Motor

Abstract

To provide an air-cooled motor having a motor with high cooling efficiency and having a configuration in which exhaust air does not flow toward a load side of the motor.SOLUTION: A motor 1 includes: a case 2 accommodating a component for driving; a shaft 3 protruding from the inside of the case 2 toward an end surface 2a located on a load side; and an air-cooled cooling unit 6. The cooling unit 6 is composed of: a fan unit 8 that operates independently of the rotation of the shaft 3 and sends air from the outside to an end surface 2b located opposite to the load side; and a heat sink unit 7 that cools the end surface 2b opposite to the load side by exhausting the air sent from the fan unit 8 while forcibly dispersing the air along the end surface 2b opposite to the load side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an air-cooled motor. [Background technology]

[0002] Conventionally, for cooling an air-cooled motor while it is in operation, there is known a motor having a cooling structure that takes in outside air into the motor, uses the air as cooling wind to cool the hot inside of the motor, and discharges the air to the outside (see Patent Documents 1 and 2). The motors disclosed in Patent Documents 1 and 2 are applied to electric motors, and have a configuration in which an air intake port and a fan that take in air from the outside are provided on the anti-load side (opposite the load side in which the motor shaft extends toward the driven object), and an exhaust port that discharges air to the outside after cooling the inside of the motor is provided on the side of the motor. In both motor configurations, the fan is axially attached to the shaft, and is configured to take in outside air into the inside of the motor by rotating the fan in conjunction with the drive of the motor. Many air-cooled motors adopt a cooling structure of this configuration.

[0003] It is also possible to adopt the idea that by increasing the outer diameter of the motor and increasing its output, the cooling effect inside the motor can also be improved. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2023-060669 [Patent Document 2] Patent No. 2022-189307 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a work site where a motor is used, it may not be permitted to allow the exhausted air after cooling to flow to the load side of the motor, i.e., the side where the motor's driven object is present. For example, in a film production line, a motor is used to drive a number of rollers for sending out (stretching, taking up, winding, etc.) the film. If the air after cooling the motor flows toward the rollers that are the driven objects on the load side, the film being produced may wrinkle or twist, which will affect the product value and reduce the yield, so it is necessary to prevent the air after cooling from flowing to the load side of the motor. In such a situation, assuming that a motor with the above-mentioned cooling structure is used, the air exhausted from the side of the motor may flow or diffuse toward the load side after leaving the motor, considering the direction of the air flowing from the air intake to the exhaust port, so a separate windshield must be installed. Furthermore, if a fan is attached to the shaft, the fan rotates and performs a cooling function only while the motor is running, i.e., while the shaft is rotating. However, when the motor is stopped, the cooling function also stops, which creates the problem that the motor, which has become hot, cannot be cooled down until the next time the motor is started again.

[0006] Similarly, taking the example of a film-forming machine line, since a large number of motors must be arranged in a set space to correspond to a large number of rollers, the motors cannot be made larger in diameter to improve their cooling efficiency; instead, small-diameter, low-output motors are required. In this way, depending on the work site, it may not be possible to improve cooling efficiency by increasing the motor diameter and power.

[0007] The present invention has been made with attention to these points, and its main object is to provide an air-cooled motor equipped with a cooling mechanism that can be cooled by outside air without increasing the size of the motor, and that does not send exhaust air after cooling to the load side without using a separate structure such as a windshield. [Means for solving the problem]

[0008] In other words, the present invention is a motor equipped with a case that houses driving parts, a shaft that protrudes from the inside of the case to the load side end face and is part of the driving parts, and an air-cooled cooling unit, wherein the cooling unit is characterized by being composed of a fan unit that operates independently of the rotation of the shaft and sends air from the outside to the anti-load side end face, and a heat sink unit that cools the anti-load side end face by forcibly diffusing the air sent in from the fan unit along the anti-load side end face and exhausting it.

