JPH0768940B2 - Rotating device using shape memory alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a rotating device utilizing the characteristics of a shape memory alloy.

<Prior Art> Conventionally, various attempts have been made to obtain a driving source by utilizing the deforming force of a shape memory alloy due to a temperature change, but in many cases, a rotational driving force is required as a driving force. hand,
Since the motion direction of the shape memory alloy is essentially a reciprocating motion, the application of the drive device using the shape memory alloy has been limited. Although it is possible to convert reciprocating motion into rotary motion by using a crank mechanism or other known mechanism, there is a disadvantage that the structure becomes complicated and a reliable rotary motion cannot be obtained.

<Problems to be Solved by the Invention> In view of the above-mentioned drawbacks of the prior art, a main object of the present invention is to use a shape memory alloy to generate a rotational driving force by utilizing temperature change. To provide.

<Means for Solving Problems> According to the present invention, such an object is meshed with a rack gear biased in different axial directions by a shape memory alloy member and a normal spring means, and the rack gear. A pair of first gears that are rotatably pivotally supported, and a pair of second gears that are coaxially and rotatably pivotally supported with respect to the first gear, respectively. A shape memory alloy comprising: a clutch spring interposed between one gear and the second gear; and a common third gear that meshes with the two second gears. This is accomplished by providing a rotating device that is utilized.

<Operation> Since the rack is driven by the balance of the force between the shape memory alloy member and the spring, the stroke of the rack gear is stabilized, and the clutch spring is used to step the two second gears. A unidirectional rotational movement can be obtained by generating movement and engaging these second gears with a common third gear.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show an embodiment of a rotating device according to the present invention. Two pivots 2 and 3 are fixed in parallel to the substrate 1, and gears 4 to 7 having different diameters are attached to the pivots 2 and 3, respectively.
Are coaxially and rotatably supported by two pieces each. A pair of gears 4, 5 or 6, 7 pivotally supported by each pivot 2 or 3 has a cylindrical boss 4 formed on the opposite end face thereof.
A single clutch spring 13 is wound around the outer peripheral surfaces of both bosses 4a, 5a by hitting each other with a and 5a. The clutch springs 13 are wound around the bosses 4a and 5a with a certain amount of winding force, and the winding directions of the clutch springs provided for the two pivots 2 and 3 are different.

Gears 5 and 7 having a relatively small diameter mesh with different teeth of a rack gear 10 having rack teeth on both sides, and the rack gear 10 has a tension coil spring 11 and a tension coil at both axial ends thereof. The shape memory alloy member 12 having a spring shape is biased in different axial directions. Further, the gears 4, 6 having a relatively large diameter are meshed with a common small-diameter gear 9 rotatably supported on the substrate 1 with an output shaft 8.

Next, the operation procedure of this embodiment will be described.

According to this rotating device, when there is a temperature change exceeding the transformation point of the shape memory alloy member 12, the rack gear 10 is displaced in the axial direction, for example, the direction indicated by the solid arrow (FIG. 1). As a result, the gears 5 and 7 are rotationally driven in different directions. However, one of the clutch springs 13 wound around the gears in different winding directions is dragged in the winding tightening direction, and for example, the gear 4 is , Is driven to rotate in the counterclockwise direction in FIG. As a result, the gear 9 is rotationally driven in the clockwise direction in FIG. 1 and is taken out from the output shaft 8.

At this time, the gear 6 is rotationally driven by the gear 9 and the gear 7 is rotationally driven by the rack gear 10. However, since the relative rotation between the gears 6 and 7 tends to loosen the clutch spring, these two gears are free from each other. Can be rotated.

Next, when the ambient temperature changes in the opposite direction and exceeds the transformation point of the shape memory alloy member 12 again, the rack gear 10 is displaced as shown by the broken arrow, and the clutch spring on the pivot 3 side is tightened. Thus, the gear 6 is rotationally driven in the direction indicated by the dashed arrow. This rotational force is transmitted to the gear 9 and is rotationally driven in the direction indicated by the dashed arrow, that is, in the counterclockwise direction, and the gear 9 and the output shaft 8 are rotationally driven in the clockwise direction.

In this way, the gear 9 and the output shaft 8 can always be rotationally driven in the same direction, that is, in the clockwise direction regardless of the displacement of the rack gear 10 in the axial direction.

According to this rotating device, in an environment with temperature change,
The temperature change can be directly converted into the driving force. Even in an environment where the temperature does not change, for example, by intermittently irradiating sunlight with a slit that is separately driven (may be driven by this rotating device), the shape memory alloy member 12 It can also cause a temperature change.

<Effects of the Invention> As described above, according to the present invention, it is possible to directly convert a temperature change into rotational power with only a simple mechanical structure,
It can be applied very suitably to various uses, and its effect is extremely large.

[Brief description of drawings]

FIG. 1 is a schematic front view of a rotating device according to the present invention. FIG. 2 is a sectional view taken along the line II-II in FIG. 1 ... Substrate, 2, 3 ... Axis 4-7 ... Gear, 8 ... Output shaft 9 ... Gear, 10 ... Rack gear 11 ... Tension coil spring 12 ... Shape memory alloy member

Claims (2)

[Claims] 1. A rack gear biased in different axial directions by a shape memory alloy member and ordinary spring means, and a pair of first gears rotatably supported so as to mesh with the rack gear. A pair of second gears that are coaxially and rotatably supported with respect to the first gear, and are respectively interposed between the first gear and the second gear that are coaxial with each other. A rotating device using a shape memory alloy, comprising: a clutch spring; and a common third gear that meshes with the second gears. 2. The rack gear has gear teeth on two different gear surfaces, and each of the gear teeth is meshed with each of the first gears.
The rotating device according to the item.