Abstract: A multi-regime continuously variable ratio transmission has a transmission input shaft, a transmission output shaft, and a ratio varying unit having a rotating input and a rotating output, the rotational axes of the input and the output being coaxial. A shunt having first and second epicyclic gear sets is connected across the ratio varying unit. One gear set has an input driven by the input shaft and an input driven by one side of the ratio varying unit and the other gear set has an input from the first gear set and an input from one side of the ratio varying unit. The gear sets rotate about a common axis and are offset with respect to, and parallel to, the rotational axes of the input and output of the ratio varying unit. A clutch is operable to selectively connect the output of the second gear set to the output shaft.

Abstract: A continuously variable transmission having a transmission input (60) and a transmission output (114) is described. The transmission has a variator (56). This is a device which transmits drive at steplessly variable ratio. It further comprises an epicyclic gear arrangement (58) incorporating a clutch arrangement (152). The epicyclic gear arrangement has three rotary members. One of these is coupled to a planet carrier (86) having at least one planet gear (94). Another of the rotary members is coupled to a main gear (90) meshing with the planet gear. The clutching arrangement serves to couple the remaining rotary member to either of first and second alternative gears (96, 98), both of which mesh with the planet gear and which rotate at different speeds. One of the aforesaid rotary members is coupled to the transmission input at a fixed drive ratio. One of them is coupled to the variator output. The last of the rotary members is coupled to the transmission output.

Abstract: The invention is concerned with a continuously variable transmission incorporating a variator of the type having at least two co-axial races (D1-D4) between which drive is transferred at a continuously variable variator ratio. The variator races are mounted for rotation about a variator shaft (15). The transmission has a layshaft (18) which is laterally separated from the variator shaft. It has two epicyclic gears. A splitter epicyclic (14) has an input member driven from the transmission input (10) and two output members arranged respectively to drive the layshaft and the variator shaft. A recirculater epicyclic has first and second input members for coupling respectively to the variator shaft and to the layshaft and a recirculater output member. An arrangement of clutches is provided for selectively engaging any of at least three regimes. In one regime the recirculater output member drives the transmission output. In another the layshaft drives the transmission output.

Abstract: The invention is concerned with a continuously variable transmission incorporating a variator of the type having at least two co-axial races (D1-D4) between which drive is transferred at a continuously variable variator ratio. The variator races are mounted for rotation about a variator shaft (16). The transmission has a layshaft (18) which is laterally separated from the variator shaft. It has two epicyclic gears. A splitter epicyclic (14) has an input member driven from the transmission input (10) and two output members arranged respectively to drive the layshaft and the variator shaft. A recirculater epicyclic has first and second input members for coupling respectively to the variator shaft and to the layshaft and a recirculater output member. An arrangement of clutches is provided for selectively engaging any of at least three regimes. In one regime the recirculater output member drives the transmission output. In another the layshaft drives the transmission output.

Abstract: A multi-regime continuously variable ratio transmission has a transmission input shaft, a transmission output shaft, and a ratio varying unit having a rotating input and a rotating output, the rotational axes of the input and the output being coaxial. A shunt having first and second epicyclic gear sets is connected across the ratio varying unit. One gear set has an input driven by the input shaft and an input driven by one side of the ratio varying unit and the other gear set has an input from the first gear set and an input from one side of the ratio varying unit. The gear sets rotate about a common axis and are offset with respect to, and parallel to, the rotational axes of the input and output of the ratio varying unit. A clutch is operable to selectively connect the output of the second gear set to the output shaft.

Abstract: The invention is concerned with a continuously variable transmission incorporating a variator of the type having at least two co-axial races (D1-D4) between which drive is transferred at a continuously variable variator ratio. The variator races are mounted for rotation about a variator shaft (16). The transmission has a layshaft (18) which is laterally separated from the variator shaft. It has two epicyclic gears. A splitter epicyclic (14) has an input member driven from the transmission input (10) and two output members arranged respectively to drive the layshaft and the variator shaft. A recirculater epicyclic has first and second input members for coupling respectively to the variator shaft and to the layshaft and a recirculater output member. An arrangement of clutches is provided for selectively engaging any of at least three regimes. In one regime the recirculater output member drives the transmission output. In another the layshaft drives the transmission output.

Abstract: The invention concerns an arrangement for control of a continuously variable transmission. The transmission includes a variator (10) having a movable torque transfer part (rollers 18) whose position corresponds to a variator drive ratio. A hydraulic actuator (28) is arranged to exert an adjustable force on the torque transfer part. The transmission further comprises a flow control arrangement which is arranged to receive as control inputs (a) the current position of the torque transfer part and (b) a demanded position for it. The demanded position may for example be determined by driver input. The flow control arrangement is adapted to supply through a supply outlet which communicates with the hydraulic actuator a flow of fluid which is modulated in accordance with an error between the two control inputs. The flow of fluid increases with increasing error.

Abstract: The invention concerns a continuously variable transmission having a transmission input (60) and a transmission output (114). The transmission has a variator (56). This is a device which transmits drive at steplessly variable ratio. It further comprises an epicyclic gear arrangement (58) incorporating a clutch arrangement (152). The epicyclic gear arrangement has three rotary members. One of these is coupled to a planet carrier (86) having at least one planet gear (94). Another of the rotary members is coupled to a main gear (90) meshing with the planet gear. The clutching arrangement serves to couple the remaining rotary member to either of first and second alternative gears (96, 98), both of which mesh with the planet gear and which rotate at different speeds. One of the aforesaid rotary members is coupled to the transmission input at a fixed drive ratio. One of them is coupled to the variator output. The last of the rotary members is coupled to the transmission output.