Abstract: A fan blade is mounted on a shaft or arranged to vary in pitch via rotation about a pitching axis. The fan blade is mounted with a center of mass offset from the shaft or pitching axis. This offset reduces torque around the shaft or pitching axis.

Abstract: A coolant distribution system uses two premixed streams of coolant at either extreme of a concentration range, and mixes these two streams in the correct percentage to obtain the desired concentration. Mixing the two streams follows a pulse width approach, and the system may use a manifold to deliver fluid to multiple machines.

Abstract: A coolant distribution system uses two premixed streams of coolant at either extreme of a concentration range, and mixes these two streams in the correct percentage to obtain the desired concentration. Mixing the two streams follows a pulse width approach, and the system may use a manifold to deliver fluid to multiple machines.

Abstract: A fan blade is mounted on a shaft or arranged to vary in pitch via rotation about a pitching axis. The fan blade is mounted with a center of mass offset from the shaft or pitching axis. This offset reduces torque around the shaft or pitching axis.

Abstract: A compact variable pitch fan has a drive fluid pitch change mechanism. A pitch change piston is constrained to follow reciprocating motion under drive fluid control within a peripheral hub from which fan blades extend outward. A pitch change sensor is mounted with the rotary union.

Abstract: A compact variable pitch fan has a drive fluid pitch change mechanism. A pitch change piston is constrained to follow reciprocating motion under drive fluid control within a peripheral hub from which fan blades extend outward. A pitch change sensor is mounted with the rotary union.

Abstract: An engine fan has fan blades capable of switching between a sucking and blowing operation when the fan is not in operation. An internal mechanism allows for blade pitch adjustment of all fan blades by twisting one blade about its own axis. End positions of the blade rotation may be held by forces generated by the rotating blades or held by a locking mechanism.

Abstract: Pitch control of a variable pitch fan is obtained using pulsed pressure. Pitch is varied incrementally either towards or away from full pitch by pulsed application of fluid to a piston used to drive the blades of the fan into or away from full pitch. Reverse pitch is used to clear debris from the fan. Valves control flow of fluid to the piston. The valve operation is controlled by a controller.

Abstract: An improved variable pitch fan comprising a fan hub, with fan blades extending radially outward from the fan hub and mounted for rotation about respective radially extending axes corresponding to each fan blade. Each fan blade has a blade surface extending perpendicularly to the radially extending axis of the fan blade, each blade surface lying between respective outer edges of the corresponding fan blade and facing rearward. A pitch shifting mechanism is mounted in the hub and interconnects with the fan blades to control the rotational position of each fan blade about the corresponding radially extending axis of the fan blade. The respective outer edges of each fan blade diverge as the fan blade extends further radially outward; and the blade surface of each fan blade has an angle of attack that decreases as the fan blade extends radially outward. Each blade surface has a constant or increasing radius of curvature as the respective fan blade extends further radially outward.

Abstract: An improved variable pitch fan comprising a fan hub, with fan blades extending radially outward from the fan hub and mounted for rotation about respective radially extending axes corresponding to each fan blade. Each fan blade has a blade surface extending perpendicularly to the radially extending axis of the fan blade, each blade surface lying between respective outer edges of the corresponding fan blade and facing rearward. A pitch shifting mechanism is mounted in the hub and interconnects with the fan blades to control the rotational position of each fan blade about the corresponding radially extending axis of the fan blade. The respective outer edges of each fan blade diverge as the fan blade extends further radially outward; and the blade surface of each fan blade has an angle of attack that decreases as the fan blade extends radially outward. Each blade surface has a constant or increasing radius of curvature as the respective fan blade extends further radially outward.

Abstract: A variable pitch fan in which the pitch of the fan blades is varied under control of a controller according to the speed of the fan. The controller is programmed to respond to increased fan speed by decreasing pitch of the fan blades. The variable pitch fan has a piston extending axially from a main shaft, about which main shaft a fan blade hub rotates. A pitch shifter is mounted on a cylinder, which itself is mounted on the piston. The pitch shifter is actuated by hydraulic fluid supplied through the main shaft to the cylinder. The piston is preferably axially stationary in relation to the main shaft. The cylinder is secured against rotational movement by cooperating out of round surfaces. Grease for the pitch shifter is supplied through the guide pin. One guide pin may be used for grease supply, while another may be used for excess grease return.

Abstract: A variable pitch fan in which the pitch of the fan blades is varied under control of a controller according to the speed of the fan. The controller is programmed to respond to increased fan speed by decreasing pitch of the fan blades. The variable pitch fan has a piston extending axially from a main shaft, about which main shaft a fan blade hub rotates. A pitch shifter is mounted on a cylinder, which itself is mounted on the piston. The pitch shifter is actuated by hydraulic fluid supplied through the main shaft to the cylinder. The piston is preferably axially stationary in relation to the main shaft. The cylinder is secured against rotational movement by cooperating out of round surfaces. Grease for the pitch shifter is supplied through the guide pin. One guide pin may be used for grease supply, while another may be used for excess grease return.

Abstract: A variable pitch fan in which the pitch of the fan blades is varied under control of a controller according to the speed of the fan. The controller is programmed to respond to increased fan speed by decreasing pitch of the fan blades. The variable pitch fan has a piston extending axially from a main shaft, about which main shaft a fan blade hub rotates. A pitch shifter is mounted on a cylinder, which itself is mounted on the piston. The pitch shifter is actuated by hydraulic fluid supplied through the main shaft to the cylinder. The piston is preferably axially stationary in relation to the main shaft. The cylinder is secured against rotational movement by cooperating out of round surfaces. Grease for the pitch shifter is supplied through the guide pin. One guide pin may be used for grease supply, while another may be used for excess grease return.

Abstract: A variable pitch fan in which the pitch of the fan blades is varied under control of a controller according to the speed of the fan. The controller is programmed to respond to increased fan speed by decreasing pitch of the fan blades. The variable pitch fan has a piston extending axially from a main shaft, about which main shaft a fan blade hub rotates. A pitch shifter is mounted on a cylinder, which itself is mounted on the piston. The pitch shifter is actuated by hydraulic fluid supplied through the main shaft to the cylinder. The piston is preferably axially stationary in relation to the main shaft. The cylinder is secured against rotational movement by at least one guide pin passing into the main shaft. Grease for the pitch shifter is supplied through the guide pin. One guide pin may be used for grease supply, while another may be used for excess grease return.