Abstract: The present invention provides a pump unit including at least one hydraulic pump with inlet and outlet ports, a pump case for accommodating the hydraulic pump having an opening through which the hydraulic pump is insertable, and a lid, called a center section, closing the pump case. The center section forms a pair of inlet/outlet passages communicating an end with the inlet and outlet ports of the hydraulic pump and an end opening through a pump case abutting surface of the center section, and a first charging passage by which hydraulic fluid is fed through the pump case abutting surface of the center section. At least one of the pump case and the center section communicates the first charging passage with the pair of inlet/outlet passages via a first hydraulic fluid feeding valve preventing the reverse flow into said first charging passage.

Abstract: An axle driving unit includes a pair of axles, a differential unit for differently connecting the pair of axles to each other, a hydraulic pump, a hydraulic motor, a motor shaft, an output gear on said motor shaft for drivingly connecting to said differential unit, a center section having a pump mounting surface and a motor mounting surface onto which said hydraulic pump and the hydraulic motor are mounted respectively, a housing constituted by a first housing part and a second housing part joined to each other at a joint surface, and a fastener fastening the center section to the first housing part. The center section is entirely disposed in the first housing part, whereby the hydraulic pump, the hydraulic motor and the output gear are entirely contained in the first housing part. The motor mounting surface may be disposed in parallel to the joint surface of the housing.

Abstract: An axle driving system which houses in a housing thereof a hydrostatic transmission, axles, and a driving gear train for connecting output means of the hydraulic transmission and axles, so as to transmit power from a driving source to the hydrostatic transmission and to change the speed, thereby driving the axles. A first chamber therein contains the hydrostatic transmission and a second chamber therein contains the driving gear train. Both the first and second chambers are independent of each other so as to prevent a foreign object, such as iron powder produced in the driving gear train, from entering the hydrostatic transmission. The system includes an L-like-shaped center section on which the hydrostatic transmission is offset such that an imaginary plane which includes a motor mounting surface passes in proximity to the axis of a pump shaft. The pump shaft is disposed perpendicular to the axles. The motor shaft is disposed in parallel thereto.

Abstract: An axle driving apparatus in which a hydraulic pump and a hydraulic motor which constitute a hydrostatic transmission are disposed on a center section. In a horizontal portion of the center section are provided a pair of linear oil passages in parallel to each other. A pair of arcuate ports are provided on a pump mounting surface formed on the horizontal portion of the center section. The pair of arcuate ports are substantially perpendicular with respect to the direction in which the oil passages extend. The axis of slanting movement of a movable swash plate of the hydraulic pump extends laterally of the vehicle body on which the axle driving apparatus is provided. The rotating direction of an arm provided on a control shaft for slantingly operating the movable swash plate is coincident with the operating direction of a control rod connected with a speed changing member. Thus, the link mechanism for connecting the speed changing member and the control arm for the movable swash plate is simplified.

Abstract: The present invention provides a tandem pump unit that includes: a first hydraulic pump and a second hydraulic pump respectively having a first pump shaft and a second pump shaft respectively having adjacent ends connected together so that the first and second pump shafts are coaxially aligned and non-rotatably connected in tandem; a common housing for accommodating the first hydraulic pump and the second hydraulic pump; and a first center section and a second center section that respectively support the first and second hydraulic pumps.

Abstract: An articulated vehicle with a working device has a first frame having a prime mover mounted thereon and supporting a first transaxle apparatus. The first transaxle apparatus includes an input shaft receiving power from the prime mover, a pair of first axles, and a hydrostatic transmission. The hydrostatic transmission comprises a variable hydraulic pump, a first hydraulic motor fluidly connected to the hydraulic pump via a fluid passage, and a housing with a flexible port fluidly connected to the fluid passage. The second transaxle apparatus includes a pair of second axles having different lengths and a second hydraulic motor. The second hydraulic motor is fluidly connected via piping to a directionally adjustable connection portion of the flexible port. Proximal ends of the first and second frames with respect to the vehicle are coupled to each other so that the first and second frames are rotatable around a vertical axis relative to each other when steered.

Abstract: The present invention provides a tandem pump unit that includes: a first hydraulic pump and a second hydraulic pump respectively having a first pump shaft and a second pump shaft respectively having adjacent ends connected together so that the first and second pump shafts are coaxially aligned and non-rotatably connected in tandem; a common housing for accommodating the first hydraulic pump and the second hydraulic pump; and a first center section and a second center section that respectively support the first and second hydraulic pumps.

