Air-cooled motor

Abstract

To provide an air-cooled motor that can efficiently cool the inside of the motor without causing a decrease in reliability due to fine foreign matter in the air. [Solution] The motor case 110 has a cylindrical portion 113, a first bottom portion 111 provided at one end of the cylindrical portion, and a second bottom portion 112 provided at the other end of the cylindrical portion; a stator 130 provided inside the motor case 110; a rotor 140 that rotates together with the rotating shaft 120; a fan 164 that rotates together with the rotating shaft 120 outside the motor case 110 on the first bottom portion 111 side, and a blower 160 that sends the airflow generated by the fan 164 to the outside of the cylindrical portion 113; a filter 150 located on the second bottom portion 112 side of the stator 130 and rotor 140, which introduces outside air into the motor case 110 and blocks foreign matter; and an internal air discharge portion 116 formed on the first bottom portion 111 so as to draw out the air inside the motor case 110 with the airflow generated by the fan 164.

Description

Technical Field

[0001] The present invention relates to an air-cooled motor, and more particularly to an air-cooled motor that efficiently cools the inside while suppressing the entry of foreign matter.

Background Art

[0002] To discharge the heat generated during the rotation of the motor, various cooling techniques exist. For example, by providing heat radiation fins (heat radiation plates) on the motor case, the heat inside the motor can be released to the outside of the motor. Also, by passing cooling air from a fan through the motor, the heat inside the motor can be efficiently released to the outside. The structure of this type of air-cooled motor is described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of the motor described in Patent Document 1, it is possible to cool the motor by the wind generated by the air-cooling fan driven by the motor.

[0005] When passing the cooling air from the fan through the inside of the motor, fine foreign matters such as dust and water droplets contained in the air may enter the motor. If fine foreign matters enter the motor, there is a possibility of causing problems such as insulation degradation of the coil and performance deterioration of the bearing. In addition, when providing foreign matter removal filters before and after the fan, it is necessary to configure the filter coarsely so as to withstand the wind pressure of the fan. In the case of such a coarse filter, foreign matters of a certain size such as fallen leaves can be blocked, but fine foreign matters cannot be blocked.

[0006] The present invention was made to solve the above-mentioned problems, and aims to provide an air-cooled motor that can efficiently cool the inside of the motor without causing a decrease in motor reliability due to fine foreign matter contained in the air. [Means for solving the problem]

[0007] The air-cooled motor according to this invention comprises a motor case having a cylindrical portion, a first bottom portion provided at one end of the cylindrical portion, and a second bottom portion provided at the other end of the cylindrical portion; a stator provided inside the motor case; a rotor rotatably mounted relative to the stator and rotating together with the rotation axis; a fan located outside the motor case on the first bottom side that rotates together with the rotation axis and sends the airflow generated by the fan to the outside of the cylindrical portion; a filtration section located on the second bottom side of the stator and rotor that introduces outside air into the motor case and blocks the passage of foreign matter; and an internal air discharge section formed at the first bottom so as to draw out the air inside the motor case with the airflow generated by the fan.

[0008] In the air-cooled motor according to this invention, the blowing section further includes an outlet that sends airflow to the outside of the cylindrical section, an internal air guide path that guides air drawn out from the internal air discharge section to the outlet, and a ventilation selection section that blocks the internal air guide path when the rotor is not rotating and opens the internal air guide path when the rotor is rotating.

[0009] In the air-cooled motor according to this invention, the filtration section is provided in a hole provided in the second bottom.

[0010] In the air-cooled motor according to this invention, the rotating shaft has a hollow section with at least one end open, and the filtration section is provided in a hole communicating with the hollow section.

[0011] In the air-cooled motor according to this invention, heat dissipation fins are further provided on the outer circumference of the cylindrical portion to release heat from the cylindrical portion to the outside and to rectify the airflow from the blowing portion.

