Rotary electric machine

Abstract

To provide a rotary electric machine to solve a problem where abnormalities in a stator winding temperature sensor cannot be determined because an air flow during rotor rotation does not pass through a rotational angle sensor in conventional rotary electric machines.SOLUTION: A rotary electric machine includes: a stator having stator windings; a rotor; a stator winding temperature sensor for measuring the temperature of the stator windings; a rotational angle sensor for measuring the rotor rotation speed installed inside a housing; a rotational angle sensor temperature estimation unit that estimates the temperature of the rotational angle sensor from the temperature characteristic of the rotational angle sensor; and a stator winding temperature estimation unit that estimates the temperature of the stator winding from the output of the rotational angle sensor temperature estimation unit, in which, as the rotor rotates, an air circulation path is formed that passes through both the stator windings and the rotational angle sensor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a rotating electric machine. [Background technology]

[0002] In automobiles equipped with a motor as a drive source, in-vehicle electric power steering devices that provide an assist force to the steering mechanism when the driver turns the steering wheel, in compressors that compress refrigerant in air conditioners, and in servomotors that require accurate position control, a stator winding temperature sensor, such as a thermistor, is provided to detect the temperature of the stator winding of the rotating electrical machine and monitor the temperature of the stator winding. This type of stator winding temperature sensor deteriorates over long-term use, and there is a possibility that its detection characteristics will deteriorate (become abnormal).

[0003] Therefore, there is a method of determining whether there is an abnormality in the stator winding temperature sensor by adding a means for estimating the stator winding temperature in addition to the stator winding temperature sensor and comparing the detected value with the estimated value.One known method of estimating the stator winding temperature is to estimate the stator winding temperature by using the temperature characteristics of a rotation angle sensor that detects the motor rotation speed. Also, a method has been proposed in which a noise shielding plate is provided between the rotation angle sensor and the motor to block noise so that the rotation angle sensor is not affected by electromagnetic noise generated from the starter winding (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-228024 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a rotating electric machine using the technology described in Patent Document 1, the air flow generated by the rotation of the rotor of the rotating electric machine passes through the stator windings but does not pass through the rotation angle sensor, resulting in poor thermal coupling between the stator windings and the rotation angle sensor, which causes a discrepancy or delay in the measurement results in temperature detection based on the installation positions of the two, and therefore there is a possibility that the error between the estimated temperature and the actual temperature will be large.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and aims to improve the thermal coupling between the stator windings and the rotation angle sensor, thereby enabling the temperature of the stator windings to be accurately estimated from the output of the rotation angle sensor. [Means for solving the problem]

[0007] The rotating electric machine of the present disclosure comprises: a housing that is a cylindrical box and supports one end of the shaft; a bracket fixed to the housing and supporting the other end of the shaft; an annular stator disposed on the inner periphery of the housing and having a core around which a winding is wound; a rotor disposed opposite to an inner periphery of the stator and attached to the shaft; A rotating electric machine having a rotation angle sensor that is built into a casing that is configured by the housing and the bracket and that measures a rotation angle of the rotor; a rotation angle sensor temperature estimation unit that estimates a temperature of the rotation angle sensor from a temperature characteristic of an output of the rotation angle sensor; a stator winding temperature estimator that estimates a temperature of the stator winding from an output of the rotation angle sensor temperature estimator; Equipped with When the rotor rotates, an air circulation path is formed that passes through both the stator winding and the rotation angle sensor. It is characterized by the following. [Effects of the Invention]