Abstract: An axle driving apparatus comprising a common housing in which a hydraulic pump and a hydraulic motor fluidly connected with each other and an axle driven by the hydraulic motor are disposed, At least one of the hydraulic pump and the hydraulic motor is variable in displacement and has a capacity changing device for changing its capacity. A hydraulic actuator is provided in the housing for controlling the capacity changing device. A control valve for hydraulically controlling the hydraulic actuator is provided in the housing. A center section for fluidly connecting the hydraulic pump and the hydraulic motor with each other is fixedly disposed in the housing and a driving part of the hydraulic actuator and the control valve are incorporated in the center section. A rotary member operatively connected to a human-operated traveling control member provided on a vehicle is rotatably supported by the housing.

Abstract: An axle driving system which houses in a housing thereof a hydrostatic transmission, axles, and a driving gear train for connecting output means of the hydraulic transmission and axles, so as to transmit power from a driving source to the hydrostatic transmission and to change the speed, thereby driving the axles. A first chamber therein contains the hydrostatic transmission and a second chamber therein contains the driving gear train. Both the first and second chambers are independent of each other so as to prevent a foreign object, such as iron powder produced in the driving gear train, from entering the hydrostatic transmission. The system includes an L-like-shaped center section on which the hydrostatic transmission is offset such that an imaginary plane which includes a motor mounting surface passes in proximity to the axis of a pump shaft. The pump shaft is disposed perpendicular to the axles. The motor shaft is disposed in parallel thereto.

Abstract: There is provided a working vehicle having first and second hydraulic pump units operatively driven by a driving source and arranged away to each other in a width direction of the vehicle. In the working vehicle, each of the first and second hydraulic pump units includes a pump body; a port block formed with an oil passage for supplying/discharging an operating fluid to/from said pump body; a pump case connected to the port block so as to define a pump body accommodating space for surrounding the pump body; and a pump shaft for rotatably driving the pump body, the pump shaft having an input end operatively connected to said driving source. A drain port for opening the pump body accommodating space outward and a charge suction port for drawing in an oil from an oil tank in order to supply a charge oil to a hydraulic circuit fluidly connecting with the corresponding hydraulic motor unit are provided respectively in first and second assemblies formed by the corresponding pump case and port block.

Abstract: A hydrostatic transaxle comprises: a housing, an interior space of the housing serving as a fluid sump; an axle supported by the housing; a hydrostatic transmission disposed in the housing so as to drive the axle, the hydrostatic transmission including a hydraulic pump disposed in the housing, a hydraulic motor disposed in the housing, and a center section disposed in the housing, wherein the hydraulic pump and the hydraulic motor are mounted onto the center section, and wherein the center section is formed therein with a fluid circuit for circulation of fluid between the hydraulic pump and the hydraulic motor, and formed with an outwardly opened hole connected to the fluid circuit; a valve holding member fitted into the hole; and a relief valve connected to the fluid circuit through valve holding member.

Abstract: There is provided an HST unit including: a first hydraulic motor unit for operatively driving one of a pair of driving wheels; a second hydraulic motor unit for operatively driving the other one of the pair of driving wheels; a hydraulic pump unit operatively connected to a driving power source, the hydraulic pump unit configuring a traveling hydrostatic transmission in cooperation with the first and second hydraulic motor units; and an attachment frame for supporting the first hydraulic motor unit, the second hydraulic motor unit and the hydraulic pump unit, the attachment frame being attachable to a vehicle frame.

Abstract: There is provided a multiple pump unit including a pump shaft, a first pump, a pump housing, a second pump and a fluid passage block connected to one end surface in an axis line direction of the pump housing. One or both contacting surfaces of the pump housing and the fluid passage block is formed with a concave portion for accommodating the second pump. The pump housing is provided with a suction fluid passage guiding hydraulic fluid to a suction opening of the first pump and a first pump discharge fluid passage having a distal end that forms a first pump discharge port. The fluid passage block is provided with a second pump discharge port having the second pump as a hydraulic source.

