FLUID MOTOR

Abstract: The fluid motor, e.g. a liquid meter, a mixing apparatus or a turbine, has a chamber (1) with a rotor having stiff blades (7) which at their outer ends are provided with plate formed wings (8) of elastomeric material. The wings (8) are by a thin, overlapping part fastened to the reverse side of the blades (7) in relation to the rotating direction. When passing between outlet (5) and inlet (4) of the chamber (1) the wings (8) are deflected by a wall part in the chamber. The rotor is smooth-running, noise-free and inexpensive to produce and repair in connection with abrasion of the wings.

Description: FLUID MOTOR -r TECHNICAL FIELD 5 The present invention relates to a fluid motor having * a shaft which is operated by means of a flowing fluid, e.g. for measuring of fluid, and having a rotor mounted in a housing having a number of blades mounted regularly around the bearing shaft, each blade composed by a stiff blade of 10 metal and a flexible, elastomeric part. BACKGROUND ART For volume measurement of flowing fluid it is known to use a rotor with blades mounted in a housing, which blades 15 are pivotally connected with a rotor body and which are forcibly guided in such a way that over one part of the cylindrical wall of the housing they are turned towards this to form a barrier between the inlet and outlet port, and over another part of the cylindrical wall of the housing 20 having a smaller diameter than the former they are deflected backwards relative to the rotating direction to form a seal¬ ing between this part of the cylindrical wall and the rotor. The known devices of this kind, e.g. water meters, are re¬ latively expensive to produce and repair, the blades being 25 difficult to exchange piece by piece, for which reason it is often necessary to exchange the whole rotor. In many cases the rotor provides an undesired, great resistance against rotation, too. Yet another drawback of some of the known liquid meters is that the pivotally connected blades 30 have a tendency to stick when the device has not been used for a longer period of time, and that they are noise gene- Λ rating. However, from US Patent Specification No. 2,753,809 ___ a motor or pump is known, the rotor of which is provided 35 with blades where a metal plate is mounted along the flexible elastomeric blade part to reinforce this part which is con- stituted by an extending tab on an elastomeric base embedded in a groove in the rotor. By this construction a relatively great amount of elastomeric material for each blade is in¬ volved, and in connection with abrasion of the material it is necessary to renew the whole blade. Besides, from US Patent Specifications No. 2,636,478 and No. 2,636,479 liquid meters are known where wings of flexible material are extending practically from the center of the hub to the circumference and which are supported by intricately constructed metal parts. Also by this construct¬ ion it is difficult to exchange worn parts piece by piece, and furthermore, the wings, which slide against the wall of the housing, involve a relatively great resistance against the movement of the rotor in the housing. DISCLOSURE OF THE INVENTION It is the object of the present invention to provide a fluid motor of the kind referred to initially having a rotor, the production of which is connected with low costs, is smooth-running, noise-free and inexpensive to repair because the worn parts are easily exchangeable. A rotor having these properties is not only desired in any volume meter which is to operate with a great accuracy, e.g. in order to secure an exact blending ratio in a dosage appara- tus, but also in an apparatus where the rotor has to function as a driving or turbine wheel. The fluid motor according to the present invention is characterized in that the elastomeric parts of the blades are plate-formed wings mounted at the radially outer ends of the stiff blades, each wing with a thin, flexible part fixed to and overlapping the outer end of the blade on the side thereof facing backwards relative to the rotating di¬ rection, whereas the part of the wing lying radially outside the stiff blade has a greater plate thickness and at the interface to the flexible part overlaps the edge of the blad . A rotor like that is smooth-running, and without gene¬ rating serious resistance the wings are able to move tightly closing along a wall in the housing concentric to the rotor ' shaft and can also without serious resistance be folded and 5 tightly closing follow the wall of the housing placed closer 1 to the shaft and form a barrier between the inlet and outlet of the housing. Where the housing of the rotor functions as a mixing chamber, to which a dosed admixture is introduced, it is besides an advantage that the wings generate a certain 10 movement in the fluids in the chamber. It has been found that the wings provide sufficient tightness at the circumference wall of the mixing chamber, deflect slightly in reverse direction and in spite hereof are sufficiently stiff against pressure influence on their re- 15 verse side, so that they provide a well running, exactly functioning measuring wheel, which e.g. operates securely in connection with water supply at common supply pressure and at small volume amounts and even at suction of the medium through the apparatus. The flexible wings generate tightness 20 even with a very small system pressure, and it is possible to mount them easily exchangeable in undercut grooves in the blades. Reduced abrasion on the wings and securing a certain distance between the major part of their surface and the sluice chamber can be achieved by providing the 25 wings with an extending bead on their front side in the ro¬ tating direction. Moreover, the flexible wings secure that the liquid flow can pass even if the rotor should be blocked by accident, because in that case some of the wings would bend backwards and act as safety control. If necessary, a 30 reinforcement, e.g. a wire net, can be embedded in the ela¬ stomeric material in the wings. . BRIEF DESCRIPTION OF THE DRAWINGS *• In the following detailed portion of the specifica- 35 tion, the present invention will be explained in more detail with reference to the drawings which schematically show an embodiment of the fluid motor according to the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS In the shown embodiment for the fluid motor according to the invention a mixing chamber 1 is shown, with a top cover above the housing of the apparatus removed. Besides, by dotted lines a feeder 2 is indicated, which via valve means at the rotor shaft (not shown) can be connected with the mixing chamber through an intake port 3. The mixing chamber 1 functions as a volume meter for a main flow of fluid which is passed in through an inlet 4 and away through an outlet 5. The flowing amount of fluid is measured by counting and recording the rotations of a shaft 6 of a rotor having stiff blades 7 of metal or plast and plate-formed wings 8 of elastomeric material fixed at the ends of these blades. During their movement through a displacement part of the chamber the wings 8 slide against a cylindrical wall with their outer ends, and in a sluice part 9 they are de¬ flected by an excentric wall part. It is shown that the wings 8 with a thin part overlap a corresponding, thin part at the end of each blade 7, and they are fixed to the side of the blades facing backwards relative to the rotating di¬ rection. It has been found that by this construction a wing wheel is achieved which is sufficiently smooth-running and tightly closing to function as an exact measuring instrument for fluids flowing with low pressure, e.g. fuel oil or water with a common supply pressure. The wings 8 can preferably be fastened with beads extending in axial direction from the thin, plate-formed parts and embedded in the undercut grooves on the backside of the metal wings 7 so that they become easily exchangeable. Further, each of the flexible wings 8 has preferably a bead 10 running in axial direction which reduces the contact surface between the wing and the wall in the sluice part 9. A reinforcement may optionally be embedded in the wings 8. The fluid motor with the described rotor can also be used as a simple flow meter or optionally as a water turbine. The rotor might e.g. be used as driving wheel in a lawn sprinkler.