[0008] According to the rotating electric machine of the present disclosure, the thermal coupling between the stator winding and the rotation angle sensor is improved, and the temperature of the stator winding can be estimated with high accuracy from the output of the rotation angle sensor. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of a rotating electric machine and a drive system for the rotating electric machine according to the present disclosure; [Figure 2] 4 is a diagram showing an example of an output temperature characteristic of a rotation sensor used in the rotating electric machine according to the first embodiment. FIG. [Figure 3] 1 is a cross-sectional view of a rotating electric machine according to a first embodiment as viewed from the side. [Figure 4] 5A and 5B are diagrams for explaining temperature changes over time in the stator windings and the coil of the rotation angle sensor. [Figure 5] FIG. 10 is a cross-sectional side view of a rotating electric machine for explaining the problem. [Figure 6] FIG. 10 is a cross-sectional view of a rotating electric machine according to a second embodiment, as viewed from the side. [Figure 7] FIG. 10 is a front view of a noise shielding plate according to a second embodiment. [Figure 8] FIG. 10 is a front view of a noise shielding plate of a first modified example according to the second embodiment. [Figure 9] FIG. 10 is a cross-sectional view of a rotating electric machine of a first modified example according to the second embodiment, as viewed from its side. [Figure 10] FIG. 10 is a perspective view of a noise shielding plate according to a second modification of the second embodiment. [Figure 11] FIG. 10 is a cross-sectional side view of a rotating electric machine according to a second modification of the second embodiment. [Figure 12] FIG. 11 is a cross-sectional side view of a rotating electric machine according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Embodiment 1 The rotating electric machine of the present disclosure particularly relates to a rotating electric machine having a function of detecting an abnormality in a temperature sensor of a stator winding. A rotating electrical machine 10 according to the first embodiment will be described below with reference to the drawings. 1 is a diagram illustrating an example of a rotating electric machine 10 and a drive system for the rotating electric machine according to the present disclosure. Hereinafter, the configuration of a failure determination function of a stator winding temperature sensor 20 of the rotating electric machine 10 will be described with reference to FIG.

[0011] The rotating electric machine 10 of the first embodiment includes a stator having stator windings 11 (hereinafter simply referred to as windings 11 or stator windings 11) wound around a stator core 12 (hereinafter simply referred to as core 12), and a rotor which is a rotating body, and is mounted on, for example, a vehicle. The rotating electric machine 10 is also used in an air conditioner compressor or a servo motor. Here, the power supply 1 shown in FIG. 1 is configured with DC power supplied from a high-voltage DC battery, or DC power which is rectified by a rectifier and then smoothed by a capacitor after three-phase AC power supplied from a power grid. The inverter 2 converts the DC power input from the power supply 1 into AC power of a given frequency and supplies it to the rotating electric machine 10.

[0012] The rotating electric machine 10 includes a stator winding 11 wound around a stator core and a rotor 13. When AC power is input to the rotating electric machine 10, a current flows through the stator winding 11, causing the rotor 13 to rotate. The rotating electric machine 10 also includes a stator winding temperature sensor 20 for detecting the temperature of the stator winding 11, and a rotation angle sensor 30 for detecting the rotation angle of the rotor 13. The stator winding temperature sensor 20 may be configured with a thermistor. The rotation angle sensor 30 may be configured with, for example, a resolver, or may be configured with a combination of a magnet and a magnetic resistance element or a Hall element, or may be configured with a combination of a metal plate and a circuit pattern (having a transmitting coil and a receiving coil).

[0013] The control unit 40, indicated by a rectangular dashed line frame, includes a rotation angle detection unit 43 that detects the rotation angle of the rotor 13 from the output value of the rotation angle sensor 30, a rotation angle sensor temperature estimation unit 44 that estimates the temperature of the rotation angle sensor 30 from the temperature characteristics of the output value of the rotation angle sensor 30, and a stator winding temperature estimation unit 45 that estimates the temperature of the stator winding from the output of the rotation angle sensor temperature estimation unit 44. The inverter includes a temperature sensor failure determination unit 42 that determines whether the stator winding temperature sensor 20 has failed, and an inverter control signal generation unit 41 that generates a control signal for the inverter 2 from the determination result of the temperature sensor failure determination unit 42, the output of a rotation angle detection unit 43, and a motor current detection unit (not shown).

[0014] An example of a method for estimating the temperature of the rotation angle sensor 30 from the temperature characteristics of the output value of the rotation angle sensor 30 will now be described with reference to FIG. FIG. 2 shows an example of how the characteristics of the output signal from a rotation sensor change with temperature.

[0015] Figure 2 shows an example where the radius of a circular Lissajous curve changes with temperature when the output signal of a rotation sensor is expressed as a circular Lissajous curve made up of a combination of a SIN signal and a COS signal (see Figures 2A and 2B). That is, as shown in Figure 2, with the horizontal axis representing the COS signal and the vertical axis representing the SIN signal, the output signal of the rotation sensor is expressed as a circular Lissajous curve (hereinafter also referred to as a Lissajous circle), and its radius changes with temperature (see Figure 2A). Therefore, it is possible to estimate the temperature of the rotation sensor based on the relationship between temperature and the radius of the Lissajous circle (see FIG. 2B). However, if the rotation sensor is equipped with a temperature detector, the detected value may also be used.