Abstract: An axle driving unit includes an axle, a hydraulic pump, a hydraulic motor having a motor shaft on which an output gear is provided to be drivingly connected to said axle, a center section having a pump mounting surface and a motor mounting surface onto which the hydraulic pump and the hydraulic motor are mounted respectively so as to be fluidly connected with each other through the center section, a housing constituted by a first housing part and a second housing part joined to each other at a joint surface, a projection integrally formed on the center section so as to be fitted to the housing, thereby fixing a position of the center section relative to the housing, and a fastener fastening the center section to the first housing part. The pump mounting surface and said motor mounting surface may be disposed perpendicular to each other said pump mounting surface and said motor mounting surface are disposed perpendicular to each other.

Abstract: There is provided a working vehicle having first and second hydraulic pump units operatively driven by a driving source and arranged away to each other in a width direction of the vehicle. In the working vehicle, each of the first and second hydraulic pump units includes a pump body; a port block formed with an oil passage for supplying/discharging an operating fluid to/from said pump body; a pump case connected to the port block so as to define a pump body accommodating space for surrounding the pump body; and a pump shaft for rotatably driving the pump body, the pump shaft having an input end operatively connected to said driving source. A drain port for opening the pump body accommodating space outward and a charge suction port for drawing in an oil from an oil tank in order to supply a charge oil to a hydraulic circuit fluidly connecting with the corresponding hydraulic motor unit are provided respectively in first and second assemblies formed by the corresponding pump case and port block.

Abstract: A pump unit for supply and discharge of hydraulic fluid into and from an actuator upon receiving driving power from a driving source is provided, in which said actuator is fluidly connected to said pump unit via a hydraulic circuit. The pump unit includes an input member operatively connected to the driving source, a first hydraulic pump body operatively connected to the input member, a pump case for accommodating the first hydraulic pump body and forming a hydraulic fluid sump, and a PTO unit accommodated within the pump case. The PTO unit includes a PTO shaft supported by the pump case so as to have an end extending outward from the pump case, and a clutch mechanism for selectively enabling and disabling transmission of driving power from the input member to the PTO shaft.

Abstract: First pump shaft having an input end is on a side opposite PTO shaft in the vehicle width direction with second pump shaft in between. First and second pump shafts are supported by a pair of bearing members respectively provided at second end wall and lid member so as to sandwich the corresponding gear, and center section. Housing has a seal case portion at a portion for supporting an end on a side closed to driving source of the PTO shaft, the seal case portion including a ring-shaped oil distributing chamber for supplying operation oil to a PTO clutch operating oil path formed in the PTO shaft so as to supply the operation fluid to the PTO clutch.

Abstract: An axle driving system which houses in a housing thereof a hydrostatic transmission, axles, and a driving gear train for connecting output means of the hydraulic transmission and axles, so as to transmit power from a driving source to the hydrostatic transmission and to change the speed, thereby driving the axles. A first chamber therein contains the hydrostatic transmission and a second chamber therein contains the driving gear train. Both the first and second chambers are independent of each other so as to prevent a foreign object, such as iron powder produced in the driving gear train, from entering the hydrostatic transmission. The system includes an L-like-shaped center section on which the hydrostatic transmission is offset such that an imaginary plane which includes a motor mounting surface passes in proximity to the axis of a pump shaft. The pump shaft is disposed perpendicular to the axles. The motor shaft is disposed in parallel thereto.

Abstract: There is provided a pump unit configured to be capable of transmitting a rotational power from a driving power source which is operatively connected thereto to an actuator through a pair of hydraulic fluid lines. The pump unit includes: an input shaft; a hydraulic pump main body; a PTO shaft; a PTO clutch mechanism; an auxiliary pump main body; a suction line; a discharge line; a charge line; a PTO hydraulic fluid line; a pressure-reducing valve; and a resistance valve. The PTO hydraulic fluid line and the charge line are fluidly connected to the primary side and a secondary side of the pressure-reducing valve, respectively.

Abstract: A power transmission apparatus for a working vehicle has substantially symmetrically disposed first and second transaxles, each of which supports a single axle, and a working apparatus driving power take-off device including an input member. A gear casing is spanned between the first and second transaxles. A primary drive shaft is disposed in the gear casing so as to be drivingly connected to a prime mover. A traveling drive train is disposed in the gear casing so as to drivingly connect the primary drive shaft to the input shafts of the respective transaxles. A working apparatus drive train is disposed in the gear casing so as to drivingly connect the primary drive shaft to the input member of the working apparatus driving power take-off device.