JP6153474B2 - Gear motor and reducer - Google Patents

Description

  The present invention relates to a gear motor in which a motor and a speed reducer are connected, and a speed reducer used therefor.

  The speed reducer may be operated continuously for a long time when the rotational speed of the input shaft is high. When used in such a high load situation, the lubricating oil or the sealing material may be deteriorated by heat due to meshing of gears or rolling of the bearing. As a countermeasure, a gear motor is disclosed in which a cooling fan is provided on the rotation shaft of the motor (see Patent Document 1). According to this structure, the speed reducer is cooled by the air flow generated by the cooling fan.

JP 2008-286357 A (FIG. 3)

  In recent years, the entire speed reducer has been made more compact to meet the needs for weight reduction and space saving. Accordingly, the heat dissipation area of the reduction gear casing is reduced, and a structure capable of cooling the reduction gear more effectively is required. The present inventor has come to recognize that there is room for improvement in the structure of the reduction gear in realizing such a demand.

  This invention is made | formed in view of such a condition, The objective is to provide the technique which can cool a reduction gear effectively with a cooling fan.

  One embodiment of the present invention relates to a gear motor. The gear motor is a gear motor in which a motor and a speed reducer are connected, and a cooling fan is provided on a rotation shaft of the motor or the speed reducer, and a leg portion is provided on the speed reducer for installation on an external installation surface. When the leg portion is installed on the installation surface, the leg portion has an installation surface installed on the installation surface and a cooling surface provided with a gap between the installation surface, and the gap is generated by the rotation of the cooling fan. The cooling surface has a first width changing portion in which the clearance width between the cooling surface and the installation surface widens from the inflow side to the outflow side of the airflow passing through the clearance. It is characterized by.

  Moreover, the other aspect of this invention is related with a reduction gear. The speed reducer is a speed reducer connected to a motor provided on a rotating shaft of a cooling fan, provided with a leg portion for installation on an external installation surface, and when the leg portion is installed on the installation surface And a cooling surface provided with a clearance between the installation surface and the installation surface, and configured to allow air flow generated by rotation of the cooling fan to pass through the clearance. The surface is characterized by having a first width changing portion in which the width of the clearance with the installation surface widens from the inflow side to the outflow side of the airflow passing through the gap.

  According to these aspects, the flow rate of the airflow passing through the gap increases, and the speed reducer can be effectively cooled by increasing the amount of heat released from the cooling surface.

  According to the present invention, the reduction gear can be effectively cooled by the cooling fan.

It is a bottom perspective view of the gear motor concerning a 1st embodiment. It is an upper perspective view of the gear motor concerning a 1st embodiment. It is a front view of the gear motor concerning a 1st embodiment. It is a right view of the gear motor which concerns on 1st Embodiment. It is a left view of the gear motor which concerns on 1st Embodiment. It is a rear view of the gear motor which concerns on 1st Embodiment. It is a top view of the gear motor concerning a 1st embodiment. It is a bottom view of the gear motor concerning a 1st embodiment. It is a partial section side view showing the state where the gear motor concerning a 1st embodiment was installed in the external structure. It is the schematic which looked at a part of motor casing concerning a 1st embodiment from direction B of Drawing 9. It is an expanded sectional view of the leg part of the reduction gear which concerns on 1st Embodiment. It is a downward perspective view which shows the part of the reduction gear of the gear motor which concerns on 1st Embodiment. It is a downward perspective view of the gear motor concerning a 2nd embodiment. It is a rear view of the gear motor which concerns on 2nd Embodiment. It is a bottom view of the gear motor which concerns on 2nd Embodiment. It is an expanded sectional view which shows the structure of a leg part when the gear motor which concerns on 2nd Embodiment is installed in the external structure. It is a downward perspective view which shows the part of the reduction gear of the gear motor which concerns on 2nd Embodiment. It is a downward perspective view of the gear motor concerning a 3rd embodiment. It is an upper perspective view of the gear motor which concerns on 3rd Embodiment. It is a right view of the gear motor which concerns on 3rd Embodiment. It is a left view of the gear motor which concerns on 3rd Embodiment. It is an expanded sectional view showing composition of a leg part when a gear motor concerning a 3rd embodiment is installed in an external structure. It is a bottom view of the gear motor which shows the structure of a leg part when the gear motor which concerns on 3rd Embodiment is installed in the external structure. It is a downward perspective view which shows the part of the reduction gear of the gear motor which concerns on 3rd Embodiment.

