1. * GB780026 (A)
Description: GB780026 (A) ? 1957-07-31
Improvements in rotary pumps, compressors or engines
Description of GB780026 (A)
PATENT SPECIFICATION
Date of Application and filing Complete Specification: Nov. 21, 1955.
780,026 No. 33322/55.
Application made in Germany on Nov. 20, 1954.
/ X g > Complete Specification Published: July 31, 1957.
Index at acceptance:-Class 110(2), A(1B4:2E:2X).
International Classification:-FO5g.
COMPLETE SPECIFICATION
Improvements in Rotary Pumps, Compressors or Engines I, FRANZ PHILIPP
NTEBEL, Austrian National, of Erlenstegenstrasse 16b, NUrnberg,
Germany, do hereby declare the invention, for which I pray that a
patent may be granted to me, and the method by which it is to be
performed, to be particularly described in and by the following
statement:-
The invention relates to rotary com10pressors and engines associated
with the flow of a gaseous or liquid medium and rotary pumps for
liquid or dry media, of the kind which include a rotor which is
mounted in a housing and has on its circumference several rotor blades
which form conveyor chambers and act as pistons, and an abutment slide
which separates the suction side from the pressure side of the rotor
and which is positively movable to cooperate with the periphery of the
rotor by means of a control device running in dependence on the rotor
drive. Such rotory pumps, compressors and engines are hereinafter
referred to as rotary machines of the kind specified.
An object of the present invention is to improve the efficiency in
rotary machines of the kind specified and to make their applicability
as universal as possible.
In a rotary machine of the kind specified according to the present
invention the rotor blades curve and have sharp edges at their outer
extremities and the abutment slide is controlled by means of a crank

2. which rotates in dependence on the rotor drive the end of the abutment
slide which bears on the periphery of the rotor having a cylindrically
constructed packing part which during rotation of the rotor is
positively conducted over the concave pressure sufaces and over the
convex surfaces of each of the rotor blades, the packing part moving
in an arcuate path the tangent to which at the [Price 3/61 point of
intersection with the circle swept out by the outer extremities of the
blades is at an acute angle to the tangent to the said circle at the
point of intersection.
A rotor having blades curved forward 50 in the direction of rotation
of the rotor has the advantage that it can be used as a pump for
gaseous and thinly liquid media, and can be run at very high speeds
with the conveying chambers always fully 55 filled, because the
conveying chambers are filled not only by the piston effect of the
rotor but also by the blades which curve forwards in the direction of
rotation shovelling the conveying medium into the 60 the conveying
chambers. The crosssection of inlet to the pump should be large so
that the rotor passes over a large working face since this helps to
achieve complete filling of the conveying chambers. After the medium
being pumped has been sucked or shovelled into the conveying chambers
it is not possible for it to be thrown out again into the input side
by any centrifugal forces caused by high 70 speeds of rotation of the
rotor because the time or reaction of the centrifugal effect is longer
than the time taken for the conveying chambers to pass through the
input side, and the fact that the blades 75 are curved forwards in the
direction of rotation also helps to prevent the ejection of the medium
from the conveying chambers.
Machines of the kind specified are 80 known which have an abutment
slide with a sharp edge which follows the periphery of the blades, but
by providing the abutment slide with a cylindrically constructed
packing part the edge is stronger and 85 more rigid and better
kinematic conditions are obtained by which cooperation with the rotor
blades is improved giving greater volumetric efficiency. The
cylindrical packing part determines the shape 90 780,026 of the rotor.
The abutment slide is operated by the shaft of the rotor by means of a
simple crank drive, which offers favourable speed and acceleration
characteristics.
Preferably the diameter of the packing part of the abutment slide, the
height of the rotor blades and the number of rotor blades are so
selected that the packing part follows the sharp tips of the rotor
blades in close contact.
According to a preferred feature of the invention the volume displaced
by the penetration of the packing part into the 16 pressure chamber is
approximately equal to the volume of each rotor blade. This tends to