Claims: C L A I M S. 1. A fluid motor having a shaft which is operated by means of a flowing fluid, e.g. for measuring of fluid, and having a rotor embedded in a housing with a number of blades regularly mounted around the bearing shaft (6) , each blade being composed by a stiff blade (7) of metal and a flexible, elastomeric part (8) , characterized in that the. elastomeric parts of the blades are plate-formed wings (8) positioned at the radially outer ends of the stiff blades, each with a thin, flexible part fastened to and overlapping the outer end of the blade (7) on its side facing backwards in the rotating direction, whereas the part of the wing (8) posi¬ tioned radially outside the stiff blade (7) has a greater plate thickness and at the interface to the flexible part overlaps the edge of the blade (7) . 2. A fluid motor according to claim 1, characterized in that each wing (8) on its thin, flexible part has a un¬ dercut rib running in the axial direction of the rotor, which rib is embedded in a corresponding undercut groove in the blade (7) . 3. A fluid motor according to claims 1-2, charac¬ terized in that on the thick part positioned outside the blade (7) each wing (8) has a bead (10) or rise on the side facing forwards relative to the rotating direction.

Inventors: STENILD EDDIE LAI, STENILD, EDDIE, LAI
Applicants: STENILD EDDIE LAI, STENILD, EDDIE, LAI
Application year: 1992
Main classification: F01C5
IPC codes: F01C5, G01F1