| 摘要 |
Generally there is provided a nonmagnetic sleeve (24) having a check valve at its inlet and housing a piston composed of material responsive to a magnetic flux. This piston (22) contains a through bore and a check valve (30) in the bore to cooperate with an inlet valve (20) to cause a pumping effect when the piston (22) is reciprocated within the sleeve. Movement of the piston (22) is caused by inducing an electrical current in a winding surrounding the sleeve and thereby causing a magnetic flux to act on the piston (22). Additional pumping power is obtained by affixing a core in a portion of the winding at the inlet to enhance the magnetically induced forces on the piston (22). In yet a further feature magnetic outer casings are provided surrounding the coil and projecting from the piston to make further use of the outer magnetic flux lines. In both embodiments, return of the piston (22) is accomplished by use of either a return spring (36) or another electromagnetic coil. |
