Improvements in or relating to Rotary Engines.
Year: 1895

page_text: Date of Application, 22nd Oct., 1895-Accepted, 29th Feb., 1898
Improvements in or relating to Rotary Engines.
A communication from JOHN EMIL GUNTHIER and AUGUST HERMAN GUNTHER,
of the Fum of Gebruder Gunther & Co., both of Lockwitz near Dresden,
in the Kingdom of Saxony, German Empire.
I ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex
Chartered Patent Agent 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:-
The present invention relates to a rotary engine, having a drum revolving in a
cylindrical box oi casing This drum rotates in the casing in such way that it
constantly touches one side only of the box and shuts off the admission of the
motor agent on one side at a time. In the drum are mounted pistons, which
evolve with and communicate motion to the drum, in which they are free to slide
radially. The engine under consideration, which is reversible, that is to say, can
revolve in both directions, is distinguished, besides its peculiar construction and
the way in which the pistons are guided, by an arrangement which obviates loss
through so-called "clearance."
The engine is represented in the accompanying drawings of which
Fig. 1 is a section on the line 1-1 of Fig. 2,
Fig. 2 18 a longitudinal central section on the line 2-2 of Fig. 1,
Fig. 3 is a section through the valve mechanism taken on line 3-3 of Fig. 2.
Fig. 4 18 a section on line 4-4 of Fig. 2 and
Fig. 3 is a detail view of the drum.
The shaft (or axle) W is arranged eccentrically in the box A and supports the
drum B. The latter touches the bottom of the box A, where a steam tight joint 18
maintained by a packing bar b, operated on by springs. One side or end of the
drum B rotates in contact with a disc A' which is pressed upon by springs and
has a packing ring a' (Fig. 2), through which arrangement the flange on the
opposite side of B is constantly pressed against the side or cover A 2 of the box.
The pistons C, CC are situated in diametrically opposite grooves SS (Fig 5)
of the drum B, and revolve round the boss D and always press against the wall of,
the box, so that they not only alter their position relatively to the drum in the
radial duection but they also alter (during their revolution) then position
relatively to the boss D, as they are sometimes in a radial position and at other
times more or less tangential. In Fig 1 both pistons occupy tangential positions.
To make this alteration of their position possible, the pistons roll on the boss with
their correspondingly curved, enlarged heads e The pistons consist of two main
parts 1 and 2, the outer one of which is machined prismatically and guides the
piston radially in the groove S. In the piston part 1 moves the other part 2
provided at its end with the enlarged head c. Between the two parts 1 and 2
there is a spring 3, which always tends to move part 1 outwards and to press the
semi-cylindrical packing strip c, placed in the groove in the part 1, tight against
the box A. With a suitable curvature of the piston heads e the packing strips c¹
equalise the difference between the tangential and the radial positions of the
pistons without any action on the part of the springs.
The position of the steamports etc. 19 symmetrical on both sides of the line 2-2

page_text: (Fig. 1), as the engine must be able to rotate in both duections. The opening,
which admits the steam when the engine is running in one direction, seives as
exhaust when the engine is running in the opposite dnection. From the
ports EE which are placed parallel to the axis of the box A and which com-
municate with the interior of the box through slots, other ports e e' lead first to
the box of the cylindrical valve and from there to the box of the sliding
valve 1. In the valve box just above the valve 1 there is a steam inlet G; with
the space under the slide valve, the exhaust pipe H is connected. The slide
valve 1 can be adjusted by means of a spindle i and a handwheel to such position
that the steam may enter from G either into e or into e¹, from the position of that
slide valve depends the direction in which the engine revolves
The distribution of steam is effected by means of the cylindrical valve Fin
such way, that the ports e and e¹-
-one of them the inlet, the other the exhaust,
are simultaneously opened or closed (see Fig. 3). To make the valve steam tight
it is placed in a removable liner f, which is prevented from tuning by means of a
set screw (Fig. 2) engaging with a peripheral gioove, but can slide in order to
compress the packing ring 2 This sliding movement is effected by turning a
nut 3 which can be held inst by a set screw 4 engaging with an annulai groove in
When the nut is turned say to the left, the case f5, with a screw thread
on its surface, is moved longitudinally; it is prevented from turning by being
connected with the line by means of a piu f6. This movement results in the
compression of the packing f7, and at the same time through the valve F the
liner is pressed against packing /2
that nut.
The space between the drum and the cylindrical box from the part at which
they are in contact on one side up to E, or E' on the other side is the clearance.
As for instance in case of the engine revolving from say left to light (as shown by
an arrow in Fig. 1) the port E cao open only after the piston C has passed it, that
is to say when the piston is in the position shown in the drawing, therefore the
entering steam would have to fill all the space down to b, which would cause
expansion and therefore great loss of heat. To obviate that, the following
arrangement is employed
Between 6 on one side and E or El on the other side there are ports & and A
communicating with the interior of the box. These communicate with each
other, as clearly shown in Fig. 4, through other ports K and K', which meet in
the usual way in a fourway cock L. Over there are check valves, m m² and
under kkcheck valves n n¹ According to the position of the fourway cock the
valves and m¹ are brought into action, whilst m and n' are rendered inoperative
71
or vice versa.
The before described engine works in the following way, if consideration is
based on the position shown on the drawing.
As soon as the piston C passes E in the duection of the arrow, the cylindrical
valve F opens
the port e-E (Fig. 3). Let us suppose at first, that the clearance
between C and E has to be filled with steam. This steam drives the piston C m
the direction of the arros, whilst at the same time on the other side of the piston
the exhaust steam is driven out though the port E¹ e But as soon as the piston
has evolved through 90° so that it is approximately in the position occupied by C¹
in Fig. 1, the cylindrical valve begins to close both the poits, at the same time
the second piston CC has passed k. The exhaust steam which has now no outlet
18 driven during the next quarter of a revolution into the space between b and E,
this steam opens the valve m', passes through K and L, lifts the valve n and
passes out through Meanwhile the piston CC has arrived at the position
originally occupied by piston C, and the cylindrical valve has opened both the
ports. The fresh steam coming in behind the piston CC need not fill the
clearance which is already filled with exhaust steam; under the combined pressure
of the live and exhaust-steam in the clearance, the check valves close. In this
way the work of the engine is not diminished by loss of heat, which otherwise
would be very considerable.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondents, and in what manner
the same is to be performed, I declare that what I claim is ;-
1. A rotary steam engine having a drum constantly touching only one side of a
cylindrical box or casing in which drum there are pistons movable in a radial
direction relatively to the dium itself and revolving concentrically within the box
which engine is also distinguished by pistons such as (C, C C) each consisting of
two main parts and having curved and enlarged heads (e) which roll on the central
boss (D) and also distinguished by the arrangement symmetrically in relation to
the contact line between drum and the box of ports such as e-E e-E¹ in which
the distribution of steam is effected by a cylindrical valve such as F and the
reversing by a slide valve such as 1 ports such as k¹ between this contact line
and the poit openings for leading the exhaust steam before the piston which ports
communicate by means of ways (K K') provided with valves such as nm¹ and n¹ m
and meet in a fourway cock (L) substantially as described and illustrated in the
accompanying diawings.
2. The combination and arrangement of paits constituting the complete rotary
engine substantially as described and illustrated in the accompanying drawings.
Dated this 22nd day of October 1895.
BOULT & WADE.