Robot

A robot including: a driving mechanism that drives a movable member with respect to a base; and a fan that cools the driving mechanism, wherein the driving mechanism is provided with a motor, and a reducer that is disposed between the base and the movable member and that moves the movable member with respect to the base by reducing the speed of the rotation of the motor, the motor and the reducer are disposed on either side of a securing plate that is secured to the base, the cooling fan is disposed on an opposite side from the securing plate with the motor interposed between the fan and the securing plate, a space in which a surface of the reducer is exposed is formed outside the reducer, and the securing plate is provided with a vent that is connected to the space by passing through the securing plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on Japanese Patent Application No. 2016-124108, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a robot.

BACKGROUND ART

In the related art, there is a known robot provided with, in order to enhance the continuous operating capability, a structure in which a cooling fan is mounted on a motor in a driving portion, and the motor is cooled by means of an airflow (for example, see Patent Literatures 1 to 3).

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Solution to Problem

An aspect of the present invention provides a robot including: a driving mechanism that drives a movable member with respect to a base; and a cooling fan that cools the driving mechanism, wherein the driving mechanism is provided with a motor and a reducer that is disposed between the base and the movable member and that moves the movable member with respect to the base by reducing the speed of the rotation of the motor, the motor and the reducer are disposed on either side of a securing plate that is secured to the base, the cooling fan is disposed on an opposite side from the securing plate, with the motor interposed between the cooling fan and the securing plate, and generates an airflow that is circulated along a surface of the motor, a space in which a surface of the reducer is exposed is formed outside the reducer, and the securing plate is provided with a vent that is connected to the space by passing through the securing plate in a thickness direction thereof, and through which the airflow generated by the cooling fan passes.

In the above-described aspect, more than one of the vent may be provided in periphery of the motor with spaces therebetween in a circumferential direction.

The above-described aspect may be provided with an airflow-guiding portion that is disposed on an opposite side from the motor with the vent interposed between the airflow-guiding portion and the motor, and that blocks the airflow that is circulated along the surface of the motor and guides the airflow to the vent.

In the above-described aspect, the airflow-guiding portion may be provided over the entire circumference in periphery of the motor.

In the above-described aspect, the airflow-guiding portion may integrally be formed with the securing plate.

DESCRIPTION OF EMBODIMENT

A robot1according to an embodiment of the present invention will be described below with reference to the drawings.

As shown inFIG. 1, the robot1according to this embodiment has one or more joints3that are driven by a motor2.FIG. 1shows, as an example, only one gravity axis among the joints3of the robot1.

Each of these joints3is provided with: a base4; a movable member5that is provided so as to be pivotable with respect to the base4; a driving mechanism6that causes the movable member5to pivot with respect to the base4; a cooling fan7that cools the driving mechanism6; and airflow-guiding portions8.

As shown inFIGS. 1 and 2, the base4is provided with a mounting base9and a flat-plate-like securing plate10that is secured to the mounting base9. In addition to the form in which the securing plate10is formed of a member that is separate from the mounting base9and is secured to the mounting base9by means of bolts or the like, the securing plate10may take a form in which the securing plate10is secured to the mounting base9by being integrally provided in a portion of the mounting base9by means of machining or the like.

The mounting base9is provided with an accommodating space (space) S that has a circular lateral sectional shape and that can accommodate a reducer11having a substantially columnar form, described later, and the securing plate10is secured at a position where the securing plate10closes off one end of the accommodating space S in the axial direction.

A center through-hole13through which a shaft12of the motor2, described later, is made to pass in the thickness direction is provided at the center of the securing plate10.

The driving mechanism6is provided with the motor2and the reducer11that transmits the rotation of the motor2to the movable member5after reducing the speed of the rotation. The motor2is provided with a flange portion14for securing the motor2to one side of the securing plate10by means of bolts (not shown). By doing so, the motor2is secured in a state in which the shaft12is made to pass through the center through-hole13, and the flange portion14is in close contact with the securing plate10at one side thereof.

