Production of hydrostatic axial piston machines by means of stepper motors
AssigneeSauer-Danfoss Inc.
InventorWilhelm Göllner
Life of this patent
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Abstract
A description is given of an adjustable hydrostatic axial piston machine whose angle can be varied by means of a servo-piston (9) to which actuating pressure can be applied and which is connected to an electrohydraulic control valve. The control valve has a control piston (15) and a control sleeve (22) which can be moved axially relative to one another. The control piston (15) can be axially adjusted with a stepper motor (10), and the control sleeve (22) is coupled mechanically or hydraulically to an adjusting mechanism (9, 7) for the angle for the purpose of feeding back the angle.
Claims3
Adjustable hydrostatic axial piston machine whose angle can be varied by means of a servo-piston (9;
- 21;
- 25;
- 37;
- 38) to which actuating pressure can be applied and which is connected to an electrohydraulic control valve whose control piston (15;
- 27;
- 33) and control sleeve (22;
- 30;
- 36;
- 39) can be moved axially relative to one another, characterized in that the control piston (15;
- 27;
- 33) can be adjusted axially by means of a stepper motor engaging a motion transmitting screw that extends axially with respect to the control piston, and the control sleeve (22;
- 36) is supported in a fashion loaded by fluid pressure on an adjusting mechanism for the angle (9;
- 7;
- 29) in order to feed back the angle, and executes an axial stroke in the event of a change in the swash angle.
Adjustable hydrostatic axial piston machine having a cylinder block (4) and a swash plate (29) whose angle can be varied by means of a servo-piston (9;
- 21;
- 25;
- 37;
- 38) to which actuating pressure can be applied and which is connected to an electrohydraulic control valve, the control valve having a control piston (15;
- 27;
- 33) and a control sleeve (22;
- 30;
- 36;
- 39), which can be moved axially relative to one another, characterized in that the control piston (15;
- 27;
- 33) can be adjusted axially by means of a stepper motor (10), and the control sleeve (22;
- 36) is mechanically coupled to an adjusting mechanism for the angle (9;
- 7;
- 29) for the purpose of feeding back the angle;
- and the stepper motor (10) has a rotor (11) which acts directly on a transmitting screw (12) in such a way that an axial movement is generated when the stepper motor rotor rotates.
An adjustable hydrostatic axial piston machine having a cylinder block (4) and a swash plate (29) whose angle can be varied by means of a servo-piston (9;
- 21;
- 25;
- 37;
- 38) to which actuating pressure can be applied and which is connected to an electrohydraulic control valve, the control valve having a control piston (15;
- 27;
- 33) and a control sleeve (22;
- 30;
- 36;
- 39), which can be moved axially relative to one another, characterized in that the control piston (15;
- 27;
- 33) can be adjusted axially by means of a stepper motor (10), and the control sleeve (22;
- 36) is mechanically coupled to an adjusting mechanism for the angle (9;
- 7;
- 29) for the purpose of feeding back the angle;
- the control sleeve (22;
- 36) is supported in a spring-loaded fashion on the adjusting mechanism for the angle (9;
- 7;
- 29) in such a way that said control sleeve executes a axial stroke movement when the angle changes;
- and the control piston (15;
- 27;
- 33) is designed in such a way and cooperates with the control sleeve (22;
- 36) in the case of axial displacement in such a way that control edges (17;
- 18;
- 19;
- 20) on the control piston (15;
- 27;
- 33) uncover openings for a flow of oil to the servo-piston (9;
- 21;
- 37;
- 38) as a result of which the position of the servo-piston, and thus of the angle, is changed until the control edges (17;
- 18;
- 19;
- 20) are closed again by the movement of the control sleeve (32;
- 36) in the same direction, with the result that proportionality is provided between a step of the stepper motor (10) and the change in the angle.
Dependencies are inferred from the claim text.