Not Applicable
Not Applicable
Not Applicable
1. Field of the Invention
1.1. The invention relates to rotating machines which are used to produce power by extracting it from a fluid, or by moving fluid by using mechanical power via a rotating shaft.
2. Description of Prior Art
2.1. Rotating machines are commonplace. Various mechanisms are used in pumps, motors, engines, etc. Many of these machines have moving parts which are designed to slide against other components, and provide a sealing interface. A well known example are rings in an internal combustion engine. They are generally used in sets, and have specific duties. Upper rings are generally used to seal the gases in the cylinders on one side of ring. Lower rings are used to control lubrication of the cylinder. Of necessity, the rings are slightly bigger than the cylinders. They are forced into the cylinders by compressing them into the necessary shape. They provide a sealing function, but have the disadvantage of adding friction to the system, and they wear with age. One manufacturer indicates that piston rings may account for approximately 24% of the mechanical friction occurring in an engine[1]. The piston ring is needed to allow the volume of gas that is captured by the piston and cylinder walls to change as the crankshaft of the engine rotates.
2.2. A Wankel engine is a prior art having a housing and inner hub assembly. In this case, the hub runs along a sun-gear, and processes around the interior. It is a well known example of a mechanism that uses seals to produce controlled volumes of enclosed fluid. The seals are a serious design consideration and have been a cause of much development and many mechanical failures. In a Wankel, the seals are forced against the outer cylinder walls with the centripetal force developed as the engine turns. This can lead to excessive force, or insufficient force, depending on the operational status of the engine[2]. Some devices have attempted to compensate for this deficiency by adding springs to the moving members, such as in the case of vane motor[3].
2.3. The mechanism described herein provides a unique means for generating an enclosed volume of gas or liquid, that changes volume as the device rotates. A benefit of the invention is that the bearings support the rotating members, and hold them in a fixed position as they rotate. Seals are not required to be pressed against an opposing sealing surface. The enclosed volumes are generated by appropriately sizing the rotating components and placing them sufficiently close to the opposing sealing surface that fluid leakage is as small as necessary. As such, when seals are used, seal wear at these interfaces is significantly reduced.
3. In one simple embodiment:
3.1 The invention consists of 4 basic components. 1. An outer housing to enclose the volume of gas or liquid, and provide mechanical structure for supporting the interior components. The housing has an interior volume that is generally cylindrical in shape. 2. An inner hub, which is also generally cylindrical in shape. The outside diameter of the hub is smaller than the inside diameter of the cavity of the outer housing. The hub also has a hole along the axis of the hub. The hole is needed to locate the inner vane component noted below. The hub is mounted in the housing with bearings so that it can rotate inside the housing. It can rotate freely and not interfere with the housing, except as may be needed for manufacturing “break in”. 3. An inner vane, which is mounted on a shaft. This shaft is also mounted in the housing on bearings, such that it can freely rotate without interference with the interior of the housing. The radial length of the vane is sized so that it touches, or nearly touches the interior of the housing walls. 4. A seal, that sits inside the hub, and allows the vane to move as the mechanism rotates. It is evident by those experienced in machine design that this summary is generic in nature, and that additional details are necessary to implement a working mechanism, such as choice of bearings and materials.
3.2 A key attribute to the device is that the inner hub has a smaller diameter than the interior cavity. This hub is offset to one side so that it touches the interior of the housing wall and effectively pinches off fluid flow at this location. A second key attribute is that the axis of the inner vane is located coaxially with the interior volume of the outer housing. The vane extends outward from its axis so that the tip of the vane touches, or nearly touches the inside of the inner cylinder of the housing. As it rotates, the end of the vane stays very close, or in contact with the inside of the housing walls. The attaching of the vane member to a centrally located shaft clearly differentiates it from the rotary engine, cited as reference 3. A third attribute to the device is that the inner hub has a hole sufficiently large down its center to allow the axis of the vane to occupy this empty volume and therefore not interfere with the hub as it rotates. A fourth attribute is that the hub has volume removed sufficiently to allow the vane and seal to be installed without interference with the hub.
4. A preferred embodiment of the invention is described as follows:
4.1
4.2 It is essential to recognize that the hub is mounted on bearings 9 to hold its position inside the outer housing, and likewise the vane mechanism is mounted on bearings 10 to hold its position inside the outer housing. Item 13 is the axial shaft of the vane member 5. The shaft is coaxial with the interior of the outer housing. The bearings keep the vane and hub in fixed relationships with the outer housing, except for their rotation. As the hub rotates, it remains in contact, or near contact with the outer housing at point 11. This relationship is sufficiently close as to prevent gross transfer of fluid from across the boundary between the two fluid volumes. In similar fashion, the end of the vane member 12 is in contact with the inner housing as it sweeps a circular path. Or, there may exist a small gap between the end of the vane and the inner housing, which is sufficiently small that it prevents gross transfer of fluid across the boundary between the two fluid volumes. In this context, “gross transfer” is understood to be dependent of the application requirements. The precision of the bearings and the precision of the components must be defined sufficiently to meet the application requirements. And it is understood that sealing components at the tip of the vane are necessary in some applications.
4.3 This invention allows the gap between moving components and the inner housing walls to be controlled sufficiently well that the two fluid volumes can be partitioned without having to force the moving components against the walls of the outer housing with extreme pressure. Because each axis is rotating on bearings, the gap can be controlled without the use of contacting rings, or pressure pads. The vane and hub are sized so that they nearly touch, or actually touch the interior surfaces of the housing, as may be necessary. This produces two volumes of fluid. These volumes can be used to move fluid through the device by mechanical rotation of the device. Or conversely, by forcing fluid though the device, rotation of the mechanical members can produce power at the output shaft of the device.
4.4 As depicted in
4.5
4.6
4.7 Regardless of the particulars of the application, ports are required to allow fluid flow through the device. The various figures have illustrated ports on the circumference of the outer housing. While this may be an acceptable location, it is recognized that more favorable locations may include ports on the ends of the cylinders for some applications, as suggested by locations 22 and 23 of
4.8