Rotating electrical machine

Abstract

A rotating electrical machine capable of removing foreign substances adhering to an electronic component or a peripheral portion thereof more reliably, while maintaining an effect of air purge, is in demand.　In the rotating electrical machine including an electronic component in a space in which a part of a rotating shaft is disposed, a plurality of air introduction portions that open toward the space are provided, and air introduced from the plurality of air introduction portions is blown to the electronic component or the peripheral portion thereof from respective different directions.

Description

rotating electrical machines

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

[0002] In order to prevent foreign matter such as cutting oil from entering the interior of a rotating electric machine, a rotating electric machine equipped with a so-called air purge function has been proposed, in which compressed air is sent between the housing and the outer cover and the compressed air is released through a gap connecting the inside and outside (see Patent Document 1).

[0003] Japanese Patent Application Publication No. 1-133538

[0004] Even if air purging is performed while a rotating electric machine is in operation, it may not be possible to completely prevent the intrusion of foreign matter if the force of the foreign matter entering the machine is strong. Furthermore, if air purging is stopped due to, for example, a shutdown of the rotating electric machine, it is difficult to prevent the intrusion of foreign matter. Meanwhile, various electronic components are provided inside the rotating electric machine. For example, a rotation sensor is provided between the housing and the outer cover as an electronic component that detects the rotational angle position and rotational speed of the rotating shaft. If foreign matter adheres to the rotation sensor, it can deteriorate the component or cause a malfunction. However, the air purging function provided in conventional rotating electric machines simply fills the interior with compressed air, making it difficult to remove foreign matter adhering to electronic components or their surroundings inside the rotating electric machine.

[0005] Therefore, there is a demand for a rotating electrical machine that can more reliably remove foreign matter adhering to electronic components or their surrounding areas while maintaining the effect of air purging.

[0006] The rotating electric machine of the present disclosure is a rotating electric machine having electronic components in a space where a part of a rotating shaft is arranged, and has a plurality of air inlet ports that open into the space, and the air introduced from the plurality of air inlet ports is blown onto the electronic components or their surrounding areas from different directions.

[0007] 1 is a configuration diagram of an electric motor 1 in a first embodiment; FIG. 2 is a perspective view showing the configuration of the X2 side of the electric motor 1 in the first embodiment; FIG. 3 is a configuration diagram of an electric motor 1A in a second embodiment; FIG. 4 is a configuration diagram of an electric motor 1B in a third embodiment; and FIG. 5 is a perspective view showing the configuration of the X2 side of an electric motor 1C in a fourth embodiment.

[0008] Hereinafter, an embodiment of a rotating electric machine according to the present disclosure will be described. The drawings attached to this specification are all schematic diagrams, and the shape, scale, aspect ratio, and the like of each part have been modified or exaggerated from the actual product for ease of understanding. Furthermore, hatching indicating cross sections of components has been omitted as appropriate in the drawings.

[0009] In the drawings accompanying this specification, the direction parallel to the central axis OA of the electric motor 1 shown in FIG. 1 is referred to as the X direction (hereinafter also referred to as the "axial direction X"). In the axial direction X, the direction in which rotational force is extracted (leftward in the drawing) is referred to as the X1 direction, and the direction opposite to the X1 direction is referred to as the X2 direction. The direction perpendicular to the axial direction X is referred to as the radial direction Y. Note that the radial direction Y perpendicular to the axial direction X is not uniquely specified, but in this specification, the vertical direction shown in FIG. 1 will be referred to as the radial direction Y, and the upward direction in the drawing will be referred to as the Y1 direction, and the downward direction will be referred to as the Y2 direction. In addition, in this specification, "direction" will also be referred to as "side" as appropriate.

[0010] First Embodiment FIG. 1 is a configuration diagram of an electric motor 1 according to a first embodiment. FIG. 2 is a perspective view showing the configuration of the X2 side of the electric motor 1 according to the first embodiment. Note that FIG. 2 shows a state in which a sensor cover 18 (described later) is removed. The electric motor according to the first embodiment is a rotating electric machine used as a power source for machine tools, for example, but its use is not limited to machine tools. Furthermore, in each embodiment including the first embodiment, an electric motor (motor) is described as an example of the rotating electric machine, but the rotating electric machine may also be a generator.