[0012] In the air-cooled motor according to this invention, a motor drive unit is further provided within the motor case at a position different from the stator in the direction along the axis of rotation of the rotating shaft. [Effects of the Invention]

[0013] The air-cooled motor according to this invention includes a blower that sends airflow generated by a fan rotating together with the rotating shaft to the outside of the cylindrical part on the outside of the first bottom side of the motor case, a filtration unit that introduces outside air into the motor case and blocks the passage of foreign matter on the second bottom side of the motor case, and an internal air discharge unit formed at the first bottom so as to draw out the air inside the motor case with the airflow generated from the blower, and the introduction and purification of new outside air, cooling of the inside of the air-cooled motor with the purified air, and the drawing out of the air inside the motor case with the airflow generated by the blower are repeatedly performed in parallel. This makes it possible to efficiently cool the inside of an air-cooled motor without causing a decrease in the reliability of the air-cooled motor due to fine foreign matter contained in the air. [Brief explanation of the drawing]

[0014] [Figure 1] This is a cross-sectional view showing a cross-section of an air-cooled motor according to Embodiment 1. [Figure 2] This is a cross-sectional view showing the cross-section of the air-cooled motor according to Embodiment 1, along with the airflow. [Figure 3] This is a cross-sectional view showing the cross-section of the air-cooled motor according to Embodiment 1, along with the airflow. [Figure 4] This is a cross-sectional view showing a cross-section of an air-cooled motor according to Embodiment 2. [Figure 5] This is a cross-sectional view showing the cross-section of the air-cooled motor according to Embodiment 2, along with the airflow. [Figure 6] This is a cross-sectional view showing the cross-section of the air-cooled motor according to Embodiment 2, along with the airflow. [Modes for carrying out the invention]

[0015] Hereinafter, embodiments of the air-cooled motor of the present invention will be described with reference to the drawings. In each figure, the same parts are denoted by the same reference numerals. Embodiment 1. First, the structure of the air-cooled motor 100 in Embodiment 1 will be described with reference to FIG. 1. FIG. 1 is a cross-sectional view showing a cross-section of the air-cooled motor 100 according to Embodiment 1. In FIG. 1, the driven body 10 is shown together with the air-cooled motor 100.

[0016] [Structure of the air-cooled motor 100] The air-cooled motor 100 mainly includes a motor case 110, a rotating shaft 120, a stator 130, a rotor 140, a filtering part 150, and a blowing part 160.

[0017] The motor case 110 is composed of a first bottom part 111, a second bottom part 112, a cylindrical part 113, heat radiation fins 115, and an internal air discharge part 116. The internal air discharge part 116 is provided on the first bottom part 111. The blowing part 160 is provided so as to contact the outside of the first bottom part 111. A hole 112h is provided in the second bottom part 112. The filtering part 150 is provided in the hole 112h. A bearing 118 for rotatably holding the rotating shaft 120 is provided at the centers of the first bottom part 111 and the second bottom part 112. Heat radiation fins 115 are provided on the outer periphery of the cylindrical part 113. The heat radiation fins 115 are provided on the outer periphery of the cylindrical part 113 so as to rectify the air flow in the direction along the axis of the rotating shaft 120. The internal air discharge part 116 is provided on the first bottom part 111 so as to suck out the air inside the motor case 110 toward the blowing part 160.

[0018] The rotating shaft 120 is provided rotatably with respect to the stator 130 via the bearing 118. A rotor 140 that rotates together with the rotating shaft 120 in the motor case 110 is provided on the rotating shaft 120. The driven body 10 is provided at one end of the rotating shaft 120. On the rotating shaft 120, outside the motor case 110 on the side of the first bottom 111, a fan 164 that rotates together with the rotating shaft 120 is further provided. The rotating shaft 120 has a hollow portion 122 with at least one end open. In the rotating shaft 120, a hole 120h communicating with the hollow portion 122 is provided on the side of the second bottom 112 rather than the stator 130 and the rotor 140.

[0019] The stator 130 is provided inside the motor case 110. A coil 135 is wound around a core portion (not shown) of the stator 130. The rotor 140 is provided rotatably together with the rotating shaft 120 with respect to the stator 130.

[0020] The filtering unit 150 introduces outside air into the motor case 110 and blocks the passage of foreign matters on the side of the second bottom 112 rather than the stator 130 and the rotor 140. The filtering unit 150 is provided, for example, at the hole 112h of the second bottom 112 and the hole 120h communicating with the hollow portion 122 as the side of the second bottom 112 rather than the stator 130 and the rotor 140. The filtering unit 150 filters fine foreign matters such as dust, dirt or water droplets, and various foreign matters larger than the fine foreign matters. Since the filtering unit 150 is not provided in the immediate vicinity of the fan 164, it is not directly affected by the wind pressure of the fan 164 and can have performance suitable for removing desired fine foreign matters. The filtering unit 150 can use a HEPA (High Efficiency Particulate Air Filter) filter or various filters having similar performance.