[0016] Furthermore, the temperature sensor failure determination unit 42 can determine whether or not the stator winding temperature sensor 20 has failed by, for example, comparing the output of the rotation angle sensor temperature estimator 44 or the stator winding temperature estimator 45 with the output of the stator winding temperature sensor 20. A detailed method for determining whether or not the stator winding temperature sensor 20 has failed will be described later.

[0017] 3 is a cross-sectional side view of rotating electric machine 10 according to embodiment 1 of the present disclosure. The structure of rotating electric machine 10 according to embodiment 1 of the present disclosure will be described below with reference to this FIG.

[0018] The rotating electric machine 10 is housed in a casing made up of a cylindrical box-shaped housing 14 and a plate-shaped bracket 15 fixedly attached to the housing 14. The casing includes a stator winding 11 and a stator core 12 that constitute the stator, which is the non-rotating part (stationary part) of the rotating electric machine; a rotor 13 that is the rotating part (of the rotating electric machine); a shaft 16 attached to the rotor; a first bearing 18 that supports one end of the shaft and a second bearing 19 that supports the other end, which are attached to and supported by the housing 14 and the bracket 15 of the casing, respectively; a stator winding temperature sensor 20 that measures the temperature of the stator winding; and a rotation angle sensor 30 that measures the rotation angle of the rotor 13 (the configuration of which will be described in detail later).

[0019] The rotor 13 has an outer diameter of, for example, 100 mm. The shaft 16 has a length of, for example, 300 mm. The housing 14 may be provided with a cooling passage through which a coolant passes, or an oil-cooled jacket through which cooling oil is sprayed onto the stator windings 11 or the stator core 12. The stator core 12, around which the stator windings 11 are wound, is formed in an annular shape and is disposed so as to surround the rotor 13. The center of the rotation axis of the rotor 13 has a through-hole through which the cylindrical shaft 16 passes.

[0020] The stator winding temperature sensor 20 is attached to the stator winding 11. The rotation angle sensor 30 is composed of a holder 33, a coil 31, and a rotor 32 (same applies below). The holder 33 is fixed to the bracket 15 by screws via a spacer 34 or the like. The coil 31 is wound around the holder 33.

[0021] The shaft 16 may pass through the center of the rotor 32, and the rotor 32 may be fixed to the shaft 16 with a rotor fixing nut 35. The outer diameter of the rotor 32 is, for example, φ50 mm. By fixing the rotor 13 and the rotor 32 of the rotation angle sensor 30 to the same shaft 16, the rotor 32 has the same rotation angle as the rotor 13, and the rotation of the rotor 13 generates an induced voltage in the coil 31 wound around the holder 33. The rotation angle of the rotor 13 can be detected by reading the fluctuations in this induced voltage.

[0022] Next, the assembly procedure for the rotating electrical machine 10 will be described. First, the stator core 12 around which the stator windings 11 are wound is fixed to the housing 14 by, for example, shrink fitting or press fitting. Next, the first bearing 18 is attached to the bottom of the housing 14. Next, the second bearing 19, the spacer 34, and the holder 33 of the rotation angle sensor 30 are attached to the bracket 15. The spacer 34 and the holder 33 are fixed to the bracket 15, for example, by screws.

[0023] Next, the shaft 16 is fixed to the rotor 13 by, for example, shrink fitting or press fitting. After that, the rotor 32 of the rotation angle sensor 30 is attached to the rotor attachment portion 17 of the shaft 16 (see the area surrounded by the dashed line in FIG. 3 ), and the rotor 32 is fixed with a rotor fixing nut 35. In order to store the shaft 16 with the rotor 13 attached in the housing 14, for example, both ends of the shaft 16 are press-fitted into the first bearing 18 and the second bearing 19, and the bracket 15 is fixed to the housing 14 by screws or the like.

[0024] Fig. 4 is a graph showing the temperature change characteristics over time of the stator winding 11 and the coil 31 of the rotation angle sensor 30. In Fig. 4, the characteristic curve shown by the solid line Cc shows the temperature change characteristics of the stator winding (hereinafter also referred to as characteristic Cc), the characteristic curve shown by the dotted line Ca shows the temperature change characteristics of the coil of the rotation angle sensor of the rotating electric machine of the first embodiment (hereinafter also referred to as characteristic Ca), and the characteristic curve shown by the dashed dotted line Cb shows the temperature change characteristics of the coil of the rotation angle sensor of the rotating electric machine 100 of the prior art (hereinafter also referred to as characteristic Cb) for explaining the problems of the rotating electric machine of the first embodiment.