[0011] 1 , the electric motor 1 of the first embodiment includes a stator 11, a rotor 12, a rotating shaft 13, and a bearing 14. The electric motor 1 also includes a housing 15, a sensor gear 16, a rotation sensor 17, a sensor cover (outer cover) 18, a first air inlet 21, and a second air inlet 22.

[0012] In Fig. 1, the stator 11 and housing 15, which are arranged on the outside in the radial direction Y, are held by a frame (not shown) provided on the outer periphery thereof. The frame is an exterior member that covers the outside of the electric motor 1. The configuration of the electric motor 1 also includes other parts that are not shown, but only the main configuration of the electric motor 1 will be described here.

[0013] The stator 11 is a component that generates a rotating magnetic field for rotating the rotor 12. The stator 11 includes an iron core and a stator frame (neither of which are shown), and is fixed inside a frame. When, for example, a three-phase alternating current is supplied to the stator 11, a rotating magnetic field is formed in the stator 11, and a rotor 12 (described later) generates a rotational force in the rotor 12 due to magnetic interaction between the stator 11 and the rotor 12, and this rotational force is output to the outside via the rotating shaft 13. The rotor 12 is a component that rotates due to magnetic interaction with the rotating magnetic field formed by the stator 11, and includes a sleeve, a permanent magnet, a covering cylinder, etc. (none of which are shown).

[0014] The rotating shaft 13 is a member that supports the rotor 12. The rotating shaft 13 is inserted so as to pass through the axial center of the rotor 12 and is fixed coaxially with the rotor 12. The rotating shaft 13 rotates together with the rotor 12. A pair of bearings 14 is fitted to both sides of the rotating shaft 13 in the axial direction X (the X1 side is not shown). The bearings 14 are members that rotatably support the rotating shaft 13 and are fixed to a housing 15 (described below). The rotating shaft 13 is held rotatably around the axial direction X by the housing 15, bearings 14, etc. A sensor gear 16 (described below) is attached to the rotating shaft 13 at a position on the X2 side of the bearings 14.

[0015] The housing 15 is a member that holds the rotating shaft 13 via the bearing 14. The housing 15 also holds other components directly or indirectly. The housing 15 is provided with a first air introduction section 21 and a second air introduction section 22. Note that although the housing 15 is illustrated in FIG. 1 as an integrated component, the housing 15 may be configured to include multiple components.

[0016] The sensor gear 16 is a rotating body that is fixed coaxially to the rotary shaft 13 and whose outer circumferential surface is adjacent to the rotation sensor 17. The sensor gear 16 rotates together with the rotary shaft 13. As shown in FIG. 2, the sensor gear 16 is configured in a substantially annular shape. Furthermore, as shown in the partially enlarged view of FIG. 1, a gap g is formed between the sensor gear 16 and the rotation sensor 17 (described later). The gap g is approximately 0.1 mm.

[0017] The rotation sensor 17 is an electronic component that detects the rotational angle position and rotational speed of the sensor gear 16 around the central axis OA. The rotation sensor 17 is provided in a space S on the X1 side of a sensor cover 18 (described later). The rotation sensor 17 is attached to a side surface of the housing 15 on the X2 side in the space S, with a sensor surface 17a facing the outer peripheral surface 16a of the sensor gear 16. Note that although an example is shown in FIGS. 1 and 2 in which the rotation sensor 17 is provided on the Y2 side in the radial direction Y (the lower side in the figures), the position at which the rotation sensor 17 is provided is not limited to the example shown in the figures.

[0018] The sensor cover (outer cover) 18 is a cover for protecting the sensor gear 16 and the rotation sensor 17. The sensor cover 18 is attached to the housing 15 and covers the opening on the X2 side of the electric motor 1. A space S formed by the housing 15 and the sensor cover 18 is a space in which a part of the rotating shaft 13 is disposed and also a space in which the rotation sensor 17 is provided. The sensor cover 18 has a hole 18a through which the rotating shaft 13 passes. Some of the compressed air that fills the space S within the sensor cover 18 by air purging flows out to the outside through a gap between the rotating shaft 13 and the hole 18a of the sensor cover 18.

