Note: Descriptions are shown in the official language in which they were submitted.
CA 02284201 1999-09-17
Gerhard Thien Case: GTM _ 1 _
Description
The invention relates to an apparatus for
generating a torque.
Such apparatuses are required in many ways in
the art, in particular as drives for machinery and the
like.
The object of the invention is to provide a
further apparatus of the type named initially which, in
particular, uses buoyancy forces to generate a torque.
This object is achieved by the apparatus
according to Claim 1.
According to the invention, therefore, at least
two bodies are coupled to one another in such a way
that they can perform a rotational movement, in which
one body moves in the direction of the force of gravity
and the other in the direction opposite thereto, each
body, when changing the direction of movement, altering
its volume so that the volume of the body or bodies
moving in the direction of the force of gravity is less
than that of the bodies moving in the opposite
direction.
The way in which the volume of each body
changes, therefore, is that it is increased when its
downward movement, in other words essentially its
movement in the direction of the force of gravity,
changes into an upward movement, in other words a
movement counter to the force of gravity, while it
diminishes as soon as the movement of the body once
again changes to the downward movement. This
alternating increase and decrease in the volume of the
bodies when the direction of movement changes ensures
that the bodies moving upwards at any given time,
because of their greater volume, experience greater
buoyancy than the downward-moving bodies. The
rotational movement of the bodies is produced thereby.
It is particularly advantageous, if the two
bodies coupled to one another are so designed that,
CA 02284201 1999-09-17
Gerhard Thien Case: GTM
despite the alternating changes of volume of the
individual bodies, the total volume ~of all bodies is
substantially constant.
Although the apparatus according to the
invention can also, in principle, be operated with an
uneven number of bodies, provision is preferably made
for the bodies to be arranged opposite one another in
pairs relative to the rotational movement. A
particularly uniform generation of torque is ensured by
this symmetrical arrangement of the bodies in pairs.
In principle, the apparatus according to the
invention can be operated in any fluid which, with
practicable changes in the volumes of the bodies,
supplies a sufficiently large increase in buoyancy for
at least the frictional forces acting in the apparatus
to be overcome. Preferably, however, provision is made
for the bodies to be immersed in a liquid during at
least part of their rotational movement. As a result of
the at least partial but expediently complete
arrangement of the apparatus in a liquid, especially in
water, a relatively large increase in buoyancy can be
achieved even with a relatively small change in volume.
For example, an increase in the volume of individual
bodies by in each case d dm3 (1 1) supplies an increase
in buoyancy of 9.81 N (1 kp).
It is particularly expedient if the individual
bodies are connected to one another by a tension member
which runs in an annular manner over at least one
deflection device, the deflection device having at
least one deflection wheel which is mounted on a shaft
from which the torque can be taken off.
In order to use as much as possible of the
difference in buoyancies to generate torque, provision
is made for each set of two bodies assigned to one
another as a pair, preferably ail bodies, to have the
same dimensions. In this manner, the apparatus can be
kept completely in equilibrium with regard to the
weights acting on it.
CA 02284201 1999-09-17
Gerhard Thien ~ Case: GTM _ 3 _
In a particularly preferred embodiment of the
invention, each body is designed as a piston-and-
cylinder unit, the piston being movable into its
extended or retracted position by the weight acting on
it as a function of the orientation of the piston-and-
cylinder unit relative to the force of gravity.
In order to ensure, in this arrangement, that
the displacement of the piston, especially its
extension movement, can take place solely on the basis
of the weight acting upon it, the piston length lk
satisfies the following equation:
lk ~ h. Pf
px
where h is the maximum depth of immersion of the body
into the liquid, pf is the density of the liquid and pk
is the density of the piston material.
It is particularly expedient if the individual
piston-and-cylinder ,units are arranged so that each
piston-and-cylinder unit, in the event of a change in
direction of movement, is automatically transferred
from its one position, in which the piston is extended
or retracted, into its other position, in which the
piston is, respectively, retracted or extended.