3. eliminate pulsation in the output which is especially harmful in long
conveying pipes. Since during the time that the relevant rotor blade
travels from the pressure to the suction side, the edge of the
abutment slide penetrates into the pressure chamber and occupies an
equivalent volume the pulsation occurring in some known displacement
pumps is prevented.
One of the reasons that machines of this kind can have high speeds of
rotation of the rotor is that the abutment slide is positively driven
by means of a crank with balance of the flywheel mass, the crankshaft
of which is connected with the rotor shaft, for example, by gear
wheels. It is arranged that the crank shaft makes for one revolution
of the rotor as many revolutions as the rotor has blades. The profile
form of the rotor is determined by the kinematics of the moving parts
and by appropriate disposition and dimensioning of these parts any
desired profile form (within limits) can be achieved.
Especially when being used for gaseous media a rotary machine
according to the invention can be operated at very high speeds as for
example a blower or scavenger pump for high speed internal combustion
engines. For such fields of use the crank drive is disposed in the
suction part of the machine housing in such a manner that the
connecting rod of the crank is connected directly to the abutment
slide.
Thus harmful oscillations of the very rigidly constructed abutment
slide are avoided and the elearance between the periphery of the rotor
and the packing part of the abutment slide can be kept very small.
Preferably the crank is geared to the rotor drive by at least two gear
wheels and for exact adjustment of the position of the rotor in
relation to the abutment slide at least the rim of one of the gear
wheels is rotatable with respect to the shaft on which it is mounted
and means are provided for fixing the rim for rotation with the shaft.
The rim is first rotatable with respect to its shaft in order to be
able to make the correct adjustment, after which the rim is fixed for
rotation with the shaft. The fix-70 ing of the rim can be done for
example by making the whole gear wheel rotatable with respect to its
axis and providing a clamping cone for fixing it to the shaft.
Alternatively the gear wheel may com-75 prise a hub disc, and a
toothed rim the rim being circumferentially adjustable on the hub
disc. The adjustment of the desired clearance between the periphery of
the rotor and the abutment slide is80 preferably achieved by the
length of the connecting rod conneeting the crank drive with the
abutment slide being adjustable by means for example of a coupling nut
or by adjustable eccentric connections at85 the ends of the connecting
rod.
For pumping materials which cannot be sucked up, such as for example

4. solidified resin products, clay soils. and loose materials the rotor
of the rotary machine 90 preferably protrudes out of an opening in the
rotor housing and directly engages the material to be pumped. For this
type of application the machine is preferably arranged on a truck in
order to be able95 to move into the material as it is removed.
In this type of application the blades of the rotor serve mainly as
conveying blades, but also have some piston-like effect in forcing the
material throuogh the 100 pressure pipe. If dry materials are to be
pumped, a somewhat conically widened pressure pipe is preferably used
in order to reduce the resistance due to friction in it to a minimum.
105 According to a preferred feature of the invention a rotary machine
for use as a pump for pumping dry media includes a second abutment
slide which enters the conveyor chambers at the inlet side of the 110
rotor and which rejects large objects from the conveyor chambers. The
second abutment slide preferably comprises a rake mounted on the
housing so as to be able to move in an approximately vertical 11S
direction and is supported on the individual rotor blades and combs
through the material to be pumped, the rake being alternately lifted
by a rotor blade and descending into its lowest postion as the 120
rotor rotates. the des.ent of the rake being for example under its own
weight or by the influence of a spring Alternatively the second
abutment slide may comprise a rake which is controlled positively by
125 means, such as eamss operated by the drive of the crank so that
the rake prongs follow the profile form of the rotor sufficiently
closely to guide away larger stones than can be handled by the
conveyor 130 780,026 chambers.
In order to prevent small stones becoming wedged between the inlet
edge of the housing and the blade edges, springs may be provided in
the spaces between the prongs of the rake and the springs being
arranged to deflect stones passing through the rake towards the centre
of the rotor, that is to say towards the inside of the conveyor
chambers.
If at least two rotors and corresponding abutment slides, separated by
a partition wall, are disposed in a machine housing, each with an
inflow and outflow pipe mounted on a common shaft so that seen in the
direction of the axis, the blades of one rotor come to lie between the
blades of the other rotor, the resulting machine can be used as a
motor, which will start in any position of the rotors, for there is
always a surface available corresponding to the projected surface of a
blade on which the driving medium can exert a torque. Thus, if the end
of one abutment slide is between two blades on the lowest point of the
one rotor, the full projected blade surface is available on which the
driving medium can act, whereas the end of the adjacent abutment slide
will be situated on the top of a blade and for this rotor there is a

