Pumps – Condition responsive control of drive transmission or pump... – Adjustable cam or linkage
Reexamination Certificate
2001-01-05
2002-10-22
Freay, Charles G. (Department: 3746)
Pumps
Condition responsive control of drive transmission or pump...
Adjustable cam or linkage
C418S063000, C418S243000
Reexamination Certificate
active
06468045
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to an energy conversion device which converts mechanical energy into pressure energy, and particularly to a rotary piston pump.
BACKGROUND OF THE INVENTION
The conventional rotary piston pumps have much more advantages than pistons of other type, but they have the following drawbacks it is difficult to manufacture them, and it is difficult to achieve reliable sealing, and the sealing effect drops deeply especially when they operate under high pressure. The main reason that results in the above drawbacks lies in that the reliability of the separating plate, which separate the high pressure chamber from the low pressure chamber, is poor, and in order to improve the sealing effect, a much more complicated manufacturing process is required.
SUMMARY OF THE INVENTION
The object of the invention is to provide a rotary piston pump in which a reliable sealing can be achieved between the high pressure chamber and the low pressure chamber.
To achieve the above object, there is provided a rotary piston pump comprising a cylinder block; a front end cover and a rear end cover fixed to the front end surface and the rear end surface of the cylinder block respectively; a cam rotor fitted in the inner chamber of the cylinder block, the portion of the cam rotor with a maximum radius coming into sliding contact with the inner wall of the cylinder block so as to form an axially extending sealing region; a shaft, the cam rotor being mounted on the shaft and being rotatable therewith; separating means for separating the axially extending sealed chamber, which is formed between the circumferential surface of the cam rotor and the inner surface of the cylinder block, into an induction chamber and an exhaustion chamber; an inlet and an outlet provided on the two sides of the separating means and communicated with the induction chamber and the exhaustion chamber respectively, wherein the separating means comprising:
an axially extending circular arc-shaped recess formed in the inner wall of the cylinder block, the central axis of the recess being parallel to the axis of the inner chamber of the cylinder block;
a cylinder provided in the recess, in an assembled state of the separating means, the cylinder being substantially co-axial with the circular arc-shaped recess and an axially extending circular gap being formed between its circumference and the circular surface of the recess;
a separating member fitted into the circular gap, the separating member being movable circumferentially in the circular gap;
biasing means for biasing the separating member towards the cam rotor.
According to one aspect of the invention, the separating member comprises two arc separating blocks which are fitted into the circular gap and located on the two sides of the cylinder in the circumferential direction, the ends of the separating blocks facing the inner chamber of the cylinder block abut against the cam rotor, and a sliding and sealing contact is achieved therebetween, the biasing means is disposed between the ends of the separating blocks opposite to the inner chamber of the cylinder block.
According to another aspect of the invention, the separating member comprises two sets of arc separating blocks which are fitted into the circular gap and located on the two sides of the cylinder in the circumferential direction, each set of arc separating blocks includes a plurality of arc separating blocks which are superposed one on another in the radial direction, the ends of the separating blocks facing the inner chamber of the cylinder block abut against the cam rotor, and a sliding and sealing contact is achieved therebetween, the biasing means is disposed between the ends of the two sets of arc separating blocks opposite to the inner chamber of the cylinder block.
According to yet another aspect of the invention, the cylinder is a free cylinder which can rotate about its own axis and can move radially and axially.
The rotary piston pump of the invention may comprises a single cylinder or a plurality of cylinders. In the case of plurality of cylinders, the cylinders are arranged in the axial direction, and the phase angle between the rotors in the cylinder blocks is equal to 360°
, where n is the number of the cylinders.
According to the invention, the arc separating blocks, which are rotatable about a rotation axis under the action of the biasing means, are used as the separating means for separating the induction chamber form the exhaustion chambers, therefore the inventive rotary piston pump is simple is in structure and is easy to manufacture, and can ensure a reliable sealing between the induction chamber and the exhaustion chamber.
REFERENCES:
patent: 116293 (1871-06-01), Freeman
patent: 826453 (1906-07-01), Thormahlen
patent: 1006093 (1911-10-01), Holt
patent: 3700357 (1972-10-01), Williams
patent: 4563137 (1986-01-01), Rineer
patent: 4759679 (1988-07-01), Mûller
patent: 5007813 (1991-04-01), Da Costa
patent: 5950452 (1999-09-01), Sakitani et al.
patent: 6250899 (2001-06-01), Lee et al.
patent: 2084104 (1991-09-01), None
patent: 94/08139 (1994-04-01), None
Freay Charles G.
Liu Han Lieh
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