[0019] Next, the configuration of the first air introduction section 21 and the second air introduction section 22 will be described. The first air introduction section 21 and the second air introduction section 22 (hereinafter also collectively referred to as "air introduction section") are compressed air injectors. Compressed air is air having a pressure of, for example, about 0.1 to 0.9 MPa. The compressed air is produced by an air compressor and then supplied to the air introduction section via air piping (neither is shown). In FIG. 1, the flow of compressed air is indicated by dashed arrows.

[0020] In the first embodiment and other embodiments described below, an example is described in which compressed air is blown onto the rotation sensor 17, but the compressed air may be blown onto the periphery of the rotation sensor 17. The periphery of the rotation sensor 17 refers to, for example, an area of ​​about several tens of millimeters around the rotation sensor 17.

[0021] 1 , the first air introduction section 21 and the second air introduction section 22 of the first embodiment are both provided in the housing 15. The first air introduction section 21 and the second air introduction section 22 are open toward the space S formed between the housing 15 and the sensor cover 18.

[0022] The first air introduction section 21 is provided on the X2 side of the second air introduction section 22 in the axial direction X of the housing 15. The first air introduction section 21 includes a passage section 211 and a joint 212. The passage section 211 is a tubular hole formed in the housing 15. The joint 212 is a component connected to the passage section 211 at one end and connected to an air pipe (not shown) at the other end. The first air introduction section 21 is configured to blow compressed air toward the rotation sensor 17 from the Y2 side toward the Y1 side (the underside of the rotation sensor 17).

[0023] The second air introduction section 22 is located closer to the X1 side of the first air introduction section 21 in the axial direction X of the sensor cover 18. The second air introduction section 22 includes a passage section 221 and a joint 222. The passage section 221 is a generally L-shaped hole formed in the housing 15. The joint 222 is connected to the passage section 221 at one end and to an air pipe (not shown) at the other end. The second air introduction section 22 is configured to blow compressed air toward the rotation sensor 17 from the X1 side toward the X2 side. According to this configuration, as shown in the partially enlarged view of FIG. 1 , the compressed air introduced from the second air introduction section 22 is blown into the gap g between the sensor surface 17a of the rotation sensor 17 and the outer peripheral surface 16a of the sensor gear 16.

[0024] 1 and 2 , the first air introduction section 21 is configured to blow compressed air from the Y2 side toward the upper side Y1 in the radial direction Y. Furthermore, the second air introduction section 22 is configured to blow compressed air from the X1 side toward the X2 side in the axial direction X. In this way, the first air introduction section 21 and the second air introduction section 22 are configured to blow compressed air toward the rotation sensor 17 from different directions. During operation of the electric motor 1, compressed air is continuously supplied to the first air introduction section 21 and the second air introduction section 22 from an air compressor.

[0025] According to the electric motor 1 of the first embodiment described above, the compressed air introduced from the first air introduction portion 21 and the second air introduction portion 22 is blown onto the rotation sensor 17 from different directions. Therefore, compared to a configuration in which compressed air is blown onto the rotation sensor 17 from the same direction at multiple air introduction portions, foreign matter adhering to the rotation sensor 17 can be more reliably removed. The same applies to a configuration in which compressed air is blown onto the periphery of the rotation sensor 17; by blowing compressed air onto the periphery of the rotation sensor 17 from different directions, foreign matter adhering to the periphery of the rotation sensor 17 can be more reliably removed.

[0026] It is possible that foreign matter may enter while the blowing of compressed air is stopped and adhere to the rotation sensor 17. Even in this case, when the blowing of compressed air is resumed, a strong airflow of compressed air hits the rotation sensor 17 or its surrounding area, so that foreign matter adhering to the rotation sensor 17 or its surrounding area can be more reliably removed.

[0027] Furthermore, by introducing compressed air from the first air introduction portion 21 and the second air introduction portion 22, air is filled in the space S formed between the housing 15 and the sensor cover 18. Some of the air filling the space S then flows out through the gap between the rotating shaft 13 and the hole 18a of the sensor cover 18 (see FIG. 1). In this way, normal air purging is also performed by introducing compressed air from the first air introduction portion 21 and the second air introduction portion 22. Therefore, according to the electric motor 1 of the first embodiment, foreign matter adhering to the rotation sensor 17 or its surrounding area can be more reliably removed while maintaining the effect of air purging.

