Patent ID: 9057371
Filing Date: 2015-06-16
Classification: F04B

Abstract:
1. A method for varying a duration of a supply stroke of a pump element, whose supply stroke is actuated by a rotatably-driven pump shaft over a predetermined rotational position range of the pump shaft, the method comprising: rotatably driving the pump shaft via a drive shaft, while the drive shaft is rotating at a constant angular speed, increasing the angular rotating speed of the pump shaft at least once during one revolution of the pump shaft, and while the drive shaft is rotating at the constant angular speed, decreasing the angular rotating speed of the shaft pump at least once during the one revolution of the pump shaft wherein the angular speed of the pump shaft over a predetermined rotational position range of the pump shaft is increased when the rotational speed of the drive shaft is below a predetermined rotational speed, and the angular speed of the pump shaft over the predetermined rotational position range of the pump shaft is decreased when the rotational speed of the drive shaft is above the predetermined rotational speed, and wherein the magnitude of the increase or decrease of the angular speed of the pump shaft increases with an increasing difference between the predetermined rotational speed of the drive shaft and the instantaneous rotational speed of the drive shaft, so that the duration of a supply stroke of the pump element and/or its supply speed remains substantially constant during changing rotational speeds of the drive shaft.