case, it is preferable because parts can be standardized among all the electromagnet assemblies 31.

[0041] FIG. 7 is an enlarged view of the vicinity of the thermistor 51 in the stator 27 immediately before the resin molding process is performed, viewed in the axial direction from the compressor side. Here, the thermistor 51 is installed in the electromagnet assembly 31 in which the first V-phase coil 35v1 is configured. As shown in the figure, the temperature sensing element 51a of the thermistor 51 is housed in a pocket 57 of an insulator 55 of the electromagnet assembly 31. When viewed in the axial direction, the temperature sensing element 51a is located slightly offset in the circumferential direction from the lead-wire bus bar 45v1. For example, in FIG. 7, the temperature sensing element 51a is located slightly offset to the right of the lead-wire bus bar 45v1. The compressor-side end face of the temperature sensing element 51a is located closer to the turbine than the lead-wire bus bar 45v1.

[0042] Two signal cables 51b of the thermistor 51 are drawn out from the compressor-side end face of the temperature sensing element unit 51a and extend across the position of the lead-line bus bar 45v1 when viewed from the axial direction. Where the signal cables 51b cross the lead-line bus bar 45v1, the two signal cables 51b pass through the turbine side of the lead-line bus bar 45v1. The distal ends of the two signal cables 51b are fitted into two grooves 42a formed in the insulating resin part 42. The grooves 42a are formed on the compressor-side end face of the insulating resin part 42 and are located to the left of the lead-line bus bar 45v1 in FIG. 7 . The grooves 42a have tabs 42b for holding the signal cables 51b in the grooves 42a. By fitting the signal cables 51b into the grooves 42a having the tabs 42b, the signal cables 51b do not easily lift up from the insulating resin part 42 toward the compressor side.

[0043] The further distal ends of the two signal cables 51b are pulled out onto the outer circumferential surface of the insulating resin part 42 through insertion holes provided at the outer peripheral ends of the grooves 42a. The signal cables 51b extend in opposite directions on the outer circumferential surface of the insulating resin part 42. A cable holding part 42d that holds the signal cables 51b is provided on the outer circumferential surface of the insulating resin part 42. The cable holding part 42d has a groove with a tab, similar to the grooves 42a, and the signal cables 51b are fitted into this groove to be held.

[0044] The cable holding portion 42d also guides the bending of the tip of the signal cable 51b. The tip of the signal cable 51b is held and guided by the cable holding portion 42d and bent outward from the outer circumferential surface, with a crimp terminal 51c provided at the tip. The signal cable 51b held by the cable holding portion 42d is pre-coated near the bent portion with a heat-shrinkable tube. This heat-shrinkable tube coating increases the rigidity of the signal cable 51b near the bent portion, and the bent shape of the bent portion is maintained by the rigidity of the signal cable 51b. As a result, the position of the crimp terminal 51c is maintained slightly outward from the cable holding portion 42d by the rigidity of the signal cable 51b. This position is adjusted to match the position of the external plug to which the crimp terminal 51c is bolted, improving the ease of bolting the crimp terminal 51c to the external plug.

[0045] As described above, the thermosensitive element 51a is temporarily stored in the pocket 57 and the signal cable 51b is routed, and then the resin molding process described above is performed. By this resin molding process, the thermosensitive element 51a of the thermistor 51 and the signal cable 51b are embedded and permanently fixed in the mold resin 50 (FIG. 2).

[0046] It should be noted that the configuration in which the signal cable 51b is fixed to the insulating resin portion 42 by the cable holding portion 42d as described above is not essential. In other words, the signal cable 51b does not necessarily need to be fixed inside the housing of the turbocharger 1. The insulating resin portion 42 may be omitted. Furthermore, the thermistor 51 may have a connector (not shown) of a predetermined structure instead of the crimp terminal 51c, and may be connected to the outside via the connector.

[0047] The effects of the turbocharger 1 having the stator 27 as described above will be described.

[0048] If the thermistor 51 is not firmly fixed before the resin molding process, there is a risk that the thermistor 51 may become misaligned due to external forces generated during assembly or resin molding. In contrast, the configuration of the stator 27 provides the pocket 57 that houses the temperature sensing element 51 a of the thermistor 51, so that the temperature sensing element 51 a is securely fixed to the tip of the core teeth 33 before the resin molding process is performed.

[0049] In this temporarily fixed state, the temperature sensor unit 51a can be displaced axially toward the compressor relative to the pocket 57. Meanwhile, the signal cable 51b, which is pulled out from the temperature sensor unit 51a toward the compressor, crosses the lead-line bus bar 45v1 when viewed axially, and at the portion where it crosses the lead-line bus bar 45v1, passes closer to the temperature sensor unit 51a than the lead-line bus bar 45v1. With this structure, the lead-line bus bar 45v1 prevents the signal cable 51b from displacing toward the compressor. This also makes it difficult for the temperature sensor unit 51a to displace toward the compressor, preventing the temperature sensor unit 51a from slipping out of the pocket 57. Therefore, even when external forces are applied during assembly or resin molding, the temperature sensor unit 51a is securely held within the pocket 57, making it unlikely that it will become displaced.

