Abstract: A hydraulically actuated continuously variable transmission (1) is provided with a hydraulic system (TH) for the control of the torque transmissible by the transmission (1) as well as the speed ratio provided by the transmission (1). The hydraulic system (TH) is provided with a mechanically driven hydraulic pump (PM) and with an electrically driven hydraulic pump (PE) for generating a pressurised flow of hydraulic medium for the actuation of the transmission. The electrically driven pump (PE) can be switched either downstream of or in parallel with the mechanically driven pump (PM).

Abstract: A hydraulically actuated continuously variable transmission (1) with two pulleys (5, 6), a drive belt (4) in frictional contact with these pulleys (5, 6) and a control device that includes at least two pressure chambers (8, 9) that are both associated with one pulley (6) and that are arranged such that a clamping force (Fs) that is exerted on the drive belt (4) by that one pulley (6) during operation of the transmission 1 is determined by the difference between the two pressures (Pline, Pcomp) that are respectively exerted therein and that are respectively actively controlled by a respective pressure control valve (13; 40) of the control device.

Abstract: A drive belt (3) includes an endless carrier (31) and a plurality of transverse members (32) of varying thickness, i.e. of varying dimension measured in the circumference direction “L” of the belt (3), which transverse members (32) are provided with a rocking edge (18) in the form an axially and radially extending section of a respective main body surface (38; 39) of the transverse member (32) that is convexly curved in radial direction. According to the invention, the design of such drive belt (3) can be improved, at least in terms of durability, by shaping the rocking edge (18) of the thinner transverse members (32) of such drive belt (3) according a larger radius of curvature in comparison with the radius of curvature of the rocking edge (18) of thicker transverse members (32) thereof.

Abstract: A drive belt (3) includes an endless carrier (31) and a plurality of transverse members (32) of varying thickness, i.e. the dimension measured in the circumference direction of the belt (3). According to the invention, the design of such drive belt (3) can be improved, at least in terms of durability, by also varying the width, i.e. the dimension measured in the axial direction “W” of the drive belt (3), of the transverse members (32) in such a way that the thinner transverse members (32) of the drive belt (3) are of a larger width than the thicker transverse members (32) thereof.

Abstract: A hydraulically actuated continuously variable transmission (1) with two pulleys (5, 6), a drive belt (4) in frictional contact with these pulleys (5, 6) and a control device that includes at least two pressure chambers (8, 9) that are both associated with one pulley (6) and that are arranged such that a clamping force (Fs) that is exerted on the drive belt (4) by that one pulley (6) during operation of the transmission 1 is determined by the difference between the two pressures (Pline, Pcomp) that are respectively exerted therein and that are respectively actively controlled by a respective pressure control valve (13; 40) of the control device.

Abstract: A hydraulically actuated continuously variable transmission (1) is provided with a hydraulic system (TH) for the control of the torque transmissible by the transmission (1) as well as the speed ratio provided by the transmission (1). The hydraulic system (TH) is provided with a mechanically driven hydraulic pump (PM) and with an electrically driven hydraulic pump (PE) for generating a pressurised flow of hydraulic medium for the actuation of the transmission. The electrically driven pump (PE) can be switched either downstream of or in parallel with the mechanically driven pump (PM).

Abstract: A push belt (6) for a continuously variable transmission comprises transverse elements (10) of at least two different types, wherein the differences between the transverse elements (10) reside in a profile (24) which is present at pulley sheave contact surfaces (18) of the transverse elements (10). On the basis of the use of at least two different types of transverse elements (10) as mentioned, many advantages are achieved, including improved traction, reduction of wear, and noise reduction. The design of the profile (24) can be such that a pattern of voids (28) is created at a contact side of the push belt (6), which voids (28) are used for receiving oil. The pattern of voids (28) can be random, or not. In the latter case, it is possible to have a path (28) for discharging oil, extending along the contact side of the push belt (6).

Abstract: A drive belt (3) includes an endless carrier (31) and a plurality of transverse members (32) of varying thickness, i.e. the dimension measured in the circumference direction of the belt (3). According to the invention, the design of such drive belt (3) can be improved, at least in terms of durability, by also varying the width, i.e. the dimension measured in the axial direction “W” of the drive belt (3), of the transverse members (32) in such a way that the thinner transverse members (32) of the drive belt (3) are of a larger width than the thicker transverse members (32) thereof.

Abstract: A drive belt (3) includes an endless carrier (31) and a plurality of transverse members (32) of varying thickness, i.e. of varying dimension measured in the circumference direction “L” of the belt (3), which transverse members (32) are provided with a rocking edge (18) in the form an axially and radially extending section of a respective main body surface (38; 39) of the transverse member (32) that is convexly curved in radial direction. According to the invention, the design of such drive belt (3) can be improved, at least in terms of durability, by shaping the rocking edge (18) of the thinner transverse members (32) of such drive belt (3) according a larger radius of curvature in comparison with the radius of curvature of the rocking edge (18) of thicker transverse members (32) thereof.

Abstract: The invention relates to a drive belt (3) including an endless carrier (31) and a plurality of transverse members (30) that are mounted on and arranged along the circumference of the carrier (31) in an essentially contiguous row. This type of drive belt (3) is well-known, in particular from its application in the friction-type belt-and-pulleys transmission. According to the invention, the efficiency of such a transmission is improved when not all transverse members (30) of the drive belt (3) take part in the frictional contact with the transmission pulleys (1, 2). This technical effect is realized, in accordance with the invention, by providing the drive belt (3) with two types of transverse members (30), whereof the second type is less wide than the first type.

