AIR DAMPER

Abstract

 An air damper for an air duct (50) includes a hatch (110), a motor (120), and a slider crank mechanism (130). The hatch (110) includes a plate section (112) and a support section (114) with a slot (115). The hatch (110) is rotatably mounted on a rotational axis (R) and the slot (115) extends radially from rotational axis (R). The motor (120) is configured to provide a torque (T) on a motor shaft (125), the motor shaft (125) being spatially separated from the rotational axis (R). The slider crank mechanism (130) is mounted on the motor shaft (125) and engaging the slot (115) to transform the torque (T) of the motor (120) into closing force (F) exerted on the hatch (110) to close the air duct (50).

Description

[0001] The present invention relates to an air damper or an air pressure damper and, in particular, to a pressure wave hatch with a crank mechanism for a high-speed train air-conditioning system.

[0002] Conventional air pressure wave hatches or dampers are actuated by an electrical servomotor. They face problems while closing the hatch. Fig. 5 shows an exemplary conventional pressure damper with a hatch 10 and a motor 20, which is formed as a cantilever. The hatch 10 is configured to close an air duct 50 upon rotation of the motor 20. For this, the hatch 10 is rotatable mounted on a motor shaft formed along one edge of the hatch 10. The motor shaft defines a rotational axis R so that the hatch 10 opens/closes the air duct 50 upon a rotational movement.

[0003] Such are damper may be used in air conditioning systems of high-speed train applications, where the air pressure can reach values of up to 2000 Pa or even higher. Depending on the area of the hatch 10 the applied force can reach values of up to or more than 300 N. For this, the conventional air dampers use servomotors with a nominal voltage of about 24 V (AC or DC) that can provide a torque of up to 5 Nm or 10 Nm. An exemplary cross-section of the hatch 10 can be approximately 0.2 m² and a maximum rotating angle between the closed and open position can reach values of up to 45°. A proper operation under these conditions is not achieved.

[0004] For example, the applied closing force may be uneven on a gasket. It may thus result in an incomplete closure. To mitigate this problem, conventional hatches uses for bigger cross sections of the hatch 10 magnets to keep the hatches closed, especially for air ducts 50 with high air pressure. However, this solution is inferior because additional magnets are needed and the hatch has to be opened against the force applied by the magnets.

[0005] Therefore, there is a demand for different air dampers that, on one hand, provide a proper closure of the hatch 10, e.g., during pressure waves applied on the hatch 10 in highspeed train applications and, on the other hand, provide a fast and easy opening of the hatch.

[0006] At least some of these problems are solved by an air damper according to claim 1. The dependent claims define further advantageous realizations of the subject matter of the independent claim.

[0007] The present invention relates to an air damper for an air duct. The air damper comprises a hatch, a motor, and a slider crank mechanism. The hatch includes a plate section and a support section. The support section includes a slot, and the hatch is rotatably mounted on a rotational axis. The slot extends radially from rotational axis. The motor is configured to provide a torque on a motor shaft. The motor shaft is spatially separated from the rotational axis. The slider crank mechanism is mounted on the motor shaft and engages (or couples to) the slot to transform the torque of the motor into closing force exerted on the hatch to close the air duct.

[0008] The slider crank mechanism may comprise a crank arm, a crank opening and a crank pin, wherein the crank opening is mounted on the motor shaft and the crank pin engages with the slot. Optionally, the motor shaft is arranged at a position where a connection line connecting the crank opening and the crank pin forms a rectangular angle with the plate section, when the air duct is closed. The connection line may thus be a normal vector on a surface defined by the plate section. Alternatively, or additionally, a length the connection line is adjusted to obtain, in the closed position, a rectangular angle between the connection line the plate section.

[0009] Optionally, the slot comprises a curved portion with a curvature radius defined by a distance between the crank opening and the crank pin to maintain the closed position of the hatch while rotating the crank arm and moving the crank pin along the curved portion (e.g. between two angular positions). For example, the curved portion may be close to or at an end of the slot. It is understood that a curved portion implies a varying gradient calculated along the moving direction of the crank pin in the slot. This provides the technical effect that there is not only a single angular position of the crank arm where the hatch is closed, but there is a range of angular positions where the hatch remains closed without the need to apply a torque on the motor. This provides further stability.