[First Embodiment]
1 is a lower perspective view of the gear motor 10 according to the first embodiment, FIG. 2 is an upper perspective view thereof, FIG. 3 is a front view thereof, FIG. 4 is a right side view thereof, and FIG. Is a left side view thereof, FIG. 6 is a rear view thereof, FIG. 7 is a plan view thereof, and FIG. 8 is a bottom view thereof. FIG. 9 is a partial cross-sectional side view showing a state where the gear motor 10 according to the first embodiment is installed in the external structure 70. The gear motor 10 is a reduction gear with a motor including the motor 20 and a reduction gear 40.

  The motor 20 includes a motor casing 21, a rotating shaft 23, and a cooling fan 25. A stator and a rotor (not shown) are accommodated in the motor casing 21, and a rotating shaft 23 is attached to the rotor. Hereinafter, the axial direction of the rotating shaft 23 will be described as the direction A.

  One end side of the rotating shaft 23 projects from one side surface 21 a of the motor casing 21. A cooling fan 25 is provided at the protruding portion of the rotating shaft 23. The cooling fan 25 rotates integrally with the rotary shaft 23 and generates an air flow in the direction A by the rotation. The motor casing 21 is provided with a bottomed cylindrical fan cover 27 that covers the cooling fan 25. The fan cover 27 includes a cylindrical peripheral wall portion 27a and a bottom wall portion 27b provided on one side (right side in FIG. 9) in the direction A of the peripheral wall portion 27a. The fan cover 27 is provided with a lead-out port 27c that opens to the other side (left side in FIG. 9) in the direction A of the peripheral wall 27a. The air flow by the cooling fan 25 flows toward the other side in the direction A (left side in FIG. 9) through the outlet 27c.

  The motor casing 21 is provided with a plurality of motor fins 29. FIG. 10 is a schematic view of a part of the motor casing 21 as viewed from the direction B in FIG. 9, and the outer shapes of the motor casing 21 and the motor fins 29 are shown by solid lines. Represented by

  The motor fins 29 are provided in a straight line so as to extend in the direction A on the outer peripheral surface 21 b of the motor casing 21 surrounding the rotating shaft 23. Between the plurality of motor fins 29, a guide path 31 that guides the air flow by the cooling fan 25 in the direction A is formed in a straight line. A part of the plurality of motor fins 29 is provided at a position overlapping with a gap 57 between a cooling surface 55 and an installation surface 71 of a reduction gear casing 41 described later when viewed from the direction A. Thereby, the airflow by the cooling fan 25 flowing out from the outlet 27 c of the fan cover 27 flows toward the other side in the direction A along the guide path 31 between the motor fins 29 and is guided to the gap 57.

  The speed reducer 40 includes a speed reducer casing 41, an input shaft (not shown), and an output shaft 45. The reduction gear casing 41 includes a main body portion 47 that houses a reduction mechanism (not shown) and leg portions 49 that are provided on the side portions of the main body portion 47. The leg portion 49 is provided on a side portion in a direction intersecting the direction A with respect to the main body portion 47 of the reduction gear casing 41. The input shaft is provided on the first side surface (the right side surface in FIG. 9) of the main body 47, and the output shaft 45 is provided on the other second side surface 47b different from the first side surface.

  The input shaft is formed integrally with the other end portion of the rotating shaft 23 protruding from the motor casing 21 (not shown, but the left end portion of FIG. 9), or the other end portion of the rotating shaft 23 and a spline, joint, etc. And the power of the rotating shaft 23 of the motor 20 is input. The reduction mechanism is, for example, an eccentric oscillating planetary gear reduction mechanism using a plurality of external gears and internal gears, and reduces the rotation of the input shaft and transmits it to the output shaft 45. Since this type of deceleration mechanism is well known, detailed description thereof is omitted.

  The leg portion 49 is provided for installation on the external installation surface 71. The installation surface 71 is formed on an external structure 70 such as a floor or a counterpart machine on which the reduction gear 40 is to be installed. The gear motor 10 including the reduction gear 40 is entirely supported by the leg portions 49. The leg portion 49 is provided with a flat plate-like fixed portion 51 (see FIGS. 6 and 7), and an external structure is provided by a fixing tool such as a bolt inserted through a through hole 51a that penetrates the fixed portion 51. 70 is fixed to the installation surface 71.