[0050] The pocket 57 for temporarily fixing the temperature sensing element 51a in this way is formed by cutting out a portion of the inner peripheral end of the insulator 55, and no separate fixture or the like is required to fix the temperature sensing element 51a. Furthermore, the existing lead wire bus bar 45v1 is used to prevent the temperature sensing element 51a from slipping out of the pocket 57, so no separate fixture or the like is required. Therefore, installation space can be reduced compared to when a separate fixture is used to attach the temperature sensing element 51a.

[0051] Furthermore, compared to attaching the temperature sensing element 51a using a separate fixture, the work is simplified and manufacturing costs are reduced. Furthermore, if the temperature sensing element 51a were attached using adhesive or the like, there is a risk that the temperature sensing element 51a would not be temporarily fixed stably due to variations in adhesive strength. In contrast, the stator 27 of this embodiment allows the temperature sensing element 51a to be temporarily fixed more stably, and the work is simplified. Furthermore, since no time is required for the adhesive to harden, the takt time is reduced, and manufacturing costs are reduced.

[0052] Furthermore, since the signal cable 51b is fitted into the groove 42a of the insulating resin part 42, the signal cable 51b does not easily rise up from the insulating resin part 42 toward the compressor even when subjected to external forces generated during assembly or resin molding. Therefore, the position of the signal cable 51b is reliably maintained until it is fixed by the resin molding process, and an event such as a part of the signal cable 51b being exposed outside the molded resin 50 is suppressed.

[0053] Furthermore, in the motor 21 of this type of turbocharger 1, the inner peripheral side of the stator 27 is likely to become hot due to reasons such as being away from a cooling water passage (not shown) arranged on the outside of the stator 27 and being close to the rotating rotor 25. Therefore, it is preferable that the temperature sensing element 51a of the thermistor 51 be installed on the inner peripheral side of the stator 27. In contrast, the pocket 57 is provided at the tip end of the core teeth portion 33, so that the temperature sensing element 51a can be arranged on the inner peripheral side of the stator 27.

[0054] Furthermore, a molded resin 50 is formed on the stator 27 by a resin molding process, and the molded resin 50 is also filled between the temperature sensing element 51a and the coil 35. Therefore, the heat of the coil 35 is transferred to the temperature sensing element 51a through the molded resin 50, and the temperature sensing element 51a can detect the heat of the coil 35 to be managed.

[0055] Furthermore, in order to detect the temperature of the coil 35 as directly as possible, it is preferable that the temperature sensing element 51a of the thermistor 51 be installed as close to the coil 35 as possible. In contrast, the coil end 35a extends axially at a position circumferentially adjacent to the pocket 57. Therefore, the temperature sensing element 51a can be installed circumferentially close to the coil end 35a, allowing the temperature of the coil 35 to be detected with high sensitivity. Furthermore, the pocket 57 has the aforementioned gap 57f, which brings the coil end 35a and the temperature sensing element 51a into close proximity through the gap 57f. The coil end 35a may also be in contact with the temperature sensing element 51a. Therefore, this gap 57f contributes to the temperature sensing element 51a detecting the temperature of the coil 35 as directly as possible.

[0056] The present disclosure can be implemented in various forms, including the above-described embodiments, with various modifications and improvements based on the knowledge of those skilled in the art. Furthermore, it is also possible to configure modified examples by utilizing the technical matters described in the above-described embodiments. The configurations of the respective embodiments may be used in appropriate combination.

[0057] 2 and 3 has been described as the turbine side and the compressor side, the turbine side and the compressor side may be reversed. Furthermore, although the embodiment has been described as including temperature sensing element unit 51a in electromagnet assembly 31 that includes first V-phase coil 35v1, temperature sensing element unit 51a may be provided in any of the six electromagnet assemblies 31. Furthermore, the bus bar across which signal cable 51b traverses may be any of lead-out bus bars 45u1, 45v1, 45w1 and connection bus bars 43u2, 43v2, 43w2, as long as it is determined according to the position of electromagnet assembly 31 on which temperature sensing element unit 51a is provided.

[0058] In addition, in the embodiment, an example has been described in which a thermistor 51 is installed in one of the six electromagnet assemblies 31 of the stator 27, but, for example, a thermistor 51 may be installed in each of multiple electromagnet assemblies 31, or a total of six thermistors 51 may be installed in each of all the electromagnet assemblies 31.

[0059] The present disclosure includes at least the following:

[0060] [1] A turbocharger comprising an assist motor unit having a rotor provided on a rotating shaft connecting a turbine impeller and a compressor impeller, and a stator provided around the rotor, wherein the stator has: a stator core; an insulator provided around the stator core; a coil wound around the insulator; a bus bar connected to one of the coil ends located on the inner periphery of both ends; and a temperature measurement unit having a temperature sensing element that detects the temperature of the coil and a signal cable drawn out from the temperature sensing element, wherein the temperature sensing element is inserted into an element pocket provided in the insulator in the direction of the rotation axis of the assist motor unit, and the signal cable is drawn out from the temperature sensing element in the opposite direction to the insertion direction of the temperature sensing element into the element pocket, and extends so as to cross the temperature sensing element side of the bus bar when viewed in the direction of the rotation axis.