[0010] Optionally, the hatch is rotatably mounted on one side by a hinge or by one or two bolts secured in a pivot bearing. In addition, the closing force, when the hatch is closed, may be applied on a side of the hatch that is opposite to the rotatably mounted side. This provides the technical effect that the closed position is reliably maintained - due the leverage of the applied closing force by the crank pin (in contrast to the conventional cantilever hatch).

[0011] Optionally, the plate section comprises a rectangular area, wherein the slider crank mechanism and/or the slot and/or the motor is/are provided only on one side of rectangular area.

[0012] Optionally, the support section comprises a first slot and a second slot arranged on two opposite sides of the hatch. Likewise, the slider crank mechanism may include a first slider crank mechanism and a second slider crank mechanism, wherein the first slider crank mechanism engages the first slot and the second slider crank mechanism engages the second slot.

[0013] Optionally, the air damper further includes a transmission rod configured to transmit the torque from the motor between the first slider crank mechanism and the second slider crank mechanism to drive both slider crank mechanisms with a single motor. Thus, the closing force is applied on the two opposite sides of the hatch.

[0014] Optionally, the motor is a first motor, and the air damper further includes a second motor. The first motor may be configured to drive the first slider crank mechanism and the second motor may be configured to drive the second slider crank mechanism to apply the closing force on the two opposite sides of the hatch.

[0015] The first slider crank mechanism may couple to the motor shaft of the motor, Then, optionally, the second slider crank mechanism is driven by a spring that provides a bias force acting towards the open position or towards the closed position. The spring may be a torsion spring to provide a torque on the crank arm of the second slider crank mechanism. When, in the closed position, the crank arm is not perpendicular to the plate section of the hatch, the spring may be configured to act in either of both directions, either towards closed position or towards the closed position. When, in the closed position, the crank arm is perpendicular to the plate section, the (torsion) spring may acting towards the open position. By this, a deadlock can be prevented. In addition, at least one further (torsion) spring may be provided to support the motor, either to close the hatch or to open the hatch.

[0016] Further embodiments relate to a train air-conditioning system with an air damper as described before.

[0017] Therefore, according to the present invention, the hatch opens and closes with a rotation movement of a crank and a sliding of a bush on one or both edges of the hatch. While closing the hatch, a motor torque drives the crank and thus applies a closing force on an end opposite to the exemplary hinged side (i.e. along which the rotational axis extends). Therefore, both sides of the hatch can be secured, one with the hinge and other with the motor torque. In other words, according to embodiments, both opposite sides of the hatch are securely fixed.

[0018] Some examples of the air damper will be described in the following by way of examples only, and with respect to the accompanying figures, in which:

Figs. 1A,1B

depict an air damper in the open and closed position according to an embodiment.

Figs. 2A,2B

depict an air damper according to another embodiment.

Fig. 3

depicts an air damper according to yet another embodiment.

Figs. 4A-4E

depict air dampers according to further embodiments.

Fig. 5

depict a conventional air damper formed as a cantilever.

[0019] Figs. 1A, 1B depict an air (pressure) damper according to an embodiment. The air damper includes a hatch 110 for closing an air duct 50. The hatch 110 is rotatably mounted on a rotational axis R (e.g. by a hinge or a pivot bearing) and comprises a slot 115, which represents an opening that extends radially from the rotational axis R. The air damper further includes a motor 120, which is configured to provide a torque T on a motor shaft 125. The air damper further includes a slider crank mechanism 130 which is mounted on the motor shaft 125 and engages the slot 115 to transform the torque T of the motor 120 into a closing force F exerted on the hatch 110 to close the air duct 50.

