Abstract: A power machine and a power conversion system for a power machine are disclosed. In an exemplary embodiment, the power conversion system includes a pump configured to provide a source of pressurized hydraulic fluid and a control valve assembly to receive the hydraulic fluid. The control valve assembly includes a first valve element configured to direct hydraulic fluid to an actuator when the first valve element is in first and second actuated positions. The control valve assembly also includes a second valve element downstream of the first spool. The first valve element is moveable between an unactuated position and the first and second actuated positions and is configured to direct hydraulic fluid received from the actuator through the second actuated position to the second valve element and to direct hydraulic fluid received from the actuator through the first actuated position to bypass the second valve element.

Abstract: A power machine and a power conversion system for a power machine are disclosed. In an exemplary embodiment, the power conversion system includes a pump configured to provide a source of pressurized hydraulic fluid and a control valve assembly to receive the hydraulic fluid. The control valve assembly includes a first valve element configured to direct hydraulic fluid to an actuator when the first valve element is in first and second actuated positions. The control valve assembly also includes a second valve element downstream of the first spool. The first valve element is moveable between an unactuated position and the first and second actuated positions and is configured to direct hydraulic fluid received from the actuator through the second actuated position to the second valve element and to direct hydraulic fluid received from the actuator through the first actuated position to bypass the second valve element.

Abstract: Disclosed embodiments include HVAC systems, and power machines incorporating the same, which utilize an improved exchanger configuration in which the two separate heating and cooling exchangers of conventional systems are replaced with one composite exchanger. The composite heating and cooling exchanger includes nested heating and cooling tubes. The configuration of the tubes can be used to improve conductive efficiency in transferring heat energy to conductive fins, as well as to improve convective efficiency by increasing dwell time of air passing through the exchanger. The disclosed composite exchanger allows for a reduction in the overall exchanger package size package used in an HVAC unit.

Abstract: A lift arm structure for use on a power machine is disclosed. As disclosed, the lift arm structure includes an articulated knee portion pivotally attached to a main lift arm portion. The articulated knee portion is pivotally coupled to a distal end of the main lift arm portion at a bend angle. The bend angle can be fixed by a fixed length rod connected to the main lift arm portion and the articulated knee portion or adjustable through an actuator operably connected to the main lift arm portion and the articulated knee portion. In some applications, the actuator is a hydraulic cylinder connected to the lift arm portion and the articulated knee portion. A rod of the cylinder is extended and retracted to increase or decrease the bend angle of the articulated knee portion. The bend angle can be adjusted utilizing input from operator input devices or machine controlled utilizing pre-programmed bend angle parameters.

Abstract: A power machine and a power conversion system for a power machine are disclosed. In an exemplary embodiment, the power conversion system includes a pump configured to provide a source of pressurized hydraulic fluid and a control valve assembly to receive the hydraulic fluid. The control valve assembly includes a first valve element configured to direct hydraulic fluid to an actuator when the first valve element is in first and second actuated positions. The control valve assembly also includes a second valve element downstream of the first spool. The first valve element is moveable between an unactuated position and the first and second actuated positions and is configured to direct hydraulic fluid received from the actuator through the second actuated position to the second valve element and to direct hydraulic fluid received from the actuator through the first actuated position to bypass the second valve element.

Abstract: A hydraulic circuit for an actuator that has a piston and piston rod that will move a load in a first direction, and which can be externally loaded in an opposite direction, includes a flow compensated valve between the actuator and a control valve. When the piston in the actuator is moved in the second opposite direction under the external load and the rate of flow of fluid out of the actuator through the flow compensated valve exceeds a selected rate, an orifice is introduced in the flow path to restrict flow from the actuator.

Abstract: A conduit connector assembly for attachments on a loader includes a mounting plate with at least one coupler section mounted on the plate and secured rigidly to a forward end of one of the lift arms of a loader. The coupler section or sections are connected with conduits to power or electrical signal sources on the loader. The coupler section or sections on the lift arm are connectable to mating coupler sections attached to conduits from an attachment that requires power and/or control signals for operation. The coupler sections are supported to one side of the lines of vision that an operator in an operator's cab of the loader needs for watching the attachment.

Abstract: Disclosed are work machine vehicles having an operator protective structure with a seat mounted in the operator protective structure. In disclosed embodiments, first and second adjustable armrest assemblies are mounted to a structure of the seat such that the first and second armrest assemblies can be adjusted in fore and aft directions relative to a seatback of the seat. Vehicle controls are integrated with the first and second adjustable armrest assemblies such that adjustment of the first and second adjustable armrest assemblies adjusts positions of the vehicle controls relative to an operator sitting on the seat. After adjustment, the vehicle controls and the operator sitting on the seat are maintained at constant relative positions with respect to each other even as the work machine vehicle moves over rough terrain and the seat moves up and down.