[0025] Next, referring to FIG. 3 and FIG. 4, the heat transfer from the stator winding 11 to the rotation angle sensor 30, the method for determining a fault in the stator winding temperature sensor 20, and the effects of the rotating electric machine of the present embodiment 1 will be described below based on specific examples.

[0026] As shown by characteristic Cc in Fig. 4, for example, assume that thermal equilibrium is reached in 90 seconds and the stator winding temperature reaches 100°C. In this case, the coil temperature of the rotation angle sensor of the rotating electric machine according to the first embodiment, shown by characteristic Ca, is 78°C, which is close to the temperature of the stator winding, but the coil temperature of the rotation angle sensor of the prior art, shown by characteristic Cb, is 50°C, which is significantly different from the stator winding temperature.

[0027] This tendency is also the same in the non-steady state before the equilibrium state is reached, and the difference between the stator winding temperature and the coil temperature of the rotation angle sensor of the rotating electric machine of embodiment 1 is always smaller than the difference between the stator winding temperature and the coil temperature of the rotation angle sensor of the prior art. Therefore, it is understood that the temperature of the coil of the rotation angle sensor of the rotary electric machine according to the first embodiment has good follow-up ability to the temperature of the stator winding.

[0028] However, for example, if an event occurs in which the stator winding temperature fluctuates significantly in a short period of time, with a rotation angle sensor of the prior art, the range of fluctuation in the coil temperature is small, so it may not be possible to determine whether the fluctuation is due to an external factor such as noise, or whether the temperature fluctuation of the stator winding is being detected.

[0029] On the other hand, the rotation angle sensor of the rotating electric machine of the first embodiment has good response to temperature changes in the stator winding, and therefore can avoid the above-mentioned phenomenon. If an abnormality occurs in the temperature detection of the stator winding, the deviation between the temperature of the stator winding and the temperature of the coil of the rotation angle sensor is immediately reflected as a large fluctuation, and it is possible to accurately detect or determine that a characteristic abnormality or failure has occurred in the temperature detection of the stator winding.

[0030] The reason for this will be considered below. First, as rotor 13 rotates, an air flow is generated in the circumferential direction from the center of the rotation axis of rotor 13, as indicated by dotted arrow A in FIG. 3. When this air flow indicated by arrow A hits stator windings 11, the heat of stator windings 11 is transferred to the air. Meanwhile, around rotation angle sensor 30, an air flow is generated as indicated by arrow B (see the dotted arrow pointing to shaft 16 in FIG. 3) toward shaft 16. Due to the above-mentioned arrows A and B, air circulates around rotor 13, stator windings 11, and rotation angle sensor 30, as indicated by solid arrow C1. Due to this air circulation indicated by arrow C1, the heat generated by stator windings 11 is transferred to coil 31 of rotation angle sensor 30.

[0031] At this time, due to the influence of factors such as the thermal resistance or heat capacity of the air, the temperature of the coil 31 of the rotation angle sensor 30 changes in a manner as shown by the dotted line in Figure 4, following the temperature of the stator winding 11, shown by the solid line. When the temperature of the coil 31 of the rotation angle sensor 30 changes, the induced voltage or the electrical resistance of the coil 31 changes due to the temperature characteristics of the coil 31. The rotation angle sensor temperature estimator 44 of the control unit 40 reads the change in the induced voltage or electrical resistance that accompanies the temperature change in the coil 31, and estimates the temperature of the rotation angle sensor 30.

[0032] As described above, in the rotating electric machine 10 of the first embodiment, the rotation angle sensor 30 and the stator winding 11 are installed in a case formed by the housing 14 and the bracket 15 so as to promote heat transfer, and therefore, for example, even if the temperature value output from the rotation angle sensor temperature estimator 44 increases, if the output value of the stator winding temperature estimator 45 does not change, it can be determined that the stator winding temperature sensor 20 is faulty.

[0033] Furthermore, the temperature sensor failure determination unit 42 may estimate the temperature of the stator winding 11 from the output value of the rotation angle sensor temperature estimation unit 44 using the thermal resistance or heat capacity specific to the rotating electric machine 10, and may determine that the stator winding temperature sensor 20 has failed if the difference between this estimated stator winding temperature estimate and the output value of the stator winding temperature estimation unit 45 is equal to or greater than a certain value.