[0020] The hatch 110 may comprise a plate section 112, which provides the closure for the air duct 50, and a support section 114, which includes the slot 115 and may provide a reinforcement for the plate section 112 to withstand the high pressure applied, e.g., in high speed train application. The hatch 110 extends radially from the rotational axis R. The motor 120 is not visible in Fig. 1A but is secured on a mounting construction 122. The motor shaft 125 is rotationally fixed to the slider crank mechanism 130 which thus rotates together with the motor shaft 125, thereby pressing down the hatch 110 onto the air duct 50 to close it. The opposite rotation may then open the air duct 50.

[0021] Fig. 1A depicts an air damper in the position where the air duct 50 is closed. In this position, the hatch 110 may be secured on one side by the rotational mounting on the rotational axis R and on the other side by the slider crank mechanism 130 that couples to the slot 115 to press down the hatch 110 and to thus maintain the closed position. For this, an exemplary anticlockwise acting torque T is applied in Fig. 1A to the motor shaft 125.

[0022] Fig. 1B illustrates the opening of the hatch 110 by a clockwise acting torque T applied to the motor shaft 125, i.e. the motor 120 rotates in an opposite direction. Thereby, an opening force F is exerted and the hatch 110 is lifted from the duct 50 to expose the interior of the duct 50 to provide the desired air ventilation. According to embodiments, the maximum opening position can be up to 45° as shown in Fig. 1B, in which case the slider crank mechanism 130 extends along a perpendicular direction with respect to the plate section 112. The achievable maximum opening position depends for a given hatch 110 and a given rotational axis R on the concrete arrangement of the position of the motor shaft 125, the location of the slot 115, angular position of the crank in the open/closed position, and a distance from the motor shaft 125 to a coupling point to the slot 115.

[0023] Fig. 2A, 2B depict an air damper according to another embodiment, wherein Fig. 2A shows cross sectional view perpendicular to the rotational axis R and Fig. 2B shows an overview.

[0024] The slider crank mechanism 130 includes a crank opening 134 which engages with the motor shaft 125. The slider crank mechanism 130 further includes a crank arm 132 and a crank pin 136. The crank pin 136 engages the slot 115 in order to exert the closing force F on the hatch 110. In this embodiment, the motor 120 or at least the motor shaft 125 is shifted to a different location relative to the rotational axis R (e.g. by shown tilted arrangement). In this shifted position, the crank arm 132 extends perpendicular to the plate section 112 of the hatch 110 in the closed position. Thus, in this embodiment, a connection line P between the crank opening 134 and the crank pin 136 is rectangular to the plate section 112. The connection line P defines thus the angular position of the crank arm 132 and is mathematically a normal direction of the surface defined by the hatch 110 or its plate section 112 (extending along shown line L). Therefore, the angle between the connection line P and a line L is ideally 90° in the closed position. This provides the advantage that ideally no torque is needed to be applied by the motor 120 to maintain the depicted closed position.

[0025] Additionally, or alternatively, the motor 120 may also include a gearing mechanism in order to provide a sufficiently strong torque applied to close the hatch 110 against an air pressure (e.g. for air flows occurring in a high-speed train application).

[0026] Fig. 3 depicts an air damper according to yet another embodiment. In the depicted embodiment the slot 115 comprises a curved portion 117. The curved portion 117 may be arranged at an end portion of the slot 115, opposite to the rotational axis R. Again, the motor unit 120 is arranged at a position such that the crank arm 132 extends in the closed position P1 perpendicular to the hatch 110. Due to the curved portion 117, the crank arm 132 can further be rotated anticlockwise about the motor shaft 125 up to a position P2 (end of curved portion 117) while maintaining the closed position of the hatch 110. For this, the curved portion 117 may have a curvature radius along the longitudinal direction of the slot 115 which equals the distance between the motor shaft 125 and the crank pin 136 implying that a further rotation of the crank arm 132 does not result in a moving of the hatch 110. In other words, along the curved portion 117, the crank arm 132 can be rotated without applying a force onto the slot 115 or on the hatch 110. It remains in the closed position.

[0027] This curved portion 117 may provide the advantage that the closed position can be secured against strong forces applied onto the hatch 110. The motor does not need to apply any torque T to keep the hatch 110 close. The mechanism can maintain its closed position without any energy consumption. And the closed position is not only achieved at one angular position, but at an angular range. Thus, the controlling is easier.

