A bulldozer includes a steering clutch, a steering brake, a hydraulic pump that discharges a lubricating oil, a first lubricating oil supply path, a second lubricating oil supply path, a third lubricating oil supply path, and a flow amount switching valve disposed on the second lubricating oil supply path. The first lubricating oil supply path supplies a portion of the lubricating oil discharged by the hydraulic pump to the steering clutch The second lubricating oil supply path supplies a portion of the lubricating oil discharged by the hydraulic pump to the steering brake. The third lubricating oil supply path supplies, to the steering brake, a portion of the lubricating oil that has passed through the steering clutch. The flow amount switching valve switches an amount of the lubricating oil supplied to the steering brake.

A stroke-controlled balancing device for hydraulic braking systems, comprising a balancing duct, a normally closed balancing valve, configured, in use, to maintain a connection between the hydraulic braking system and the balancing duct either closed or open, a stem having an external surface and an internal surface. A balancing channel is provided on the internal surface of the stem, said channel being hydraulically connected to the balancing duct, and the balancing valve is configured to slide, in use, along the external surface of the stem in order to open the connection between the braking system and the balancing duct. A braking system comprising the balancing device, as well as a method of operation of the braking system, are also described.

A stroke-controlled balancing device for hydraulic braking systems, comprising a balancing duct, a normally closed balancing valve, configured, in use, to maintain a connection between the hydraulic braking system and the balancing duct either closed or open, a stem having an external surface and an internal surface. A balancing channel is provided on the internal surface of the stem, said channel being hydraulically connected to the balancing duct, and the balancing valve is configured to slide, in use, along the external surface of the stem in order to open the connection between the braking system and the balancing duct. A braking system comprising the balancing device, as well as a method of operation of the braking system, are also described.

A hydraulic motor has a primary side and a secondary side. A hydraulic pump is to be driven by the engine to supply an operation fluid to the primary side. A bypass circuit is to connect the primary side and the secondary side. An electromagnetic valve is configured to control a flowing amount of the operation fluid in the bypass circuit to control an amount of the operation fluid supplied to the primary side. A filter is disposed in a fluid tube connected to the secondary side. A relief valve is disposed between the hydraulic pump and the primary side. A controller is to control the electromagnetic valve to drive the hydraulic motor in a case where a temperature of the operation fluid is low when the engine is started.

A hydraulic motor has a primary side and a secondary side. A hydraulic pump is to be driven by the engine to supply an operation fluid to the primary side. A bypass circuit is to connect the primary side and the secondary side. An electromagnetic valve is configured to control a flowing amount of the operation fluid in the bypass circuit to control an amount of the operation fluid supplied to the primary side. A filter is disposed in a fluid tube connected to the secondary side. A relief valve is disposed between the hydraulic pump and the primary side. A controller is to control the electromagnetic valve to drive the hydraulic motor in a case where a temperature of the operation fluid is low when the engine is started.

A dig system which allows for a vehicle to perform a dig maneuver, without sacrificing drivability. An actuator places the dig system in one of four different modes of operation, where the front wheels are placed in either a first configuration or a second configuration, where the front wheels are positioned at a desired steering angle, and one of the front or rear wheels is braked and prevented from rotating. The transfer case transfers power to one or more of the non-braked wheels, and disconnects from the remaining wheels. One or more of the non-braked wheels are rotated such that the vehicle pivots about an axis which extends through one of the wheels. One of the rear wheels is braked when performing a front dig maneuver, and one of the front wheels is be braked when performing a reverse dig maneuver.

A braking circuit including at least an auxiliary right valve (200) and an auxiliary left valve (300) suitable to allow braking on both sides, right and left of a vehicle, when this is required, but allowing to apply a pressure braking only on one of the two sides, right or left, when this is required to provide a steering function, characterized in that the circuit further comprises a master valve (400) having two positions: a first position when the vehicle has a velocity under a threshold wherein separate and selective right or left braking is authorized and a second position when the vehicle has a velocity above said threshold wherein said master valve (400) connects both a right braking line (204, 1205) and a left braking line (304, 1305) to an output braking line (110) so that if a braking is requested both right braking line (204, 1204) and left braking line (304, 1305) are under pressure and selective right or left braking is forbidden.

A braking circuit including at least an auxiliary right valve (200) and an auxiliary left valve (300) suitable to allow braking on both sides, right and left of a vehicle, when this is required, but allowing to apply a pressure braking only on one of the two sides, right or left, when this is required to provide a steering function, characterized in that the circuit further comprises a master valve (400) having two positions: a first position when the vehicle has a velocity under a threshold wherein separate and selective right or left braking is authorized and a second position when the vehicle has a velocity above said threshold wherein said master valve (400) connects both a right braking line (204, 1205) and a left braking line (304, 1305) to an output braking line (110) so that if a braking is requested both right braking line (204, 1204) and left braking line (304, 1305) are under pressure and selective right or left braking is forbidden.

A low-pressure vehicle braking system and method of operation that controls the supply of brake fluid based on the pressure differential between left and right master cylinders associated with the different wheel brakes allowing for pressure harmonization between the left and right wheel brake circuits and a brake system module suitable for installation on an existing vehicle.

A low-pressure vehicle braking system and method of operation that controls the supply of brake fluid based on the pressure differential between left and right master cylinders associated with the different wheel brakes allowing for pressure harmonization between the left and right wheel brake circuits and a brake system module suitable for installation on an existing vehicle.