Abstract:
A method is provided for controlling operation of a pedal cycle (10) having a rear hub-mounted electro-mechanical transmission arrangement in which a chain-driven rear sprocket (80), an input electrical machine (120) and the hub (100) are each coupled to a respective branch of a three-branch epicyclic gear set (140). Allowing for natural variations in input torque by a cyclist over a cycle of the crank arms (50), a substantially constant current is caused to exist in the input electrical machine (120) such that a change in torque applied by the cyclist results in a change in transmission ratio between the rear sprocket (80) and the hub (100), thereby providing a form of automatic and continuously variable transmission for the pedal cycle (10).
Abstract:
A bicycle transmission system includes an input (2) constituted by a bicycle crankshaft, which is connected, in use, to the pedals (4) of a bicycle, and an output (32), which is connected, in use, to a bicycle sprocket wheel (34). The input (2) and output (32) are connected to respective shafts of a three branch epicyclic gearset including a sun gear (18), which is in mesh with a plurality of planet gears (16), which are rotatably carried by a common planet carrier (12) and are in mesh with an annulus gear (20). The rotors of first and second electric motor/generators (22, 24) are connected to respective shafts of the gearset via respective step-up gearing (26, 18; 28, 20) with step-up ratios of at least 5 and at least 8, respectively. The electrical connections of the stators of the motor/generators are connected together via a controller (30) arranged to selectively control the electrical power transmitted to or from an electrical energy store (31) to the motor/generators or between them. The Ro ratio of the gearset, that is to say the ratio of the speed of the annulus gear (20) to the speed of the sun gear (18) when the planet carrier (12) is held stationary, is between −2 and −4.
Abstract:
An automotive propulsion system includes an internal combustion engine (6) with an inlet air duct (66) and an output shaft (10), which is connected to the input shaft of a transmission system (58) of continuously variable transmission ratio. The transmission system comprises a differential gearset comprising at least three shafts (10, 12), two of which constitute the input shaft and output shaft, respectively and all of which carry at least one gear wheel in mesh with at least one gear wheel carried by one of the other shafts. The transmission system also includes two electric motor/generators (42, 46; 50, 52), the rotors (42, 50) of which are connected to respective shafts and the electrical connections (43, 45) of which are connected to a controller (62) arranged to control the flow of electrical power between them. The propulsion system also includes an electrically driven supercharger (60) communicating with the inlet duct (66) and connected to the controller (62). The controller (62) is programmed so that, at least at speeds of the transmission input shaft (10) and/or transmission output shaft (12) lower than a predetermined threshold value, it is selectively able to direct electrical power from at least one of the motor/generators, which is operating as a generator, to the electric motor of the supercharger (60) so as to increase or decrease the pressure in the inlet duct (66) and thus also the torque applied to the output shaft (12) of the engine.
Abstract:
An automotive vehicle transmission system has two epicyclic gearsets, each having a sun member and a carrier member, carrying at least one planet member, which is in driving engagement with the sun member and with an annulus member. The carrier member of the first epicyclic gearset constitutes the input to the transmission system and the carrier member of the second epicyclic gearset constitutes the output from the transmission system. Two members of the first epicyclic gearset are connected to rotate with a respective member of the second epicyclic gearset, whereby the two carrier members are not connected together. The transmission system also includes first and second motor/generators having first and second stators connected to ground and first and second rotors connected to respective members of the epicyclic gearsets other than those constituting the input and the output. One of the motor/generators is connected to both sun members or to both annulus members, the carrier member of one of the gearsets being connected to that one of the sun member and the annulus member of the other gearset which is not connected to a motor/generator. The electrical connections of the first stator are connected to the electrical connections of the second stator, whereby, in use, electrical power is transferred between the first and second motor/generators.
