Technical Field
[0001] The present disclosure relates to a damper for a ventilation system, and especially
to a device and a method for controlling the rotation of the damper blades between
an open position and a closed position.
Background
[0002] In ventilation systems for large structures, such as buildings and ships there is
a need for valves that provide flow control. Such valves may be arranged, as non-limiting
examples, at intakes or exhausts to/from the ventilation system, or between sections
of the ventilation system.
[0003] A particular kind of valve is referred to as a damper, and comprises a plurality
of damper blades, which are rotatable between an open position and a closed position.
[0004] A common way to control the rotation of damper blades is by using links or gears
connected to the blades.
[0005] In this type of system for controlling the blade rotation, it is sometimes desirable
to evenly distribute the power exerted on the gears while rotating adjacent blades
in opposite directions. Prior art solutions, for example as described in
EP0154089A2 or
US3746042A, use a combination of geared links and gears to distribute the power exerted on the
gears rotating the blades.
[0006] Hence, a particular problem with this type of damper is the amount of complex parts
needed and the complex and time-consuming mounting of the blade controlling parts
to the damper. Therefore, there is a need for a damper which provides fewer and less
complex system parts and which enables time-effective and uncomplicated mounting and
operation.
[0007] Yet another problem is the play which arises between components of the system, and
which especially over a chain of components may become so large as to affect the operation
of the system, e.g. with respect to its damper/shut off properties and/or its acoustic
properties.
[0008] Hence, there is a need for an improved damper.
Summary
[0009] It is an object of the present invention to provide an improved solution that alleviates
the mentioned drawbacks with present devices.
[0010] The invention is defined by the appended independent claims, with embodiments being
set forth in the dependent claims, in the following description and in the attached
drawings.
[0011] According to a first aspect, there is provided a damper for a ventilation system
comprising a plurality of damper blades, each presenting a longitudinal direction
and being rotatable about an axis parallel with the longitudinal direction, a torque
transferring element fixedly connected to each blade and rotatable about the axis
associated with the respective blade, wherein the torque transferring elements associated
with adjacent blades interact with each other, such that each pair of adjacent blades
are rotatable in opposite directions, characterized by a link connecting at least
two of the torque transferring elements with each other, said at least two torque
transferring elements being arranged to rotate in the same direction.
[0012] With this arrangement, only a few parts, torque transferring elements and a link
are needed for rotation of the damper blades and the torque transferring elements
and the link are easily mounted to the blades and frame of the damper.
[0013] Moreover, the use of both torque transferring elements and the link reduce the effect
of play between torque transferring elements.
[0014] Further, the torque transferring elements may be engaged to the blades via a blade
gable. The blade gable may be configured to engage with the short sides of the blades
and comprise a protruding part extending along the axis along which the blade and
torque transferring element rotate and by this part engage with the center of the
torque transferring element whereby the blade, blade gable, and torque transferring
element all rotate around the same axis. The protruding part of the gable may extend
through a damper frame into the torque transferring element such that the blades and
blade gable are located on different sides of the frame in relation to the torque
transferring elements and link.
[0015] The link may be connected to every third, every second or all torque transferring
elements arranged to rotate in the same direction. Interconnecting the torque transferring
elements via the link may allow the gears to rotate simultaneously, at the same speed,
and to the same distance which may give an even rotation of the blades and an evenly
distributed force on the torque transferring elements.
[0016] A second link may be connected to all torque transferring elements arranged to rotate
in an opposite direction. A second link may be located on the opposite sides of the
blades along the longitudinal extension in relation to the first link.
[0017] The damper may comprise at least four blades and at least four torque transferring
elements. The blades, extending along a longitudinal direction may be arranged such
that the blades are in parallel to each other with respect to this direction and the
axis around which they rotate. Further, the blades may be arranged inside a damper
frame which may constitute a quadrangular shape where the inner dimensions of the
frame correspond to the outer dimensions of the closed position of the blades such
that, in the closed position, essentially no air penetrates through the damper. The
blades may comprise torque transferring elements on both short sides of the blades.
Torque transferring elements may be located on a first and/or second short side of
the blades. Torque transferring elements on both sides may further facilitate the
even rotation of the blades while torque transferring elements on one side may further
reduce the complexity in mounting and the amount of parts required. The first and
the second link may be engaged with the torque transferring elements on the first
and second side respectively.
[0018] The torque transferring elements may comprise gear wheels or the like. The gear wheels
may comprise teeth around part or whole of the circumference. The torque transferring
elements may alternatively comprise a sun and planet gear, a partial gear, rack and
pinion, non-circular gear, or other gears or wheels or the like comprising a friction
circumference, which allow for torque transfer through opposite rotation of adjacent
elements. In such cases, biasing may be applied, e.g. through elasticity of the elements.
