JP7271586B2 - actuator - Google Patents

Description

The present disclosure relates to actuators.

For example, Patent Literature 1 discloses an actuator that includes an electric motor and a speed reducer.

JP 2015-119566 A

Here, since the electric motor generates heat as it is driven, it is necessary to release the heat so that the temperature of the electric motor does not rise excessively. Japanese Patent Application Laid-Open No. 2002-200003 employs a configuration in which a heat sink is provided in the vicinity of the electric motor to suppress the temperature rise of the electric motor. Further, in general, a structure for heat dissipation using an electric heat dissipation fan or the like may be adopted. However, such a configuration poses a problem in terms of space saving.

An actuator proposed in the present disclosure includes an electric motor, an output section that outputs a rotational force of the electric motor, a transmission mechanism including a train wheel that transmits the rotational force of the electric motor to the output section, and the transmission mechanism. and a heat exhaust part protruding from the accommodating part along the direction in which the rotating shaft of the electric motor extends; and a heat transfer member forming a heat path. According to this actuator, it is possible to suppress the temperature rise of the electric motor while realizing space saving.

It is the left view which looked at the actuator which concerns on 1st Embodiment from the left. It is the back view which looked at the actuator which concerns on 1st Embodiment from the back. It is the front view which looked at the actuator which concerns on 1st Embodiment from the front. It is the bottom view which looked at the actuator which concerns on 1st Embodiment from the downward direction. It is the left view which looked at the actuator which concerns on the modification of 1st Embodiment from the left. It is the back view which looked at the actuator which concerns on the modification of 1st Embodiment from the back. It is the left view which looked at the actuator which concerns on 2nd Embodiment from the left. It is the back view which looked at the actuator which concerns on 2nd Embodiment from the back. It is the front view which looked at the actuator which concerns on 2nd Embodiment from the front. It is the left view which looked at the actuator which concerns on 3rd Embodiment from the left. It is the back view which looked at the actuator which concerns on 3rd Embodiment from the back.

Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. In the following description, the direction indicated by arrow X1 in each drawing is rightward, the direction indicated by arrow X2 is leftward, the direction indicated by arrow Y1 is forward, the direction indicated by arrow Y2 is rearward, and the direction indicated by arrow Z1 is indicated by arrow Z1. The direction is defined as upward, and the direction indicated by arrow Z2 is defined as downward. Note that each figure showing the first embodiment shows an example in which the rotation axis ax1 of the electric motor 10 extends in the front-rear direction, and the output section 30 is positioned in front of the actuator 100 . However, the posture when the actuator 100 is used is not limited to those illustrated. That is, the rotating shaft ax1 of the electric motor 10 may extend in the horizontal direction or may extend in the vertical direction. The same applies to other embodiments and modifications.

[First Embodiment]
An actuator 100 according to a first embodiment will be described with reference to FIGS. 1 to 4. FIG. FIG. 1 is a left side view of the actuator according to the first embodiment as seen from the left. FIG. 2 is a rear view of the actuator according to the first embodiment as seen from the rear. FIG. 3 is a front view of the actuator according to the first embodiment as seen from the front. FIG. 4 is a bottom view of the actuator according to the first embodiment, viewed from below.

The actuator 100 has an electric motor 10 , a speed reducer 20 and an output section 30 .

The electric motor 10 is a device that accommodates at least a coil, a rotor, a stator, and a shaft in an exterior case 11 that constitutes the exterior of the electric motor 10, and that generates a rotational force about a rotation axis ax1. Since the configuration and arrangement of the coil, rotor, and stator of the electric motor 10 are not particularly limited, detailed description thereof will be omitted. In FIGS. 1 and 2, the electric motor 10 is viewed from the outside, that is, only the exterior case 11 of the electric motor 10 is shown, and the illustration of the internal structure thereof is omitted.

FIGS. 1 and 2 show an electric motor 10 including a substantially cubic exterior case 11 having a top side 10T, a bottom side 10B, a left side 10L, and a right side 10R.