[0021] The air blowing unit 160 is provided with an air blowing cover 161, an air blowing bottom 162, a fan base 163, a fan 164, an internal air induction path 165, an air ventilation selection unit 166, and an air outlet 167. The air blowing unit 160 may be provided on the same side as the driven body 10 or on the opposite side of the driven body 10. The blower cover 161 is provided with a flat section 161a parallel to the first bottom section 111, and an outer circumferential inclined section 161b on the outer periphery of the flat section 161a that guides the airflow generated by the fan 164 to the outside of the cylindrical section 113. Near the center of the flat section 161a of the blower cover 161, there is an opening 161h for taking in outside air for the fan 164. The blower bottom 162 is provided so as to be in contact with the first bottom 111. The fan base 163 supports the fan 164 and rotates the fan 164 by the rotation of the rotating shaft 120. The fan 164 is provided near the outer circumference of the fan base 163 and generates airflow from outside air taken in through the opening 161h. The internal air guide path 165 is a path that guides the air inside the motor case 110, which is drawn out from the internal air discharge section 116, to the outlet 167.

[0022] The ventilation selection section 166 is made of a thin membrane and blocks the internal air induction path 165 when the rotor 140 is not rotating, and opens the internal air induction path 165 when the rotor 140 is rotating. The blocking and opening of the ventilation selection section 166 may be performed by centrifugal force during rotation, or by the effect of airflow generated by the fan 164, for example, by suction due to negative pressure. When the rotor 140 is not rotating, the ventilation selection section 166 blocks the internal air induction path 165, so foreign matter cannot enter the motor case 110 from the outlet 167 through the internal air discharge section 116. The outlet 167, through the outer sloping portion 161b of the blower cover 161 and the opening 162h provided in the blower bottom portion 162, sends the airflow generated by the fan 164 along the heat dissipation fins 115 on the outside of the cylindrical portion 113. At the outlet 167, the airflow from the fan 164 draws air from inside the motor case 110 out through the internal air discharge portion 116 and sends it out to the outside of the cylindrical portion 113 along with the airflow from the fan 164.

[0023] [Air cooling inside the air-cooled motor 100] Figure 2 illustrates how the air-cooled motor 100 efficiently cools its interior without causing a decrease in motor reliability due to fine foreign matter in the air. Figure 2 is a cross-sectional view of the air-cooled motor 100 according to Embodiment 1, showing the airflow.

[0024] First, the airflow provided by the blower unit 160 and the air suction from inside the motor case 110 will be explained below. As the fan 164 rotates due to the rotation of the rotating shaft 120, outside air is drawn in through the opening 161h (Figure 2(a)). The drawn-in outside air passes between the flat surface 161a and the fan base 163 of the blower cover 161 due to the rotation of the fan 164 (Figure 2(b)), and is redirected downwards in Figure 2 by the outer circumferential inclined surface 161b of the blower cover 161, and is guided as airflow to the outside of the cylindrical section 113 from the outlet 167 (Figure 2(c)). The air inside the motor case 110 is drawn out from the internal air discharge section 116 (in Figure 2(i)) by the negative pressure created by the airflow from the fan 164 (in Figure 2(c)), guided through the internal air guide path 165, passing through the ventilation selection section 166, and guided to the outside of the cylindrical section 113 together with the airflow from the fan 164 (in Figure 2(d)). The airflow from the fan 164 that reaches the outlet 167 (Figure 2(c)) and the air inside the motor case 110 that is drawn out and reaches the outlet 167 (Figure 2(d)) flow along the heat dissipation fins 115 on the outside of the cylindrical section 113 from the outlet 167 (Figure 2(e)). The airflow along the heat dissipation fins 115 (Figure 2(e)) also promotes the cooling of the motor case 110.

