JPS59188074A - Heat engine - Google Patents

Abstract

PURPOSE:To provide for ensured power transmission and other advantages by composing a heat engine of a pair of sprockets, an endless chain which connects them and a plurality of form memorizing alloy members each of which is fixed at both ends thereof to both ends of each piece of the chain with one roller joined thereto between them. CONSTITUTION:A heat engine 11 is composed of a pair of sprockets 12 and 13 which turn in one direction only and an endless chain 14 which connects them to each other. A plurality of form memorizing alloy coils 15 each of which is fixed at both ends thereof to side rollers 14b of each set of three rollers with a middle roller 14a linked therebetween are jointed to the chain 14. Each of the coils 15 pocesses the form memorizing effect as to show the contracted state in the temperature range higher than the reverse transformation point. When the left side pieces B of the chain 14 are cooled, for example, the coils 1 are elongated so that the chain 14 is shown straight while when the right side pieces A thereof are heated, the coils 15 are contracted so that the chain 14 are shown zigzag, whereby turning the chain 14.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to improving the structure of a heat engine that utilizes thermal contraction of a shape memory alloy member.

Description of Prior Art FIG. 1 is a schematic plan view showing a conventional example of a heat engine using a shape memory alloy member. A heat engine 1 using a conventional shape-memory metal-containing member includes a pair of rotating bodies 2,
3 and a shape memory alloy coil 4 that connects this rotating body. The shape memory metal-containing coil 4 is subjected to a shape memory effect imparting treatment so that it assumes a fully elongated shape at a temperature higher than the reverse transformation temperature. The heat engine 1 is driven by heating the left side portion 4a of the shape memory alloy coil 4 to a temperature higher than the reverse transformation temperature, and cooling the right side portion 4b to a humidity lower than the transformation temperature. That is, by applying heating and cooling, the left side portion 4a and the right side portion 4b are expanded and contracted, respectively, thereby rotating the rotating bodies 2 and 3.

In addition to the heat engine shown in FIG. 1, heat engines in which two rotating bodies are connected using a belt-shaped shape memory alloy member have also been proposed. However, these devices using a belt or a coiled shape memory alloy member have the drawback that the belt or coil tends to slip, and therefore, reliable power transmission cannot be achieved and large torque cannot be transmitted. Further, even if the belt is used while allowing slippage, the belt gradually wears out due to the slippage, and there is a problem in that the belt needs to be replaced in a complicated manner.

Furthermore, since it is necessary to apply initial tension during installation, there is also a drawback that the diameter of the rotating bodies used and the distance between the rotating bodies are severely limited.

OBJECT OF THE INVENTION Therefore, the object of the invention is to overcome the above-mentioned disadvantages and to
An object of the present invention is to provide a heat engine that can achieve reliable power transmission and has a long life.

Structure of the Invention The present invention is characterized in that it includes a pair of sprockets, a chain connecting the sprockets, and a plurality of shape memory alloy members each having both ends fixed to the chain with at least one rope interposed therebetween. have

The shape memory alloy member to be fixed may be fixed at both ends "with at least one roller in between." Therefore, both ends may be fixed to a chain with a plurality of rollers in between.

The "shape memory alloy member" used in this invention includes:
Shape memory alloy members made of shape memory alloys in various shapes such as a coil shape, a plate shape, or a wire shape can be used.

Other features of the invention will become clear from the following description of embodiments with reference to the drawings.

DESCRIPTION OF THE EMBODIMENTS FIG. 2 is a schematic plan view of an embodiment of the present invention. The heat engine 11 of this embodiment includes a pair of sprockets 12.13 that rotate in only one direction as indicated by arrow X, and a chain 14 that connects the sprockets 12.13. The chain 14 also includes one roller 1.
The rollers 14b on both sides of the roller 14a sandwich the roller 4a.
, a plurality of shape memory alloy coils 15 fixed to 14b.
is installed. Therefore, in the heat engine 11 of this embodiment, every other roller 14b, 14b...
· are connected by a plurality of shape memory alloy coils 15.

The shape memory alloy coil 15 is subjected to a shape memory effect imparting treatment so that it exhibits a contracted state at a temperature higher than the reverse transformation temperature. Therefore, as is clear from FIGS. 3 and 4, which are enlarged views of the requirements of the embodiment shown in FIG. 2, when cooled, the shape memory alloy coil 15 expands and contracts as shown in FIG. Chain 14 is stretched linearly. On the other hand, when heated to a temperature higher than the transformation temperature, the shape memory alloy coil 15 contracts and assumes the shape shown in FIG. 4.

Therefore, by injecting a cooling medium into the zone B of the left side of the chain 14 in FIG. , chain 1
4 is rotationally driven between a pair of sprockets 12 and 13.

By the way, in this embodiment, the chain 14 and the pair of sprockets 12 and 13 rotate together, so that power can be reliably transmitted.

Preferably, the cooling medium for cooling and the high-temperature medium for heating are injected into the chain 14 as countercurrent flows, or the cooling and heating zones are separated and immersed, which can increase the efficiency of heating and cooling. It is from.

FIGS. 5 and 6 are partially cutaway side views for explaining other embodiments of the present invention. FIG. 5 shows a state where the shape memory alloy member is expanded and corresponds to FIG. 3 of the previous embodiment, and FIG. 6 shows a state where the shape memory alloy member is contracted and is a view corresponding to FIG. This figure corresponds to Figure 4. In the embodiment shown in FIGS. 5 and 6, a plate-shaped shape memory alloy member 2 is used instead of the shape memory alloy coil 15 of the previous embodiment.
5 is used. The other parts of the construction are the same as those in the embodiment shown in FIGS. 2 to 4, so their explanation will be omitted. As is clear from FIGS. 5 and 6, even when the plate-shaped shape memory alloy member 25 is used, the chain 14 can be partially expanded and contracted by utilizing its shape recovery effect. The paired sprockets 12 and 13 can be rotated reliably and with a large torque.

In each of the embodiments described above, both ends of the shape memory base metal member were connected to the rollers 14b, 14b, but the present invention is not limited to this.

That is, it is only necessary that both ends be fixed to the chain "with at least one roller in between." Therefore, for example, both ends may be fixed across two or more rollers, or both ends may be fixed to a portion other than the rollers.

Effects of the Invention As described above, the present invention includes a pair of sprockets, a chain connecting the sprockets, and a plurality of shape memory alloy members having both ends fixed to the chain with at least one roller in between. Because of this, power can be reliably transmitted through the engagement of the sprocket and chain.

Further, since no slip occurs, a considerably large torque can be transmitted and there is almost no risk of wear. Furthermore, because there is no severe expansion and contraction, there is less fatigue in the chain material. Therefore, a long-life heat engine can be achieved.

It should be pointed out that this invention can be applied to heat engines in general that are driven by heating and cooling.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing an example of a heat engine using a conventional shape memory alloy member. FIG. 2 is a plan view showing an embodiment of the present invention. 3 and 4 are enlarged plan views showing the main parts of the practical example shown in FIG. 2. FIG. 3 shows the state when the shape memory alloy coil is expanded, and FIG. It is a figure which shows the state when a shape memory alloy coil contracts. 5 and 6 are partially cutaway plan views for explaining the operation of another embodiment of the present invention, and correspond to FIGS. 3 and 4 of the previous embodiment. 11...Heat engine, 12.13...Sprocket, 14...Chain, 14a...Roller, 15
゜25...Shape memory alloy member.

Claims (1)

[Claims] A heat engine comprising a pair of sprockets, a chain connecting the sprockets, and a plurality of shape memory alloy members fixed at both ends to the chain with at least one roller in between.