[0034] That is, if the thermal resistance between the stator winding and the rotation angle sensor coil is R, the heat capacity from the stator winding to the stator winding temperature sensor is Cs, the heat capacity from the stator winding to the rotation angle sensor temperature sensor is Cr, the estimated temperature of the stator winding is Ts, the rotation angle sensor temperature is Tr, the amount of heat contributed to the stator temperature (this value changes from moment to moment) is Qs, and the superscript representing the current time is t, and the superscript representing a time in the past by a time Δt is t-Δt, then the following equations (1) and (2) which represent a general transient thermal circuit network hold.

[0035]

number

number

[0036] On the other hand, the temperature of the stator winding is directly detected by a temperature sensor such as a thermistor. A threshold is set when the deviation between the temperature detected by this temperature sensor and the estimated temperature Ts of the stator winding becomes, for example, 30% or more, and if this threshold is exceeded, it is determined to be a fault. Note that the above formulas (1) and (2) are model formulas that simplify the phenomenon, so if there are other heat dissipation paths or heat-generating components, it is sufficient to expand the above formulas (1) and (2) and add the above heat dissipation paths or heat-generating components to these formulas.

[0037] 5 is a cross-sectional side view of the rotating electric machine 100, which is the subject of the present disclosure, for explaining the rotating electric machine. In the rotating electric machine 100, a noise shielding plate 60 for shielding noise is provided in the axial direction of the shaft 16 between the rotation angle sensor, which is composed of the holder 33, coil 31, and rotor 32, and the stator windings 11. This noise shielding plate 60 is installed for the purpose of suppressing a decrease in the detection accuracy of the rotation angle, which would otherwise be caused by electromagnetic noise generated from the stator windings 11 deteriorating the characteristics of the rotation angle sensor 30.

[0038] Even when the noise shielding plate 60 is provided as shown in FIG. 5, air circulates as indicated by arrow C2 when the rotor 13 rotates. However, due to the presence of the noise shielding plate 60, this circulating air hardly passes through the coil 31 of the rotation angle sensor 30, and the thermal coupling between the stator winding 11 and the coil 31 of the rotation angle sensor 30 deteriorates.

[0039] When the thermal coupling deteriorates, the temperature difference between the stator winding 11 and the coil 31 of the rotation angle sensor 30 or the magnitude of the temperature change over time (a certain period of time) is smaller than in the case of the rotating electric machine of the present disclosure, as shown by characteristic Cb in Figure 4. For this reason, in the rotating electric machine 100, even if the temperatures detected or estimated from the output values ​​of the stator winding temperature sensor 20 and the rotation angle sensor 30 are compared, it is not possible to accurately determine whether the stator winding temperature sensor 20 has failed.

[0040] In contrast, in the rotating electric machine 10 of embodiment 1, the rotation angle sensor 30 and the stator winding 11 are installed so as to promote heat transfer inside the housing. As a result, the thermal coupling between the stator winding and the rotation angle sensor is increased, making it possible to accurately determine failure of the stator winding temperature sensor.

[0041] Embodiment 2 Fig. 6 is a cross-sectional side view of a rotating electric machine 10a according to embodiment 2. Fig. 7 is a front view of a noise shielding plate 50a according to embodiment 2. Note that components having the same functions and actions as those in embodiment 1 are given the same reference numerals and their description will be omitted.

[0042] The noise shielding plate 50a will be described with reference to Fig. 6. As shown in Fig. 6, the noise shielding plate 50a is provided with a first opening 51 and a second opening 52, which are ventilation holes for allowing air to pass through (these will be described in more detail later). The mounting position of the noise shielding plate 50a is set in the axial direction of the shaft 16 between the rotation angle sensor 30 (hereinafter simply referred to as the rotation angle sensor 30) which is composed of the holder 33, the coil 31, and the rotor 32, and the stator winding 11. The noise shielding plate 50a is fixed to the housing 14 with, for example, screws, and is preferably made of metal.

[0043] 7, the structure of the noise shielding plate 50a and its positional relationship with the coil 31 of the rotation angle sensor 30 will be described. A shaft through-hole 54 through which the shaft 16 passes is provided in the center of the noise shielding plate 50a.

