A system for forming a negative pressure in a negative pressure reservoir of a brake system includes, an engine having an intake manifold and a camshaft, a vacuum pump connected to the camshaft through a clutch device and generating a pump negative pressure, a turbocharger having a compressor supplying a compressed air to the engine, a pump negative pressure line connecting the vacuum pump and the negative pressure reservoir and supplying the pump negative pressure to the negative pressure reservoir, an intake negative pressure line connecting the negative pressure reservoir and the intake manifold and supplying the intake negative pressure of the intake manifold to the negative pressure reservoir, and a negative pressure source selection apparatus configured to control opening and closing of the pump negative pressure line and the intake negative pressure line based on operation of the turbocharger.

A system for forming a negative pressure in a negative pressure reservoir of a brake system includes, an engine having an intake manifold and a camshaft, a vacuum pump connected to the camshaft through a clutch device and generating a pump negative pressure, a turbocharger having a compressor supplying a compressed air to the engine, a pump negative pressure line connecting the vacuum pump and the negative pressure reservoir and supplying the pump negative pressure to the negative pressure reservoir, an intake negative pressure line connecting the negative pressure reservoir and the intake manifold and supplying the intake negative pressure of the intake manifold to the negative pressure reservoir, and a negative pressure source selection apparatus configured to control opening and closing of the pump negative pressure line and the intake negative pressure line based on operation of the turbocharger.

Valves having a sprung gate of various constructions are disclosed. In one embodiment, the sprung gate includes a first endless elastic band having an inner perimeter defining an open space sandwiched between a first gate member and a second gate member that each define an opening therethrough in an open position portion thereof. The first endless elastic band is sandwiched therebetween with its open space oriented for alignment with the opening in both of the first and second gate members, which are aligned with one another to form a passage through the sprung gate. In one aspect, the first endless elastic band in positioned inward a distance from the outer sides of the first and second gate members and spaces the first gate member a distance apart from the second gate member thereby defining a channel having a bottom defined by the first endless elastic band.

Valves having a sprung gate of various constructions are disclosed. In one embodiment, the sprung gate includes a first endless elastic band having an inner perimeter defining an open space sandwiched between a first gate member and a second gate member that each define an opening therethrough in an open position portion thereof. The first endless elastic band is sandwiched therebetween with its open space oriented for alignment with the opening in both of the first and second gate members, which are aligned with one another to form a passage through the sprung gate. In one aspect, the first endless elastic band in positioned inward a distance from the outer sides of the first and second gate members and spaces the first gate member a distance apart from the second gate member thereby defining a channel having a bottom defined by the first endless elastic band.

A turbocharger generating a vacuum negative pressure may include a compressor which receives, through a turbocharger shaft, a rotational force of a turbine which rotates based on exhaust gas from an engine and turbo-charges an intake which is supplied to the engine, and a motorless vacuum pump coupled to the turbine through a center housing which is coupled to the compressor and is configured to be rotated by the turbocharger shaft, thus generating a vacuum negative pressure.

A turbocharger generating a vacuum negative pressure may include a compressor which receives, through a turbocharger shaft, a rotational force of a turbine which rotates based on exhaust gas from an engine and turbo-charges an intake which is supplied to the engine, and a motorless vacuum pump coupled to the turbine through a center housing which is coupled to the compressor and is configured to be rotated by the turbocharger shaft, thus generating a vacuum negative pressure.

Recirculation systems for engine intake air are disclosed having a turbocharger compressor with an inlet and an outlet, a recirculation pathway connecting fluid flow from the outlet of the turbocharger compressor to fluid flow into the inlet of the turbocharger compressor, and a recirculation valve assembly controlling fluid flow through the recirculation pathway. The recirculation valve assembly includes an actuator operating a valve coupled to an aspirator assembly that produces vacuum when the fluid flows through the recirculation pathway from the inlet to the outlet and when fluid flows through the recirculation pathway from the outlet to the inlet. Fluid flows through the recirculation pathway from the outlet to the inlet when the turbocharger generates boost. The vacuum generated by the aspirator assembly is in fluid communication with the actuator to move the valve between two or more positions.

A system for controlling a vacuum pump in a gasoline vehicle with a clutch includes a clutch installed between a driving source supplying power of an engine and a vacuum pump to selectively interrupt the power supplied from the driving source to the vacuum pump. A pressure sensor is configured to sense a pressure of a vacuum line installed between the vacuum pump and a brake booster. A controller is configured to compare the pressure measured by the pressure sensor with a target pressure value to selectively interrupt the clutch.

A system for controlling a vacuum pump in a gasoline vehicle with a clutch includes a clutch installed between a driving source supplying power of an engine and a vacuum pump to selectively interrupt the power supplied from the driving source to the vacuum pump. A pressure sensor is configured to sense a pressure of a vacuum line installed between the vacuum pump and a brake booster. A controller is configured to compare the pressure measured by the pressure sensor with a target pressure value to selectively interrupt the clutch.

A locomotive brake system includes a brake cylinder with an integrated parking brake; a main reservoir; and a brake system controller for controlling the pressure in the brake cylinder. The brake system uses main reservoir pressure to pressurize the brake cylinder to achieve the parking brake output force using the brake cylinder.