In accordance with at least one aspect of this disclosure, a pump includes a housing having one or more fluid inlets and one or more fluid outlets. The housing is configured to act as a pump housing for passing a fluid from the one or more fluid inlets to the one or more fluid outlets and configured to act as a stator for a motor. The pump also includes a cylinder encased within the housing and mounted on a shaft for rotation within the housing. The cylinder is configured to act as an impeller to drive fluid from the one or more fluid inlets through the housing to the one or more fluid outlets and configured to act as a rotor for the motor.