[0061] [2] The turbocharger according to [1], wherein the bus bar extends radially inward from an insulating material located on the outer periphery side of the coil end and is connected to the coil end, and a portion of the signal cable between a portion crossing the bus bar and a cable end drawn out to the outside of the stator is fitted into a groove formed in the insulating material.

[0062] [3] A turbocharger according to [1] or [2], wherein a plurality of electromagnet assemblies each having the stator core, the insulator, and the coil are arranged in the circumferential direction, the bus bar extends radially between two adjacent electromagnet assemblies as viewed from the axial direction, and both of the two signal cables drawn out from the temperature sensing element unit are drawn out from the temperature sensing element unit in a direction opposite to the insertion direction of the temperature sensing element unit into the element pocket, extend across the bus bar as viewed from the rotation axis direction, and pass through the temperature sensing element unit side of the bus bar.

[0063] [4] A turbocharger described in any one of [1] to [3], wherein the coil end portion extends in the axial direction and is positioned adjacent to the temperature-sensing element portion in the element pocket in the circumferential direction.

[0064] [5] The turbocharger according to any one of [1] to [4], wherein a molded resin is filled between the temperature-sensing element portion and the coil.

[0065] [6] A turbocharger described in any one of [1] to [5], wherein a gap is formed in the element pocket to expose a portion of the temperature-sensing element portion within the element pocket, and the coil and the temperature-sensing element portion are in close proximity through the gap.

[0066] REFERENCE SIGNS LIST 1 Turbocharger 6 Turbine impeller 7 Compressor impeller 14 Rotating shaft 21 Motor (assist motor section) 25 Rotor 27 Stator 31 Electromagnet assembly 35 Coil 35a Coil end 42 Insulating resin section (insulating material) 42a Groove 43u2 Connection bus bar 43v2 Connection bus bar 43w2 Connection bus bar 45u1 Lead line bus bar 45v1 Lead line bus bar 45w1 Lead line bus bar 50 Molded resin 51 Thermistor (temperature measurement section) 51a Temperature sensing element section 51b Signal cable 53 Stator core 55 Insulator 57 Pocket (element pocket) 57f Gap H Rotation axis

Claims

1. The turbine impeller and the compressor impeller are connected to each other via a rotor provided on a rotation shaft, and a stator provided around the rotor. The stator includes: A stator core; an insulator provided around the stator core; A coil wound around the insulator; a bus bar connected to one of the coil ends located on the inner periphery side of both ends of the coil; a temperature measuring unit having a temperature sensing element unit that detects the temperature of the coil and a signal cable drawn out from the temperature sensing element unit; The temperature sensing element unit is the assist motor unit is inserted in a direction of a rotation axis of the assist motor unit into an element pocket provided in the insulator, The signal cable includes: The temperature sensor is pulled out from the temperature sensor unit in a direction opposite to the direction in which the temperature sensor unit is inserted into the element pocket, the turbocharger extending across the temperature sensing element side of the bus bar as viewed from the rotation axis direction.

2. The bus bar extends radially from an insulating material located on the outer circumferential side of the coil end to the inner circumferential side and is connected to the coil end, 2. The turbocharger according to claim 1, wherein a portion of the signal cable between a portion crossing the bus bar and a cable end portion drawn to an outside of the stator is fitted into a groove formed in the insulating material.

3. a plurality of electromagnet assemblies each having the stator core, the insulator, and the coil are arranged in a circumferential direction; the bus bar extends radially between two adjacent electromagnet assemblies when viewed in the axial direction, The two signal cables drawn out from the temperature sensing element unit are both The temperature sensor is pulled out from the temperature sensor unit in a direction opposite to the direction in which the temperature sensor unit is inserted into the element pocket, The turbocharger according to claim 1 , wherein the first and second electrodes extend across the bus bar when viewed from the rotation axis direction and pass through a side of the bus bar facing the temperature sensing element.

4. The turbocharger according to claim 1 , wherein the coil end portion extends in an axial direction and is positioned adjacent to the temperature sensing element portion in the element pocket in a circumferential direction.

5. The turbocharger according to claim 1 , wherein a molding resin is present between the temperature sensing element portion and the coil.

6. 2. The turbocharger according to claim 1, wherein a gap is formed in the element pocket to expose a portion of the temperature-sensing element portion within the element pocket, and the coil and the temperature-sensing element portion are in close proximity to each other through the gap.

7. A turbocharger as described in claim 2, wherein the groove has a claw that holds the signal cable.

8. A turbocharger as described in claim 2, wherein the insulating material is ring-shaped with a portion of the bus bar embedded in it.

9. A turbocharger as described in claim 1, wherein the temperature sensing element portion is stored in the element pocket with its longitudinal direction facing the axial direction.