Abstract: A cooling system for an annular stator housed within a transmission casing includes a first curved tube sufficiently sized to at least partially circumscribe the stator when the tube is placed within the casing. The first tube has a plurality of circumferentially spaced fluid openings. An intake conduit connects the first tube to the transmission casing to deliver fluid through the tube for flow through the fluid openings to cool the stator. Preferably, a second like curved tube is also provided and a connector tube connects the first and second tubes to allow fluid flow therebetween. A method of assembling a cooling system is also provided.

Abstract: An electrically variable transmission having two planetary gear sets, two motor/generators, and six torque transfer devices to provide input split, compound split, output split, neutral, electric reverse and mechanical reverse modes of operation. The electrically variable transmission includes: an input member to receive power from an engine; an output member; first and second motor/generators; and first and second differentially geared planetary gear sets each having first, second and third gear members. The input member is not continuously connected with any member of the planetary gear sets, and the output member is continuously connected to the first member of the second planetary gear set. The first and second motor/generators are each continuously connected to at least one member of the planetary gear sets. The first member of the first planetary gear set is continuously connected with the third member of the second planetary gear set.

Abstract: A hybrid electromechanical transmission includes first, second and third planetary gear sets, an input member, an output member, and first and second motor generators. At least one of the gear members in the first planetary gear set is connected to the first motor/generator. At least one of the gear members in the third planetary gear set is connected to the second motor/generator. First and second interconnecting members continuously connect members of the first planetary gear set with members of the second planetary gear set. Five torque-transmitting mechanisms selectively interconnect members of the planetary gear sets with a stationary member or with other members of the planetary gear sets. One of the five torque-transmitting mechanisms is operative to selectively disconnect the second planetary gear set from the third planetary gear set so that the second motor/generator may drive the output member while disconnected from the first motor/generator and the input member.

Abstract: A planet carrier assembly has a plurality of pinion gears rotatably mounted on pinion pins, each pin having a slot formed thereon. A locator ring is assembled onto the pinion pins and rotated in a manner such that the locator ring engages the slots in the pinion pins and a plurality of tabs and protuberances engage complementary components formed on a housing member of the planet carrier assembly. The locator ring ensures both axial and rotational positioning of the pinion pins within the planet carrier housing.

Abstract: A rotatable torque-transmitting apparatus includes a stationary piston and a rotatable apply plate. The rotatable apply plate is disposed adjacent a rotatable housing and separated therefrom by a return spring assembly which in a preload condition is trapped between the apply plate and the rotatable housing to limit the disengaged force which is transmitted between the rotatable housing and the stationary piston.

Abstract: A hybrid electromechanical transmission includes first, second and third planetary gear sets, an input member, an output member, and first and second motor generators. At least one of the gear members in the first planetary gear set is connected to the first motor/generator. At least one of the gear members in the third planetary gear set is connected to the second motor/generator. First and second interconnecting members continuously connect members of the first planetary gear set with members of the second planetary gear set. Five torque-transmitting mechanisms selectively interconnect members of the planetary gear sets with a stationary member or with other members of the planetary gear sets. One of the five torque-transmitting mechanisms is operative to selectively disconnect the second planetary gear set from the third planetary gear set so that the second motor/generator may drive the output member while disconnected from the first motor/generator and the input member.

Abstract: The present invention provides an electrically variable transmission having two motor/generators, two differential gear sets such as planetary gear sets, and five torque transfer devices arranged to provide improved launch, performance and gradeability, and enabling five fixed speed ratios. An input member is continuously connected to one member (preferably a ring gear) of the first planetary gear set, and an output member is continuously connected to one member (preferably a carrier) of the second planetary gear set. One motor/generator is continuously connected to another member (preferably a sun gear) in the first planetary gear set as well as being selectively connected to a member (preferably a ring gear) of the second planetary gear set. The second motor/generator is continuously connected to the remaining member (preferably a sun gear) of the second planetary gear set, and is selectively connected to the remaining member (preferably a carrier) of the first planetary gear set.

Abstract: An electrically variable transmission includes: an input member to receive power from an engine; an output member; first and second motor/generators; and first and second differentially geared planetary gear sets each having first, second and third gear members. The input member is continuously connected to the first member of the first planetary gear set, and the output member is continuously connected to the first member of the second planetary gear set. The first motor/generator is continuously connected to the second member of the first planetary gear set, and selectively connected to the second member of the second planetary gear set. The second motor/generator is continuously connected with the third member of the second planetary gear set. Five or six torque transfer devices selectively connect members of the planetary gear sets with each other or with ground. The torque transfer devices are engageable in combinations of two or three to provide five or six available fixed speed ratios.

Abstract: A hydraulically-actuatable clutch and method is operable as an overdrive clutch in a transmission system having a transmission main shaft portion. The clutch is engageable between a transmission housing and a sun gear and rotor hub to provide for grounding of the sun gear and rotor hub to the transmission housing. The clutch may either be engaged or disengaged from the transmission housing. The clutch does not allow the rotor and sun gear to rotatably slip with respect to the transmission housing when the clutch is engaged to ground the rotor and sun gear to the transmission housing. When the clutch is disengaged, the rotor and sun gear may rotate with the transmission main shaft portion.