Abstract:
A hub comprises a cylindrical, hollow hub member (2), which is mounted to rotate about its axis and in whose interior is a transmission system having an input (10), which is mounted to rotate about the axis, and an output connected to rotate with the hub member. The transmission system comprises first and second epicyclic gearsets (14, 16). The first gearset (14) comprises a first sun gear (18), which is mounted to rotate about the axis and is in mesh with a plurality of first planet gears (20) mounted to rotate about respective planet shafts (22) carried by a first common carrier (24), which is mounted to rotate about the first axis. The second gearset (16) comprises a second sun gear (28), which is mounted to rotate about the axis and is in mesh with a plurality of second planet gears (30) mounted to rotate about respective planet shafts (32) carried by a second common carrier (34). The first and second sun gears (18, 28) are connected to the rotors (38, 40) of first and second electric motor/generators, respectively. The power connections of the two stators (42, 46) are connected via a controller (50) arranged to control the transmission of power from one motor/generator to the other.
Abstract:
An infinitely variable drive transmission including an input member, a summing gear set, and a variable speed transmission having an input element drivable by the input member and an output element, the output element of the variable speed transmission being connectable to one element of the summing gear set, to provide a first path between the input member and the summing gear set. The input member being connectable to another element of the summing gear set to provide a second path between the input member and the summing gear set. The summing gear set includes a driven member drivable by at least one further element of the summing gear set and drive transmitting means connectable between the output element of the variable speed transmission and the other element of the summing gear set.
Abstract:
A transmission system includes an input (22), an output (34) and an epicyclic geartrain comprising first and second gearsets. The first gearset comprises a first sun gear (2) in mesh with a set of first planet gears (4), which are rotatably carried by a first planet carrier (6) and are in mesh with a first annulus gear (8). The second gearset comprises a second sun gear (10), which is connected to rotate with the first sun gear (2) and is in mesh with a set of second planet gears (12), which are rotatably carried by a second planet carrier (14) and are in mesh with a second annulus gear (18). One of the planet carriers (6) of one of the gearsets is connected to rotate with the annulus gear (18) of the other gearset. The two connected sun gears (2), (10) and the input (22) are connected to the rotors (24, 20) of respective electric motor generators (E2, E1), the electrical stator connections of which are connected together via a controller (30) arranged to control the flow of electrical power between them. The input (22) is selectably connectable to the other (14) of the planet carriers and to the other (8) of the annulus gears by first (C2) and second (C1) selectably operable clutches, respectively, whereby the transmission system has two regimes.
Abstract:
An automotive vehicle transmission system has two epicyclic gearsets and a first and second electrically connected motor/generator. Components of the epicyclic gearsets and the motor/generators are connected such that, when the transmission system is in use, electrical power is transferred between the first and second motor/generators.
Abstract:
A loader vehicle comprising a body having a front end and a rear end and provided with ground engageable propulsion means, an operator's compartment and a boom assembly, comprising a lift arm assembly and a pivot member which projects transversely from the inner end of the lift arm assembly on one side thereof and extends transversely across the body from said one side of the lift arm assembly and which is pivotally mounted on the body, adjacent the rear end thereof, for movement of the lift arm assembly between a raised position and a lowered position in which the lift arm assembly extends forwardly alongside the operator's compartment and means for carrying a material handling implement at an outer end of the boom assembly so as to be disposed forward of the front end of the body, wherein the pivot member is pivotally mounted, for movement about a first axis, on a torsion member, which extends transversely across the body, by first pivotal mounting means disposed at positions which are spaced apart transversely of the torsion member and the torsion member is pivotally mounted on the body, for movement about a second axis which is parallel to the first axis and which extends transversely of the body, by second pivotal mounting means disposed at positions which are spaced apart transversely of the body.
Abstract:
A piston which is reciprocable within a cylinder is rigidly connected to a bearing housing by a connection. The connection comprises a rigid tube fixed to the piston and a rigid rod fixed to the housing which extends within the tube coaxially thereof. The tube has an internal thread which engages with an external thread on the rod such that rotation of the tube changes the length of the connection and hence the position of the piston within its cylinder. The tube is rotated by way of a worm spindle which engages with longitudinal grooves formed on the external surface of the tube. The arrangement can be used particularly to vary the compression ratio of an internal combustion engine having a counter rotating crank drive.