Electricity generators are provided that can include: members having opposing bases that include chambers to facilitate the conversion of source energy to mechanical energy with one of the members rotating in relation to another of the members and a housing about the rotating member. Generator components can be operably engaged to the housing and rotating member to generate electricity. Methods for generating electricity are also provided. The methods can include: rotating a first cylindrical member in relation to a fixed second member about a center rod along a shared axis within a housing; and generating electricity between conductive components along both the sidewalls of the first cylindrical member and the housing.

A vane cell machine includes a housing, rotor, curved ring, spring, and pressure piece. The rotor is configured to rotate about a rotation axis and includes a plurality of plate-like wings that are radially displaceable. The curved ring surrounds the rotor and delimits a movement path of the wings. Each pair of adjacent plate-like wings delimits a corresponding operating chamber. The housing surrounds and enables displacement of the curved ring. The spring is positioned between the curved ring and the housing, is pretensioned, and is configured to load the curved ring. The pressure piece is positioned between the spring and the curved ring, and sealingly abuts the housing and the curved ring so as to delimit a first and second pressure chamber from each other. The housing and the curved ring further delimit the first and second pressure chambers.

A vane pump or motor assembly includes a housing having an inner cavity with an inner wall disposed about a first central axis. A rotor is disposed in the inner cavity and is rotatable about a second axis that is offset from the first axis to create a variable width space between the rotor and the inner wall. Vanes are moveably carried by the rotor and engage the inner wall to partition the variable width space into a plurality of chambers of increasing and decreasing volume in response to rotating the rotor. Each vane is in the form of a leaf vane having a mounting end formed with a hook portion and wherein the rotor includes corresponding recesses with latch portions that engage of each respective hook portion and supports the leaf vanes for outward swinging movement relative to the rotor for engaging the inner wall of the inner cavity.