The reducer11has a columnar form having an external diameter that is smaller than that of the above-described accommodating space S, is provided with, at one end thereof in an axis-O direction, a securing portion15for securing the reducer11itself to the securing plate10by means of bolts or the like, and is provided, at the other end thereof in the axis-O direction, with an output shaft portion16for securing the reducer11to the movable member5. The securing portion15is provided, at the center thereof, with an insertion hole (not shown) into which the shaft12of the motor2is inserted along the axis-O direction.

In other words, the reducer11is configured so as to form a substantially cylindrical space between an outer circumferential surface of the reducer11and an inner circumferential surface of the accommodating space S by being accommodated in the accommodating space S in which one end thereof is closed off by the securing plate10and by securing the securing portion15to the securing plated10.

A gear (not shown) that engages with an input shaft gear (not shown) disposed in the insertion hole of the reducer11is secured to the shaft12of the motor2.

The driving mechanism6is assembled by, in a state in which the reducer11is secured to the securing plate10by means of the securing portion15, inserting the shaft12of the motor2into the insertion hole via the center through-hole13from an opposite side from the reducer11, with the securing plate10interposed between the motor12and the reducer11, by engaging the gear secured to the shaft12with the input shaft gear in the insertion hole of the reducer11, and by securing the motor2to the securing plate10by using the flange portion14.

In this embodiment, a plurality of vents17are provided in the securing plate10with spaces therebetween in the circumferential direction so as to surround the motor2. The individual vents17pass through the securing plate10in the thickness direction thereof and are connected to the substantially cylindrical space formed in the periphery of the reducer11in the accommodating space S.

The cooling fan7is secured to a head portion of the motor2and circulates a generated airflow A along a surface of the motor2toward the flange portion14from the head portion side.

The two airflow-guiding portions8are disposed, as a pair, so as to surround the motor2over substantially the entire circumference at positions that are radially further outside than the vents17are by bending strip-like plate members into arc shapes, and are secured to the securing plate10by means of screws or the like.

By doing so, the airflow A that is circulated along the surface of the motor2is blocked by the airflow-guiding portions8in the process of being circulated so as to be spread radially outward by colliding with the securing plate10, and is guided so as to pass through the vents17in the securing plate10.

The operation of the thus-configured robot1according to this embodiment will be described below.

With the robot1according to this embodiment, when the shaft12is rotated by actuating the motor2, the rotation of the shaft12is transmitted to the movable member5after the speed thereof is reduced by the reducer11, and thus, the movable member5is rotationally moved with respect to the base4at a rotational speed that is lower than that of the shaft12of the motor2. Because the torque is amplified as a result of the speed reduction by the reducer11, it is possible to perform work by moving a load attached to a distal end of the movable member5.

In this case, although heat is generated in the motor2and the reducer11due to loss associated with the work, in this embodiment, after cooling the motor2by flowing over the surface of the motor2, the airflow A generated by the cooling fan7flows into the substantially cylindrical space at the outer circumference of the reducer11by passing through the vents17in the securing plate10and is circulated in this space. Because the outer circumferential surface of the reducer11is exposed in this space, the airflow A also cools the reducer11.

In contrast, as shown inFIGS. 5 and 6, with a conventional robot30, because an airflow A generated by a cooling fan31is circulated only over the surface of a motor32and is not circulated in a space in which an outer circumferential surface of a reducer33is exposed, cooling of a driving mechanism34by the cooling fan31is limited to cooling of the motor32, and the reducer33is not cooled.

In other words, with the robot1according to this embodiment, because not only the motor2but also the reducer11is cooled by the airflow A generated by the cooling fan7, there is an advantage in that, by suppressing an increase in the temperature of the driving mechanism6as a whole, it is possible to enhance the durable life of the driving mechanism6, and it is also possible to enhance the continuous operating capability of the robot1.

In particular, because the plurality of vents17are provided in the securing plate10with spaces therebetween in the circumferential direction so as to surround the periphery of the motor2, the airflow A generated by the cooling fan7is branched into the plurality of vents17, and thus, it is possible to make the airflow A flow over regions of the outer circumferential surface of the reducer11with spaces therebetween in the circumferential direction. By doing so, there is an advantage in that it is possible to efficiently cool the entire reducer11in a uniform manner.

