Improvements in Centrifugal Pumps.
Year: 1898

page_text: Date of Application, 30th Dec., 1898-Accepted, 4th Feb., 1899
COMPLETE SPECIFICATION.
Improvements in Centrifugal Pumps.
I, FRED LOBNITZ, Director of Lobnitz & Coy. Ltd, residing at Clarence House,
Renfrew, County of Renfrew, Scotland, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement.-
This invention relates to centiifugal pumps and specially to the pumps of
this class as are generally used for diedging sand or dealing with gutty liquids.
The main objects of the invention aie, fist, to reduce friction by dispensing
with the use of the usual stuthing box, second, to reduce the wear of the shaft by
preventang ingress of sand to the shaft bearing, and, third, to increase the effi-
ciency of the pump by preventing leakage of air to the interior of the pump
when it is iunung.
And in order that my saad invention may be properly understood I have here-
unto appended an explanatory sheet of drawings, which shows, by way of
example, a centrifugal pump as used for sand diedging
On the drawings.-
Fig, 11s a vertical section taken through the bearing of the pump. The
other parts of the pump are broken away
Fig. 2 is a similar section showing a modified way of carrying out the inven-
tion.
On the drawings the same reference letters wherever repeated indicate the
same or similar parts
a is the pump fan and b is it, boss
c is the pump shaft which, as shown,
is overhung is the pump casing shown broken away e is a bearing ring.
f is a bush at the inside of the ring is an oil cup
Under my invention, for the purpose of preventing an, when the pump 18
working, leaking into the vacuum space at the interior of the pump and also for
the purpose of preventing sand and water gaining access to the shaft bearing
when the pump 18 stopped, 1 secure at the inner end of the ring e a flexible 1ng h,
which may be made of dia rubber o similar material, and which projects
forward into a circular groove cut in the face of a ring, secured to the boss b
of the fan A certain amount of clearance is left between the sides of the flexible
ringh and the walls of the groove so that it may freely expand outwards and
contract inwards in said groove This flexible ring is pieforably made in
halves, suitably jointed together, for convenience in fitting in place and for
renewal.
The ring is preferably so fitted in place that it can be readily renewed when-
ever necessary
The flexible ring h may be firmly held in place and protected by the plate k
and metal ring
With this arrangement whenever the pump is set in motion the suction causes
the ring to expand and bear tightly against the outer wall of the groove
thereby effectually prevent leakage of air inwards to reduce the vacuum, on the

page_text: other hand, when the pump is stopped, the flexible ring contracts and, owing to
the pressure, bears tightly against the inner wall of the groove 2, thereby pre-
venting sand and water gaining access to the shaft bearing
Instead of ananging the flexible ng hin the bearing e it may, as shown at
Fig 2, be secured to a reduced part b on the boss b The flexible ing can be
held in place by a flanged metal ring m In thus arrangement the bearing e
would have a giooved ing n let into or secured to it In this case whilst the
action of the ing is the same as before the centrifugal action, caused by the
evolving fan, helps to expand the ing hand thereby cause it to act more
efficiently.
There may be used in lieu of or in conjunction with the aforesaid flexible
ngh two cup leather rings o, p, arranged, back to back, around the shaft c.
These ings, in the airangement shown at Fig 1, are held in place between the
plate and the outwardly flanged end of the bush f, whilst, in the airangement
shown at Fig 2, they are held in place between the inner flange of the grooved
ring n, and the outwardly flanged end of the bush f
The cup athero prevents, oi tends to prevent, sand and water gaining access
to the shaft bearing when the pump is stopped, whilst the cup leather prevents,
on tends to prevent, air leaking into the inside of the pump and also the lubi-
cant used on the shaft being drawn into the pump by the suction
In order to further assist in preventing the ingiess of an to the pump when
it is in motior a leather ung g may be fitted at the outside of the beating This
1ing which passes 1ound the shaft is held in position by a cucular cover
It is to be understood that, if so desired, either the ug h, the cup leather o,
the
cup leather
P, or the ring g may be used alone or that any two or more of
these features can be used in combination. Further it is also to be understood
that these features either singly or in combination can be used in bearings at
both sides of such pump fans as have two bearings
Owing to the fact that the usual stuffing box with gland 16 done away with
the friction caused by the rapid revolution of the shaft is much reduced
The cup rings 0, 1, and the ring q may be made of rubber or other well known
material having similar properties if so desired
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed I declare that what
I consider novel and desue to claim 18.-
1 The application and use, in centrifugal pumps, of a flexible ring working
in a grooved ring, or the equivalent thereof, substantially as and for the purpose
set forth.
2 The application and use, in centrifugal pumps, either alone or in combina-
tion with the flexible ring (h) of one or more cup ngs or their equivalent
arranged round the shaft of the pump fan, substantially as and for the purpose
set forth
3 A centrifugal pump having its parts constructed, arranged and combined
together, substantially as hereinbefore described and shown at Fig 1 or at Fig. 2
of the drawings annexed
Dated this 29th day of December 1898.