[0025] Next, we will explain the introduction of outside air into the motor case 110 and air cooling. As the air inside the motor case 110 is drawn out from the internal air exhaust port 116 (Figure 2 (i)), new outside air is introduced into the motor case 110 as follows. The filtration unit 150, located in a hole 120h that communicates with the hollow portion 122 within the rotating shaft 120, filters out fine foreign matter such as dust, dirt, or water droplets, as well as various foreign matter larger than fine foreign matter, from the outside air ((f1) in Figure 2) on the second bottom 112 side of the stator 130 and rotor 140, and introduces the purified air into the motor case 110 ((g1) in Figure 2). Furthermore, the filtration unit 150 rotates in conjunction with the rotation of the rotating shaft 120. Therefore, the air introduced when the filtration unit 150 on the rotating shaft 120 is facing right in Figure 2 is indicated by the solid arrow g1, and the air introduced when the filtration unit 150 on the rotating shaft 120 is facing left in Figure 2 is indicated by the dashed arrow g1.

[0026] The filter section 150, located in the hole 112h of the second bottom 112, filters out fine foreign matter such as dust, dirt, or water droplets, as well as various foreign matter larger than fine foreign matter, from the outside air ((f2) in Figure 2) on the second bottom 112 side of the stator 130 and rotor 140, and introduces the purified air into the motor case 110 ((g2) in Figure 2).

[0027] The air filtered and purified in the filtration section 150 (g1 and g2 in Figure 2) passes through the space between the stator 130 and the rotor 140, cooling the stator 130 and the rotor 140 (h in Figure 2). The air that passes through the space between the stator 130 and the rotor 140 (h in Figure 2) is drawn out from the internal air discharge section 116 provided at the first bottom 111, as previously explained (i in Figure 2).

[0028] As described above, the air-cooled motor 100 repeatedly performs the following actions in parallel: introducing and purifying (in (g1) and (g2)) fresh outside air (in (f1) and (f2) in Figure 2), cooling the inside of the air-cooled motor 100 with the purified air (in (h) in Figure 2), drawing air out of the motor case 110 with the airflow generated by the blower unit 160 (in (b) and (c) in Figure 2) (in (i) in Figure 2), and sending out (in (e)) the airflow from the fan 164 that has reached the outlet 167 (in (c) in Figure 2) and the air drawn out from inside the motor case 110 that has reached the outlet 167 (in (d) in Figure 2) along the heat dissipation fins 115. This makes it possible to efficiently cool the inside of the air-cooled motor 100 without causing a decrease in the reliability of the air-cooled motor 100 due to fine foreign matter contained in the air.

[0029] Although only one filtration unit 150 is shown in Figure 2, the filtration unit 150 provided in the hole 112h of the second bottom 112 is not limited to this. As shown in Figure 3, multiple filtration units 150 can be provided in the hole 112h of the second bottom 112. The introduction of outside air into the hollow section 122 within the rotating shaft 120 may be on the side closer to the blower section 160 ((f1) in Figure 3), as shown in Figure 3. In this case, the filtration section 150 provided in the hole 120h communicating with the hollow section 122 should be located on the second bottom section 112 side of the stator 130 and rotor 140. Furthermore, the introduction of outside air through the rotating shaft 120 may be a combination of both Figure 2 and Figure 3.

[0030] [Effects obtained by Embodiment 1] The air-cooled motor 100 according to Embodiment 1 can achieve the following effects.

[0031] (1) The air-cooled motor 100 according to Embodiment 1 includes a motor case 110 having a cylindrical portion 113, a first bottom portion 111 provided at one end of the cylindrical portion 113, and a second bottom portion 112 provided at the other end of the cylindrical portion, a stator 130 provided inside the motor case 110, a rotor 140 rotatably mounted relative to the stator 130 and rotating together with the rotation shaft 120, and a rotating outside the motor case 110 on the first bottom portion 111 side that rotates together with the rotation shaft 120 The motor case 110 includes a fan 164, a blower 160 that sends the airflow generated by the fan 164 to the outside of the cylindrical section 113, a filter 150 located on the second bottom 112 side of the stator 130 and rotor 140 that introduces outside air into the motor case 110 and blocks the passage of foreign matter, and an internal air discharge section 116 formed on the first bottom 111 that draws out the air inside the motor case 110 with the airflow generated by the fan 164. The air-cooled motor 100 repeatedly performs the following actions in parallel: introducing and purifying fresh outside air, cooling the inside of the air-cooled motor 100 with the purified air, drawing air out of the motor case 110 with the airflow generated by the blower 160, and sending the airflow from the fan 164 that has reached the outlet 167 along the heat dissipation fins 115, along with the air drawn out from inside the motor case 110 that has reached the outlet 167. This makes it possible to efficiently cool the inside of the air-cooled motor 100 without causing a decrease in the reliability of the air-cooled motor 100 due to fine foreign matter contained in the air.

