This application claims priority to Israel Application No. 258,954, filed Apr. 26, 2018, the entirety of which is incorporated herein by reference.
The present disclosure relates to the field of propulsion devices.
Many attempts have been made in the prior art to convert an easily generated centrifugal force (i.e. by means of a rotating power source such as an electric power source) into a linear force, and therefore into linear displacement, by restraining or directing a revolving mass. In general, the magnitude of the generated centrifugal force is proportional to the mass, the radius of gyration, and the square of the angular velocity.
While the mass is revolving about a center, an unbalanced centrifugal force may be generated in one direction by changing the radius of gyration within one sector of the curved path. Thus, a first magnitude of centrifugal force will be generated within the first sector and a second magnitude of centrifugal force will be generated within a second sector. The magnitude of the resultant unbalanced centrifugal force will thus be equal to the difference between the first and second magnitudes, when the two sectors are separated by 180 degrees.
Some prior art centrifugal force converting apparatuses, such as those disclosed in CA 2 816 624 and US 2011/0041630, provide a rotational mechanism that produces reciprocating translation. The change in direction results in a momentum transfer that disadvantageously reduces the magnitude of a propulsion force derived from the generated centrifugal force.
It would therefore be desirable to provide an apparatus for converting a centrifugal force to a unidirectional linear force that is conducive in propelling a vehicle in a desired direction.
GB 2 078 351 discloses a device with a pair of arms counter rotating about a common axle at an equal rotational speed. One arm carries a mass in the form of two weights, one of which is transferable to the other arm and back again at 180° intervals where the arms pass each other. As a result, the centrifugal force of the mass is converted to a linear force that moves the device along the rails. One disadvantage of this device is that a complicated weight transfer mechanism needs to be employed to produce an unbalanced force during half of the circular path of both arms.
U.S. Pat. No. 5,388,470 discloses a centrifugal force drive machine for generating force in a controlled direction that includes a machine frame with a shaft mounted for rotation about its axis. At least one mass is mounted on the shaft for rotation. Each mass has a center of gravity which is moveable radially with respect to the shaft between the position in which the mass is rotationally balanced about the shaft and a position in which the mass is unbalanced. A control member in an operative connection between the mass and the frame is provided to constrain radial movement of the mass between the balanced position and the unbalanced position during each revolution. When a mass is in the unbalanced position, the centrifugal force generated by the rotation of the mass is transmitted to the control member, thereby generating a linear force in the controlled direction.
In some embodiments, the control member of U.S. Pat. No. 5,388,470 includes an opening in the machine frame that is bounded by a continuous track that is offset in the controlled direction from the center of rotation of the shaft. A first mass is mounted on the shaft for rotation at a constant radius, and a second mass is mounted on the shaft for rotation at a variable radius of rotation, so that the rotation becomes unbalanced and a centrifugal force having a component in the controlled direction and transferred to the frame is generated when the second mass travels through the portion of the track which lies in the controlled direction. The rotation is balanced when the second mass travels over the remainder of the track where the center of rotation of the two masses substantially coincide. However, the magnitude of the unidirectional linear force that is generated from the centrifugal force is disadvantageously reduced due to the angular acceleration that the second mass experiences as it undergoes rotation at a variable radius of rotation.
US 2005/0160845 discloses a mass retentive linear impeller for converting rotational energy into directional linear energy induced motion, which comprises a plurality of tracks with a plurality of torque carriages slidably attached to the tracks. The torque carriages include two counter-rotating flywheels, and two rotating arms are attached to a central axis of the flywheel. A weight is located at the distal end of each rotating arm to induce a centrifugal force that is converted into forward thrust for a vehicle when a carriage pawl is releasably engaged to ratchet teeth of the tracks. Side-to-side motion is neutralized by the counter-rotating flywheels and backward motion is neutralized by allowing the carriage to slide back along the tracks. The magnitude of the unidirectional linear force generated by this apparatus is also reduced by having to periodically engage the carriage pawl, resulting in a dissipation of kinetic energy.
It is an object of the present disclosure to provide an apparatus that optimizes the conversion of generated centrifugal force to a unidirectional force without need of large-magnitude torque or a complicated weight transfer mechanism. It is an additional object of the present disclosure to provide a centrifugal force converting apparatus that employs a single mass for generating the centrifugal force. Other objects and advantages of the disclosure will become apparent as the description proceeds.
The present disclosure provides a centrifugal force converting apparatus that may include a curvilinear, variable-radius continuous track along which a single weighted roller is urged to traverse during rotation of a vertical shaft; a displaceable platform connected to the track; a linear guide connected to the shaft along which a carriage connected to the roller is slidable; and a speed controller for controllably varying rotational speed of the shaft, wherein the track may be configured with a plurality of different sectors, such that centrifugal force generated during revolving advancement of the roller along the track may increase from a minimal value at a first sector at which the center of mass of the carriage substantially coincides with the shaft to a maximum value at a second sector at which the center of mass of the carriage may be separated from the shaft by a maximum value, and may be reduced from the second sector to the first sector in response to a reduction in shaft speed caused by the speed controller, and wherein the generated centrifugal force may be transmitted to the platform via the roller and may be converted thereby to a propelling force to unidirectionally propel the platform.
