GB2091810A - Rotary fluid-machines - Google Patents

Abstract

A motor for producing reciprocating motion has a pair of unbalanced rotating disks 3 driven by fluid eg. compressed air, issuing from a nozzle 4, the resultant force on a support body 1 due to the centrifugal forces acting on the revolving disks being aligned with the nozzle axis, as indicated by a double arrow. As shown, the disks may have inter-meshing teeth 6,7. Alternatively, the disks may have radial blades (15), Figure 7 (not shown), or the form of conventional cams, Figure 8 (not shown). <IMAGE>

Description

SPECIFICATION Power producing device This invention relates to a power producing device and more particularly to a power producing device for converting rotational motion to linear motion so as to produce reciprocating motion.

Crank mechanisms or mechanism having rotary cams with levers connected thereto have been used for converting rotational motion to reciprocating motion. These hitherto used mechanism are likely to produce detrimental vibrations in transverse and vertical directions other than the power directions, that is, directions of the reciprocating motion caused by the rotations of the cranks or cams. In addition, the cranks, cams and levers require wide spaces for their rotations and the cranks and cams need bearing members, resulting in large-sized constructions which are disadvantageous for such mechanisms.

It is an object of the invention to provide a power producing device which eliminates the above disadvantages of the prior art, and which is simple in construction and able to be smaller in size and produces reciprocating motion in power directions, restraining vibration in directions other than the power directions.

According to the invention there is provided a power producing device comprising two equal, out of balance rotatable masses arranged to rotate in opposite directions and at the same speed, the masses having their centres of gravities equally spaced relative to their axis of rotation and placed so that said rotation results in a reciprocating force along a line bisecting the line connecting the axes of rotation.

The preferred device comprises two rotary disks equal in weight supported side by side by shafts on a support member and rotatable in reverse directions at the same rotating speed, centers of gravity of the rotary disks being located by equal distances from their respective rotating centers and on a line connecting the rotating center of the disks and between the rotating centers, thereby rendering centrifugal forces of the rotary disks unbalanced only in one linear direction to obtain a vibration source which causes the support member to move reciprocatively in that linear direction.

Various methods my be employed to shift the centers of gravity of the rotary disks, for example, forming the disks circular to which weights are eccentpicallyfixed, or partially opening at shifted positions to thicken the parts or forming the disks in irregular shapes as cams.

In order to rotate the rotary disks, there may be means such as a motor and its transmission mechanism or a fluid such as air, any one of which may be used for the purpose. It is, however, most preferable that both the rotary disks are formed in their outer periphery with teeth adapted to be engaged with each other, against whose engaging surfaces pneumatic air is jetted to cause the rotary disks to rotate, whereby both the rotary disks are rotated at the same speed in opposite directions with such a simple constructions.

The power producing device according to the invention may be used as a power source for various kinds of apparatus requiring reciprocating motion.

For example, a grinding wheel may be mounted on a front end of the support member of the power producing device which is thus able to be used as a reciprocating grinding tool.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a sectional plan view of a device according to the invention; Figure2 is a sectional view taken along a line (ll)-(ll) in Figure 1; Figures 3 - 5 are plan views of principal parts of the device for explaining the operative conditions thereof; Figure 6 is a perspective view of the device; Figure 7 is a plan view of a modified principal parts; and Figure 8 is a plan view of another modified principal parts.

Embodiments of the present invention will be explained with reference to drawings. Figures 1 and 2 illustrate a support fixture (1), rotary disks (2) and (3), and a nozzle (4) for jetting compressed air.

The support fixture (1) is adapted to be arranged movably in its longitudinal direction on a casing (not shown) of any of various kinds of apparatuses. The support fixture (1) is formed in one end with a cavity chamber (5) opening in three directions, in which the two rotary disks (2) and (3) are side by side rotatably supported by means of shafts (2') and (3').

The rotary disks (2) and (3) are formed in their outer peripheries with teeth (6) and (7), respectively. These teeth (6) and (7) are adopted to engage with each other and are the same as in number such that both the rotary disks (2) and (3) rotate at the same rotating speed.

Both the rotary disks (2) and (3) are rotated in reverse rotating directions at the same speed by jetting compressed air against the enaging surfaces of the teeth (6) and (7) through the nozzle (4).

The rotary disks (2) and (3) are equal to each other in diameter and weight and are formed with apertures (8') and (9') at locations offset by the same distance from the shafts (2') and (3'), their rotating centers, respectively, within which apertures (8') and (9') weights (8) and (9) are fitted and integrally fixed, respectively.

The weight (8) and (9) are formed by a material which has a larger mass than that of the rotary disks (2) and (3), for example, a metal, if the rotary disks (2) and (3) are formed by a synthetic resin, whereby centers of gravity (G) and (G') of the rotary disks (2) and (9).

It should also be understood that the weights (8) and (9) are equal to each other in weight, while the shifted distances of the centers of gravity (G) and (G') from the rotating centers are also equal to each other.

The rotary disks (2) and (3) are mounted on the support fixture (1) in the relative position shown in Figure 1 wherein the centers of gravity (G) and (G') or the weight (8) and (9) lie on the center line (10) connecting the shafts (2') and (3') and between both the shafts (2') and (3'). In other words, no matter how the rotary disks (2) and (3) are rotated, the centers of gravity (G) and (G') or the weights (8) and (9) are always in symmetry with respect to a tangent (10') perpendicular to the center line (10).