[0044] The noise shielding plate 50a has an outer diameter D1 larger than the outer diameter d of the coil 31 of the rotation angle sensor 30, and has a plurality of first openings 51 arranged in an annular shape at intervals outside (on the outer periphery of) this outer diameter d. The outer diameter d of the coil 31 is, for example, 75 mm, and the outer diameter D1 of the noise shielding plate 50a is, for example, 165 mm. Each of the first openings 51 has a radial size of 10 mm and a minimum circumferential size of 12 mm, for example. Furthermore, a plurality of second openings 52 are arranged at intervals in an annular shape at positions closer to the inner periphery (inner periphery side) than the outer diameter d of the coil 31. The second openings 52 are preferably arranged on a line L1 connecting the first opening 51 and the center of the rotation axis of the shaft 16. Furthermore, the coil 31 of the rotation angle sensor 30 is preferably arranged on the line L1 connecting the first opening 51 and the second opening 52.

[0045] Threaded holes 55 through which screws pass are provided near the outer periphery of noise shielding plate 50a. It is desirable that first opening 51 is not positioned on line L2 connecting threaded holes 55 and the center of the rotational axis of shaft 16. Furthermore, noise shielding plate 50a does not necessarily have to be flat, as long as it has a structure that matches the structure of rotating electric machine 10, including rotor 13, stator windings 11, and rotation angle sensor 30, i.e., a structure that prevents rotor 13 and shaft 16 from contacting each other during rotor rotation. Furthermore, noise shielding plate 50a does not necessarily have to be disk-shaped, and may be, for example, a polygonal flat plate.

[0046] Next, the assembly procedure of the rotating electrical machine 10a according to the second embodiment will be described. First, the stator core 12 is fixed to the housing 14 by, for example, shrink fitting or press fitting. Next, the first bearing 18 is attached to the bottom of the housing 14 (the right end portion of the housing 14 in FIG. 6). Next, the second bearing 19, the spacer 34, and the rotation angle sensor holder 33, which is made up of the holder 33, the coil 31, and the rotor 32, are attached to the bracket 15. Then, the spacer 34 and the holder 33 are fixed to the bracket 15 by, for example, screws. Next, the shaft 16 is fixed to the rotor 13 by, for example, shrink fitting or press fitting.

[0047] Thereafter, the shaft 16 with the rotor 13 attached is housed in the housing 14, and one end of the shaft 16 is press-fitted into the first bearing 18. Next, the shaft 16 is passed through the shaft through-hole 54 of the noise shielding plate 50a, and the noise shielding plate 50a is attached to the housing 14. Next, the rotor 32 of the rotation angle sensor 30 is attached to the rotor attachment portion 17 of the shaft 16, and fixed with a rotor fixing nut 35. Finally, while one end of the shaft 16 is press-fitted into the second bearing 19, for example, the bracket 15 is fixed to the housing 14 by screws or the like (this fixing point is also called the fixing point).

[0048] Next, the effects of the rotary electric machine 10a according to the second embodiment will be described with reference to FIGS. Electromagnetic noise is generated from the stator winding 11, but because the noise shielding plate 50a is in contact with the housing 14, which is connected (grounded) to the earth (not shown), the noise to the noise shielding plate 50a is dissipated to the earth via the housing 14. This prevents the characteristics of the rotation angle sensor 30 from deteriorating due to the influence of noise. In this case, the screw hole 55, which is the contact point between the noise shielding plate 50a and the housing 14, is arranged on the line L2, which is not the line connecting the first opening 51 and the center of the rotation axis of the shaft 16, thereby preventing the path to the ground from being extended and suppressing a decrease in the noise shielding effect of the noise shielding plate 50a. In other words, the path G2 to the ground, shown by a dashed line on the line L2 in Fig. 7, is shorter than the path G1 to the ground, shown by a dashed line on the line L1, etc., and therefore a decrease in the noise shielding effect of the noise shielding plate 50a can be suppressed.

[0049] Furthermore, in the rotating electric machine 10a of the second embodiment, as in the rotating electric machine 10 of the first embodiment, rotation of the rotor 13 generates air flows indicated by dotted arrows A and B in FIG. 6 . Although the noise shielding plate 50a is located between the rotation angle sensor 30 and the stator winding 11, the noise shielding plate 50a has first and second openings 51 and 52 for ventilation through which air passes, causing air to circulate as indicated by the solid arrow C1. Here, the coil 31 of the rotation angle sensor 30 is positioned on the line L1 connecting the first opening 51 and the second opening 52 in FIG. 7 . This allows the air circulating as indicated by the solid arrow C1 to effectively hit the coil 31 of the rotation angle sensor 30, and the heat generated in the stator winding 11 is efficiently transferred to the coil 31 of the rotation angle sensor 30.

