Pumps – Motor driven – Pump within rotary working member
Reexamination Certificate
2000-12-27
2003-03-04
Tyler, Cheryl J. (Department: 3746)
Pumps
Motor driven
Pump within rotary working member
C417S356000, C417S423140, C415S900000, C604S151000
Reexamination Certificate
active
06527521
ABSTRACT:
BACKGROUND OF INVENTION
The present invention relates to a magnetically driven axial-flow pump. More specifically, this invention relates to a pump of which the vane is magnetically driven and which is built in a pipe to feed the fluid in it.
The magnetically driven axial-flow pump of the present invention can be used for any purposes in any technical fields as far as it is supposed to impel the fluid in a pipe. The pump can be used as medical blood pumps, industrial fluid pumps, and engines for movement such as marine motors.
The Japanese Unexamined Patent Publication No. 71492/H5 (1993) disclosed a magnetically driven axial-flow pump.
Referring to
FIG. 2
, the pump of the prior art will be described. A cylindrical rotor
144
is disposed in an expanded part
140
a
of a pipe
140
so as to be rotatable freely. An impeller
142
is fixed inside the cylindrical rotor
144
. The impeller
142
consists of a shell-shaped stator
142
a
and vanes
142
b
, the latter fixed radially to the former. The vanes
142
b
are also fixed to the inner surface of the cylindrical rotor
144
. On the other hand, disposed around the expanded part
140
a
of the pipe
140
are a stator coil
146
for turning the rotor
144
and magnetic bearings
148
for holding the rotor
144
afloat.
The electromagnetic action between the stator coil
146
and the rotor
144
turns the rotor
144
and hence the impeller
142
to impel the fluid in the pipe
140
in the direction of arrow “F”.
The axial flow pump of the prior art has the following shortcomings.
(1) The shell-shaped stator
142
a
and the vanes
142
b
have to be made separately and then combined to become the impeller
142
. Besides, the vanes
142
b
have also to be fixed to the inner surface of the cylindrical rotor
144
. The assembling work of the stator/rotor assembly is very complex. Although the individual parts can be machined with NC lathes, it is almost impossible to mechanize the assembling work.
(2) In case that the pump is to be used as a blood pump, any gaps have to be sealed, however small they may be. Accordingly, the joints between the stator
142
a
and the vanes
142
b
and those between the rotor
144
and the vanes
142
b
have to be coated somehow, which increases the necessary man-hours. Moreover, because one cannot look at the inside of the stator/rotor assembly once it is assembled, it is impossible to inspect visually the coating condition inside it. Thus, the pump is not reliable enough as a blood pump.
(3) The contact area between the shell-shaped stator
142
a
and the fluid is relatively large. Accordingly, if the pump is used as a blood pump, it is likely to destroy blood tissues and hence not suitable as a blood pump.
In accordance with the above, the object of the present invention is to provide a magnetically driven axial-flow pump which is easy to manufacture and highly suitable as a blood pump.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a magnetically driven axial-flow pump comprising (i) an electromagnet unit arranged about the periphery of a pipe, (ii) a cylindrical rotor accommodated in the pipe, (iii) permanent magnets mounted on the periphery of the rotor, and (iv) a spiral vane formed on the inner surface of the rotor. A hollow is formed in the axial center portion of the vane.
The advantages offered by the present invention are as follows. Because the vane has a hollow in its axial center portion, the rotor and the vane can be made as one piece with an NC machine. Besides, because the occurrence of gaps in the otherwise-inevitable joint between the rotor and the vane is precluded, it is unnecessary to coat such a joint to fill such gaps. Thus, it is easy to make the rotor and the vane.
Furthermore, there are no gaps between the rotor and the vane as mentioned above and there is no object in contact with blood in the center portion of the vane. Therefore, various germs do not enter blood, no thrombi are formed, blood tissues are not destroyed, and hence the pump is suitable as a blood pump.
REFERENCES:
patent: 1534451 (1925-04-01), Kauter
patent: 2500400 (1950-03-01), Cogswell
patent: 3719436 (1973-03-01), McFarlin
patent: 4688998 (1987-08-01), Olsen et al.
patent: 4995857 (1991-02-01), Arnold
patent: 5290227 (1994-03-01), Pasque
patent: 5368457 (1994-11-01), Watanabe et al.
patent: 5501574 (1996-03-01), Raible
patent: 6000915 (1999-12-01), Hartman
patent: 5-71492 (1993-03-01), None
Kubovcik & Kubovcik
Nipro Corporation
Solak Timothy P.
Tyler Cheryl J.
LandOfFree
Magnetically driven axial-flow pump does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetically driven axial-flow pump, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetically driven axial-flow pump will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3061812