In this embodiment, because the airflow-guiding portions8that block the airflow A generated by the cooling fan7are provided, there is an advantage in that it is possible to efficiently cool the reducer11by guiding the airflow A to the vents17without allowing the airflow A to escape.

In this embodiment, although the airflow-guiding portions8are formed, in the form of strip-like members, as members that are separate from the securing plate10and are secured to the securing plate10by means of bolts, alternatively, as shown inFIGS. 3 and 4, the airflow-guiding portions8may be formed integrally with the securing plate10by using portions that protrude therefrom like peripheral walls at the surface of the securing plate10on the motor2side. By doing so, it is possible to decrease the number of components and reduce costs. In this case, the airflow-guiding portions8may be formed of step portions instead of being formed like the peripheral walls.

The number and spacing of the vents17may be arbitrary. The vents17may be provided at equal spacings or unequal spacings. The shape of the vents17may be circular, oval or polygonal.

As a result, the following aspect is read from the above described embodiment of the present invention.

An aspect of the present invention provides a robot including: a driving mechanism that drives a movable member with respect to a base; and a cooling fan that cools the driving mechanism, wherein the driving mechanism is provided with a motor and a reducer that is disposed between the base and the movable member and that moves the movable member with respect to the base by reducing the speed of the rotation of the motor, the motor and the reducer are disposed on either side of a securing plate that is secured to the base, the cooling fan is disposed on an opposite side from the securing plate, with the motor interposed between the cooling fan and the securing plate, and generates an airflow that is circulated along a surface of the motor, a space in which a surface of the reducer is exposed is formed outside the reducer, and the securing plate is provided with a vent that is connected to the space by passing through the securing plate in a thickness direction thereof, and through which the airflow generated by the cooling fan passes.

With this aspect, when the motor of the driving mechanism is driven, the rotation of the motor is transmitted to the movable member after the torque of the motor is amplified by reducing the speed of the rotation by the reducer, and thus, the movable member is moved with respect to the base. The airflow generated by actuation of the cooling fan cools the motor by being circulated along the surface of the motor, and is also circulated in the space formed outside the reducer by passing through the vent provided in the securing plate. Because the surface of the reducer is exposed in this space, the reducer is also cooled by the airflow. By doing so, it is possible to enhance the continuous operating capability by effectively cooling the motor and the reducer, which generate heat by being driven.

In the above-described aspect, more than one of the vent may be provided in periphery of the motor with spaces therebetween in a circumferential direction.

By doing so, after cooling the motor by being circulated along the surface of the motor, the airflow generated by the cooling fan is circulated in the space outside the reducer by being branched by the plurality of vents. By doing so, it is possible to uniformly cool the entire reducer by the airflow that is being circulated along a plurality of regions with spaces therebetween in the circumferential direction.

The above-described aspect may be provided with an airflow-guiding portion that is disposed on an opposite side from the motor with the vent interposed between the airflow-guiding portion and the motor, and that blocks the airflow that is circulated along the surface of the motor and guides the airflow to the vent.

By doing so, because the airflow that is generated by the cooling fan and that is circulated along the surface of the motor is blocked by the airflow-guiding portion and is guided to the vent, it is possible to efficiently cool the driving mechanism including the motor and the reducer by utilizing the airflow without waste.

In the above-described aspect, the airflow-guiding portion may be provided over the entire circumference in periphery of the motor.

By doing so, because the airflow that is generated by the cooling fan and that is circulated along the surface of the motor is blocked by the airflow-guiding portion over the entire circumference, it is possible to efficiently cool the driving mechanism including the motor and the reducer by utilizing the airflow without waste by preventing the airflow from escaping from any location in the circumferential direction.

In the above-described aspect, the airflow-guiding portion may integrally be formed with the securing plate.

By doing so, it is possible to decrease the number of components and to reduce costs.

REFERENCE SIGNS LIST