[0009] In an air-cooled motor having such a configuration, the air taken in from the outside by the fan unit is not sent into the inside of the motor, but is directed at the end face of the case on the opposite load side. The air is forcibly diffused by the heat sink unit to the end face of the case on the opposite load side, cooling the end face. Furthermore, the heat sink unit exerts a heat dissipation effect on the end face of the case on the opposite load side, while discharging the cooled air along the end face of the opposite load side. At that time, the heat cooled at the end face of the case on the opposite load side is also transmitted to the peripheral wall of the case and the internal driving components, and it was found from the verification results that the inside of the motor can be cooled at the same time. Furthermore, since the fan unit operates independently of the rotation of the shaft, it can be rotated at all times, and the motor can be kept cooled before and even when the motor is stopped, thereby suppressing temperature rise. Furthermore, since the cooled air is exhausted while being diffused along the end face of the case on the opposite load side, it will not flow to the load side unless there is an air flow from the opposite load side to the load side in the installation environment of the motor, there is no effect on the driven object on the load side or the surrounding products, etc., even if a separate member such as a windshield is not provided. The motor of the present invention does not need to be enlarged in diameter, and is therefore suitable for use as a small, low-output motor in the above-mentioned film-forming machine line and the like.

[0010] In such a motor, the cooling section is preferably configured to ensure that the external air sent in by the fan section is directed toward the anti-load end face of the case while being reliably diffused by the heat sink section so that no air flow toward the load side occurs around the motor. The cooling section is preferably configured so that the heat sink section is attached to the anti-load end face of the case so as to surround its center, and the fan section is composed of a base that sandwiches the entire heat sink section between the anti-load end face of the case and a fan body that is attached to the base directly facing the anti-load end face of the case through an air intake port opened in the center of the base.

[0011] A more suitable heat sink section configuration is one that includes multiple thin plate-like fins that stand perpendicular to the end face of the case on the non-load side, and that are arranged in a direction that is approximately perpendicular to the radial direction of the case. Such a configuration of the heat sink section allows the outside air sent in from the fan body to be diffused evenly over the entire end face of the case on the non-load side through the gaps between the fins, while also achieving high heat dissipation efficiency through the fins, thereby improving the cooling effect of the entire motor through the end face of the case on the non-load side.

[0012] An example of a configuration for realizing such a heat sink unit at a low cost is a heat sink unit that includes a plurality of heat sinks that are rectangular in plan view and have a plurality of thin plate-like fins aligned in one direction, and that surround the center of the end face on the opposite load side of the case to form a regular polygon when the end face on the opposite load side is viewed from the front. If the interior angles of the regular polygon formed by adjacent heat sinks are relatively small, it is considered that the vortex of the air sent from the fan accumulates in the interior angles, resulting in a slight decrease in cooling efficiency. Therefore, it is considered that the number of heat sinks is preferably 5 to 6 or more, and the regular polygon is preferably a regular pentagon or regular hexagon or more. When a commercially available heat sink is used for the heat sink unit with such a configuration to reduce the price, it is sufficient to adopt a heat sink of an appropriate size and number in consideration of the diameter of the case. Effect of the Invention

[0013] Based on the novel idea and verification results that the entire motor can be cooled appropriately if the end face of the case on the opposite load side is efficiently cooled, the present invention adopts a configuration in which air taken in from the outside by a fan section independent of the shaft drive is continuously blown onto the end face of the opposite load side as a cooling section provided on the end face of the case on the opposite load side, the air is diffused onto the end face of the opposite load side by a heat sink section while also dissipating heat, and the cooled air is exhausted to the outside along the end face of the opposite load side. Therefore, according to the present invention, the motor is appropriately cooled while the cooled air is not caused to flow towards the load side, thereby suppressing the influence of the air flow towards the load side, and an air-cooled motor suitable for small motors can be provided. [Brief description of the drawings]