The output unit 30 outputs the torque of the electric motor 10 to the outside of the actuator 100 . The output unit 30 preferably includes a shaft portion that rotates about the rotation axis ax2. In the first embodiment, an example in which the output unit 30 outputs the rotational force of the electric motor 10 around a rotation axis ax2 coaxial with the rotation axis ax1 of the electric motor 10 is shown. The output unit 30 may be a separate member from the speed reducer 20 or may constitute a part of the speed reducer 20 .

The speed reducer 20 includes a transmission mechanism 21 that reduces the rotational force of the electric motor 10 and transmits it to the output section 30 and a housing 22 that houses the transmission mechanism 21 . The transmission mechanism 21 includes a gear train including a plurality of gears. In FIG. 1, illustration of a specific configuration of the transmission mechanism 21 is omitted, and a region where the transmission mechanism 21 is arranged is indicated by a dashed line. Housing 22 includes a housing portion 221 that houses transmission mechanism 21 . 1 shows an example in which the housing portion 221 is provided in front of the electric motor 10, and the rear surface of the housing portion 221 is provided so as to be orthogonal to the direction in which the rotation axis ax1 of the electric motor 10 extends. there is

Here, the electric motor 10 generates heat as it is driven. Therefore, in the first embodiment, the heat transfer member 40 is used to release the heat generated by the electric motor 10 to the housing 22 to suppress the temperature rise of the electric motor 10 .

Specifically, the housing 22 is formed with a heat exhaust portion 222 projecting from the accommodating portion 221 along the direction in which the rotation axis ax1 of the electric motor 10 extends. The heat exhaust part 222 has a plate shape along the side surface of the electric motor 10 . 1 to 4 show an example in which the heat exhaust portion 222 is provided below the lower surface 10B of the electric motor 10 and extends along the lower surface 10B. Note that, in the first embodiment, the heat exhaust portion 222 is a portion that does not accommodate parts such as the gear train of the transmission mechanism 21 .

Also, a gap G is formed between the heat exhaust portion 222 and the lower surface 10B of the electric motor 10 . A heat transfer member 40 is provided in the gap G. The heat transfer member 40 is provided in contact with both the lower surface 10</b>B of the electric motor 10 and the heat exhaust portion 222 of the housing 22 .

The heat transfer member 40 is a separate member from the electric motor 10 and the speed reducer 20 . The heat transfer member 40 is a member with high thermal conductivity that transfers heat generated by the electric motor 10 to the heat exhaust portion 222, and is preferably made of heat transfer silicon, for example. However, this is only an example, and the heat transfer member 40 may be made of other synthetic resin or the like having high thermal conductivity. The thermal conductivity of the heat transfer member 40 is preferably 4 [W/(m·K)] or more, for example.

Moreover, the housing 22 of the speed reducer 20 is preferably made of metal with high thermal conductivity such as aluminum. At least the heat exhaust portion 222 of the housing 22 is preferably made of metal with high thermal conductivity, such as aluminum. The thermal conductivity of the heat exhaust part 222 is preferably 100 [W/(m·K)] or more, for example.

In the actuator 100 of the first embodiment, the heat generated by the electric motor 10 is transmitted to the heat exhaust portion 222 of the housing 22 through the heat transfer member 40, and radiated into the air at the heat exhaust portion 222. . As a result, the temperature rise of the electric motor 10 is suppressed. In FIGS. 1 and 2, the heat transfer path of heat generated by the electric motor 10 is indicated by arrows.

In the actuator 100 of the first embodiment, temperature rise of the electric motor 10 can be suppressed without separately providing an electric heat radiation fan or the like. That is, no electric power is required for exhaust heat. In addition, the actuator 100 can be applied to places where quietness is required, since no noise is generated by driving the heat radiation fan. Further, it is possible to suppress the temperature rise of the electric motor 10 with a simple configuration without using a heat radiation fan or the like, and as a result, it is possible to suppress the manufacturing cost. Further, by adopting a configuration that conducts heat to a part of the speed reducer 20 that is arranged near the electric motor 10, space saving can be realized.

As the contact area of the heat transfer member 40 with respect to the electric motor 10 and the housing 22 increases, the heat exhaust effect increases. The electric motor 10 has a shape such that the direction in which the rotation axis ax1 extends is the longitudinal direction. Therefore, among the side surfaces of the electric motor 10, the area of the surface along the direction in which the rotation axis ax1 extends is relatively large. In the first embodiment, since the heat transfer member 40 is brought into contact with the lower side surface 10B, which is a relatively large surface of the surface of the electric motor 10, a high heat exhaust effect can be obtained. .