[0028] Furthermore, the compressed air introduced from the second air introduction portion 22 is blown into the gap between the sensor surface 17a of the rotation sensor 17 and the outer peripheral surface 16a of the sensor gear 16. Therefore, foreign matter adhering to the gap between the sensor surface 17a of the rotation sensor 17 and the outer peripheral surface 16a of the sensor gear 16 can be more accurately removed.

[0029] In the first embodiment, the first air introduction section 21 and the second air introduction section 22 are both provided in the housing 15, so compressed air can be blown from a position close to the rotation sensor 17 or its periphery. Furthermore, because the air introduction sections are not provided in the sensor cover 18, the sensor cover 18 can be easily attached and detached, and maintenance is also easy.

[0030] Second Embodiment An electric motor 1A of a second embodiment differs from that of the first embodiment in the configuration of the air introduction portion. The other configurations of the electric motor 1A of the second embodiment are the same as those of the first embodiment. Therefore, in the description and drawings of the second embodiment, the same reference numerals as those of the first embodiment are used for the same components and the like, and redundant description will be omitted.

[0031] Fig. 3 is a configuration diagram of an electric motor 1A according to the second embodiment. As shown in Fig. 3, in the electric motor 1A according to the second embodiment, the first air introduction section 21 and the second air introduction section 22 are both provided in the sensor cover 18. The first air introduction section 21 and the second air introduction section 22 are open toward the space S formed between the housing 15 and the sensor cover 18.

[0032] The first air introduction section 21 is provided on the X2-side side surface of the sensor cover 18. In this embodiment, the first air introduction section 21 is configured with a joint 212. The joint 212 is attached to a hole 18b provided on the X2-side side surface of the sensor cover 18. The first air introduction section 21 is configured to blow compressed air toward the rotation sensor 17 from the X2 side toward the X1 side. According to this configuration, the compressed air introduced from the first air introduction section 21 is blown into the gap g (see FIG. 1 ) between the sensor surface 17a of the rotation sensor 17 and the outer peripheral surface 16a of the sensor gear 16.

[0033] The second air introduction section 22 is provided on the Y2-side side surface of the sensor cover 18. In this embodiment, the second air introduction section 22 is configured by a joint 222. The joint 222 is attached to a hole 18c provided on the Y2-side side surface of the sensor cover 18. The second air introduction section 22 is configured to blow compressed air toward the rotation sensor 17 from the Y2 side toward the Y1 side.

[0034] 3 includes the first air inlet 21 and the second air inlet 22 described above, and therefore, like the electric motor 1 of the first embodiment, can more reliably remove foreign matter adhering to the rotation sensor 17 or its periphery while maintaining the effect of the air purge. The first air inlet 21 and the second air inlet 22 of the second embodiment are both provided on the sensor cover 18, which makes it easy to attach the air inlet and install air piping (not shown).

[0035] (Third Embodiment) An electric motor 1B of a third embodiment differs from that of the first embodiment in the configuration of the air introduction portion. The other configurations of the electric motor 1B of the third embodiment are the same as those of the first embodiment. Therefore, in the description and drawings of the third embodiment, the same reference numerals as those of the first embodiment are used for the same components and the like, and redundant description will be omitted.

[0036] Fig. 4 is a configuration diagram of an electric motor 1B according to a third embodiment. As shown in Fig. 4, the electric motor 1B according to the third embodiment includes a first air introduction section 21, a second air introduction section 22, and a third air introduction section 23. The first air introduction section 21, the second air introduction section 22, and the third air introduction section 23 are open toward a space S formed between the housing 15 and the sensor cover 18.

[0037] In this embodiment, the configurations of the first air introduction section 21 and the second air introduction section 22 are the same as those of the first embodiment, and therefore redundant description will be omitted. The first air introduction section 21 is configured to blow compressed air toward the rotation sensor 17 from the Y2 side toward the Y1 side (the underside of the rotation sensor 17).

[0038] The second air introduction section 22 is configured to blow compressed air from the X1 side toward the X2 side of the rotation sensor 17. According to this configuration, the compressed air introduced from the second air introduction section 22 is blown into the gap g (see FIG. 1 ) between the sensor surface 17 a of the rotation sensor 17 and the outer peripheral surface 16 a of the sensor gear 16.