[0028] The curved portion 117 may be arranged directly at the end of the slot 115. Optionally, when viewed in the moving direction of the pin 136 when closing the hatch 110, beyond the curved portion 117 another straight portion of the slot 115 can be formed. Although the hatch 110 may slightly open at the other straight portion of the slot 115, this can provide a locking, because the air pressure in the air duct 50 will press the crank pin 136 against the end portion of the slot 115 and will thus stabilize this position.

[0029] Fig. 3 shows further the open position P0 of the crank arm 132, which can be achieved by a clockwise rotation about the motor shaft 125. The maximum opening position is again reached when the crank arm 132 is perpendicular to the plate section 112 as shown on the left-hand side of Fig. 3. Also this position is a stable position so that no motor torque T is needed in order to maintain this position - even though a high-pressure air flow may be applied to the hatch 110.

[0030] According to embodiments, the crank pin 136 moves when closing the hatch first towards the rotational axis R and then away from the rotational axis R. This provides the advantage that the leverage is maximized at the closed position (e.g. the crank pin 136 is maximally separated from the rotational axis R). Thus, the hatch 110 can reliably close the air duct 50, even if high pressure is applied.

[0031] Figs. 4A-4E depict air dampers according to further embodiments.

[0032] Fig. 4A depict an air damper, wherein, in the closed position, the crank pin 136 is arranged at a position opposite to the rotational axis R. This may be achieved by moving the motor shaft 125 further away from the rotational axis R. Thus, in the closed position, the closing force F acts close to an end position of the slot 115. Therefore, the hatch 110 is secured on two opposite sides, i.e. on one side by the rotational mounting at the rotational axis R (e.g. by a hinge) and, on the opposite side, by the crank pin 136 applying the closing force F on the hatch 110. In the depicted embodiment, three corners of a rectangular shaped hatch 110 will be secured. The acting force on the hatch 110 can be disturbed equally on the hinge at the axis R and the crank pin 136 so that again high lever is utilized by placing the crank pin 136 at the end position, instead of closer to the rotational axis R.

[0033] In this embodiment, however, the motor 120 has to apply a torque T (e.g. acting anticlockwise) in order to press the hatch 110 down onto the opening of the air duct 50 (not shown in Fig. 4A). To keep this position, the motor 120 may include a worm drive that can maintain its current angular position without much energy consumption (e.g. using lower voltage).

[0034] In addition, the depicted embodiment includes merely a single slot 115 formed on one side of the hatch 110 extending radially from the rotational axis R. Therefore, this embodiment provides the advantage that a single motor 120 is enough to close and/or to open the hatch 110.

[0035] Fig. 4B shows an air damper according to another embodiment, wherein the support section 114 includes a first slot 115a and a second slot 115b. Likewise, the slider crank mechanism 130 may include a first slider crank mechanism and a second slider crank mechanism, wherein the first slider crank mechanism 130a engages the first slot 115a and the second slider crank mechanism (not shown) engages the second slot 115b. The motor 120 applies the torque T onto the crank arm of the first slider crank mechanism 130a (not shown in Fig. 4B) to provide the closing/opening force F. In addition, another motor (not shown in Fig. 4B) may apply another torque to the crank arm of the second slider crank mechanism (not shown in Fig. 4B). Thus, the hatch 110 is moved by two motors.

[0036] This provides the advantage that the hatch 110 can be moved without a risk of titling or canting the hatch 110 caused by strong air pressure. In addition, even if one motor breaks, the other motor may provide sufficient torque T to open or close the hatch 110. This redundancy improve the reliability of the air damper.

[0037] Fig. 4C shows an embodiment, wherein the air damper includes a transmission rod 127 which extends between two slider crank mechanisms 130a, 130b arranged on opposite sides of the hatch 110. This transmission rod 127 is configured to transmit a torque T applied by the motor unit 120. Thus, only a single motor can drive both slider crank mechanisms 130a, 130b, i.e. also the second slider crank mechanism 130b on the right-hand side where no motor is present.

