JPH022504B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a rope-type power transmission device that transmits power using a pulley and a rope, and in particular,
The present invention relates to a rope-type power transmission device in which a driving pulley and a driven pulley are provided so as to be movable relative to each other around orthogonal axes while maintaining a parallel state between the axes.

(Prior Art) As is well known, devices that transmit power using pulleys and ropes are used in power transmission systems of various devices because of their extremely simple configuration.

By the way, when such a rope-type power transmission device is actually incorporated into a power transmission system, the driving pulley and the driven pulley must be provided so that they can move relative to each other around orthogonal axes while maintaining the parallel state between the axes. Sometimes. An example of this is, for example, in a working robot, where power is transmitted from the arm side to the band joint via the wrist joint. If the drive pulley and the driven pulley can move relative to each other around orthogonal axes while maintaining parallel axes, the power transmission function cannot be achieved by simply wrapping a rope between the drive pulley and the driven pulley. There may be cases where this is not possible. That is, as shown in FIG. 4, the drive shaft 2 supported by the member 1
For example, when the drive pulley 3 is attached to the driven shaft 5 supported by the member 4, the driven pulley 6 is attached to the driven pulley 6, and the rope 7 is stretched between the drive pulley 3 and the driven pulley 6. 2 and the center of the driven shaft 5 in the direction shown by the solid arrow 9 in the figure, that is, the driving shaft 2 is perpendicular to the driven shaft 5 while remaining parallel to it. When it is possible to rotate around an axis, the following phenomenon occurs. Now, when the member 1 rotates about the line 8, the driving pulley 3 tilts with respect to the driven pulley 6 due to this rotation, and due to this inclination, the force is applied between the driving pulley 3 and the driven pulley 6. The rope 7 being passed is twisted around the line 8. When the rope 7 is twisted in this way, the effective length between the drive pulley 3 and the driven pulley 6 in the rope 7 becomes shorter, and as a result, as shown by the two-dot chain line in the figure, the drive shaft 2 has a A large force is applied to move the drive shaft 2 closer to the driven shaft 5. Of course, this force is also applied to the driven shaft 5 as a reaction. For this reason, the drive shaft 2
There may be a case where the bearing friction resistance of the bearing and the driven shaft 5 increases significantly, making it impossible to drive the drive pulley 3 itself.

Therefore, in order to solve this problem, as shown in FIG.
0 and 11, and these pulleys 10 and 11 make the distance between the rope 7 sufficiently narrow between the driving pulley 3 and the driven pulley 6, so that when the member 1 is rotated about the line 8, It has been considered to prevent the effective length of the rope 7 from becoming short.

With such a configuration, even if the member 1 rotates around the line 8, a large force that would cause the drive shaft 2 and the driven shaft 5 to approach each other will not act. However, with the above configuration, the two pulleys 10 and 11
is used to form a so-called aperture mechanism.
Moreover, since the outer diameters of these pulleys 10 and 11 cannot be made smaller than a value determined by the bending strength of the rope 7, it has been difficult to reduce the overall size and weight.

(Problems to be Solved by the Invention) As described above, unless the aperture mechanism is simplified, the overall size and weight cannot be reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rope-type power transmission device in which one pulley constituting the throttle mechanism can be omitted, thereby contributing to the reduction in size and weight of the entire device.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides the above-mentioned method in which a rope is wrapped around a drive pulley and a driven pulley that are movable relative to each other around orthogonal axes while maintaining the parallel state between the axes. A rope-type power transmission device comprising a throttle mechanism that transmits the rotation of the driving pulley to the driven pulley via the rope and forcibly narrows the distance between the ropes between the driving pulley and the driven pulley, The throttle mechanism is connected to one of the drive pulley or the driven pulley, and is in close proximity to the one pulley;
and one throttle pulley supported by the support system of the one pulley, and after the rope extends along the outer periphery of the other pulley of the driving pulley or the driven pulley, the rope is connected to the one pulley. and said throttle pulley to the outer periphery of said one pulley, extends along the outer periphery of said one pulley, then reaches the outer periphery of said throttle pulley, and extends along the outer periphery of said throttle pulley. Later, it is stretched along a path from between the throttle pulley and the one pulley to the outer periphery of the other pulley.