Further, by forming the heat exhaust portion 222 along the lower side surface 10B having a relatively large area among the surfaces of the electric motor 10, the volume of the heat exhaust portion 222 can be increased. Therefore, the heat capacity of the heat exhaust part 222 can be increased, and a high heat exhaust effect can be obtained in the heat exhaust part 222 . In addition, in the first embodiment, an example in which the entire area of the lower surface 10B of the electric motor 10 faces the heat exhaust portion 222 is shown, but the present invention is not limited to this. The area of the electric motor 10 that faces the heat exhaust section 222 is preferably at least larger than the area that does not face the heat exhaust section 222 .

Further, in the first embodiment, a portion of the housing 22 of the speed reducer 20 disposed near the electric motor 10 is used as the heat exhaust portion 222, thereby suppressing the thickness of the heat transfer member 40 and A thermal path can be formed. Specifically, by forming the heat exhaust portion 222 along the lower side surface 10B of the electric motor 10, heat transfer is performed with a thickness that fills the gap G between the lower surface 10B of the electric motor 10 and the heat exhaust portion 222. A heat transfer path can be formed by providing the member 40 . Thereby, a high heat exhaust effect can be obtained while suppressing the amount of material of the heat transfer member 40 .

Moreover, it is preferable that the heat transfer member 40 is provided in contact with a portion of the electric motor 10 that is likely to be heated. In the electric motor 10, the temperature of the coil is particularly likely to rise. The coils are arranged side by side in the circumferential direction outside the rotation axis ax1 of the electric motor 10 in the radial direction. Therefore, the temperature of the electric motor 10 is particularly likely to rise on the side surface located radially outward of the rotation axis ax1. In the first embodiment, the heat transfer member 40 is brought into contact with the lower surface 10B of the electric motor 10, which tends to increase in temperature, so that the heat generated in the electric motor 10 can be discharged more efficiently. .

Further, the housing 22 may be provided with a positioning portion for positioning the housing 22 with respect to other members outside the actuator 100 . The other member may be, for example, a housing of a device in which the actuator 100 is accommodated, various devices provided near the actuator 100, and the like. In the first embodiment, an example in which a first positioning portion 221a is provided on the lower surface of the housing portion 221 and a first positioning portion 222a is provided on the lower surface of the heat exhaust portion 222 is shown. The first positioning portion 221a and the second positioning portion 222a are spaced apart in the direction in which the rotation axis ax1 of the electric motor 10 extends. As described above, in the first embodiment, the heat exhaust portion 222 has a shape whose longitudinal direction is the direction in which the rotation axis ax1 of the electric motor 10 extends. It is possible to increase the distance from the positioning portion 222a. Therefore, it is possible to improve the positioning accuracy of the housing 22 with respect to other members. However, the present invention is not limited to this, and the two positioning portions may both be provided on the lower surface of the heat exhaust portion 222 .

The first positioning portion 221 a and the second positioning portion 222 a are preferably pins protruding from the lower surface of the housing 22 . However, the present invention is not limited to this, and the first positioning portion 221a and the second positioning portion 222a may be holes into which pins are fitted. Also, the number of positioning portions is not limited to two, and may be three or more.

[Modification of First Embodiment]
A modification of the first embodiment will be described with reference to FIGS. 5 and 6. FIG. FIG. 5 is a left side view of an actuator according to a modification of the first embodiment, viewed from the left. FIG. 6 is a rear view of an actuator according to a modification of the first embodiment, viewed from the rear. The actuator 101 according to the first embodiment has the same configuration as the actuator 100 described with reference to FIGS. 1 to 4 except for the configuration of the heat transfer member. Further, in FIG. 5, the heat transfer paths of the heat generated by the electric motor 10 are indicated by arrows in the same manner as in FIGS.