Abstract: A push belt (6) for a continuously variable transmission comprises transverse elements (10) of at least two different types, wherein the differences between the transverse elements (10) reside in a profile (24) which is present at pulley sheave contact surfaces (18) of the transverse elements (10). On the basis of the use of at least two different types of transverse elements (10) as mentioned, many advantages are achieved, including improved traction, reduction of wear, and noise reduction. The design of the profile (24) can be such that a pattern of voids (28) is created at a contact side of the push belt (6), which voids (28) are used for receiving oil. The pattern of voids (28) can be random, or not. In the latter case, it is possible to have a path (28) for discharging oil, extending along the contact side of the push belt (6).

Abstract: Drive belt provided with a continuous band having a radially inwardly oriented surface and a radially outwardly oriented surface, and with an array of plate-like transverse elements engaging the continuous band.

Abstract: Drive belt provided with a continuous band having a radially inwardly oriented surface and a radially outwardly oriented surface, and with an array of plate-like transverse elements engaging the continuous band.

Abstract: Roller vane pump, in particular suited for pumping fluid in a continuously variable automatic transmission of a motor vehicle, provided with a pump housing accommodating a substantially cylindrical carrier, which is rotatable about a central axis, and a cam ring encompassing the carrier in the radial direction, whereby a radial clearance between the carrier and the cam ring varies along a circumference of the carrier, and with a pump shaft extending co-axial with said central axis through the carrier, characterised in that there is provided in the pump housing a bearing bush having an essentially cylindrical central bore through which the pump shaft extends.

Abstract: A roller vane pump, in particular suited for pumping fluid in a continuously variable automatic transmission of a motor vehicle, is provided with a pump housing (12) accommodating a carrier (4) rotatable around a central axis (4a) of the carrier in a direction of rotation by a pump shaft (5), on the periphery of the carrier (4) there is provided a slot (6), which extends in a substantially radial direction and accommodates an essentially cylindrically shaped roller element (7) having a roller diameter (DR) for interaction with a radially inner cam surface (2a) of a cam ring (2) encompassing the carrier (4) in radial direction. The cam surface (2a) is located at a radial distance (R) from the central axis (4a) that varies in dependence on an angular rotation (&phgr;) according to a cam curve (R{&phgr;}).

Abstract: Roller vane pump, in particular suited for pumping fluid in a continuously variable automatic transmission of a motor vehicle, provided with a pump housing accommodating a substantially cylindrical carrier, which is rotatable about a central axis, and a cam ring encompassing the carrier in the radial direction, whereby a radial clearance between the carrier and the cam ring varies along a circumference of the carrier, and with a pump shaft extending co-axial with said central axis through the carrier, characterised in that there is provided in the pump housing a bearing bush having an essentially cylindrical central bore through which the pump shaft extends.

Abstract: The invention relates to a roller vane pump suitable for pumping transmission fluid in an automatic transmission for motor vehicles. The pump is provided with a pump housing (2), a rotatable carrier (3) being located in the interior of the pump housing (2), a cam ring (5) surrounding the carrier (3) in radial direction, and roller elements (7) being provided in slots (6) in the carrier periphery. The spaces between the pump housing (2), the carrier (3), the cam ring (5) and the roller elements (7) define a number of pump chambers (8). Furthermore, the pump is provided with feed apertures (9) for allowing a flow of fluid to a pump chamber (8) and with discharge apertures (10) for allowing a flow of fluid from a pump chamber (8). According to the invention constructional measurements are taken to avoid the occurrence of cavitation and to obtain higher pump efficiency.

Abstract: The invention relates to a roller vane pump suitable for pumping transmission fluid in an automatic transmission for motor vehicles. The pump is provided with a pump housing (2), a rotatable carrier (3) being located in the interior of the pump housing (2), a cam ring (5) surrounding the carrier (3) in radial direction, and roller elements (7) being provided in slots (6) in the carrier periphery. The spaces between the pump housing (2), the carrier (3), the cam ring (5) and the roller elements (7) define a number of pump chambers (8). Furthermore, the pump is provided with feed apertures (9) for allowing a flow of fluid to a pump chamber (8) and with discharge apertures (10) for allowing a flow of fluid from a pump chamber (8). According to the invention constructional measurements are taken to avoid the occurrence of cavitation and to obtain higher pump efficiency.

Abstract: The invention relates to a roller vane pump suitable for pumping transmission fluid in an automatic transmission for motor vehicles. The pump is provided with a pump housing (2), a rotatable carrier (3) being located in the interior of the pump housing (2), a cam ring (5) surrounding the carrier (3) in radial direction, and roller elements (7) being provided in slots (6) in the carrier periphery. The spaces between the pump housing (2), the carrier (3), the cam ring (5) and the roller elements (7) define a number of pump chambers (8). Furthermore, the pump is provided with feed apertures (9) for allowing a flow of fluid to a pump chamber (8) and with discharge apertures (10) for allowing a flow of fluid from a pump chamber (8). According to the invention constructional measurements are taken to avoid the occurrence of cavitation and to obtain higher pump efficiency.

Abstract: The invention relates to a roller vane pump suitable for pumping transmission fluid in an automatic transmission for motor vehicles. The pump is provided with a pump housing (2), a rotatable carrier (3) being located in the interior of the pump housing (2), a cam ring (5) surrounding the carrier (3) in radial direction, and roller elements (7) being provided in slots (6) in the carrier periphery. The spaces between the pump housing (2), the carrier (3), the cam ring (5) and the roller elements (7) define a number of pump chambers (8). Furthermore, the pump is provided with feed apertures (9) for allowing a flow of fluid to a pump chamber (8) and with discharge apertures (10) for allowing a flow of fluid from a pump chamber (8). According to the invention constructional measurements are taken to avoid the occurrence of cavitation and to obtain higher pump efficiency.