(Function) Even if either the drive pulley or the driven pulley is also used for the throttle function, the throttle performance is not affected in any way. Therefore, even if the driving pulley and the driven pulley move relative to each other around the orthogonal axes while maintaining the parallel state between their axes, no force acts between the two pulleys in a direction that causes them to approach each other.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a rope-type power transmission device according to an embodiment of the present invention, and the same parts as in FIG. 5 are designated by the same symbols. Therefore, detailed explanation of the overlapping parts will be omitted.

In this embodiment, an aperture pulley 21 is attached to the member 4 via a support shaft 22 in close proximity to the lower edge of the driven pulley 6 in the figure, and the drive pulley 3 and the driven pulley 6 are connected via the pulley 21. Rope 7 is being hung between the two. That is, the rope 7 is endless, and when explained based on the positional relationship shown in FIG. It is passed between the driven pulley 6 and the pulley 21, and then, as shown in FIG. Subsequently, it is stretched along a route that passes between the driven pulley 6 and the pulley 21 and reaches the upper side of the driving pulley 3. Therefore, the portions of the pulley 21 and the driven pulley 6 indicated by A and B in the figure constitute a constriction portion.

With such a configuration, when the drive pulley 3 rotates in the direction shown by the solid line arrow 23, the rope 7 is sent in the directions shown by the solid line arrows 24 and 25, and as a result, the driven pulley 6 and the pulley 21 rotate in the direction shown by the solid line arrow 23.
Rotate in the directions shown by 7 and 28. Therefore, the rotation of the drive pulley 3 can be transmitted to the driven pulley 6 via the rope 7. In this case, A and B in the diagram
Since the part indicated by constitutes the aperture part, member 1
Even if it rotates in the direction indicated by the solid arrow 9 in the figure, no large force acts between the drive shaft 2 and the driven shaft 5 in the direction of bringing these two shafts closer together.

In this way, a good squeezing effect can be achieved by using only one squeezing pulley 21. Therefore, the number of pulleys can be reduced by one compared to the conventional one, which ultimately contributes to reducing the size and weight of the entire device.

FIG. 3 shows another embodiment of the present invention, in which the same parts as in FIG. 1 are designated by the same reference numerals.

In this embodiment, the driven pulley 6 and the pulley 21 constitute an aperture mechanism, and the driven pulley 21 is used for direction change to transmit rotational force to a new driven pulley 29.

Even in the case of such a configuration, the same effects as in the embodiment described above can be obtained.

In addition, each of the above-mentioned embodiments is an example in which only member 1 rotates, but member 4 or members 1 and 4
Of course, this method can also be applied to the case where the robot rotates. Furthermore, in each of the above-mentioned embodiments, the aperture mechanism is composed of a driven pulley and one aperture pulley, but depending on the installation conditions, the aperture mechanism may be composed of a driving pulley and one aperture pulley. It's okay.

[Effects of the Invention] As described above, according to the present invention, either the driving pulley or the driven pulley is also used for squeezing, so the number of squeezing pulleys can be reduced, and the device It can contribute to realizing the overall size and weight reduction.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a rope type power transmission device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line X-X in FIG. 1, and FIG. 3 is another embodiment of the present invention. FIG. 4 is a diagram for explaining the problems of the rope type power transmission device, and FIG. 5 is a schematic side view of the rope type power transmission device according to the related art. FIG. 1, 4... Member, 2... Drive shaft, 3... Drive pulley, 5... Driven shaft, 6... Driven pulley, 7...
Rope, 21... Pulley for squeezing.

Claims (1)

[Claims] 1. A rope is wrapped around a driving pulley and a driven pulley that are movable relative to each other around orthogonal axes while maintaining the parallel state between the axes, and the rotation of the driving pulley is transmitted to the driven pulley via the rope, and the driving In a rope type power transmission device comprising a throttle mechanism for forcibly narrowing the distance between the ropes between a pulley and the driven pulley, the throttle mechanism connects one of the drive pulley or the driven pulley to the It is composed of one throttle pulley that is close to one of the pulleys and supported by the support system of the one pulley, and the rope is attached to the outer periphery of the other pulley of the driving pulley or the driven pulley. After extending along the outer periphery of the one pulley from between the one pulley and the drawing pulley, extending along the outer periphery of the one pulley, reaching the outer periphery of the drawing pulley, and reaching the outer periphery of the drawing pulley. A rope-type power transmission device, characterized in that the rope extends along the outer periphery of the pulley, and then is stretched along a path from between the throttle pulley and the one pulley to the outer periphery of the other pulley.