An HST of the present invention includes a main plate and a sub-plate supporting a center section, a pump-side swash plate holder and a motor-side swash plate holder by their inner surfaces facing each other. The main plate is provided with an extended region that extends farther outward in a planar direction of the main plate than an installation space of the center section, the pump-side swash plate holder and the motor-side swash plate holder and than the sub-plate as viewed along a direction in which the main plate and the sub-plate face each other.

A drive train configuration is disclosed. The drive train incorporates an engine having hydraulic pumps contained substantially inside the engine housing and with an engine shaft driving the hydraulic pumps. A porting block or center section is mounted to the engine housing to provide hydraulic communication between the hydraulic pumps located inside the engine housing and hydraulic motors located outside the engine housing. The hydraulic motor output shafts drive gears connected to axles to propel a vehicle.

A hydraulic transaxle comprises an axial piston hydraulic pump having a variable displacement, and a transaxle casing incorporating the hydraulic pump. The hydraulic pump includes a movable swash plate and a pair of trunnion shafts. The transaxle casing includes a pair of side walls, and includes a pair of casing holes each of which penetrates each of the side walls between an inside and an outside of the transaxle casing. The pair of trunnion shafts are passed through the respective casing holes. The swash plate is formed with a pair of swash plate holes in the respective side portions facing the respective side walls in the inside of the transaxle casing. Proximal end portions of the respective trunnion shafts are inserted into the respective swash plate holes. A distal end portion of one of the trunnion shafts projects from the corresponding casing hole to the outside of the transaxle casing.

A ramping subsystem of a control system for a dual path electronically controlled hydrostatic transmission is used to modify the commanded rate of change of pump and motor acceleration, deceleration and direction change command (performed to command machine motion from forward to reverse or vice versa) in order to achieve desired machine performance and operator feel. Pump and motor acceleration, deceleration and direction change command rates are then further modified using scaling tables based on selected maximum machine speed using operator input device.

A ramping subsystem of a control system for a dual path electronically controlled hydrostatic transmission is used to modify the commanded rate of change of pump and motor acceleration, deceleration and direction change command (performed to command machine motion from forward to reverse or vice versa) in order to achieve desired machine performance and operator feel. Pump and motor acceleration, deceleration and direction change command rates are then further modified using scaling tables based on selected maximum machine speed using operator input device.

A hydraulic transaxle of the present invention includes an axle, a hydraulic static transmission (“HST”), a center case that has pair of oil passages for circulating the hydraulic oil between the hydraulic pump and the hydraulic motor, and a gear mechanism that transmits an output of the HST to the axle. A case supports the axle and accommodates the HST while also forming an oil reservoir. A hydraulic motor of the HST includes a motor shaft, a cylinder block with a plurality of cylinders fixed to the motor shaft, a plurality of pistons inserted into the cylinders, a fixed swash plate abutted by the plurality of pistons, and a fixed swash plate holder that supports the fixed swash plate with respect to the case. The motor shaft of the hydraulic motor is supported by the center case and the fixed swash plate holder.

A hydraulic transaxle of the present invention includes an axle, a hydraulic static transmission (“HST”), a center case that has pair of oil passages for circulating the hydraulic oil between the hydraulic pump and the hydraulic motor, and a gear mechanism that transmits an output of the HST to the axle. A case supports the axle and accommodates the HST while also forming an oil reservoir. A hydraulic motor of the HST includes a motor shaft, a cylinder block with a plurality of cylinders fixed to the motor shaft, a plurality of pistons inserted into the cylinders, a fixed swash plate abutted by the plurality of pistons, and a fixed swash plate holder that supports the fixed swash plate with respect to the case. The motor shaft of the hydraulic motor is supported by the center case and the fixed swash plate holder.

Disclosed is a system comprising a variator and a transmission. The transmission housing includes a mounting joint transmission face and one or more transmission ports disposed in the mounting joint transmission face that are fluidly connected in a one-to-one correspondence to one or more transmission channels in the transmission housing. The variator housing may comprise a mounting joint variator face coupled to the mounting joint transmission face and one or more variator ports disposed in the mounting joint variator face. The one or more variator ports may be fluidly connected in a one-to-one correspondence to one or more variator channels in the variator housing. The one or more variator ports are fluidly connected in a one-to-one correspondence to the one or more transmission ports without the use of one or more external hoses to fluidly connect the one or more variator ports to the one or more transmission ports.

Disclosed is a system comprising a variator and a transmission. The transmission housing includes a mounting joint transmission face and one or more transmission ports disposed in the mounting joint transmission face that are fluidly connected in a one-to-one correspondence to one or more transmission channels in the transmission housing. The variator housing may comprise a mounting joint variator face coupled to the mounting joint transmission face and one or more variator ports disposed in the mounting joint variator face. The one or more variator ports may be fluidly connected in a one-to-one correspondence to one or more variator channels in the variator housing. The one or more variator ports are fluidly connected in a one-to-one correspondence to the one or more transmission ports without the use of one or more external hoses to fluidly connect the one or more variator ports to the one or more transmission ports.

A motor-hydraulic machine unit includes an electric motor, a hydraulic machine, and a connection body that has a planar connection surface which delimits first and second working connections. The first and second working connections are each in fluid exchange connection with the hydraulic machine via an assigned first fluid duct in the connection body. The electric motor and the hydraulic machine have a common axis of rotation which is arranged substantially parallel to the connection surface. The hydraulic machine and the electric motor are arranged on opposite sides of the connection body in the direction of the axis of rotation. The connection body is traversed by a drive aperture in the direction of the axis of rotation. The electric motor and the hydraulic machine are in rotary drive connection in a region of the drive aperture.