The apparatus may be preferably configured to convert the generated centrifugal force to a non-regressive propelling force, which may be a linear propelling force or a rotary propelling force. The apparatus may undergo non-planar motion.
In one aspect, the first sector may include a constant-radius segment of a relatively short radius from the shaft, and the second sector may include a constant-radius segment of a relatively long radius from the shaft, to facilitate advancement of the roller along the first and second sectors without being subjected to angular acceleration. The constant-radius segment of the first sector may include a peripheral length which may be significantly shorter than the peripheral length of the constant-radius segment of the second sector.
In one aspect, the track may be configured with one or more varying-radius segments positioned between the first and second sectors.
In one aspect, the apparatus may further comprise a control system for synchronizing the shaft speed with an instantaneous peripheral position of the roller along the track.
In one aspect, the control system may include a controller in data communication with the motor, and one or more sensors in data communication with the controller for detecting the instantaneous peripheral position of the roller along the track, wherein the controller may be configured to maintain an angular velocity of the shaft and of the guide connected thereto at a predetermined controlled value that will cause a predetermined sector-specific centrifugal force to be generated.
The present disclosure is also directed to a method for converting centrifugal force to a unidirectional force, that may include the steps of irremovably engaging a roller with a curvilinear, continuous variable-radius track and fixedly connecting said roller to an unbalanced mass which is slidably mounted on a linear guide connected to a vertical shaft constituting a center of rotation; rotatably driving said shaft to cause said roller to undergo revolving advancement along said track, to guide said unbalanced mass and to thereby generate centrifugal force in response to an instantaneous distance of said roller from the center of rotation; synchronizing a speed of said shaft with an instantaneous peripheral position of said roller along said track to maintain an angular velocity of said shaft and of said guide connected thereto at a predetermined controlled value that will cause a predetermined sector-specific centrifugal force to be generated, such that the generated centrifugal force increases from a minimal value at a first sector of said track at which the center of mass of said unbalanced mass substantially coincides with said shaft to a maximum value at a second sector said track at which the center of mass of said unbalanced mass may be separated from said shaft by a maximum value, and may be reduced from the second sector to the first sector in response to a reduction in shaft speed; and transmitting the generated centrifugal force, via said roller, to a displaceable platform connected to said track and to thereby unidirectionally propel said platform.
Specific exemplary embodiments of the inventive subject matter now will be described with reference to the accompanying drawings. This inventive subject matter may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive subject matter to those skilled in the art. In the drawings, like numbers refer to like elements. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. As used herein the term “and/or” includes any and all combinations of one or more of the associated listed items.
It should be initially understood that all of the features disclosed herein may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
According to some embodiments, the apparatus of the present disclosure may transmit a generated centrifugal force to a platform to which a track may be connected, which may cause the platform to undergo motion in a desired direction. As will be described hereinafter, the apparatus may be configured to generate a centrifugal force in a positive direction when a revolving roller moves through certain sectors of the track, and may be prevented from generating a centrifugal force in a negative direction when the revolving roller moves through other sectors of the track. Accordingly, the platform may advance in a desired unidirectional direction with an advantageously efficient rate of conversion from centrifugal force to linear force. A propelled vehicle comprising the presently disclosed apparatus may include a wheeled vehicle, a tracked vehicle, a marine vehicle, a submarine vehicle, an airborne vehicle, and/or a space vehicle, among others.
In one embodiment, the revolving roller may have at least two functions. A first function may be to define a magnitude of the generated centrifugal force according to a distance of the roller from the center of rotation and by the path that the roller follows as it is displaced along the track and guides an unbalanced mass. A second function may be to serve as a mechanism by which the generated centrifugal force may be transmitted to the platform.
Referring now to
In some embodiments, apparatus 100 may include an elongated roller-positioning rail 120 that may function as a linear guide overlying track 110. In some embodiments, rail 120 may be coupled to a central portion of apparatus 100 that includes a shaft 125 via one or more brackets 128. Shaft 125 may, in some embodiments, constitute a center of rotation. A carriage mass 130 may have a pre-determined or configurable mass and may be slidably coupled to rail 120. A roller 129 may be coupled to carriage mass 130 and configured to engage with track 110. Although not shown in
With the rotation of shaft 125, roller-positioning rail 120 may also rotate. As illustrated, for example, in
One aspect of the disclosure that may be advantageously varied is the configuration of the track (e.g., track 110) to which the revolving roller (e.g., 129) may be coupled. As shown in
Generally, and with reference to
The configuration of each transitional region may depend on various factors such as the size of the vehicle or vessel to be propelled, the desired speed of the propelled vehicle or vessel, and the strength of the materials used in the apparatus, among others. By way of just one example, apparatus 100 may have a sector A-B of 30°, a sector B-C of 80°, a sector C-D of 20°, a sector D-E of 80°, and a sector E-A of 150°. An exemplary apparatus 100 may also have a carriage 130 with a mass of 2 kg and a rail 120 and track 110 corresponding to a change in radius of gyration ranging from 8 cm to 16 cm. Segment E-A may also be semielliptical with a ratio of major axis to minor axis of 2 to 1.