1 to 4, an example in which the heat transfer silicon, which is the heat transfer member 40, is provided in the gap G between the electric motor 10 and the heat exhaust portion 222 of the housing 22 has been described, but the present invention is not limited to this. For example, as shown in FIGS. 5 and 6, a heat transfer sheet 140 that is a heat transfer member may be attached across the side surface of the electric motor 10 and the heat exhaust portion 222 of the housing 22 . Note that the heat transfer sheet 140 is preferably made of a material with high thermal conductivity, such as a graphite sheet.

Also, for example, the heat transfer sheet 140 may be flexible. Thereby, the heat transfer sheet 140 can be attached regardless of the shape and arrangement of the electric motor 10 and the housing 22 . FIG. 6 shows a configuration in which the left side surface 10L of the electric motor 10 and the left side surface of the heat exhaust section 222 are not flush with each other. Both the electric motor 10 and the housing 22 can be contacted.

As shown in FIGS. 5 and 6, in the actuator 101 of the modified example of the first embodiment, the heat transfer sheet 140 is attached to the left side surface 10L of the electric motor 10 and the left side surface of the heat exhaust section 222. . Similarly, a heat transfer sheet 140 is attached to the right side surface 10</b>R of the electric motor 10 and the right side surface of the heat exhaust portion 222 . By adopting such a configuration, the heat generated by the electric motor 10 is transferred to the heat exhaust portion 222 through the heat transfer sheet 140 . Thereby, the temperature rise of the electric motor 10 can be suppressed.

Moreover, the heat transfer sheet 140 is preferably attached so as to contact not only the side surface of the heat discharging section 222 but also the side surface of the housing section 221 . As a result, the heat generated by the electric motor 10 is directly transmitted not only to the exhaust heat section 222 but also to the housing section 221 . As a result, the temperature rise of the electric motor 10 can be suppressed more efficiently.

A gap G may be formed between the lower surface 10B of the electric motor 10 and the heat exhaust portion 222, as in the first embodiment. As a result, the air permeability between the electric motor 10 and the housing 22 is improved, and the heat generated by the electric motor 10 is easily radiated into the air. Moreover, the heat transfer sheet 140 is preferably provided across the electric motor 10 and the heat exhausting section 222 so as to cover at least part of the gap G. As shown in FIG.

In addition, in the modification of the first embodiment, the lower surface 10B of the electric motor 10 and the heat exhausting portion 222 may be brought into contact with each other. For some reason, it is difficult to make surface contact. Therefore, as shown in FIGS. 5 and 6, a gap G is formed to improve air permeability, and the heat generated by the electric motor 10 is transferred to the heat exhaust portion 222 through the heat transfer sheet 140. , the temperature rise of the electric motor 10 can be suppressed more efficiently.

Note that the configuration of the first embodiment and the configuration of its modification may be combined. That is, in the actuator 100 having the heat transfer member 40 provided in the gap G shown in FIGS. 1 to 4, the heat transfer sheet 140 as the heat transfer member may be further provided.

[Second embodiment]
Next, an actuator 200 according to a second embodiment will be described with reference to FIGS. 7 to 9. FIG. FIG. 7 is a left side view of the actuator according to the second embodiment as seen from the left. FIG. 8 is a rear view of the actuator according to the second embodiment as seen from the rear. FIG. 9 is a front view of the actuator according to the second embodiment as seen from the front. The same reference numerals are used for the same configurations as those described in the first embodiment, and detailed description thereof will be omitted. 7 and 8, like FIGS. 1 and 2, the heat transfer paths of the heat generated by the electric motor 10 are indicated by arrows. In addition, in FIG. 7, the inner peripheral surface of the heat exhaust portion 222 and the outer shape of the electric motor 10 surrounded by the heat exhaust portion 222 are indicated by dashed lines.

In the second embodiment, a housing 2200 of a speed reducer 220 includes an accommodating portion 2201 that accommodates the transmission mechanism 21, and a heat exhaust portion 2202 that protrudes from the accommodating portion 2201 along the direction in which the rotation axis ax1 extends.

The heat exhaust part 2202 has a tubular shape surrounding the side surface of the electric motor 10 . That is, the heat exhaust part 2202 is provided so as to surround the upper side surface 10T, the lower side surface 10B, the right side surface 10R, and the left side surface 10L of the electric motor 10. As shown in FIG. Also, a gap G is formed between the heat exhaust portion 2202 and each side surface of the electric motor 10 .