Abstract: A work machine includes a frame supported for movement over the ground, a prime mover for driving movement of the frame, an operator compartment supported on the frame and a cradle coupling the operator compartment to the frame. The cradle is pivotable between an operating position and a service position and includes a biasing mechanism for biasing cradle toward the service position and an isolation mount coupling the operator compartment to the cradle. The isolation mount permits deflection of the operator compartment relative to the cradle along a selected axis. A latch mechanism releasably couples the cradle to the frame and a handle is provided for actuating the latch mechanism. The isolation mount includes a deformable member having a void defining the selected axis. The axis can be aligned with a force exerted on the cradle by the operator compartment to reduce stress on the biasing member.

Abstract: A work machine includes a frame supported for movement over the ground, a prime mover for driving movement of the frame, an operator compartment supported on the frame and a cradle coupling the operator compartment to the frame. The cradle is pivotable between an operating position and a service position and includes a biasing mechanism for biasing cradle toward the service position and an isolation mount coupling the operator compartment to the cradle. The isolation mount permits deflection of the operator compartment relative to the cradle along a selected axis. A latch mechanism releasably couples the cradle to the frame and a handle is provided for actuating the latch mechanism. The isolation mount includes a deformable member having a void defining the selected axis. The axis can be aligned with a force exerted on the cradle by the operator compartment to reduce stress on the biasing member.

Abstract: A track vehicle includes a cab operable to support an operator. Left and right motors each rotate an output shaft at a first speed, and a speed reduction system is operably coupled to each output shaft. Left and right drive shafts are driven by the speed reduction system at a second speed that is slower than the first speed. Left and right drive sprockets are mounted for rotation with the respective first and second drive shafts. Left and right track carriages support the cab and left and right tracks are mounted for rotation about the track carriages in response to rotation of the respective left and right drive shafts, such that the left and right tracks are driven by the left and right drive sprockets to move the track vehicle along a ground surface.

Abstract: Disclosed are work machine vehicles having an operator protective structure with a seat mounted in the operator protective structure. In disclosed embodiments, first and second adjustable armrest assemblies are mounted to a structure of the seat such that the first and second armrest assemblies can be adjusted in fore and aft directions relative to a seatback of the seat. Vehicle controls are integrated with the first and second adjustable armrest assemblies such that adjustment of the first and second adjustable armrest assemblies adjusts positions of the vehicle controls relative to an operator sitting on the seat. After adjustment, the vehicle controls and the operator sitting on the seat are maintained at constant relative positions with respect to each other even as the work machine vehicle moves over rough terrain and the seat moves up and down.

Abstract: A hydraulic circuit for an actuator that has a piston and piston rod that will move a load in a first direction, and which can be externally loaded in an opposite direction, includes a flow compensated valve between the actuator and a control valve. When the piston in the actuator is moved in the second opposite direction under the external load and the rate of flow of fluid out of the actuator through the flow compensated valve exceeds a selected rate, an orifice is introduced in the flow path to restrict flow from the actuator.

Abstract: A conduit connector assembly for attachments on a loader includes a mounting plate with at least one coupler section mounted on the plate and secured rigidly to a forward end of one of the lift arms of a loader. The coupler section or sections are connected with conduits to power or electrical signal sources on the loader. The coupler section or sections on the lift arm are connectable to mating coupler sections attached to conduits from an attachment that requires power and/or control signals for operation. The coupler sections are supported to one side of the lines of vision that an operator in an operator's cab of the loader needs for watching the attachment.

Abstract: A track vehicle includes a cab operable to support an operator. Left and right motors each rotate an output shaft at a first speed, and a speed reduction system is operably coupled to each output shaft. Left and right drive shafts are driven by the speed reduction system at a second speed that is slower than the first speed. Left and right drive sprockets are mounted for rotation with the respective first and second drive shafts. Left and right track carriages support the cab and left and right tracks are mounted for rotation about the track carriages in response to rotation of the respective left and right drive shafts, such that the left and right tracks are driven by the left and right drive sprockets to move the track vehicle along a ground surface.

Abstract: A track frame or undercarriage is made to support a rubber track on suitable guide rollers. A tensioning roller is provided as one of the guide rollers on the interior of the track and is mounted on a pivoting bracket. The pivoting bracket moves the tensioning roller to a working position for creating tension in the track. An actuator provides a known force on the pivoting bracket to move the tensioning roller to its working position, using a controlled pressure applied to the actuator. Drive sprockets for the track are mounted onto a drive case that is mounted to the frame through pivoting linkages such that the drive case and the drive sprocket can be held in a working position and retracted away from the track. The position of the tensioning roller is maintained within set limits of retractions during use, by providing a stop to limit the amount that the tensioning roller can retract.

Abstract: A track frame or undercarriage is made to support a rubber track on suitable guide rollers. A tensioning roller is provided as one of the guide rollers on the interior of the track and is mounted on a pivoting bracket. The pivoting bracket moves the tensioning roller to a working position for creating tension in the track. An actuator provides a known force on the pivoting bracket to move the tensioning roller to its working position, using a controlled pressure applied to the actuator. Drive sprockets for the track are mounted onto a drive case that is mounted to the frame through pivoting linkages such that the drive case and the drive sprocket can be held in a working position and retracted away from the track. The position of the tensioning roller is maintained within set limits of retractions during use, by providing a stop to limit the amount that the tensioning roller can retract.