  FIG. 11 is an enlarged cross-sectional view of the leg portion 49. The leg 49 has an installation surface 53 installed on the installation surface 71 and a cooling surface 55 provided with a gap 57 between the installation surface 71 when installed on the installation surface 71. The installation surface 53 is provided on the bottom surface of the fixed portion 51 so as to extend in the direction A. A pair of installation surfaces 53 are provided so as to be located on both sides of the axis 23a (see FIG. 8) of the rotation shaft 23 of the motor 20 in plan view.

  The cooling surface 55 is provided as a groove bottom surface of a groove portion formed on the bottom surface of the leg portion 49, and is provided between the pair of installation surfaces 53. As shown in FIG. 11, a gap 57 between the cooling surface 55 of the speed reducer 40 and the installation surface 71 of the external structure 70 penetrates in the direction A and opens to the motor side (right side in FIG. 11). 59 and an outlet 61 that opens to the non-motor side (left side in FIG. 11). The inflow port 59 is located in front of the airflow outflow direction by the cooling fan 25 from the outlet 27c of the fan cover 27 and in front of the airflow direction of the airflow passing through the conduit 31 between the plurality of motor fins 29. To be provided. The inflow port 59 is provided so as to be positioned in front of the flow direction of the air flow by the cooling fan 25. The gap 57 includes a first flow path 67 extending from the inflow port 59 to the outflow port 61, and an air flow by the cooling fan 25 flows through the first flow path 67. As described above, the gear motor 10 is configured such that the air flow from the cooling fan 25 can pass through the gap 57. The gap 57 has a cross-sectional area that is significantly narrower than the space 73 on the upstream side of the gap 57 in the path through which the air flow by the cooling fan 25 flows, and functions as an air flow restriction.

  The cooling surface 55 includes a first width changing portion 63 provided on the air flow outflow side in the gap 57, and a second width changing portion 65 provided on the air flow inflow side from the first width changing portion 63. The first width changing portion 63 is provided so as to be continuously connected to the second width changing portion 65, and is provided from the boundary position with the second width changing portion 65 to the outlet 61 of the gap 57. The second width changing portion 65 is provided from the inlet 59 of the gap 57 to the middle position in the direction A, that is, from the inlet 59 to the middle position of the gap 57 in the air flow direction.

  The first width changing portion 63 is formed by a first inclined surface 64 that is inclined so that a gap width between the first width changing portion 63 and the installation surface 71 continuously increases from the motor side toward the non-motor side. The first width changing portion 63 has a gap width that increases from the inflow side to the outflow side of the airflow passing through the gap 57.

  The second width changing portion 65 is formed by a second inclined surface 66 that inclines so that the gap width with the installation surface 71 continuously narrows from the motor side toward the non-motor side. The width of the second width changing portion 65 narrows from the inflow side to the outflow side of the air flow passing through the gap 57.

  Next, the operation of the gear motor 10 according to the present embodiment will be described. When the rotary shaft 23 of the motor 20 is driven to rotate, the input shaft of the speed reducer 40 rotates integrally with the rotary shaft 23. The rotation of the input shaft is decelerated by the speed reduction mechanism and transmitted to the output shaft 45. At this time, the cooling fan 25 rotates integrally with the rotating shaft 23 of the motor 20 to generate an air flow.

  The air flow by the cooling fan 25 flows through the outlet 27 c of the fan cover 27, and flows toward the other side in the direction A (left side in FIG. 9) along the guide path 31 between the motor fins 29. When the air flow from the cooling fan 25 is guided to the inlet 59 of the gap 57 between the cooling surface 55 of the reduction gear casing 41 and the installation surface 71 of the external structure 70, the airflow flows from the inlet 59 through the first flow path 67. Flow to exit 61.

  At this time, the air flow by the cooling fan 25 is throttled by passing through the gap 57, the flow velocity is increased, and the heat transfer coefficient of the cooling surface 55 is increased. Therefore, the heat generated by the meshing of the gears, the rolling of the bearing and the like inside the reduction gear casing 41 is effectively radiated from the reduction gear casing 41 through the cooling surface 55, and the entire reduction gear 40 is effectively removed by the cooling fan 25. Can be cooled.