[0038] The transmission rod 127 may connect both crank openings 134 of both slider crank mechanism 130 (see e.g. Fig. 2). In order to maintain a desired opening angle of the hatch 110, the lengths of the crank arms 132 can be increased accordingly to provide enough space for opening of the hatch 110. Alternatively, the transmission rod 127 may connect both crank pins 136. Since the crank pins 136 can be rotationally fixed to the crank arms 132, the transmitted torque drives the crank pin 136 up or down in the slot 115 and thus results in a transmission of the closing force. In this case, the transmission rod 127 can be placed close to the plate section 112 as shown in Fig. 4C.

[0039] Figs. 4D and 4E illustrate an air damper according to yet another embodiment, wherein the support section 114 includes again a first slot 115a on the left-hand side and a second slot 115b on the right-hand side. In the depicted embodiment there is no transmission rod as in Fig. 4C, but the second slider crank mechanism 130b includes a spring 138 that applies a bias force, e.g., onto the crank arm 132 of the second slider crank mechanism 130b. This bias force may act towards the open position.

[0040] Fig. 4D shows the closed position where the crank arm 132 will be again perpendicular to the plate section 112. The spring 138 may be a torsion spring applying a torque on the crank arm 132 towards to open position (i.e. acting anticlockwise in Fig. 4D). Therefore, at the shown closed position, only a slight torque needs to be applied by the motor 120 on the left-hand side (at the first slider crank mechanism 130a) to open the hatch 110, because the spring 138 will support this opening force acting on the hatch 110. A deadlock situation can thus be avoided, where the second slider crank mechanism 130b on the right-hand side would be unable to move from the rectangular situation as shown in Fig. 4D - in particular when high pressure is applied on the hatch 110.

[0041] Fig. 4E shows further details of the torsion spring 138 arranged, e.g., on the second slider crank mechanism 130b. The spring 138 provides a torque acting on the crank arm 132 of the second slider crank mechanism. According to further embodiments, the spring 138 is torsion spring providing a torque towards the closed position. This may be of advantage of the air damper as shown in Fig. 4A, where the closed position is not the rectangular situation of Fig. 4D that is prone to a deadlock situation. When applying a torsion spring in the embodiments of Fig. 4A, the applied toque by the torsion spring can relieve the motor that otherwise has to maintain the complete torque for maintaining the closed position. In the embodiment of Fig. 4A, another slot and another slider crank mechanism may be formed, which can be driven such torsion spring.

[0042] According to embodiments, the components of the air damper are adapted to meet the following demands: The motor 120 may be a servo motor that can provide a motor torque of up to or more than 10 Nm resulting in an exemplary force of 145 N. The force, on the other hand, acting on the hatch 110 may withstand an air pressure of up to or more than 4000 Pa. With an exemplary cross-sectional area of 0.093758 m², the exemplary pressure of 4000 Pa results in a force acting on the hatch of 375 N. This force can be distributed with an exemplary ratio of 120:80 between a force RH = 151,875 N acting on the hinge at the rotational axis R and a force RC = 223,125 N provided by the crank pin 136. The latter one has to be taken by the torque motor 120. If the crank arm 132 is not perpendicular, but is an angle Q away from the perpendicular situation, the above motor can hold the hatch 110 in the closed position up to about 40° (RC × Sin(40) = 143,5 N < 145N).

[0043] Embodiments provide the following advantages:
The electrical motor 120 needs less torque T to maintain an open and/or a closed position using the crank and slotted lever (the slider crank mechanism 130). Therefore, the size of the electrical motor 120 can be reduced resulting in fewer component costs and less power consumption. Furthermore, less stiffening is needed in order to maintain the closed position when compared to the conventional cantilever of Fig. 5, where the closing force is only applied on one side. This, too, results in fewer material costs and less weight. Furthermore, a quick return mechanism can be added for opening and closing. Finally, the added spring 138 can operate in the closed position to prevent a mechanical lock.

[0044] The description and drawings merely illustrate the principles of the disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its scope.