In a further embodiment of the invention, the
cylinder chambers of the individual piston-and-cylinder
units are connected to one another in order to permit a
fluid exchange, the cylinder chambers being connected
to one another in an annular manner, preferably via a
hose.
In this manner, a self-contained fluid system
can be formed in the cylinder chambers connected to one
another, the effect of which is that the pressure
created by the retraction of a piston changing to
downward movement can be output via the self-contained
fluid system to the piston of the piston-and-cylinder
unit which is changing over to upward movement, which
piston is moving out into its extended position, so
that an additional pressure on the piston assists its
CA 02284201 1999-09-17
Gerhard Thien Case: GTM
movement into the extended position in order to
increase the volume and compensate for any frictional
losses arising.
The fluid used in the cylinder chambers may be
simply air or another gas; it is also possible,
however, for example, to use a very light oil or a
similar liquid as a fluid, which has the advantage that
the pressure can be transferred particularly well.
The invention is explained below by way of
example with reference to the drawing, in which:
Figure 1 shows a greatly simplified diagram-
matic representation of an apparatus according to the
invention having a pair of bodies to generate a
buoyancy difference,
Figure 2a shows a simplified diagrammatic
sectional representation of a piston-and-cylinder unit
with the piston extended,
Figure 2b shows a simplified diagrammatic
sectional representation of a piston-and-cylinder unit
with the piston retracted, and
Figure 3 shows a simplified diagrammatic
representation of an apparatus according to the
invention with a plurality of bodies for generating a
buoyancy difference, arranged in pairs.
In the figures of the drawing, components which
correspond to one another are provided with identical
reference numbers.
As Figure 1 shows, the apparatus according to
the invention for the generation of a torque comprises
a deflection device 10 for a tension member 11 to which
two piston-and-cylinder units 12 are attached as a pair
of bodies for generating a buoyancy difference. The
deflection device 10 comprises a deflection wheel 13,
which is mounted on a shaft 14, from which the torque
generated by the apparatus according to the invention
can be taken off. For example, a generator for the
generation of electrical energy may be connected to the
shaf t 14 .
CA 02284201 1999-09-17
Gerhard Thien Case: GTM _ 5 _
As a deflection wheel 13, depending on the
tension member 11 used, it is possible to use a toothed
wheel or a cable drum or the like. Correspondingly, the
tension element 11 can be designed as a chain, cable,
toothed belt, tension belt or the like.
In order to transmit to the tension member 11
the forces acting on the piston-and-cylinder units 12,
each piston-and-cylinder unit 12 is held on the tension
member 11 by means of fixing pins 15 or the like set at
a distance apart in the longitudinal direction of the
tension member 11.
As a result of this fixing of the piston-and-
cylinder units 12 on the tension means 11, that is to
say as a result of the fixing means set at a distance
apart in the longitudinal direction of the tension
means 11 and thus in the direction of movement of the
piston-and-cylinder units 12, what is achieved is that
the piston-and-cylinder units 12 retain the same
orientation relative to the respective direction of
movement throughout the rotational movement, so that
when the direction of movement is changed relative to
the force of gravity they automatically alter their
position relative to gravitation.
In order to connect the cylinder chambers 16 of
the piston-and-cylinder units 12 to one another, so
that the latter communicate with one another, w hose 17
or similar connection is provided as a fluid line and
is fixed via corresponding connection pieces 18 and
connectors 19 to the cylinders 20 of the piston-and
cylinder units 12, so that the hose 17 is in fluid
connection with the respective cylinder chambers 16.