  Further, since the cooling surface 55 has the first width changing portion 63, as shown in FIG. 11, the narrower portion 63a on the inflow side where the gap width between the first width changing portion 63 and the installation surface 71 is narrower, The air flow passing through the wide portion 63b on the outflow side where the gap width is wide has a slower flow velocity. As a result, a pressure difference is generated such that the dynamic pressure of the air flow passing through the wide portion 63b is lower than the dynamic pressure of the air flow passing through the narrow portion 63a, and the gap between the first width changing portion 63 and the installation surface 71 is generated. An air flow easily flows from the inflow side to the outflow side. Therefore, the flow rate of the air flow passing through the gap 57 is increased, and the cooling effect of the entire speed reducer 40 is improved by the increase in the amount of heat radiation from the cooling surface 55.

  Further, since the first width changing portion 63 of the cooling surface 55 is formed by the first inclined surface 64, the cross-sectional area of the flow path does not change rapidly in the air flow direction, and the first width changing portion 63 and the installation surface The occurrence of pressure loss in the airflow passing between the airflow and the airflow passage 71 is suppressed.

  In addition, since the cooling surface 55 has the second width changing portion 65, the second width changing portion 65 and the installation surface 71 are more narrow than the narrow portion 63 a where the gap width between the first width changing portion 63 and the installation surface 71 is the narrowest. A wide portion 65a having a wide gap width is provided on the air flow inflow side. In this example, the wide width portion 65 a having the widest gap width with the installation surface 71 in the second width changing portion 65 becomes the inflow port 59. As a result, since the opening area of the inlet 59 of the gap 57 is larger than when the second width changing portion 65 is not provided, the air flow can be easily taken from the inlet 59, and the gap 57 is moved from the inlet side to the outlet side. The flow becomes easy to flow. Therefore, the flow rate of the air flow passing through the gap 57 is increased, and the cooling effect of the entire speed reducer 40 is improved by the increase in the amount of heat radiation from the cooling surface 55.

  Further, since the second width changing portion 65 of the cooling surface 55 is formed by the second inclined surface 66, the flow path cross-sectional area does not change abruptly in the air flow direction, and the second width changing portion 65 and the installation surface. The occurrence of pressure loss in the air flow passing between the airflow and the air pressure 71 is suppressed, and aerodynamic noise is hardly generated.

  In addition, since a part of the plurality of motor fins 29 is provided at a position that overlaps the gap 57 when viewed from the direction A, the air flow by the cooling fan 25 is separated along the guide path 31 between the motor fins 29. It becomes easy to guide to 57. Therefore, the flow rate of the air flow passing through the gap 57 is increased, and the cooling effect of the entire speed reducer 40 is further improved by further increasing the amount of heat released from the cooling surface 55.

  As shown in FIG. 8, the cooling surface 55 has the same length L <b> 1 along the direction A together with the length L <b> 2 along the direction A in the range where the leg portion 49 is installed on the installation surface 71. It is. The length L1 of this range is the length along the direction A of the installation surface 53 in the illustrated example. Thereby, the cooling surface 55 of a large area can be ensured in the range in which the leg part 49 is installed, and the cooling effect of the entire speed reducer 40 is further improved by increasing the amount of heat radiation from the cooling surface 55.

  The first inclined surface 64 described above is not particularly limited with respect to the angle θ inclined with respect to the installation surface 71 of the external structure 70 as shown in FIG. Therefore, it is preferably greater than 0 ° and not more than 10 °, more preferably not more than 5 °.

  FIG. 12 is a lower perspective view showing a part of the speed reducer 40 of the gear motor 10 according to the first embodiment.

[Second Embodiment]
FIG. 13 is a lower perspective view of the gear motor 10 according to the second embodiment, FIG. 14 is a rear view thereof, and FIG. 15 is a bottom view thereof. The gear motor 10 according to the second embodiment is similar in appearance to the first embodiment in its upper perspective view, front view, right side view, left side view, and plan view. FIG. 16 is an enlarged cross-sectional view illustrating the configuration of the leg portion 49 when the gear motor 10 according to the second embodiment is installed in the external structure 70. In the following embodiments, the same elements as those described in the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted.

  The gear motor 10 according to the second embodiment is different in the configuration of the cooling surface 55 from the first embodiment. The cooling surface 55 has the first width changing portion 63 according to the first embodiment, but does not have the second width changing portion 65. The first inclined surface 64 that forms the first width changing portion 63 is provided over the entire length in the direction A of the cooling surface 55. In other words, the first inclined surface 64 is provided over the entire length in the flow direction of the airflow passing through the gap 57 on the cooling surface 55.

  FIG. 17 is a lower perspective view showing a part of the speed reducer 40 of the gear motor 10 according to the second embodiment.