The magnitude of the generated centrifugal force may be modeled by the following relation: Fc=mω2r, where Fc is the generated centrifugal force, m is the mass of carriage 130, w is the angular velocity of the center of mass of carriage 130 about shaft 125, and r is the radius of gyration of the center of mass of carriage 130. Thus, the magnitude of the centrifugal force will be reduced when roller 129 moves within sector A-B because the radius of gyration is relatively short, and may even be equal to 0 when the center of mass 130 coincides with the center of rotation of shaft 125. In like manner, the magnitude may be increased when roller 129 moves within sector D-E since the radius of gyration may be relatively long. If the apparatus 100 is characterized by non-planar motion, the center of mass may be replaced by a center of gravity.
A parameter that may be more influential in controlling the magnitude of the generated centrifugal force, however, is angular velocity, as the generated centrifugal force is proportional to the square of the angular velocity. Accordingly, the magnitude of the centrifugal force may remain constant when roller 129 moves within a short-radius sector (e.g., sector A-B) so long as the relative angular velocity were increased.
It has now been discovered that a non-regressive linear propelling force may be provided by generating a cyclical, sector-specific centrifugal force upon reducing the speed of shaft 125 when roller 129 moves within a reduced-radius segment and increasing the speed of shaft 125 when roller 129 moves within an increased-radius segment. The generated negative centrifugal force that would cause the platform to be propelled in a rearward direction may then be negligible, or even nonexistent, when roller 129 moves within a reduced-radius segment and the speed of shaft 125 is minimized, resulting in non-regressive movement of platform 115. As referred to herein, “non-regressive movement” may occur when the magnitude of generated negative centrifugal force is no more than 10% of the magnitude of maximally generated positive centrifugal force. On the other hand, a positive centrifugal force may be generated when roller 129 moves within an increased-radius segment and the speed of shaft 125 is increased.
In order to generate a cyclical, sector-specific centrifugal force, the speed of shaft 125 may be a function of the instantaneous peripheral position of roller 129 along track 110. Accordingly, a centrifugal force of maximal magnitude may be generated, for example, when roller 129 is positioned within the relatively long, constant-radius segment D-E, to maximize conversion of the generated centrifugal force to a linear force for propelling the vehicle, since the roller is not subjected to angular acceleration while undergoing rotation at a constant radius of rotation. Similarly, a centrifugal force of minimal magnitude may be generated when roller 129 is positioned within the relatively short, constant-radius segment A-B. Yet, roller 129 may not become stalled even though the speed of shaft 125 may be set to a minimal value in this segment since the roller may not be subjected to angular deceleration which could cause its speed to be excessively low while undergoing rotation at a constant radius of rotation.
In some embodiments, apparatus 100 may be disposed along a pair of transportation rails 132 like those illustrated, for example, in
Referring now to
It will be appreciated that any other number of centrifugal force converting apparatuses may be employed to produce a resultant force that will cause a platform to be propelled non-regressively in a desired linear or rotary direction.
Rotating power source 930 may be commanded to generate a sufficient amount of torque so that the center of mass of carriage 130 may rotate at a sufficiently high angular velocity to generate a predetermined centrifugal force, in addition to the torque utilized by roller 129 to undergo angular acceleration when revolving along a variable-radius segment as provided by the following relation: τA=Iα, where τA is the torque acting on roller 129 as a result of undergoing angular acceleration, I is the rotational inertia of roller 129, and α is the angular acceleration of roller 129 when undergoing rotary motion with respect to a given segment. When roller 129 is displaced about a constant-radius segment, it is not angularly accelerated and the value of τA is equal to zero.
Speed controller 940 may include one or more gears with one or more possible gear ratios. The instantaneous gear ratio of speed controller 940 may define the speed of shaft 125, and thus the kinetic energy of carriage 130 and roller 129, as well as the magnitude of the generated centrifugal force.
Referring now to
Referring now to
As shown in
While some embodiments of the invention have been described by way of illustration, it will be apparent that the invention can be carried out with many modifications, variations and adaptations, and with the use of numerous equivalents or alternative solutions that are within the scope of persons skilled in the art, without exceeding the scope of the claims.
Number | Date | Country | Kind |
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258954 | Apr 2018 | IL | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IL2019/050434 | 4/17/2019 | WO | 00 |