Abstract: A dog clutch operable as an engine/motor disconnect clutch within a gasoline/electric transmission system is provided. The clutch is housed on the main shaft of the transmission. The main shaft is divided into a first main shaft portion releasably connected to a first electric motor/generator and a first gear set and a second main shaft portion connected to a second electric motor/generator and second gear set. The clutch includes a hydraulically actuatable piston slidably located coaxially with the first main shaft portion and second main shaft portion. The first main shaft portion is spring-biased and juxtaposed with the piston. A member of the first gear set is releasably engaged with the first main shaft portion which, through the second main shaft portion, is engaged with a member of the second gear set.

Abstract: The invention provides a structural member for a vehicle transmission formed with an annular recess in fluid communication with a fluid source and at least partially enclosing and defining an interior space of the transmission. An interior component, such as a motor/generator, is located in the interior space. The annular recess directs cooling fluid provided from the fluid source onto the interior component. The end cover includes structure defining a flow passage in fluid communication with a fluid source and also defining an annular recess in fluid communication with the flow passage. The flow passage and the annular recess are cooperatively configured for directing fluid provided from the fluid source onto an interior component in the interior space for cooling the interior component. Preferably, the interior component is an electric motor/generator that includes a stator having electric windings. The fluid is directed from the annulus onto the electric windings.

Abstract: The invention provides an electrically variable transmission including an input member to receive power from an engine about a primary axis; an output member connected to a transfer member for transmitting power to a secondary axis; first and second motor/generators; first and second torque transfer devices; and first and second planetary gear sets each having first, second and third members. The input member is continuously connected to the first member of the first gear set, and the output member is continuously connected to the first member of the second gear set. The first motor/generator is continuously connected to the second member of the first gear set. The second motor/generator is continuously connected with the third member of the first or second gear set. The transfer member is positioned between the first and second motor/generators.

Abstract: The invention provides an electrically variable transmission including an input member to receive power from an engine; an output member connected to a transfer gear; first and second motor/generators; and first and second simple planetary gear sets each having first, second and third members. The input member is continuously connected to the first member of the first gear set, and the output member is continuously connected to the first member of the second gear set. The first motor/generator is continuously connected to the second member of the first gear set. The second motor/generator is continuously connected with the third member of the first or second gear set. The transfer gear and first and second torque transfer devices are positioned between the first and second gear sets.

Abstract: The invention provides an electrically variable transmission including an input member to receive power from an engine about a primary axis; an output member connected to a transfer member for transmitting power to a secondary axis; first and second motor/generators; and first and second simple planetary gear sets each having first, second and third members. The input member is continuously connected to the first member of the first gear set, and the output member is continuously connected to the first member of the second gear set. The first motor/generator is continuously connected to the second member of the first gear set. The second motor/generator is continuously connected with the third member of the first or second gear set. First and second torque transfer devices are positioned on one side of the transfer member, and the first and second gear sets are positioned on an opposite side of the transfer member.

Abstract: An electrically variable transmission includes: an input member to receive power from an engine; an output member; first and second motor/generators; and first and second differentially geared planetary gear sets each having first, second and third gear members. The input member is continuously connected to the first member of the first planetary gear set, and the output member is continuously connected to the first member of the second planetary gear set. The first motor/generator is continuously connected to the second member of the first planetary gear set, and selectively connected to the second member of the second planetary gear set. The second motor/generator is continuously connected with the third member of the second planetary gear set. A first torque transfer device selectively grounds the second member of the second planetary gear set. A second torque transfer device selectively connects the second member of the second planetary gear set to the second member of the first planetary gear set.

Abstract: The present invention provides an electrically variable transmission having two planetary gear sets, two motor/generators, and six torque transfer devices to provide input split, compound split, output split, neutral, electric reverse and mechanical reverse modes of operation. The electrically variable transmission includes: an input member to receive power from an engine; an output member; first and second motor/generators; and first and second differentially geared planetary gear sets each having first, second and third gear members. The input member is not continuously connected with any member of the planetary gear sets, and the output member is continuously connected to the first member of the second planetary gear set. The first and second motor/generators are each continuously connected to at least one member of the planetary gear sets. The first member of the first planetary gear set is continuously connected with the third member of the second planetary gear set.

Abstract: A rotatable torque-transmitting apparatus includes a stationary piston and a rotatable apply plate. The rotatable apply plate is disposed adjacent a rotatable housing and separated therefrom by a return spring assembly which in a preload condition is trapped between the apply plate and the rotatable housing to limit the disengaged force which is transmitted between the rotatable housing and the stationary piston.

Abstract: A pressure holding apparatus incorporates a hydraulic pressure system having an engine-driven pressure source, a pressure holding valve, and a torque-transmitting mechanism. The torque-transmitting mechanism is selectively engaged and disengaged by fluid pressure from the engine-driven pressure source during normal powertrain operation. The torque-transmitting mechanism apply chamber is pressurized with the oil by the pressure holding valve when the engine operation is discontinued.

Abstract: A pressure holding apparatus incorporates a hydraulic pressure system having an engine-driven pressure source, a pressure holding valve, and a torque-transmitting mechanism. The torque-transmitting mechanism is selectively engaged and disengaged by fluid pressure from the engine-driven pressure source during normal powertrain operation. The torque-transmitting mechanism apply chamber is pressurized with the oil by the pressure holding valve when the engine operation is discontinued.

Abstract: A hybrid powertrain includes a prime mover engine driving a multi-ratio transmission. A gear transfer mechanism is connected between said transmission and a plurality of vehicle drive wheels. An electric power unit, such as a motor/generator is drivingly connected with the gear transfer mechanism in parallel power flow relation with an output power flow from said transmission.