[Third Embodiment]
18 is a lower perspective view of the gear motor 10 according to the third embodiment, FIG. 19 is an upper perspective view thereof, FIG. 20 is a right side view thereof, and FIG. 21 is a left side view thereof. The gear motor 10 according to the third embodiment has the same appearance as that of the first embodiment in its front view, plan view, and rear view. 22 is an enlarged cross-sectional view showing the configuration of the leg portion 49 when the gear motor 10 according to the third embodiment is installed on the external structure 70, and FIG. 23 is a gear motor 10 showing the configuration of the leg portion 49 at that time. FIG. The gear motor 10 according to the third embodiment is different from the first embodiment in the configuration of the cooling surface 55.

  As shown in FIG. 23, the leg portion 49 has a first groove portion 81 extending on the bottom surface in the direction A, and second groove portions 83 branched from the first groove portion 81 and extending on both sides in the direction B intersecting the direction A. It is formed. The cooling surface 55 is provided as a groove bottom surface of the first groove portion 81 and the second groove portion 83. In the present embodiment, the second groove 83 is formed to extend in a direction orthogonal to the direction in which the first groove 81 extends. However, the angle formed with respect to the extending direction of the first groove portion 81 is not particularly limited as long as the second groove portion 83 is branched so as to extend in a direction intersecting with the extending direction of the first groove portion 81.

  In the gear motor 10 according to the present embodiment, when the leg portion 49 is installed on the installation surface 71 of the external structure 70, the second channel 69 is provided between the installation surface 71 and the second channel 69. A cooling surface 55 is formed so as to be provided. In FIG. 23, a range in which the first channel 67 and the second channel 69 are provided is indicated by a one-dot chain line. The first flow path 67 is provided between the groove bottom surface of the first groove portion 81 and the installation surface 71. The first flow path 67 extends in the direction A, and an inflow port 59 is opened on the motor side, and an outflow port 61 is opened on the non-motor side. The first flow path 67 extends from the inflow port 59 to the outflow port 61.

  The second flow path 69 is branched from the first flow path 67 and extends on both sides in the direction B intersecting the direction A, and an air flow outlet 62 is opened on the outflow side. Of the cooling surface 55, the groove bottom surface of the second groove portion 83 that defines the second flow path 69 is provided to be inclined at the same angle as the first inclined surface 64.

  In the gear motor 10 according to the above embodiment, when the air flow from the cooling fan 25 is guided to the inlet 59 of the gap 57 between the speed reducer casing 41 and the external structure 70, the first flow path 67 is formed from the inlet 59. Through to the outlet 61 in the direction P1. At this time, the air flow by the cooling fan 25 also flows to the second flow path 69 branched from the first flow path 67 and flows to the outlet 62 through the second flow path 69 in the direction P2.

  In the gear motor 10 described above, the cooling surface 55 is formed so that the first flow path 67 and the second flow path 69 are provided. Therefore, the cooling surface 55 having a larger area can be secured than when the second flow path 69 is not provided between them, and the cooling effect of the entire speed reducer 40 is further improved by increasing the amount of heat radiation from the cooling surface 55.

  Note that, like the gear motor 10 according to the present embodiment, the second flow path 69 branched from the first flow path 67 may be provided in the gear motor 10 according to the second embodiment.

  FIG. 24 is a perspective view showing a part of the speed reducer 40 of the gear motor 10 according to the third embodiment.

  As mentioned above, although this invention was demonstrated based on embodiment, embodiment only shows the principle and application of this invention. In the embodiment, many modifications and arrangements can be made without departing from the spirit of the present invention defined in the claims.

  The speed reducer 40 according to each embodiment exemplifies the case where the eccentric swing type planetary gear speed reduction mechanism is accommodated in the main body 47. Other speed reduction mechanisms may be accommodated in the main body 47 of the speed reducer 40. For example, a parallel axis speed reduction mechanism or an orthogonal axis speed reduction mechanism may be accommodated. That is, the speed reduction mechanism accommodated in the main body 47 is not particularly limited.

  Although the cooling fan 25 is provided on the rotating shaft 23 of the motor 20, the cooling fan 25 may be provided on an input shaft or an output shaft 45 as a rotating shaft of the speed reducer 40. In this case, the input shaft protrudes from one side surface of the speed reducer casing 41, the cooling fan 25 is provided at a position shifted from the front end of the input shaft to the other end side, and the remaining portion is provided as a motor. You may connect with 20 rotating shafts 23.