[0019] Further, each blade may be rotatable between an open position and a closed position.
In the open position the blades may be rotated such that air is allowed to pass through
the damper. In the closed position the blades may be rotated such that air cannot
pass through the damper. In the closed position the damper blades may touch or overlap
as no to allow any air penetration there between. As the torque transferring elements
are fixedly connected to the blades, the rotation of the torque transferring elements
occurs simultaneously with the rotation of the blades and the open and closed positions
of the blades correspond to a first and second position of the torque transferring
elements.
[0020] The damper may further comprise an actuator connected to one of the torque elements,
to an additional torque element which directly or indirectly interacts with said torque
element, or to a link. The actuator may serve to activate the rotation of the gears
and thereby rotating the blades between the open and closed positions.
[0021] According to a second aspect, there is provided a method for operating a damper for
a ventilation system is presented. The method comprising the steps of applying a drive
force to cause a first damper blade to rotate in a first direction about a longitudinal
axis thereof, causing a second, adjacent damper blade to rotate in a direction opposite
said first direction by means of interaction between torque transferring elements
associated with the first and second damper blades, respectively, causing a third
damper blade, arranged adjacent the second damper blade, to rotate in the same direction
as the first damper blade by means of interaction between torque transferring elements
associated with the second and third damper blades, respectively, and also transferring
torque from the first to the third blade by means of a link member connected to the
first and third blades.
[0022] With this arrangement, the operation of the damper is easily performed by the drive
force evenly spreading the power over the torque transferring elements via their interconnecting
link. This also reduces the effect of play between torque transferring elements.
[0023] As all torque transferring elements rotating in the same direction may be interconnected
via a link, the power and rotation is evenly distributed. Further, since all torque
transferring elements interact with at least one other torque transferring element,
applying drive force to one wheel consequently may cause simultaneous rotation of
all torque transferring elements and thereby also simultaneous rotation of the blades
fixedly attached to the torque transferring elements.
[0024] The link member may be connected at a radial distance from a center of the respective
torque transferring element. The link member being connected at a radial distance
from the center or respective torque transferring element facilitates the simultaneous
rotation of the torque transfer elements interconnected by the link. As the drive
force causes the first damper blade to rotate, the rotation of the respective torque
transferring element also causes a movement of the link. The link interconnecting
to other torque transfer elements in turn facilitates simultaneous rotation of the
interconnected torque transfer elements.
[0025] The torque transferring element may comprise a gear member, such as a gear wheel.
The gear wheels may comprise teeth around part or whole of the circumference. The
torque transferring elements may alternatively comprise wheels comprising a high friction
circumference.
[0026] The method may comprise a step of causing a fourth damper blade, arranged adjacent
the third damper blade, to rotate in the same direction as the second damper blade
by means of interaction between torque transferring elements associated with the third
and fourth damper blades, respectively. As the torque transferring elements interact,
for example by meshing of gear wheel teeth, rotation of one element also causes rotation
of the elements with which it interacts.
[0027] The method may further comprise the step of transferring torque from the second to
the fourth damper blade by means of a second link member connected to the second and
fourth blades. The second link member may be located on the opposite side of the blades,
with respect to their direction of extension, to the first link member. Links on both
sides of the blades may further facilitate the simultaneous rotation of the blades
and the power distribution between the torque transfer elements.
[0028] The method may further comprise the step of causing the first and fifth blades to
rotate in the same direction and interconnecting the first and a fifth torque transfer
elements by a link member. The force from the drive force causing the first wheel
to rotate may be transferred to the fifth wheel by the interconnecting link also facilitating
rotation of the interconnected torque transfer elements.
[0029] The method may further comprise the step of causing the second and sixth blade to
rotate in the same direction and interconnecting the second and sixth torque transferring
elements by a link member. The force from the drive force causing the first torque
transferring element to rotate also causes rotation of the second, adjacent torque
transferring element with which it interacts. The link interconnecting the second
torque transferring element with the sixth torque transferring element may facilitate
simultaneous rotation of these in the same direction.
Brief Description of the Drawings
[0030]
Figure 1 shows a perspective view of a damper.
Figure 2 shows an angled view of a damper.
Figure 3 shows a perspective view of a link.
Figure 4 shows a detailed view of a torque transfer element.
Figure 5 shows a perspective view of a blade gable at a short side of the blade.
Figure 6 shows a perspective view of a damper.