Further, in the second embodiment, the heat transfer member 240 surrounds the side surface of the electric motor 10 and is provided so as to be in contact with both the side surface of the electric motor 10 and the heat exhaust portion 2202 .

More specifically, the heat transfer member 240 has a tubular shape provided so as to contact each of the upper side surface 10T, the lower side surface 10B, the right side surface 10R, and the left side surface 10L of the electric motor 10 . Also, the heat transfer member 240 is provided so as to come into contact with the inner peripheral surface of the heat exhaust portion 2202 . As a result, the heat generated by the electric motor 10 is transferred to the heat exhaust portion 2202 through the heat transfer member 240 . However, the heat transfer member 240 is not limited to a tubular shape. good too.

The heat transfer member 240 may be made of the same material as the heat transfer member 40 described in the first embodiment. That is, the heat transfer member 240 is preferably made of synthetic resin or the like having high thermal conductivity, such as heat transfer silicon.

In the second embodiment, since the heat transfer member 240 has a cylindrical shape surrounding the electric motor 10, the contact area of the heat transfer member 240 with respect to the electric motor 10 and the heat exhaust section 2202 is smaller than that in the first embodiment. big. Therefore, the heat generated by the electric motor 10 can be more efficiently transferred to the exhaust heat section 2202 . As a result, the temperature rise of the electric motor 10 can be suppressed more efficiently. Although FIG. 7 shows an example in which the rear portion of the electric motor 10 is exposed from the heat exhausting portion 2202, the smaller the amount of the electric motor 10 exposed from the heat exhausting portion 2202, the better the heat exhausting effect. be able to. In other words, the larger the area of the electric motor 10 surrounded by the heat exhaust portion 2202, the more the heat exhaust effect can be enhanced. Specifically, for example, the area of the electric motor 10 surrounded by the heat exhausting section 2202 may be larger than the area not surrounded by the heat exhausting section 2202 .

[Third Embodiment]
Next, an actuator 300 according to a third embodiment will be described with reference to FIGS. 10 and 11. FIG. FIG. 10 is a left side view of the actuator according to the third embodiment, viewed from the left. FIG. 11 is a rear view of the actuator according to the third embodiment as seen from the rear. The same reference numerals are used for the same configurations as those described in the first embodiment, and detailed description thereof will be omitted.

In the third embodiment, an example in which the rotation axis ax1 of the electric motor 10 and the rotation axis ax2 of the output section 30 are not on the same straight line but are arranged in parallel with each other will be described. Also, in the third embodiment, an example in which the output section 30 is provided at the rear portion of the actuator 300 will be described.

An actuator 300 according to the third embodiment has an electric motor 10 and a reduction gear 320 . The speed reducer 320 includes a transmission mechanism 321 including a gear train and the like, and a housing 322 . A dashed line shown in FIG. 10 indicates a region where the transmission mechanism 321 is arranged.

The housing 322 includes an accommodating portion 3221 and a heat exhaust portion 3222 extending rearward from the upper portion of the accommodating portion 3221 . In the housing 322, as shown in FIG. 10, the transmission mechanism 321 is accommodated in the accommodation portion 3221 and the heat exhaust portion 3222. As shown in FIG. That is, the transmission mechanism 321 is not housed only in the housing portion 3221 but is housed across the housing portion 3221 and the heat exhausting portion 3222 . With such a configuration, the rotational force of the electric motor 10 is transmitted to the output section 30 through the transmission mechanism 321 .

A gap G is formed between the upper surface 10T of the electric motor 10 and the lower surface of the heat exhaust portion 3222 . A heat transfer member 340 is provided in the gap G. As shown in FIG. The heat transfer member 340 is provided so as to contact both the upper surface 10T of the electric motor 10 and the lower surface of the heat exhaust portion 3222 .

The heat transfer member 340 may be made of the same material as the heat transfer member 40 described in the first embodiment. That is, the heat transfer member 340 is preferably made of synthetic resin or the like having high thermal conductivity, such as heat transfer silicon.

