Methods, apparatus, systems, and articles of manufacture are disclosed to adjust a pitch axis of a blade of an engine. An example blade apparatus includes: a hub to facilitate movement of blades in an engine, the engine having a radial center line; and a trunnion connected to the hub. The example trunnion includes a slot to accommodate a first blade, and at least one of the trunnion or the first blade is positioned with at least one of a tilt or a lean with respect to the radial center line to form a pitch axis offset from the radial center line such that the pitch axis is not parallel to or co-linear with the radial center line. The example hub is to rotate the first blade about the pitch axis.

A gas turbine engine includes a fan having a plurality of fan blades configured to rotate about a central axis of the gas turbine engine. Each fan blade is configured to pivot about a pitch axis that extends radially away from the central axis to vary a pitch of the fan blade.

A variable pitch bladed disc including a plurality of blades, each being of variable pitch about a blade axis of rotation and having a root, the plurality of blades including at least one first blade and at least one second blade, a plurality of rotor connecting shafts, each shaft having a root and a tip, the root of each blade being mounted on the tip of a corresponding rotor connecting shaft via a pivot so as to allow each blade to be rotated about the blade axis of rotation, the first blade having a first rotation axis inclination such that the rotation axis thereof is inclined in a fixed manner with respect to a radial axis passing through the root of the corresponding shaft, and the second blade has a second rotation axis inclination different from the first rotation axis inclination.

Conventional gas turbine engines are generally optimized to operate at nearly a fixed speed with fixed blade geometries for the design operating condition. When the operating condition of the engine changes, the flow incidence angles may not be optimum with the blade geometries resulting in reduced off-design performance. By contrast, according to embodiments of the present invention, articulating the pitch angle of turbine blades in coordination with adjustable nozzle vanes improves performance by maintaining flow incidence angles within the optimum range at all operating conditions of a gas turbine engine. Maintaining flow incidence angles within the optimum range can prevent the likelihood of flow separation in the blade passage and also reduce the thermal stresses developed due to aerothermal loads for variable speed gas turbine applications.

A variable pitch bladed disc including a plurality of blades, each being of variable pitch about a blade axis of rotation and having a root, the plurality of blades including at least one first blade and at least one second blade, a plurality of rotor connecting shafts, each shaft having a root and a tip, the root of each blade being mounted on the tip of a corresponding rotor connecting shaft via a pivot so as to allow each blade to be rotated about the blade axis of rotation, the first blade having a first rotation axis inclination such that the rotation axis thereof is inclined in a fixed manner with respect to a radial axis passing through the root of the corresponding shaft, and the second blade has a second rotation axis inclination different from the first rotation axis inclination.

A fan is disclosed. The fan includes a base mountable to a ceiling; a base motor contained in the base; a multi-section shaft operably connected to the base motor and moveable between a collapsed position and an extended position; and a fan assembly connected to the multi-section shaft and including a fan motor and at least one fan blade operably connected to the fan motor, wherein in response to a signal, the base motor raises or lowers the fan assembly by moving the multi-section shaft between the collapsed position and the extended position

A fan is disclosed. The fan includes a base mountable to a ceiling; a base motor contained in the base; a multi-section shaft operably connected to the base motor and moveable between a collapsed position and an extended position; and a fan assembly connected to the multi-section shaft and including a fan motor and at least one fan blade operably connected to the fan motor, wherein in response to a signal, the base motor raises or lowers the fan assembly by moving the multi-section shaft between the collapsed position and the extended position.

A hidden fan and a fan lamp are disclosed. The hidden fan includes a turntable assembly and a plurality of fan blade assemblies arranged at the turntable assembly, the turntable assembly has a turntable and a limit wheel configured to rotate relative to the turntable, the turntable has a plurality of fan blade fixing portions, and the plurality of fan blade fixing portions are annularly arranged around a center of the turntable, at least one of the fan blade assemblies has a fan blade and a return elastic component, the fan blade has a fixed portion and a linkage portion arranged at a side of the fixed portion, the fixed portion is arranged at the corresponding fan blade fixing portion, the linkage portion is connected with the limit wheel.

A gas turbine engine includes a fan having a plurality of fan blades configured to rotate about a central axis of the gas turbine engine. Each fan blade is configured to pivot about a pivot axis that extends radially away from the central axis to vary a pitch of the fan blade. The fan further includes a counterforce system configured to resist forces that urge the fan blades away from their pitch positions during operation of the gas turbine engine.

A fan is disclosed. The fan includes a base mountable to a ceiling; a base motor contained in the base; a multi-section shaft operably connected to the base motor and moveable between a collapsed position and an extended position; and a fan assembly connected to the multi-section shaft and including a fan motor and at least one fan blade operably connected to the fan motor, wherein in response to a signal, the base motor raises or lowers the fan assembly by moving the multi-section shaft between the collapsed position and the extended position.