Detailed Description
[0031] The present invention will be described more fully hereinafter with reference to
the accompanying drawings. In the drawings, like numbers refer to like elements.
[0032] A damper 1 according to the invention is illustrated in figure 1. The damper 1 comprises
blades 4, a link 2, and gear wheels 3. The link 2 is connected to gear wheels 3 at
a radial distance from the center of the connected gear wheel. The radial distance
may be on the order of 50-100 % of a radius of the respective element. The blades
are rotatable about an axis parallel to a longitudinal direction B along which they
extend. The link 2 and gear wheels are separated from the blades 4 by the damper frame
6. The blades 4 are illustrated in an open position.
[0033] Damper blades 4 may be on the order of 200-2000 mm long and 50-200 mm wide. The sides
of the damper frame 6 may thus be on the order of 200-2000 mm.
[0034] Figure 2 show a more detailed view of part of the damper 1. The blades 4 are illustrated
in the closed position. The link 2 is rotatably connected to at least two gear wheels
3 by a connecting part 34, rotatably connecting the link 2 to the protruding part
of the gear wheel 3. The gear wheels 3 interact with each other by meshing of gear
teeth such that the rotation of adjacent gear wheels occurs in opposite directions,
R
1 and R
2. The connecting part may be a nut, a pin, a shaft or similar device which is capable
of rotatably fastening the link 2 to the gear wheel 3.
[0035] In figure 3, a link 2 is illustrated. The link 2 extends along a longitudinal axis
A and comprises engagement holes 21 which connect to the protruding part 32 of the
gear wheel (illustrated in fig. 4).
[0036] A gear wheel 3 is illustrated in figure 4. The gear wheel comprises teeth 31 configured
to interact with teeth 31 of adjacent gear wheels 3. Further, the gear comprises a
protruding part 32 configured to be connected to the engagement holes 21 of the link
2. Multiple gear wheels may thereby be interconnected via the link engaging with other
gear wheels. The gear wheel 3 further comprises a locking part 32 configured to engage
with the protruding part 51 of the blade gable 5.
[0037] The protruding part 51 may comprise a snap arrangement for interaction with the gear
wheels.
[0038] Such a snap arrangement may comprise one or more axially extending flexible tongues,
which each carry a locking element at a distal portion thereof. The locking element
may taper towards the distal end of the tongue, so as to form a ramp surface.
[0039] The gear wheels may present a central recess for interaction with the snap arrangement.
This central recess may provide a locking surface for interaction with the locking
element.
[0040] The locking element and the locking surface may thus be adapted to interact so as
to provide axial locking of the blade 4 relative to the gear wheel 3.
[0041] In figure 5 a blade gable 5 connected to a short side 41 of a blade 4 is illustrated.
The blade gable 5 comprises a protruding part 51 extending along the axis C around
which the blade rotates. The protruding part 51 may extend through the damper frame
6 such that the blade 4 and blade gable 5 are separated from the gear wheels 3 by
the frame 6, further illustrated in fig. 1.
[0042] Figure 6 illustrates the damper according to the invention comprising antransmission
cover 7 fixed to the side of the damper 1 and covering the gear wheel 3 and link 2.
[0043] This transmission cover 7 may, together with the frame 6, form a housing for the
gears 3 and the link 2. The cover 7 may provide a mounting device for mounting the
actuator (not shown) and/or for mounting e.g. a lever, in case manual operation is
desired.
[0044] The actuator may be connected to one fo the gears, e.g. by means of an extension
of the gear's rotational axis through a hole in the cover 7.
[0045] The operation of the damper is as follows. A drive power may be applied to one of
the gears, either by hand, if the damper is to be manually operated, or by means of
an actuator.
[0046] The drive power may thus be applied as a torque to one of the gears, or as a linear
force to one of the links.
[0047] The application of the drive power causes the gear to rotate along with its associated
damper blade.
[0048] The rotation of this gear will cause at least one adjacent gear to rotate in the
opposite direction, and thus the associated adjacent blade to rotate in this opposite
direction.
[0049] Hence, every pair of adjacent blades will rotate in opposite directions.
[0050] By arranging a plurality of adjacent and meshing gears with associated adjacent damper
blades, there is provided a chain of meshing gears.
[0051] With at least two, preferably all, or every second or every third, gears which rotate
in the same direction being interconnected by a link, this link will also transmit
a force to those gears with which it is connected, thus reducing the effect of play
between gears.
[0052] Alternatively to the above description, the gear wheels as described may be replaced
by for example circular, non-circular gear wheels or partial gear wheels. Wheels comprising
a high friction circumference such as to allow rotation of two adjacent wheels without
slipping may also be considered.