  The first width changing portion 63 of the cooling surface 55 is formed by a first inclined surface 64 in which the gap width between the cooling surface 55 and the installation surface 71 continuously increases from the inflow side to the outflow side of the airflow passing through the gap 57. The case was illustrated. In addition, the first width changing portion 63 may be formed by combining a plurality of flat surfaces, inclined surfaces, or the like so that the gap width with the installation surface 71 gradually increases. The second width changing portion 65 also combines a plurality of flat surfaces, inclined surfaces, and the like if the gap width between the second width changing portion 65 and the installation surface 71 becomes narrower from the inflow side to the outflow side of the air flow passing through the gap 57. May be formed.

  The cooling surface 55 may be provided with fins as a plurality of protrusions for promoting heat exchange with the air flow passing through the gap 57. The cooling surface 55 may be formed such that the length L1 in the direction A is different from the length L2 in the direction A in the range where the installation surface 53 is provided in the leg portion 49.

  Moreover, when the leg part 49 is installed in the installation surface 71 of the external structure 70, the 1st flow path 67 formed between the cooling surface 55 and the installation surface 71 demonstrates what extends linearly in the direction A. However, the shape is not limited to this, and may extend in a curved shape or an L shape.

  Although 1st Embodiment demonstrated the example provided so that the 1st inclined surface 64 and the 2nd inclined surface 66 might be connected continuously, surfaces, such as another flat surface, may be provided among them. . Further, a flat surface may be provided at a position where the second inclined surface 66 is provided.

  In the above-described embodiment, the case where the present invention is applied to a gear motor is illustrated, but the present invention may be applied to a reduction gear. The gear motor 10 is not particularly limited with respect to the shapes of the motor casing 21 and the fan cover 27 that appear on the external appearance of the motor 20, and may be formed in a known shape.

10 gear motor, 20 motor, 23 rotating shaft, 25 cooling fan, 29 motor fin, 40 speed reducer, 49 leg, 53 mounting surface, 55 cooling surface, 57 clearance, 63 first width changing portion, 65 second width changing portion 71 Installation surface.

Claims (7)

A gear motor in which a motor and a reduction gear are connected,
A cooling fan is provided on the rotating shaft of the motor or the speed reducer,
The speed reducer is provided with legs for installation on an external installation surface,
The leg portion, when installed on the installation surface, has an installation surface installed on the installation surface, and a cooling surface provided with a gap between the installation surface,
An air flow generated by the rotation of the cooling fan is configured to be able to pass through the gap,
The gear motor according to claim 1, wherein the cooling surface has a first width changing portion in which a clearance width between the cooling surface and the installation surface increases as it goes from the inflow side to the outflow side of the air flow passing through the clearance.   The cooling surface is provided on the inflow side of the air flow from the first width changing portion, and a second width in which a gap width between the cooling surface and the installation surface becomes narrower from the inflow side to the outflow side of the air flow passing through the gap. The gear motor according to claim 1, further comprising a changing portion.   2. The gear motor according to claim 1, wherein the first width changing portion is provided over an entire length in a flow direction of an air flow passing through the gap on the cooling surface. The cooling fan is provided on a rotating shaft of the motor;
The gear motor according to any one of claims 1 to 3, wherein the motor is provided with a plurality of motor fins at a position overlapping the gap when viewed from the axial direction of the rotating shaft.   When the leg portion is installed on the installation surface, a first flow path extending from the inlet to the outlet of the air flow passing through the gap, and a second flow path that branches off from the first flow path and opens. The gear motor according to claim 1, wherein the cooling surface is formed so as to be provided.   The length of the cooling surface along the axial direction of the rotating shaft is the same as the length along the axial direction of the rotating shaft in a range where the leg portion is installed on the installation surface. The gear motor according to any one of 1 to 5. A reduction gear connected to a motor,
Legs for installation on the external installation surface are provided,
The leg portion, when installed on the installation surface, has an installation surface installed on the installation surface, and a cooling surface provided with a gap between the installation surface,
An air flow generated by rotation of a cooling fan provided on the rotation shaft of the motor or the speed reducer is configured to be able to pass through the gap,
The speed reducer according to claim 1, wherein the cooling surface has a first width changing portion in which a clearance width between the cooling surface and the installation surface is increased from an inflow side to an outflow side of the air flow passing through the clearance.

Images