[0014] [Figure 1] 1 is a side view showing a schematic external appearance of a motor according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic rear view showing a state seen from the anti-load side corresponding to FIG. 1 . [Diagram 3] FIG. 4 is a side view showing the motor of the embodiment in a state before the fan is attached; [Figure 4] FIG. 4 is a schematic rear view showing a state seen from the anti-load side corresponding to FIG. 3 . [Diagram 5] 5 is a schematic cross-sectional view showing the results of a thermal analysis of the motor according to the embodiment during cooling; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] As shown in Figs. 1 and 2, the motor 1 according to this embodiment is a relatively small one in which the shaft 3 protrudes from one end face 2a (end face 2a on the load side) of a generally cylindrical case 2. The case 2 is composed of a cylindrical frame 21 which serves as the main body and constitutes the peripheral wall, and a bottomed round dish-shaped cover 22 which is placed on the other end face side of the frame 21. The bottom face 22b of the cover 22 constitutes the other end face 2b (end face 2b on the opposite load side) of the case 2. As shown in Fig. 5, inside the case 2, a stator 4 is disposed as a driving component, and a rotor 5 is disposed inside the stator 4, and the shaft 3 is fixed to the radial center of the rotor 5. The shaft 3 protrudes from the end face 2a on the load side of the case 2, and a drive target (not shown) is connected to its tip. Furthermore, the motor 1 according to this embodiment has a configuration in which a cooling unit 6 is attached to the end face 2b on the opposite load side of the case 2 (specifically, the bottom face 22b of the cover 22). In motor 1 of the present embodiment, in order to further enhance the cooling effect of cooling section 6, the thickness of the peripheral wall portion of case 2 is configured to be thicker than that of a typical motor of this type.

[0017] The cooling section 6 is composed of a heat sink section 7 attached to the bottom surface 22b of the cover 22, which is the end surface 2b on the anti-load side of the case 2, and a fan section 8. Figures 3 and 4 correspond to Figures 1 and 2 and show a schematic diagram of a state in which only the heat sink section 7 of the cooling section 6 is attached to the bottom surface 22b of the cover 22 (a state before the fan section 8 is attached).

[0018] The heat sink section 7 uses a plurality of heat sinks 71 having a rectangular shape in plan view, in which a large number of thin plate-like fins 71a are aligned in one direction, and these heat sinks 71 are attached to the bottom surface 22b of the cover 22, which is the end surface 2b on the anti-load side of the case 2, so as to surround the center and draw a regular polygon. In this embodiment, in order to prevent damage due to vibration during motor operation, six heat sinks 71 having approximately the same configuration are arranged close to each other without contacting each other, arranged so that the space formed surrounding the center of the bottom surface 22b of the cover 22 is approximately regular hexagonal, and attached to the bottom surface 22b by screws or the like. In this state, all the fins 71a of each heat sink 71 are in a state of standing in a direction perpendicular to the bottom surface 22b, and in particular, the fins 71a near the longitudinal center of each heat sink 71 are arranged so as to extend in the radial direction of the case 2 when the bottom surface 22b is viewed from the front. That is, the fins 71a of each heat sink 71 are arranged in a direction substantially perpendicular to the radial direction of the case near the longitudinal center of the heat sink 71. Therefore, the gaps between adjacent fins 71a also extend in the radial direction of the case 2 when the bottom surface 22b is viewed directly, at least near the longitudinal center of each heat sink 71, and in the same heat sink 71, all the gaps between adjacent fins 71a are open outward in that direction. The inner space surrounded by the six heat sinks 71 is a substantially closed space by the base 82 of the fan unit 8, which will be described next.

[0019] The fan unit 8 is composed of a fan body 81, which is made up of a fan 81a that rotates to blow air onto the bottom surface 22b of the cover 22 and a frame 81b that protects the periphery of the fan 81a, and a base 82 that attaches the fan body 81 to the bottom surface 22b of the cover 22. Generally, the fan 81a and the frame 81b are integral, but they may be separate. The fan body 81 is attached to the base 82 so that the diameter of the fan 81a is smaller than the diameter of the bottom surface 22b of the cover 22 and the center of the fan 81a and the center of the bottom surface 22b of the cover 22 are approximately aligned. Therefore, the fan 81a is driven by an appropriate motor (not shown) so that it rotates independently of the rotation of the shaft 3.

[0020] The base 82 is a disk-shaped member that is larger than the frame 81b of the fan main body 81, larger than the space formed inside the six heat sinks 71 and the area including the portion where each heat sink 71 contacts the bottom surface 22b of the cover 22, and has a diameter smaller than the diameter of the bottom surface 22b of the cover 22, and a circular air intake port 82a having approximately the same size as the fan 81a is provided in the center. The base 82 is attached to the bottom surface 22b of the cover 22 so as to sandwich the heat sink part 7 between the bottom surface 22b of the cover 22. To achieve this, a spacer 22c having approximately the same height as each heat sink 71 is attached to the bottom surface 22b of the cover 22 between the short sides of the adjacent heat sinks 71, and the base 82 is fixed to the bottom surface 22b of the cover 22 by screwing each spacer 22c or the like.