[0032] (2) In the air-cooled motor 100 described in (1) above, the blower unit 160 further includes an outlet 167 that sends airflow to the outside of the cylindrical unit 113, an internal air guide path 165 that guides air drawn out from the internal air discharge unit 116 to the outlet 167, and an air selection unit 166 that blocks the internal air guide path 165 when the rotor 140 is not rotating and opens the internal air guide path 165 when the rotor 140 is rotating. In this air-cooled motor 100, when the rotor 140 is rotating, the airflow from the fan 164 is guided to the outlet 167, and at the same time, the air drawn out from the internal air discharge section 116 is guided to the outlet 167 through the internal air induction path 165 and the open ventilation selection section 166. On the other hand, when the rotor 140 is not rotating, the ventilation selection section 166 blocks the internal air induction path 165. As a result, when the rotor 140 is not rotating, foreign matter cannot enter the motor case 110 from the outlet 167 through the internal air discharge section 116.

[0033] (3) In the air-cooled motor 100 described in (1) to (2) above, the filtration section 150 is provided in the hole 112h provided in the second bottom 112. In this air-cooled motor 100, the filtration unit 150 filters out fine foreign matter such as dust, dirt, or water droplets, as well as various foreign matter larger than fine foreign matter, contained in the outside air, on the second bottom 112 side of the stator 130 and rotor 140, and introduces purified air into the motor case 110, thereby ensuring that the stator 130 and rotor 140 are reliably cooled.

[0034] (4) In the air-cooled motor 100 described in (1) to (3) above, the rotating shaft 120 is provided with a hollow section 122 with at least one end open, and the filtration section 150 is provided in a hole 120h that communicates with the hollow section 122. In this air-cooled motor 100, the filtration unit 150 is located on the second bottom 112 side of the stator 130 and rotor 140 and is provided on the rotating shaft 120. It filters out fine foreign matter such as dust, dirt, or water droplets contained in the outside air, as well as various foreign matter larger than fine foreign matter, and introduces the purified air into the motor case 110, thereby ensuring that the stator 130 and rotor 140 are reliably cooled.

[0035] (5) In the air-cooled motor 100 described in (1) to (4) above, heat dissipation fins 115 are further provided on the outer circumference of the cylindrical portion 113 to release heat from the cylindrical portion 113 to the outside and to rectify the airflow from the blower portion 160. In this air-cooled motor 100, the airflow along the heat dissipation fins 115 also promotes the cooling of the motor case 110.

[0036] Embodiment 2. The configuration of the air-cooled motor 100 in Embodiment 2 will be explained with reference to Figure 4. Figure 4 is a cross-sectional view showing a cross-section of the air-cooled motor 100 according to Embodiment 2. In Figure 4, the driven unit 10 is shown together with the air-cooled motor 100.

[0037] [Structure of the air-cooled motor 100] In Figure 4, the same reference numerals are used for objects identical to those in Figure 1, thereby omitting redundant explanations and focusing on the differences. The air-cooled motor 100 mainly comprises a motor case 110, a rotating shaft 120, a stator 130, a rotor 140, a filtration unit 150, a blower unit 160, and a motor drive unit 170. A partition wall 119 is provided in the motor case 110. The partition wall 119 is located between the first bottom 111 and the second bottom 112, and is provided in a manner that allows for ventilation between the space where the stator 130 and rotor 140 are installed and the space where the motor drive unit 170 is installed. The motor drive unit 170 supplies drive current to the coil 135 and is located on the second bottom 112 side of the stator 130 and rotor 140. The motor drive unit 170 has an inverter and other components and generates heat when generating drive current.