[0053] It may be considered to connect the link to the gear wheel not by an engaging hole
but by for example a part engaging with a hole, protrusion or recess in the gear wheel
or other connection elements that allow the link to be rotatably connected to the
gear wheel. Yet another alternative may be an additional gear on the gear wheel interacting
with yet an additional gear wheel on the link, such as the commonly know sun and planet
solution.
[0054] In one alternative solution, gears may be located on both sides of the damper frame.
In this solution two links may be used, one on each side of the damper frame wherein
a first link is connected to the gears rotating in a first direction and the second
link is connected to the gears rotating to a second direction, opposite to that of
the first direction.
[0055] In another alternative solution gears may be located on one side of the damper frame
and wheels without gear teeth may be located on the other side of the frame. In this
solution, the link may be connected to the wheels on the one side and no link need
be used on the gear side of the frame.
[0056] The link may be connected to at least two of the gears rotating in the same direction
but is not required to be connected to all gears with the same direction of rotation.
[0057] For example, the link may be connected to the two outermost gear wheels having the
same direction of rotation.
[0058] The gear wheels may be produced from plastic, metal, or other suitable material.
The gear wheels, or similar element used to transfer torque, may present an effective
radius corresponding to about ½ of a width of the blades 4. For example, the radius
may be ½ of the blade width +/-10 %, preferably +/- 5 % or +/- 1 %.
[0059] The link and blades may be produced from plastic, metal, or other suitable material.
1. A damper (1) for a ventilation system comprising:
a plurality of damper blades (4), each presenting a longitudinal direction (B) and
being rotatable about an axis parallel with the longitudinal direction,
a torque transferring element (3) fixedly connected to each blade and rotatable about
the axis associated with the respective blade,
wherein the torque transferring elements associated with adjacent blades interact
with each other, such that each pair of adjacent blades are rotatable in opposite
directions (R1, R2),
characterized by
a link (2) connecting at least two of the torque transferring elements with each other,
said at least two torque transferring elements being arranged to rotate in the same
direction.
2. The damper (1) according to claim 1, wherein the link (2) is connected to every third,
every second or all torque transferring elements (3) arranged to rotate in the same
direction.
3. The damper (1) according to claim 1 or 2, wherein a second link (2) connected to all
torque transferring elements (3) arranged to rotate in an opposite direction.
4. The damper (1) according to any of the previous claims comprising at least four blades
(4) and at least four torque transferring elements (3).
5. The damper (1) according to any of the previous claims, wherein the blades (4) comprise
torque transferring elements (3) at both short sides (41) of the blades.
6. The damper (1) according to any one of the preceding claims, wherein the torque transferring
elements (3) comprise gear wheels or the like.
7. The damper (1) according to any of the previous claims, wherein each blade (4) is
rotatable between an open position and a closed position.
8. The damper (1) according to any of the previous claims, further comprising an actuator
connected to one of the torque elements (3), to an additional torque element which
directly or indirectly interacts with said torque element, or to a link (2).
9. A method of operating a damper (1) for a ventilation system, comprising:
applying a drive force to cause a first damper blade (4) to rotate in a first direction
about a longitudinal axis thereof,
causing a second, adjacent damper blade to rotate in a direction opposite said first
direction by means of interaction between torque transferring elements (3) associated
with the first and second damper blades, respectively,
causing a third damper blade, arranged adjacent the second damper blade, to rotate
in the same direction as the first damper blade by means of interaction between torque
transferring elements associated with the second and third damper blades, respectively,
and
also transferring torque from the first to the third blade by means of a link member
(2) connected to the first and third blades.
10. The method according to claim 9, wherein the link member (2) is connected at a radial
distance from a center of the respective torque transferring element (3).
11. The method according to claim 9 or 10, wherein the torque transferring element (3)
comprises a gear member, such as a gear wheel.
12. The method according to any one of claims 9-11, further comprising causing a fourth
damper blade (4), arranged adjacent the third damper blade, to rotate in the same
direction as the second damper blade by means of interaction between torque transferring
elements (3) associated with the third and fourth damper blades, respectively.
13. The method according to claim 12, further comprising transferring torque from the
second to the fourth damper blade (4) by means of a second link member (2) connected
to the second and fourth blades.
14. The method according to any one of claims 9-13, causing the first and a fifth blades
(4) to rotate in the same direction and interconnecting the first and fifth torque
transfer elements (3) by a link member (2).
15. A method according to any one of claims 9-14, causing the second and a sixth blades
(4) to rotate in the same direction and interconnecting the second and sixth torque
transferring elements (3) by a link member (2).