[0021] In this manner, the pedestal 82 is attached to the bottom surface 22b of the cover 22 after the heat sink 71 is attached, and the fan body 81 is further attached to the pedestal 82, thereby completing the attachment of the fan unit 8 to the bottom surface 22b of the cover 22. In this state, the regular hexagonal space formed inside the six heat sinks 7 is a closed space in the axial direction of the shaft 3 except for the gap between the air intake port 82a of the pedestal 82 and the fan 81a and the slight gaps between the heat sinks 71, and is a closed space in the radial direction of the case 2 except for the slight gaps between the heat sinks 71 and the gaps between the fins 71a of each heat sink 71.

[0022] Here, when the fan unit 8 is operated (fan 81a is driven to rotate), as shown by the arrows in Figures 1 and 2, the fan 81a takes in air from the outside, and cools it by blowing the outside air through the air intake port 82a of the base 82 against the bottom surface 22b of the cover 22, which is the end surface 2b on the anti-load side of the case 2. This air is confined in the hexagonal space formed by the heat sink unit 7, but is exhausted to the outside through the gaps between the fins 71a of each heat sink 71. At that time, the fins 71a dissipate the heat of the motor 1 transmitted from the bottom surface 22b of the cover 22, while also being cooled (forced cooling) by the exhausted air. Furthermore, by operating the fan unit 8 so as to constantly take in a predetermined amount of air (preferably the amount of air necessary for cooling when the motor is at rated loss) from the time the motor 1 starts to drive, the anti-load side of the motor 1 is forcibly cooled from the time the motor 1 starts to rotate at low speeds, and the temperature of the anti-load side of the motor 1 can be kept lower than that of the load side, making it easier for heat from the motor 1 to be transferred to the anti-load side. Furthermore, even when the motor is restarted to drive, because cooling is forcibly performed from the time the motor starts to drive, the temperature difference between the anti-load side and the load side can be increased from the time the motor starts to rotate at low speeds, making it easier for heat from the motor 1 to be transferred to the anti-load side. Therefore, the entire motor 1 can be effectively cooled on the anti-load side of the motor 1.

[0023] FIG. 5 shows the state of the cooling of such a motor monitored by thermal analysis. This figure shows the result of thermal analysis when the fan 81a is continuously operated so as to always take in a predetermined amount of air (preferably the amount of air necessary for cooling at the time of the motor rated loss) regardless of the rotation speed of the motor 1 from the start of motor drive. In this figure, the heat sink part 7 and the fan part 8 constituting the cooling part 6 are not shown, and the motor 1 other than that is shown as a vertical cross section of the upper half. In this figure, the high and low of the temperature are expressed by the shade of the color, and the lighter the color, the lower the temperature, and the darker the color, the higher the temperature. From the result of this thermal analysis, it was found that the temperature of the cover 22 closest to the cooling part 6 was the lowest, and the temperature increased in the order from the anti-load side of the case 2 to the load side, the anti-load side of the stator 4, and the load side of the stator 4. However, it was confirmed that even the load side of the stator 4, the rotor 5, and the shaft 3, which were the hottest, were within the specified temperature rise value. Furthermore, it was confirmed that the overall temperature distribution of the motor 1 was such that the temperature was relatively lower on the anti-load side than on the load side, and the anti-load side was cooled more effectively.

[0024] From the above, it was found that the motor 1 of this embodiment can efficiently cool the motor 1 during operation by providing the cooling section 6 on the end surface 2b of the case 2 on the opposite load side, taking in air from the fan section 8 into the cooling section 6, diffusing the taken-in air along the end surface 2b on the opposite load side by the heat sink section 7, and discharging the air from the gaps of the fins 71a of each heat sink 71. With such a motor 1, a sufficient cooling effect can be obtained without taking in outside air into the case 2 for cooling as in the conventional case, and the exhaust air after cooling does not flow to the load side, so that there is an advantage that the load object or product on the load side is not affected. Therefore, it can be said that the motor 1 of this embodiment is suitable as an air-cooled motor used in a film production line or the like where it is not desired to blow air toward the film product.