[0038] [Air cooling inside the air-cooled motor 100] Figure 5 illustrates how the air-cooled motor 100 efficiently cools its interior without causing a decrease in motor reliability due to fine foreign matter in the air. Figure 5 is a cross-sectional view of the air-cooled motor 100 according to Embodiment 2, showing the airflow.

[0039] The airflow provided by the fan 164 of the blower unit 160 (a, b, and c in Figure 5) and the air suction from inside the motor case 110 (i and d in Figure 5) are the same as in Embodiment 1, so their explanation will be omitted. The following describes the introduction of outside air into the motor case 110 and air cooling. As the air inside the motor case 110 is drawn out from the internal air exhaust port 116 (Figure 5 (i)), new outside air is introduced into the motor case 110 as follows.

[0040] The filter unit 150, located in a hole 120h communicating with the hollow section 122 within the rotating shaft 120, is positioned closer to the second bottom 112 than the stator 130 and rotor 140, and near the motor drive unit 170. It filters out fine foreign matter such as dust, dirt, or water droplets, as well as various foreign matter larger than fine foreign matter, contained in the outside air ((f1) in Figure 5), and introduces the purified air into the motor case 110 ((g1) in Figure 5). The introduction of outside air ((f1) in Figure 5) into the hollow section 122 within the rotating shaft 120 may also occur on the side closer to the blower unit 160, as shown in Figure 3. Furthermore, the filtration unit 150 rotates in conjunction with the rotation of the rotating shaft 120. Therefore, the air introduced when the filtration unit 150 on the rotating shaft 120 is facing right in Figure 5 is indicated by the solid arrow g1, and the air introduced when the filtration unit 150 on the rotating shaft 120 is facing left in Figure 5 is indicated by the dashed arrow g1.

[0041] The filter section 150, located in the hole 112h of the second bottom 112, is on the second bottom 112 side of the stator 130 and rotor 140 and near the motor drive unit 170. It filters out fine foreign matter such as dust, dirt, or water droplets, as well as various foreign matter larger than fine foreign matter, contained in the outside air ((f2) in Figure 5), and introduces the purified air into the motor case 110 ((g2) in Figure 5).

[0042] The air filtered and purified in the filtration section 150 (g1 and g2 in Figure 5) cools the motor drive section 170 as it passes near it, and cools the stator 130 and rotor 140 as it passes through the space between them (h in Figure 5). The air that has passed through the space between the stator 130 and rotor 140 (h in Figure 5) is drawn out from the internal air discharge section 116 provided in the first bottom section 111, as previously described (i in Figure 5).

[0043] As described above, the air-cooled motor 100 repeatedly performs the following actions in parallel: introducing and purifying (in (g1) and (g2)) fresh outside air (in (f1) and (f2)) in Figure 5; cooling the motor drive unit 170 with the purified air (in (g1) and (g2)) in Figure 5; cooling the stator 130 and rotor 140 with the purified air (in (h)) in Figure 5; drawing out air from inside the motor case 110 (in (i)) using the airflow generated by the blower unit 160 (in (b) and (c)) in Figure 5; and sending out (in (e)) the airflow from the fan 164 that has reached the outlet 167 (in (c)) along the heat dissipation fins 115 (in (e)) with the air that has been drawn out and reached the outlet 167 (in (d)) using the airflow from inside the motor case 110. This makes it possible to efficiently cool the stator 130, rotor 140, and motor drive unit 170 inside the air-cooled motor 100 without causing a decrease in the reliability of the air-cooled motor 100 due to fine foreign matter contained in the air.

[0044] The airflow in other configurations of the air-cooled motor 100 in Embodiment 2 will be explained with reference to Figure 6. Figure 6 is a cross-sectional view showing the airflow of the air-cooled motor 100 according to Embodiment 2.

[0045] [Structure of the air-cooled motor 100] In Figure 6, the same reference numerals are used for objects identical to those in Figure 4, thereby omitting redundant explanations and focusing on the differences. The air-cooled motor 100 mainly comprises a motor case 110, a rotating shaft 120, a stator 130, a rotor 140, a filtration unit 150, a blower unit 160, and a motor drive unit 170. A partition wall 119 is provided in the motor case 110. The partition wall 119 is located between the first bottom 111 and the second bottom 112, and is provided in a manner that allows for ventilation between the space where the stator 130 and rotor 140 are located and the space where the motor drive unit 170 is located. The motor drive unit 170 is located closer to the first bottom 111 than the stator 130 and rotor 140.