5. balance of torque. In the position in which the two abutmert slides
are situated half way along the blades then each half projected blade
surface is available for both abutment slides as effective surfaces on
which the driving medium can act. In the intermediate positions the
effective surface of one blade is smaller and the other
correspondingly larger, but they always together form a surface, which
corresponds to the projected surface of a complete blade. If a number
of rotor units are disposed next to each other then a correspondingly
higher power is achieved with the same diameter of rotor. The inflow
of the driving medium when the machine is used as a motor is
preferably arranged in such a manner that the direction of rotation of
the rotor is the opposite of that as when the machine is used as a
pump, that is to say the blades are curved in a direction opposite to
the direction of rotation of the rotor. By this means the rotor acts
not only as a rotary piston, but in addition as a turbine to utilize
the outflowing energy. In addition the abutment slide itself acts as a
piston during its outward movement and, through the crank mechanism
and the toothed wheels, imparts power to the rotor shaft, compensating
the non-uniformity of the torque produced by the rotor.
The invention may be performed in a various ways and two specific
embodiments will now be described by way of example with reference to
the accompanying drawings in which:Fig. 1 is a vertical section of a
rotary 70 pump embodying the invention; Fig. 2 is a horizontal section
of the pump shown in Fig. 1; Fig. 3 is a graphical representation of
the kinematics, by which the profile form 75 of the rotor of the pump
shown in Fig.
1 is produced; Fig. 4 is a representation of the volume displaced by
the packing part of the abutment slide penetrating the chambers on 80
the rotor compared with the volume of the blades of the rotor; Fig. 5
is a vertical section through the housing of a rotary pump in which
the housing is open at the bottom; and 85 Fig. 6 is a front elevation
of the scraping rake of the pump shown in Fig. 5.
In the pump shown in Figs. 1 to 4 the housing 1 is provided with a
suction pipe 90 lb and a pressure pipe la. A rotor 2 is fixed on a
shaft 4 with the curvature of the blades pointing in the direction of
rotation which is shown by the arrow. A swingable abutment slide 3
having a 95 cylindrical packing part 3a follows during its arcuate to
and fro movement the profile form of the rotor 2. The to and fro
movement of the abutment slide 3 is effected by a crank 5 with a
balance 100 weight 5a forming a fly-wheel, and a connecting rod 6, the
latter being joined by means of a bolt 7 to the abutment slide 3.
The drive of the rotor 2 is from the crank shaft 5, which is connected
to the 105 rotor shaft 4 through gear wheel 9 and a hub disc 11, the
hub disc 11 having a toothed rim 10. For the exact adjustment of the

6. postion of the rotor 2, the periphery of which must be closely
followed by the 110 packing part 3a of the abutment slide 3, the hub
disc 11 is keyed on to the shaft 4, and the toothed rim 10 is made
adjustable cireumferentially on the hub disc, circumferential slots
(not shown) being 115 provided in the hub disc 11 through which
clamping bolts holding the toothed rim to the hub disc may pass. This
allows an adjustment or turning of the toothed rim by one tooth pitch.
After exact adjustment of the rotor 2 to the abutment slide 3 the
toothed rim 10 is screwed tight to the hub disc 11 and its position
secured by means of a set pin. Alternatively a clamping cone or the
like could be used lg-r for fixing the toothed rim to the hub disc 11.
In order to obtain the desired clearance between packing part 3a and
the periphery of the rotor 2 the length of the 130 780,026 connecting
rod 6 can be adjusted, for example by a coupling nut.
The profile form of the rotor is determined by the kinematics of the
moving parts and by appropriate disposition and dimensioning of these
parts any desired profile form (within limits) can be achieved. The
determination of the profile form of the rotor shown in Fig. 1. which
10has four blades, is illustrated in the graphical representation
shown in Fig. 2.
In this representation the determination of the profile of only one
rotor blade is shown, for the sake of clarity, that is one quarter of
the profile form of the rotor.
In the graphical representation the rotor is regarded as being
stationary and the pivot of the abutment slide is shown rotating in
the direction of the arrowX through an are of 90 from the point 0y
through positions ly to 7y to the point 8y. The length from the centre
of the packingz part 3a to the pivot of the abutment slide s shown as
R and circular arcs of radius Rt are struck from the various positions
0y to 8y of the pivot of the abutment slide and are shown in the
drawing as ares O"' to 8"'.
The circle of revolution of the crank pin is shown in the top right of
the drawing and the positions of the crank pin are shown as 0" 'to 7"
these eor, esponding respectively with the positions 0y to 7y of the
pivot of the abutment slide whose position 8y again corresponds with
position 0" of the crank pin. Ares 0 to 7 are struck from each of the
positions of the crank pin of radius equal to the length of the
connecting rod. Arcs are struck about the centre of the rotor from the
points of intersection of arcs 0 to 7 with the arc 0"'. The points of
intersection of these ares with respective arcs 1" to 8"' represent
the positions 0' to 8' of the centre of the paelking part 3a on the
abutment slide 3 corresponding to the positions 0y to 8y of the pivot
of the abutment slide. The circles drawn around these centres 0' to 8'
with a radius corresponding to the radius of the packing part 3a,