In the actuator 300 of the third embodiment, the heat generated by the electric motor 10 is transferred to the heat exhaust portion 3222 of the housing 322 through the heat transfer member 340, as in the first embodiment. Therefore, the temperature rise of the electric motor 10 is suppressed.

In each of the above-described embodiments and modifications, the speed reducer 20 including the transmission mechanism 21 that reduces the rotational force of the electric motor 10 and transmits it to the output unit 30 has been described as an example, but the present invention is not limited to this. For example, a transmission including a transmission mechanism that changes the rotational force of the electric motor 10 and transmits it to the output section 30 may be used. In this case, part of the housing of the transmission may be the heat exhaust section.

Reference Signs List 10 electric motor 10T upper side 10B lower side 10R right side 10L left side 11 exterior case 20,220,320 speed reducer 21,321 transmission mechanism 22,220,322 housing 221,2201,3221 Accommodating portion 222, 2202, 3222 Heat exhausting portion 222a Positioning portion 30 Output portion 40, 240, 340 Heat transfer member 100, 101, 200, 300 Actuator G Gap ax1 Rotational axis, ax2 Rotational axis.

Claims (12)

an electric motor including at least a coil and an exterior case that houses the coil ;
an output unit that outputs the rotational force of the electric motor;
a transmission mechanism including a train wheel that transmits the rotational force of the electric motor to the output unit;
a housing including at least an accommodating portion that accommodates the transmission mechanism; and a heat exhaust portion that projects from the accommodating portion along a direction in which the rotating shaft of the electric motor extends;
a heat transfer member that is provided between the exterior case and the heat exhaust section and that constitutes a heat transfer path that transfers heat generated by the electric motor to the heat exhaust section;
actuator. The heat exhaust part has a plate shape along the side surface of the exterior case ,
The actuator according to claim 1. A region of the side surface of the exterior case that faces the heat exhaust part is larger than a region that does not face the heat exhaust part,
3. The actuator according to claim 2. The heat exhaust part has a tubular shape surrounding the side surface of the exterior case ,
The actuator according to claim 1. A region of the exterior case surrounded by the heat exhaust part is larger than a region not surrounded by the heat exhaust part,
The actuator according to claim 4. The heat transfer member is provided in contact with both the exterior case and the heat exhaust section,
The actuator according to any one of claims 1-5. A gap is formed between the heat exhaust part and a side surface of the exterior case ,
The heat transfer member is provided in the gap,
The actuator according to any one of claims 1-6. an electric motor;
an output unit that outputs the rotational force of the electric motor;
a transmission mechanism including a train wheel that transmits the rotational force of the electric motor to the output unit;
a housing including at least an accommodating portion that accommodates the transmission mechanism; and a heat exhaust portion that projects from the accommodating portion along a direction in which the rotating shaft of the electric motor extends;
a heat transfer member forming a heat transfer path for transferring heat generated by the electric motor to the heat exhaust part;
has
A gap is formed between the heat exhaust part and a side surface of the electric motor,
The heat transfer member is provided across the heat exhaust part and the electric motor so as to cover at least part of the gap.
actuator . The heat transfer member is sheet-shaped,
The actuator according to claim 8. The heat transfer member is provided in contact with the heat exhaust portion and the storage portion,
10. Actuator according to claim 9. The transmission mechanism is a mechanism that decelerates the rotation of the electric motor and transmits it to the output unit.
The actuator according to any one of claims 1-10. an electric motor;
an output unit that outputs the rotational force of the electric motor;
a transmission mechanism including a train wheel that transmits the rotational force of the electric motor to the output unit;
a housing including at least an accommodating portion that accommodates the transmission mechanism; and a heat exhaust portion that projects from the accommodating portion along a direction in which the rotating shaft of the electric motor extends;
a heat transfer member forming a heat transfer path for transferring heat generated by the electric motor to the heat exhaust portion;
has
At least one of a first positioning portion and a second positioning portion for positioning the housing is provided in the heat exhausting portion,
The first positioning portion and the second positioning portion are provided apart from each other in a direction in which the rotating shaft of the electric motor extends,
One of the first positioning portion and the second positioning portion is provided in the heat exhaust portion, and the other is provided in the accommodation portion,
actuator .

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