[0039] In addition, in this embodiment, the configuration of the third air introduction section 23 is the same as the first air introduction section 21 of the second embodiment, so duplicated description will be omitted. In this embodiment, the third air introduction section 23 is configured to blow compressed air from the X2 side toward the X1 side of the rotation sensor 17. According to this configuration, the compressed air introduced from the third air introduction section 23 is blown into the gap g (see FIG. 1 ) between the sensor surface 17 a of the rotation sensor 17 and the outer peripheral surface 16 a of the sensor gear 16.

[0040] The electric motor 1B of the third embodiment shown in Figure 4 is equipped with the first air introduction section 21, the second air introduction section 22, and the third air introduction section 23 described above, and therefore, like the electric motor 1 of the first embodiment, can more reliably remove foreign matter adhering to the rotation sensor 17 or its surrounding area while maintaining the effect of the air purging.

[0041] The first air introduction section 21, the second air introduction section 22, and the third air introduction section 23 of the third embodiment each blow compressed air onto the rotation sensor 17 from different directions, which can more efficiently remove foreign matter adhering to the rotation sensor 17. A similar effect can be obtained when the compressed air is blown onto the periphery of the rotation sensor 17.

[0042] According to the second air introduction section 22 and the third air introduction section 23 of the third embodiment, compressed air is blown into the gap g between the sensor surface 17 a of the rotation sensor 17 and the outer peripheral surface 16 a of the sensor gear 16 from opposite sides in the axial direction X. Therefore, foreign matter adhering to the gap g between the sensor surface 17 a of the rotation sensor 17 and the outer peripheral surface 16 a of the sensor gear 16 can be removed more accurately and efficiently.

[0043] (Fourth Embodiment) An electric motor 1C of the fourth embodiment differs from the first embodiment in the configuration of the second air introduction section 22A. The other configurations of the electric motor 1C of the fourth embodiment are the same as those of the first embodiment. Therefore, in the description and drawings of the fourth embodiment, the same reference numerals as those of the first embodiment are used for the same components and the like, and redundant description will be omitted.

[0044] Fig. 5 is a configuration diagram of an electric motor 1C according to a fourth embodiment. As shown in Fig. 5, in the electric motor 1C according to the fourth embodiment, the second air introduction section 22A includes a joint 222 and an extension pipe 223. The extension pipe 223 is a pipe-shaped member, and one end of the extension pipe 223 is connected to the joint 222. The other end of the extension pipe 223 opens toward the gap g (see Fig. 1) between the sensor surface 17a of the rotation sensor 17 and the outer peripheral surface 16a of the sensor gear 16.

[0045] In the present embodiment, the first air introduction section 21 is configured to blow compressed air toward the rotation sensor 17 from the Y2 side toward the Y1 side. Furthermore, the second air introduction section 22A is configured to blow compressed air in a direction perpendicular to the direction (Y direction) in which the first air introduction section 21 blows compressed air, when viewed from the axial direction X. As described above, in the fourth embodiment, the first air introduction section 21 and the second air introduction section 22A are configured to blow compressed air toward the rotation sensor 17 from different directions.

[0046] The electric motor 1C of the fourth embodiment shown in Figure 5 is equipped with the first air introduction section 21 and the second air introduction section 22A described above, and therefore, like the electric motor 1 of the first embodiment, can more reliably remove foreign matter adhering to the rotation sensor 17 or its surrounding area while maintaining the effect of the air purging.

[0047] Furthermore, the second air introduction section 22A of the fourth embodiment includes an extension pipe 223 that opens toward the gap g between the rotation sensor 17 and the sensor gear 16. With this configuration, the compressed air introduced from the extension pipe 223 is blown from a position close to the foreign matter adhering to the rotation sensor 17, so that a stronger airflow of compressed air can be applied to the foreign matter. Therefore, foreign matter adhering to the gap g between the rotation sensor 17 and the sensor gear 16 can be removed more accurately and quickly.

[0048] (Modifications) Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. Furthermore, these embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these.