7. describe exactly the shape of a rotor blade. To obtain the sharp edged
form of rotor blade which is most suitable in conveying technique the
radius of the eylindrieal packing part 3a must be suitably selected in
relation to the radius -R and to the radii Id and P3 of the root and
tip circles respectively of the rotor blades. If in the arrangement
shown in 69 the graphical representation the radius of the
cy-lindrical packing part were greater than shown. the tip of the
blade would he clipped off and the packing part 3a would move over the
blade point with a correspondingly large play and would thus produce a
passage between the section and the pressure sidles.
If however. the radius of the packing part 3a were smaller than shown,
the point if the blade would be 70 greatly rounde.d.1i and would not
satisfy the requirements of,-roneying technique.
the radius of the paeking part:3ja of the abutment slide 1.) shuld he
kept very small, as in the arrangement shlown in Fig. 75 5, whlich is
a rotary pump for materials containing sand and stone. in which ease
the abutment slide 1 serves also as a scraper, a pointed (, M of lade
can nevertheless he -,tained. if the difference 80 between ER and R is
made correspondinglly large. S appr..imately equals R2.
the difference betweeRn P, and I. is kept small in comparison with P:-
and several rotor blades are provided, so that the85 distance of pitch
letween one rotor blade and the next is kept small in comparison with
the blade heilit.
Fig. 4 shows diasrammatically the volume displacerneut -ransed by the
penetration of the alutment slide into the pressure chamber. whihl
displacement is marked F. For eliminatino the pulsation which occurs
in known displacement pumps, the blade l-oime F. should he 95
substantially equal t,, the volume F.
A rotary pump is slhown in Fiz. 5 having a machine housing open at the
bottom the,rotor 131 being in direct engagemrent with the material to
be conveyed. The rotor 1.2 is mounted rotatably in the housing 12 on
thie shaft 14. The abutment slide 1.5 mounted for rotation about the
axis 16 is set in swinging movemnent by the crank 17 tlinLouh the
connectin-. rod 18, which is connected at the point 16a on the
abutment slide 15, permanent sealing of the pressure side of the
machine being produced. The drive of the rotor 13 is carried out from
the shaft 110 of the crank 17 thronu2h the pair of bevel wheels 21,
the worm 19 and worm wheel 20. In order not to allw stones St. which
are too large for the eonveyor chambers.
to pass into the machine a guide rake 22 115 rotatably mounted on,a
stationary bolt 24 is provided. Its dolwnward movement is effected by
its own weight its upward movement being caused lby each of the rotor
blades. the.uaile rakie being on a 120 sufficiently long lever arm to
permit it to be mov-ed by the Elades as they pass the rake. The

8. operation no the guide rake 22.
however, could be effected by a control cam fitted outside thle
housing 12, an exact 125 followinr of the proflle form of the rotor
not heing necessary.
The spring 22 fitted on the guide rake protrudes in between the rake
prongs 25 and prevents smaller stones passing 130 780,026 between the
inlet edge of the housing and the blade tips. In Fig. 6 the guide rake
22 with its rake prongs 25 and springs 23 is shown seen from the
front.
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