Abstract: A method and system for determining at least one property associated with a selected axis of a manipulator (2). The elasticity of the links (4, 6, 9, 10, 13, 14) and joints (3, 5, 7, 8, 11, 12) of a manipulator (2) can be modeled and the resulting compliance can be determined. A certain method is used to control the manipulator (2) such that certain quantities related to actuator torque and/or joint position can be determined for a certain kinematic configuration of the manipulator (2). Depending on the complexity of the manipulator (2) and the number of properties that are of interest, the manipulator (2) is controlled to a plurality of different kinematic configurations in which configurations the quantities are determined. Thereafter, a stiffness matrix (K) for each component of the manipulator (2) can be determined, and a global stiffness matrix (MSM) for the total manipulator (2) can be determined in order to determine at least one property of the selected axis.

Abstract: A method and system for determining at least one property associated with a selected axis of a manipulator (2). The elasticity of the links (4, 6, 9, 10, 13, 14) and joints (3, 5, 7, 8, 11, 12) of a manipulator (2) can be modeled and the resulting compliance can be determined. A certain method is used to control the manipulator (2) such that certain quantities related to actuator torque and/or joint position can be determined for a certain kinematic configuration of the manipulator (2). Depending on the complexity of the manipulator (2) and the number of properties that are of interest, the manipulator (2) is controlled to a plurality of different kinematic configurations in which configurations the quantities are determined. Thereafter, a stiffness matrix (K) for each component of the manipulator (2) can be determined, and a global stiffness matrix (MSM) for the total manipulator (2) can be determined in order to determine at least one property of the selected axis.

Abstract: A pump arrangement particularly intended for pumping water from deep wells, in which a feed pump unit (2) located at ground level transmits power and motion to delivery pump unit (3), so that during a working stroke of the pump arrangement water is raised through a delivery pipe (5) which is connected to the delivery pump unit (3) via a pressure valve (10), and in which during a return stroke of the pump arrangement water flows into the delivery pump unit through a well-water inlet pipe which is connected to the delivery pump unit via suction valve (11). In accordance with the invention a compressible and expandable chamber (6) in the feed pump unit (2) is connected to a similarly compressible and expandable chamber (7) in the delivery pump unit (3) by means of a hydraulic line (4), and the two chambers (6, 7) and the hydraulic line (4) together form a closed hydraulic system.

Abstract: A pump arrangement particularly intended for pumping water from deep wells, in which a feed pump unit (2) located at ground level transmits power and motion to delivery pump unit (3), so that during a working stroke of the pump arrangement water is raised through a delivery pipe (5) which is connected to the delivery pump unit (3) via a pressure valve (10), and in which during a return stroke of the pump arrangement water flows into the delivery pump unit through a well-water inlet pipe which is connected to the delivery pump unit via suction valve (11). In accordance with the invention a compressible and expandable chamber (6) in the feed pump unit (2) is connected to a similarly compressible and expandable chamber (7) in the delivery pump unit (3) by means of a hydraulic line (4), and the two chambers (6, 7) and the hydraulic line (4) together form a closed hydraulic system.

Abstract: In a rotodynamic cross flow machine at least one vane (4) is positionably fixed in the rotor (40') so as to be able to pivot about two axes which are at least approximately perpendicular one to another, and of which at least one subtends an angle between 5.degree. and 85.degree. or between 95.degree. and 175.degree. with a plane comprising the rotational axis (1) of the rotor and the pivot point (14, 15) of the respective vane. Thereby is achieved, among other things, that the position of the vane can be set during operation in a simple way with the aid of a stationary setting means (18) which changes the inclination of an end element (5) of the rotor to which end element the vane is connected in said manner. The invention is applicable among other things to the construction of water turbines which have to work with a small head.