As shown in detail in Figures 2a and 2b, a
piston 21 is slidingly arranged in each cylinder 20 so
that if the cylinder 20 is arranged as shown in Figure
2a, with its open side downwards, it slides downwards
into its drawn-out or extended position as a result of
the weight acting upon it. In order to prevent the
piston 21 from falling out of the cylinder 20 during
CA 02284201 1999-09-17
Gerhard Thien Case: GTM
this, the cylinder 20 has, for example, an inward-
directed flange 22, while the piston 21 bears an
outward-directed flange 23 interacting with the former.
Arranged on the flange 22 are sealing means, not shown
in detail , which seal of f the cyl finder chamber 16 in a
gastight manner without substantially impeding the
displacement movement of the piston 21, in order to
ensure that the medium surrounding the piston-and
cylinder unit 12 cannot penetrate into the cylinder
chamber 16.
In what follows, it is assumed that the
apparatus according to the invention is completely
arranged in water and that the cylinder chambers 16,
which are connected to one another via the hose 17 and
form a self-contained fluid system, are filled with
air. Instead of water, another medium may also be used,
having a low viscosity and the highest possible
density. When water is used, as is assumed here, the
lightest possible oil may be used instead of air as the
fluid filling the cylinder chamber 16. An essential
factor for the selection of the flowable media provided
in the apparatus according to the invention is that the
density of the medium provided in the cylinder chambers
16 should be less, preferably very much less, than that
of the medium surrounding the piston-and-cylinder units
12 .
The density difference between air and water is
so great that, in the explanation of the invention
which follows, the mass of the air contained in the
cylinder chambers 16 can be disregarded completely.
In order to ascertain the resulting force FR
transmitted via the tension member 11 to the periphery
of the deflection wheel 13 in order to generate the
torque, the forces acting on the piston-and-cylinder
units 12 will initially be considered individually.
Acting on the piston-and-cylinder unit 12 shown on the
left in Figure 1, in addition to its weight Gl, is the
buoyancy FA(Vl) generated by the surrounding water which
CA 02284201 1999-09-17
Gerhard Thien Case: GTM _ ~ _
brings about an apparent reduction in the weight G1. The
buoyancy depends in a known manner on the volume V1 of
the piston-and-cylinder unit 12 shown on the left in
Figure 1 and is calculated by the equation
FA (V1) =g ~ pf . V1. In this case, g is the acceleration due
to gravity and pf is the density of the medium
surrounding the piston-and-cylinder units 12, in other
words water.
Correspondingly, the piston-and-cylinder unit
12 shown on the right in Figure 1 is subjected not only
to the weight Gr acting upon it but also to the buoyancy
FA (Vr) , which satisfies the equation FA (Vr) =g ~pf ~ Vr, Vr
being the volume of the right-hand piston-and-cylinder
unit 12, in other words the piston-and-cylinder unit 12
with the piston 21 retracted.
Bearing in mind the fact that the forces
transmitted from the left-hand and right-hand piston-
and-cylinder unit 12 to the tension member 11 act in
opposite directions relative to the tension member 11
and the buoyancy in each case acts contrary to the
force of gravity, the following equation is obtained
for the resultant force FR:
Ftt = FA ( ~1~ ) ' FA ( Vr ) + Gr - G1
With the above equations for the buoyancy
forces, the following equation is then obtained for the
resultant force FR:
FR = g'Pf' (V~ - VR) + (Gr - G~)
If, then, as is preferably provided in this
invention, the piston-and-cylinder units 12 are
designed in the same way, so that they also have the
same weight, the weights cancel each other out and the
resultant force FR acting on the deflection wheel 13 in
order to generate the torque at the shaft 14 then
depends only on the volume difference ~V = V1 - Vr
CA 02284201 1999-09-17
Gerhard Thien Case: GTM _ g _
between the two piston-and-cylinder units 12. The
volume difference ~V corresponds, in the case of a
cylindrical piston 21, to the product of the piston
stroke lh and the cross-sectional area of the piston Ak.