[0025] In particular, the cooling section 6 is configured such that the heat sink section 7 is attached so as to surround the center of the anti-load side end face 2b (the bottom surface 22b of the cover 22), and the fan section 8 is configured such that the entire heat sink section 7 is sandwiched between the anti-load side end face 2b (the bottom surface 22b of the cover 22) and the base 82 and the fan body 81 is attached to the base 82 facing directly against the anti-load side end face 2b (the bottom surface 22b of the cover 22) through an air intake port 82a opened in the center of the base 82.Therefore, the external air sent in by the fan section 8 is directed against the anti-load side end face 2b (the bottom surface 22b of the cover 22) while being reliably diffused by the heat sink section 7, thereby improving the cooling efficiency of the cooling section 6.

[0026] In addition, the heat sink section 7 has multiple thin plate-shaped fins 71a that are erected vertically to the anti-load side end face 2b (the bottom surface 22b of the cover 22) and are arranged in a direction approximately perpendicular to the radial direction of the case 2. Therefore, the external air sent in from the fan section 8 is diffused evenly throughout the anti-load side end face 2b (the bottom surface 22b of the cover 22) through the gaps between the fins 71a, and the fins 71a also provide a high heat dissipation effect, further improving the cooling effect of the entire motor 1.

[0027] Furthermore, the heat sink section 7 is composed of multiple heat sinks 71 with multiple fins 71a aligned in one direction, and these heat sinks 71 are arranged to surround the center of the end face 2b (the bottom surface 22b of the cover 22) on the anti-load side to form a regular hexagon. This makes it possible to use commercially available heat sinks, for example, and to construct the heat sink section 7 simply and at low cost.

[0028] The present invention is not limited to the above-mentioned embodiment. For example, when the heat sink part is composed of a plurality of heat sinks, it is not limited to the configuration in which six heat sinks form a regular hexagon, but may form an appropriate regular polygon according to the number of heat sinks, may apply heat sinks of different sizes to form an appropriate polygon, or may manufacture a dedicated annular heat sink to form the heat sink part alone. Also, it is not limited to a heat sink in which a plurality of thin plate-like fins are aligned, but may apply heat sinks having fins of various shapes, but it is important to adopt a heat sink equipped with fins having a shape, arrangement, etc. that diffuses the external air sent from the fan at the end face on the opposite load side and prevents the exhausted air from flowing to the load.

[0029] In addition, with regard to the fan section, the specific configuration such as the fan body, base, and the size of the air intake port formed in the base can be appropriately selected to have the necessary air blowing power and cooling efficiency depending on the size of the case and the degree of temperature rise of the entire motor.

[0030] Furthermore, the specific configurations of the various parts of the motor excluding the cooling part are not limited to those in the above embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0031] 1. Motor 2. Case 3...Shaft 6…Cooling section 7…Heat sink section 8. Fan Section 71…Heat sink 81…Fan body 81a…Fan 82…Pedestal 82a...Air supply port

Claims

1. A motor including a case for accommodating driving components, a shaft that protrudes from the inside of the case toward a load side end face side and is a part of the driving components, and an air-cooled cooling unit, A motor characterized in that the cooling section is composed of a fan section that operates independently of the rotation of the shaft and sends air from the outside to the end face on the anti-load side, and a heat sink section that cools the end face on the anti-load side by forcibly diffusing the air sent from the fan section along the end face on the anti-load side and exhausting it.

2. The heat sink portion is attached so as to surround a central portion of the end surface on the opposite load side, 2. The motor according to claim 1, wherein the fan section is composed of a base that sandwiches the entire heat sink section between itself and the end face on the anti-load side, and a fan body that is attached to the base directly facing the end face on the anti-load side through an air intake port that opens in the center of the base.

3. 3. The motor according to claim 2, wherein the heat sink portion comprises a plurality of heat sinks each having a rectangular shape in a plan view with the fins aligned in one direction, the plurality of heat sinks surrounding a central portion of the end face on the anti-load side and arranged to form a regular polygon when the end face on the anti-load side is viewed directly from the front.

Images