[0046] [Air cooling inside the air-cooled motor 100] This section describes how the air-cooled motor 100 efficiently cools its interior without causing a decrease in motor reliability due to fine foreign matter contained in the air. The airflow provided by the fan 164 of the blower unit 160 (a, b, and c in Figure 6) and the air suction from inside the motor case 110 (i and d in Figure 6) are the same as in Embodiment 1, so their explanation will be omitted. The following describes the introduction of outside air into the motor case 110 and air cooling. As the air inside the motor case 110 is drawn out from the internal air exhaust port 116 (Figure 6 (i)), new outside air is introduced into the motor case 110 as follows.

[0047] The filter unit 150, located in a hole 120h communicating with the hollow section 122 within the rotating shaft 120, filters out fine foreign matter such as dust, dirt, or water droplets, as well as various foreign matter larger than fine foreign matter, contained in the outside air ((f1) in Figure 6), on the second bottom 112 side of the stator 130 and rotor 140, and introduces the purified air into the motor case 110 ((g1) in Figure 6). The introduction of outside air ((f1) in Figure 6) into the hollow section 122 within the rotating shaft 120 may be on the side closer to the blower unit 160, as shown in Figure 3. The filter unit 150 also rotates in conjunction with the rotation of the rotating shaft 120. Therefore, the air introduced when the filtration unit 150 on the rotating shaft 120 is facing right in Figure 6 is indicated by the solid arrow g1, and the air introduced when the filtration unit 150 on the rotating shaft 120 is facing left in Figure 6 is indicated by the dashed arrow g1.

[0048] The filter section 150, located in the hole 112h of the second bottom 112, filters out fine foreign matter such as dust, dirt, or water droplets, as well as various foreign matter larger than fine foreign matter, from the outside air ((f2) in Figure 6) on the second bottom 112 side of the stator 130 and rotor 140, and introduces the purified air into the motor case 110 ((g2) in Figure 6).

[0049] The air filtered and purified by the filtration section 150 (g1 and g2 in Figure 6) cools the stator 130 and rotor 140 as it passes through the space between them (h1 in Figure 6), and cools the motor drive section 170 as it passes near it (h2 in Figure 6). The air that has passed near the motor drive section 170 (h2 in Figure 6) is drawn out from the internal air discharge section 116 provided at the first bottom section 111, as previously described (i in Figure 6).

[0050] As described above, the air-cooled motor 100 repeatedly performs the following actions in parallel: introducing and purifying (in (g1) and (g2)) fresh outside air (in (f1) and (f2)) in Figure 6; cooling the stator 130 and rotor 140 with the purified air (in (h1)) in Figure 6; cooling the motor drive unit 170 with the purified air (in (h2)) in Figure 6; drawing out air from inside the motor case 110 (in (i)) using the airflow generated by the blower unit 160 (in (b) and (c)) in Figure 6; and sending out (in (e)) the airflow from the fan 164 that has reached the outlet 167 (in (c)) along the heat dissipation fins 115 (in (e)) with the air that has been drawn out and reached the outlet 167 (in (d)) using the airflow from inside the motor case 110. This makes it possible to efficiently cool the stator 130, rotor 140, and motor drive unit 170 inside the air-cooled motor 100 without causing a decrease in the reliability of the air-cooled motor 100 due to fine foreign matter contained in the air.

[0051] [Effects obtained by Embodiment 2] The air-cooled motor 100 according to Embodiment 2 can achieve the following additional effects in addition to those of the air-cooled motor 100 of Embodiment 1.