[0045] Furthermore, while each embodiment may stand on its own as a separate example, it is to be noted that in other embodiments the defined features can be combined differently, i.e. a particular feature descripted in one embodiment may also be realized in other embodiments. Such combinations are covered by the disclosure herein unless it is stated that a specific combination is not intended.

LIST OF REFERENCE SIGNS

[0046] 

10, 110

hatch

20,120

motor

50

air duct

112

plate section

114

support section

115

slot(s)

117

curved portion

122

mounting construction for motor

125

motor shaft

127

transmission rod

130

slider crank mechanism(s)

132

crank arm

136

crank pin

134

crank opening (hole)

138

spring

R

rotational axis

T

motor torque

F

translational force

P, P1, P2

angular position(s) of crank arm

Claims

1. Air damper for an air duct (50),
characterized by:

- a hatch (110) including a plate section (112) and a support section (114) with a slot (115), the hatch (110) is rotatably mounted on a rotational axis (R) and the slot (115) extends radially from rotational axis (R);

- a motor (120) configured to provide a torque (T) on a motor shaft (125), the motor shaft (125) being spatially separated from the rotational axis (R); and

- a slider crank mechanism (130) mounted on the motor shaft (125) and engaging the slot (115) to transform the torque (T) of the motor (120) into closing force (F) exerted on the hatch (110) to close the air duct (50).

2. The air damper according to claim 1, wherein the slider crank mechanism (130) comprises a crank arm (132), a crank opening (134) and a crank pin (136), wherein the crank opening (134) is mounted on the motor shaft (125) and the crank pin (136) engages with the slot (115),
characterized in that:
the motor shaft (125) is arranged at a position where a connection line (P) connecting the crank opening (134) and the crank pin (136) forms a rectangular angle with the plate section (112), when the air duct (50) is closed.

3. The air damper according to claim 2,
characterized in that:
the slot (115) comprises a curved portion (117) with a curvature radius defined by a distance between the crank opening (134) and the crank pin (136) to maintain the closed position of the hatch (110) while rotating the crank arm (132) and the crank pin (136) moves along the curved portion (117).

4. The air damper according to one of the preceding claims,
characterized that:
the hatch (110) is rotatably mounted on one side by a hinge or by one or two bolts secured in a pivot bearing, wherein the closing force (F), when the hatch (10) is closed, is applied on a side of the hatch (110) that is opposite to the rotatably mounted side.

5. The air damper according to one of the preceding claims, wherein the plate section (112) comprises a rectangular area,
characterized in that:
at least one of the following is provided only on one side of rectangular area: the slider crank mechanism (130), the slot (115), the motor (120).

6. The air damper according to one of the preceding claims,
characterized in that:

the support section (114) comprises a first slot (115a) and a second slot (115b) arranged on two opposite sides of the hatch (110); and

the slider crank mechanism (130) includes a first slider crank mechanism (130a) and a second slider crank mechanism (130b), wherein the first slider crank mechanism (130a) engages the first slot (115a) and the second slider crank mechanism (130b) engages the second slot (115b).

7. The air damper according to claim 6,
characterized by further including:
a transmission rod (127) configured to transmit the torque (T) from the motor (120) between the first slider crank mechanism (130a) and the second slider crank mechanism (130b) to drive both slider crank mechanisms (130a, 130b) with a single motor (120) to apply the closing force (F) on the two opposite sides of the hatch (110).

8. The air damper according to claim 6,
characterized in that:
the motor (120) is a first motor (120) and the air damper further includes a second motor, the first motor (120) is configured to drive the first slider crank mechanism (130a) and the second motor is configured to drive the second slider crank mechanism (130b) to apply the closing force (F) on the two opposite sides of the hatch (110).

9. The air damper according to claim 6,
characterized in that:
the first slider crank mechanism (130a) couples to the motor shaft (125) of the motor (120) and the second slider crank mechanism (130b) is driven by a spring (138) that provides a bias force acting towards the open position or towards the closed position.

10. The air damper according to claim 9,
characterized in that:
the spring (138) is a torsion spring to provide a torque on crank arm opening (134) of the second slider crank mechanism (130b).

11. A train air-conditioning system with an air damper according to one of the preceding claims.

Drawing