The following then applies for the resultant force FR:
FR = g'pf'lh'Ak
In order to ensure that the piston 21 can be
displaced into its extended position against the force
acting on its free surface area 21', an upward force in
Figure 2a, which is brought about by the water pressure
prevailing in each case, the piston length lk is
preferably selected so that it satisfies the following
equation:
lk ~ h, Pf
px
In this equation, h is the maximum possible
depth of immersion of the piston-and-cylinder unit 12,
and hence of the piston 21, in other words the distance
between the lowest position of the free surface area
21' of the piston 21 and the water surface, and pk is
the density of the piston material.
The function of the apparatus according to the
invention will now be explained in detail with
reference to Figure 3, which shows an example of
embodiment of the invention having 14 piston-and
cylinder units 12 in each case arranged in pairs with
one another. In addition to the upper deflection device
10, this apparatus has a lower deflection device 13
with a deflection wheel 33 which is arranged on a lower
shaft 34.
As can be seen in Figure 3, the six piston-and-
cylinder units 12 arranged on the left-hand side each
have a volume which is greater by 0V - Vl - Vr _ lh.Ak
than the piston-and-cylinder units 12 arranged on the
right-hand side, since in their case the pistons 21 are
CA 02284201 1999-09-17
Gerhard Thien Case: GTM _ g _
in the extended position. As a result of this, a
resultant force FR acting on the tension member 11 is,
disregarding frictional losses and the like, 6~g~pf~OV.
This force FR causes the piston-and-cylinder units 12 to
make a rotational movement, in which the piston 21 of
each piston-and-cylinder unit 12.2a, which unit
alternates from the upward movement on the left-hand
side to the downward movement on the right-hand side,
is pushed solely as a result of the weight acting upon
it into the cylinder 20 in order to reduce the volume.
At the same time, a piston-and-cylinder unit 12.2b in
the region of the lower deflection device 30 alternates
from the downward movement on the right-hand side to
the upward movement on the left-hand side, the piston
21 moving out from the cylinder 20 to enlarge the
volume as a result of the weight acting upon it,
against the water pressure prevailing in this region.
Since each set of two piston-and-cylinder units
12 are assigned to each other as pairs, so that they
are arranged opposite each other relative to the
rotational movement, such as the top and bottom piston-
and-cylinder units l2.la and l2.lb or the piston-and-
cylinder units 12.2a and 12.2b, the pushing-in of a
piston 21 takes place on each occasion, in other words
on the change from the position of the piston-and-
cylinder unit l2.la to that of the piston-and-cylinder
unit 12.2a, while on the corresponding change from the
position of the piston-and-cylinder unit 12.1b to that
of the piston-and-cylinder unit 12.2b, the piston is
moved out. As a result of the compression of the air
volume in the cylinder chamber 16 of the piston-and-
cylinder unit 12.2a, which results in an increase in
the air pressure within the self-contained system, the
extension of the piston 21 of the correspondingly
opposite piston-and-cylinder unit 12.2b is assisted.
On the assumption that, for example, steel
having a density of 7.87 kg/dm3 is to be used as the
material for the piston 20 of the piston-and-cylinder
CA 02284201 1999-09-17
Gerhard Thien Case: GTM - 10 -
unit 12 and the apparatus is arranged at its lowest
point about 2 m deep in water, a piston length lk of
about 25 cm is necessary. If, accordingly, a piston
having a diameter of, for example, 22 cm and the
necessary length of 25 cm is used, and is capable of
performing a piston stroke of 20 cm, a volume change OV
of about 4 dm3 is obtained, which results in a buoyancy
of about 40 N (corresponding to 4 kg of compressed
water). With six such piston-and-cylinder units, then,
. 10 a resultant force FR of 235 N is obtained which,
depending on the diameter of the deflection wheel 13,
generates a corresponding torque at the shaft 14 which
could be used to drive a generator for the generation
of electrical energy.
By suitable selection of materials and
appropriate sizing of the individual components of the
apparatus according to the invention, torques over a
wide range can be achieved in a simple manner.