[0049] In the air introduction section of the first or second embodiment, compressed air may be introduced from one location, and the passage may be branched inside the housing 15 or outside the sensor cover 18 to distribute the compressed air to the first air introduction section 21 and the second air introduction section 22. This embodiment can also be applied to the air introduction sections of the third and fourth embodiments.

[0050] In each embodiment, the pressure of the compressed air introduced from the air introduction portion may be the same or different. For example, in the air introduction portion of the first embodiment, the pressure of the compressed air introduced into the second air introduction portion 22 may be higher than the pressure of the compressed air introduced into the first air introduction portion 21. The compressed air introduced into the second air introduction portion 22 is blown into the gap g between the rotation sensor 17 and the sensor gear 16. Therefore, by making the pressure of the compressed air introduced into the second air introduction portion 22 higher than the pressure of the compressed air introduced into the first air introduction portion 21, foreign matter adhering to the gap between the rotation sensor 17 and the sensor gear 16 can be more accurately removed.

[0051] In each embodiment, compressed air may be continuously introduced through the air introduction port while the motor is operating, and the introduction of compressed air through the air introduction port may be stopped while the motor is not operating. Furthermore, the introduction and stopping of compressed air may be performed at different times for each air introduction port.

[0052] The following supplementary notes are further disclosed regarding the above-described embodiment. (Supplementary Note 1) A rotating electric machine (1) having an electronic component (17) in a space formed between a housing (15) that holds a rotating shaft (13) and an outer cover (18) through which the rotating shaft passes, the rotating electric machine (1) having a plurality of air inlet ports (21, 22) that open into the space, and air introduced from the plurality of air inlet ports is blown onto the electronic component or its surroundings from different directions. (Supplementary Note 2) Air introduced from the plurality of air inlet ports is blown onto the electronic component or its surroundings from different directions in the radial and / or axial directions of the rotating shaft. (Supplementary Note 3) The space in which a portion of the rotating shaft is disposed is formed by a housing and an outer cover, and the housing and the outer cover each have at least one air inlet port. (Supplementary Note 4) The space in which a portion of the rotating shaft is disposed is formed by a housing and an outer cover, and the housing or the outer cover has a plurality of air inlet ports. (Supplementary Note 5) The rotating shaft is provided with a rotating body (16) that rotates coaxially with the rotating shaft and has an outer circumferential surface that is close to the electronic component, and air introduced from at least one of the air introduction parts is blown between the electronic component and the outer circumferential surface of the rotating body. (Supplementary Note 6) The air introduced from at least one of the air introduction parts is blown between the electronic component and the outer circumferential surface of the rotating body via an extension pipe (223) provided in the air introduction part.

[0053] 1, 1A, 1B, 1C: electric motor (rotating electric machine), 13: rotating shaft, 15: housing, 16: sensor gear, 17: rotation sensor (electronic component), 18: sensor cover (outer cover), 21: first air introduction section, 22, 22A: second air introduction section, 23: third air introduction section, 223: extension tube

Claims

1. A rotating electric machine that has electronic components in the space where a part of the rotating shaft is located, It is equipped with multiple air inlet openings that open toward the aforementioned space, A rotating electric machine in which air introduced from multiple air inlets is blown onto the electronic component or its surrounding area from different directions.

2. The rotating electric machine according to claim 1, wherein the air introduced from the multiple air inlets is blown onto the electronic component or its surrounding area from different directions in the radial and / or axial directions of the rotating shaft.

3. The space in which a portion of the rotating shaft is located is formed by the housing and the outer cover. The rotating electric machine according to claim 1 or 2, wherein the housing and the outer cover each include at least one air intake.

4. The space in which a portion of the rotating shaft is located is formed by the housing and the outer cover. The rotating electric machine according to claim 1 or 2, wherein the housing or the outer cover comprises a plurality of air intake sections.

5. The aforementioned rotating shaft comprises a rotating body that rotates coaxially with the aforementioned rotating shaft and whose outer surface is in close proximity to the electronic component. The rotating electric machine according to claim 1 or 2, wherein the air introduced from at least one of the air inlets is blown between the electronic component and the outer surface of the rotating body.

6. The rotating electric machine according to claim 5, wherein the air introduced from at least one of the air inlets is blown between the electronic component and the outer surface of the rotating body via an extension pipe provided in the air inlet.