[0050] As described above, the rotating electric machine 10a of the second embodiment prevents electromagnetic noise generated by the stator winding 11 from deteriorating the characteristics of the rotation angle sensor 30, and by increasing the thermal coupling between the stator winding 11 and the rotation angle sensor 30, it is possible to accurately determine a failure of the stator winding temperature sensor 20. Furthermore, even if the distance between the stator winding 11 and the rotation angle sensor 30 is shortened in the axial direction of the shaft 16, the presence of the noise shielding plate 50a prevents electromagnetic noise from deteriorating the characteristics of the rotation angle sensor 30. This allows the axial length of the motor to be shortened, making it possible to provide a compact motor.

[0051] Fig. 8 is a diagram showing a noise shielding plate 50b (hereinafter also referred to as Modification 1) obtained by modifying the noise shielding plate 50a of the rotary electric machine 10a according to Embodiment 2. The structure of the noise shielding plate 50b according to Modification 1 will be described with reference to Fig. 8. The noise shielding plate 50b of Modification 1 has an outer diameter of D2. A specific value of D2 is, for example, 145 mm. The first opening 51 of the noise shielding plate 50b of Modification 1 is formed as a gap between the outer periphery of the noise shielding plate 50b and the housing 14. The second opening 52 of the noise shielding plate 50b of Modification 1 is formed at the same position as the shaft through-hole 54 of the noise shielding plate 50b, through which the shaft 16 passes.

[0052] FIG. 9 is a cross-sectional side view of a rotating electric machine 10b to which a noise shielding plate 50b according to a first modification of the rotating electric machine 10a according to the second embodiment is attached. 8 and 9, noise shielding plate 50b of Modification 1 has a hole in its central axis portion whose diameter is larger than the outer diameter of rotor 13, and its outer periphery is attached to bracket 15 by fixing member 56, which is a polygonal pillar such as a hexagonal pillar. Fixing member 56 is made of metal, and noise shielding plate 50b is connected to the ground via fixing member 56 and bracket 15 by housing 14, which is connected to the ground. Air circulates in the direction of arrows C1, shown by solid lines, passing through first opening 51, gaps between fixing members 56, and second opening 52, promoting heat transfer between stator winding 11 and rotation angle sensor 30, making it possible to obtain the same effects as those described with reference to FIGS. 6 and 7.

[0053] Next, a rotating electric machine 10c (hereinafter also referred to as Modification 2), which is another modification of the rotating electric machine 10a of Embodiment 2, will be described below with reference to Figs. 10 and 11. Fig. 10 or 11 shows a noise shielding plate 50c of Modification 2. The noise shielding plate 50c of Modification 2 shown in Fig. 10 or 11 is formed by bending the noise shielding plate 50a of Fig. 7 into a cup shape at the position of diameter D2, as shown in Fig. 10. When such a noise shielding plate 50c is used, the same effects as when the above-mentioned noise shielding plate 50a or noise shielding plate 50b is used can be achieved.

[0054] Embodiment 3 12 is a cross-sectional side view of a rotating electric machine 10d according to embodiment 3. Components having the same functions and actions as those in embodiments 1 and 2 are denoted by the same reference numerals, and a description thereof will be omitted. One difference from embodiment 2 is that the first opening 51 of the noise shielding plate 50d or the second opening 52 of the noise shielding plate 50c has a bent portion 53.

[0055] This bent portion 53 is formed integrally with the noise shielding plate 50d, and is bent (extended) from the noise shielding plate 50d to either the left or right of the axial direction of the shaft 16 of the rotation angle sensor 30 or the stator winding 11. In other words, it is bent in an out-of-plane direction of the shaft 16. Note that this bent portion 53 is formed by press working when forming the opening of the noise shielding plate 50d. Furthermore, this bent portion 53 may be formed from a separate member from the member that forms the main portion of the noise shielding plate 50d (portions other than the bent portion 53).