With this arrangement, when the compressed air is jetted in the tangential direction through the nozzle (4) against the engaging surfaces of the teeth (6) and (7) of the rotary disks (2) and (3), the rotary disks (2) and (3) are rotated in reverse rotating directions at the same speed so as to be subjected to centrifugal forces (P) owing to the shifted positions of the weights (G) and (G').

At the moment that the centers of gravity (G) and (G') are positioned on the center line (10) as shown in Figures 1 and 4, the centrifugal forces (P) act in opposite directions as as to be cancelled with each other. In semicircular paths of the centers of gravity (G) and (G') from Figure 1 to Figure 4, however, when the centers of shafts (2') and (3') and in parallel with the tangent (10), respectively, both the centrifugal forces (P) act in the same directions (toward the left as viewed in the drawings) in parallel with the tangent (10'), while in the other positions of the cenetrs of gravity (G) and (G'), components (P) of the centrifugal forcess (P) act in the same directions in parallel with the tangent (10'), but components (1) of the centrifugal forces (P) act in opposite directions in parallel with the center line (10) so as to be cancelled with each other (Figure 3).

In the paths of the centers of gravity (G) and (G'), therefore, the rotary disks (2) and (3) are subjected to the centrifugal forces (P) and (P ) which act through the shafts (2') and (3') on the support fixture (1) which is consequently moved toward the left as viewed in the drawing.

In the other semicircular paths of the centers of gravity (G) and (G') from Figure 4to Figure 1, the rotary disks (2) and (3) are subjected to the centrifugal forces (P) and (P ) in the direction oposite to the direction above described in the same manner (Figure 5) to cause the support fixture (1) to move in one direction in the drawing.

Accordingly, when the rotary disks (2) and (3) are continuously rotated, the support fixture (1) performs reciprocating motion in the direction of the tangent (10'). The centrigual forces (P) orcompo- nents (P ) in the direction of the center line (10) are cancelled with each other to restrain vibration in this direction which would otherwise occur.

A cycle number of the reciprocating motion of the support fixture (1 ) can be increased by speeding up the rotation of the rotary disks (2) and (3), while a stroke of the reciprocating motion can be elongated by increasing the weight of the weights (8) and (9).

Figure 7 illustrates a modified embodiment of the invention, wherein rotary disks (12) and (13) are provided with a plurality of blades (14) and (15) extending from their outer peripheries and are rotatably arranged side by side spaced apart from each other to avoid interengagement of the blades (14) and (15).

The rotary disks (12) and (13) are provided with weights (8) and (9) in the same manner as the earlier embodiment.

Byjetting compressed air equal in pressure and flow rate through nozzles (16) and (16) against the blades (14) and (15) ofthe rotary disks (12) and (13), they are rotated at the same speed in reverse directions, respectively, while the weights (8) and (9) are maintained in a constant condition.

Figure 8 shows modified rotary disks in which rotary disks (22) and (23) are in the form of cams whose centers of gravity (G) and (G') are shifted from centers (22') and (23') of rotation, respectively.

In Figure 8, the rotary disks (22) and (23) are rotated at the same speed in reverse rotating directions by means of motors, gear mechanisms or the like.

The preferred device according to the invention comprises two rotary disks equal in weight supported side by side by shafts on a support member and rotatable in opposite directions at the same speed, whose centers of gravity are shifted by an equal distance from respective centers of rotation and located between the centers of rotation and on a line connecting both the centers as above described, whereby when both the rotary disks are rotated, centrifugal forces owing to the off-center of the centers of the gravity act on the support member through the shafts only in the tangential direction of the rotary disks to cause reciprocating movement of the support member in the tangential direction.

Accordingly, at least the preferred device according to the invention enables various kinds of reciprocating apparatus such as a small type grinder to be driven with the aid of the reciprocating motion undergoing by the support member. As the centrifugal forces causd by both the rotary disks other than the forces in the direction of the reciprocatging motion are cancelled with each other, vibration as transverse oscillation can be restrained, thereby eliminating any transverse oscillation in various kinds of apparatuses to facilitate their operation and to improve their accuracy.

Moreover, the rotary disks are arranged on the support member thereby to simplify a support structure which in comparison with a conventional crank mechanism requires only a small required for the rotary members.

Claims (8)

1. A power producing device comprising two equal, out of balance rotatable masses arranged to rotate in opposite directions and at the same speed, the masses having their centers of gravities equally spaced relative to axes or rotation and placed so that said rotation results in a reciprocating force along a line bisecting the line connecting the axes of rotation.

2. A device according to claim 1, wherein the said masses are defined by circular discs weighted to have their centers of gravity offset from their axes of rotation.

3. A device according to claim 2, wherein the discs have toothed peripheries and the teeth of the respective discs are engaged.

4. A device according to claim 2, wherein the discs have radial blades.

5. A device accoring to claim 3 or 4, including a drive means coprising fluid jet means for directing jets of fluid along said line of the reciprocating force to impinge on said teeth or blades to cause same to rotate.

6. A device according to any proceeding claim, wherein the rotating masses are mounted shafts carried by a support.

7. A power producing device comprising two rotary disks equal in weight supported side by side by shafts on a support member and rotatable in opposite directions at the same rotating speed, centers of gravity of said rotary disks being shifted by an equal distance from respctive rotating centers of said disks and on a line connecting said rotating centers of the disks and between said rotating centers.

8. A power producing device substantially as hereinbefore described with reference to the accompanying drawings.