[0052] The air-cooled motor 100 according to Embodiment 2 includes a motor case 110 having a cylindrical portion 113, a first bottom portion 111 provided at one end of the cylindrical portion 113, and a second bottom portion 112 provided at the other end of the cylindrical portion; a stator 130 provided inside the motor case 110; a rotor 140 rotatably mounted relative to the stator 130 and rotating together with a rotation shaft 120; a fan 164 located outside the motor case 110 on the first bottom portion 111 side and rotating together with the rotation shaft 120, and a blower 160 that sends the airflow generated by the fan 164 to the outside of the cylindrical portion 113; a filter 150 located on the second bottom portion 112 side of the stator 130 and rotor 140, which introduces outside air into the motor case 110 and blocks the passage of foreign matter; and an internal air discharge portion 116 formed on the first bottom portion 111 so as to draw out the air inside the motor case 110 with the airflow generated by the fan 164. Furthermore, a motor drive unit 170 is provided within the motor case 110 at a position different from the stator 130 in the direction along the axis of the rotating shaft. This air-cooled motor repeatedly performs the following actions in parallel: introducing and purifying fresh outside air, cooling the stator 130 and rotor 140 with the purified air, cooling the motor drive unit 170 with the purified air, drawing air out of the motor case 110 with the airflow generated by the blower unit 160, and discharging the airflow from the fan 164 that reaches the outlet 167 along the heat dissipation fins 115, along with the air drawn out from inside the motor case 110 that reaches the outlet 167. As a result, even if the motor drive unit 170 is included inside the air-cooled motor 100, it becomes possible to efficiently cool the inside of the air-cooled motor 100 without causing a decrease in the reliability of the air-cooled motor 100 due to fine foreign matter contained in the air.

[0053] [Other embodiments] To maintain the airflow along the heat dissipation fins 115 of the motor case 110 that reaches the outlet 167, a flow straightening cover may be provided on the outside of the heat dissipation fins 115 and close to the outlet 167. [Explanation of Symbols]

[0054] 10 Driven body, 100 Air-cooled motor, 110 Motor case, 111 First bottom, 112 Second bottom, 112h Hole, 113 Cylindrical section, 115 Heat dissipation fin, 116 Internal air discharge section, 118 Bearing, 120 Rotating shaft, 120h Hole, 122 Hollow section, 130 Stator, 135 Coil, 140 Rotor, 150 Filtration section, 160 Blower section, 161 Blower cover, 161a Flat section, 161b Outer circumference inclined section, 161h Opening, 162 Blower bottom, 162h Opening, 163 Fan base, 164 Fan, 165 Internal air induction path, 166 Ventilation selection section, 167 Outlet, 170 Motor drive section.

Claims

1. A motor case (110) having a cylindrical portion (113), a first bottom portion (111) provided at one end of the cylindrical portion, and a second bottom portion (112) provided at the other end of the cylindrical portion, The stator (130) provided inside the motor case (110), A rotor (140) is rotatably mounted on the stator (130) and rotates together with the rotation shaft (120), The motor case (110) on the first bottom (111) side is equipped with a fan (164) that rotates together with the rotating shaft (120) on the outside, A blower (160) that sends the airflow generated by the fan (164) to the outside of the cylindrical portion (113), Located on the second bottom (112) side of the stator (130) and rotor (140), there is a filter (150) that introduces outside air into the motor case (110) and blocks the passage of foreign matter, The motor case (110) has an internal air discharge section (116) formed on the first bottom (111) so as to draw out the air inside the motor case (110) with the airflow generated by the fan (164), Air-cooled motor.

2. The aforementioned air blower (160) An outlet (167) that sends the aforementioned airflow to the outside of the cylindrical portion (113), An internal air guide path (165) that guides the air drawn out from the internal air discharge section (116) to the outlet (167), The device further includes a ventilation selection unit (166) that blocks the internal air induction path (165) when the rotor (140) is not rotating, and opens the internal air induction path (165) when the rotor (140) is rotating. The air-cooled motor according to claim 1.

3. The filtration section (150) is provided in the holes (112h) provided in the second bottom section (112), The air-cooled motor according to claim 1.

4. The rotating shaft (120) includes a hollow portion (122) with at least one end open, The filtration section (150) is provided in a hole (120h) that communicates with the hollow section (122). The air-cooled motor according to claim 1.

5. The cylindrical portion (113) is further provided with heat dissipation fins (115) on its outer circumference to release heat from the cylindrical portion (113) to the outside and to rectify the airflow from the blower portion (160). The air-cooled motor according to claim 1.

6. The motor case (110) is further provided with a motor drive unit (170) at a position different from the stator (130) in the direction along the axis of the rotating shaft. The air-cooled motor according to claim 1.

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