[0056] The effects of the rotary electric machine 10d according to the third embodiment will be described below. The noise shielding plate 50d in the third embodiment is also provided with the first opening 51 and the second opening 52, which creates air circulation as indicated by the solid arrow C1. This promotes heat transfer between the stator winding 11 and the coil 31 of the rotation angle sensor 30, enabling accurate detection of a malfunction in the stator winding temperature sensor 20. The presence of the bent portion 53 also increases the total area of ​​the noise shielding plate 50d, enhancing the noise shielding effect. Furthermore, by changing the angle of the bent portion 53, the flow of circulating air can be appropriately changed (through optimal design), further enhancing the thermal coupling between the stator winding 11 and the coil 31 of the rotation angle sensor 30.

[0057] Although the present disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are contemplated within the scope of the technology disclosed in this specification. Specifically, although the components of the rotating electric machine of the present disclosure have been described above as being fixed to one another by screwing, shrink fitting, or press fitting, this is not a limitation and the components may be fixed to one another by adhesive. Furthermore, this also includes, for example, cases in which at least one component is modified, added, or omitted, or even cases in which at least one component is extracted and combined with a component of another embodiment. [Explanation of symbols]

[0058] 1 power supply, 2 inverter, 10, 10a, 10b, 10c, 10d rotating electric machine, 11 stator winding, 12 stator core, 13 rotor, 14 housing, 15 bracket, 16 shaft, 17 rotor mounting portion, 18 first bearing, 19 second bearing, 20 stator winding temperature sensor, 30 rotation angle sensor, 31 coil, 32 rotor, 33 holder, 34 spacer, 35 rotor fixing nut, 40 control unit, 41 inverter control signal generation unit, 42 temperature sensor failure determination unit, 43 rotation angle detection unit, 44 rotation angle sensor temperature estimation unit, 45 stator winding temperature estimation unit, 50a, 50b, 50c, 50d noise shielding plate, 51 first opening, 52 second opening, 53 bent portion, 54 shaft through hole, 55 screw hole, 56 fixing member

Claims

1. a housing that is a cylindrical box and supports one end of the shaft; a bracket fixed to the housing and supporting the other end of the shaft; an annular stator disposed on the inner periphery of the housing and having a core around which a winding is wound; a rotor disposed opposite to an inner periphery of the stator and attached to the shaft; A rotating electric machine having a rotation angle sensor that is built into a casing that is configured by the housing and the bracket and that measures a rotation angle of the rotor; a rotation angle sensor temperature estimation unit that estimates a temperature of the rotation angle sensor from a temperature characteristic of an output of the rotation angle sensor; a stator winding temperature estimator that estimates a temperature of the stator winding from an output of the rotation angle sensor temperature estimator; Equipped with When the rotor rotates, an air circulation path is formed that passes through both the stator winding and the rotation angle sensor. A rotating electric machine characterized by:

2. a stator winding temperature sensor for measuring the temperature of the stator winding; a temperature sensor failure determination unit that compares an output of the rotation angle sensor temperature estimation unit or an output of the stator winding temperature estimation unit with an output of the stator winding temperature sensor to determine whether or not the stator winding temperature sensor has failed; Equipped with 2. The rotating electrical machine according to claim 1.

3. a noise shielding plate for shielding electromagnetic noise generated from the stator winding between the stator winding and the rotation angle sensor in the axial direction of the shaft; 3. The rotating electric machine according to claim 1 or 2.

4. The noise shielding plate is provided with a first opening for ventilation on the outer periphery side and a second opening for ventilation on the inner periphery side, and a through hole in the center portion through which the shaft passes.

4. The rotating electrical machine according to claim 3.

5. a coil of the rotation angle sensor is disposed on a line connecting the second opening and the first opening; 5. The rotating electrical machine according to claim 4.

6. The housing is grounded, and the first opening and the second opening provided in the noise shielding plate are disposed at positions away from a line connecting at least one of a plurality of fixing points at which the noise shielding plate is fixed to the housing and the center of the rotation axis of the shaft.

5. The rotating electrical machine according to claim 4.

7. The housing is grounded, and the noise shielding plate is fixed to the bracket via a metal fixing member.

4. The rotating electrical machine according to claim 3.

8. 5. The rotating electric machine according to claim 4, wherein the noise shielding plate has a bent portion that is bent in an out-of-plane direction of the noise shielding plate at the first opening or the second opening.

9. 7. The rotating electric machine according to claim 6, wherein the noise shielding plate has a bent portion that is bent in an out-of-plane direction of the noise shielding plate at the first opening or the second opening.

Images