Actuator for fluid flow controllers
Technical field of the invention
The present invention relates to actuators for fluid flow controllers, such as damper or HVAC actuators.
Background of the invention
All actuators for fluid flow controllers, such as damper actuators, comprise an electric motor, a gearing, a motor driver circuit, a housing, and a mounting system fitted for the shaft of the fluid flow controller. In addition, damper actuators further often comprise various mechanisms e.g. for smart control, mounting, fault protection, and voltage conversion.
The damper shafts are marketed in different designs, such as D-profile, square profile, and plate-shaped. In order to handle the many different damper shaft profiles, some damper actuators are provided with an adaptor, which is mounted with a shackle or a locking ring that holds the damper shaft (see e.g.,
WO201 3013334, US2019024819). However, mounting the adaptor with a shackle or locking ring is difficult and increases the mounting time. Furthermore, there is a risk of the shackle breaking, and the installer might lose the locking ring or the tools with which he or she is working. This solution is also difficult to use for thin damper actuators, which many customers prefer. This solution requires a separate gear release solution. Finally, this is an expensive solution as it requires many parts to manufacture and assemble. Other solutions have a universal hole in which to tighten a screw, bracket or jaws to the damper shaft (see e.g., WO2013013334, W02007006162,
CN103282677). A universal hole in which the damper shaft is clamped is even more difficult to install than a shackle and also increases the installation time, especially if there is no separate gear release and the damper actuator must be
mounted horizontally.
Yet other solutions provide the same damper actuator in different versions for the different damper shaft profiles. Selling the same damper actuator in different versions is the most expensive solution of all as it requires a larger product range and stock, and the production costs are markedly increased relative to the other solutions. Furthermore, this solution still requires a separate gear release mechanism.
During mounting of the damper actuator, it is advantageous to be able to place the damper actuator on the damper shaft facing in the direction in which the clamping points are located.
In order to be able to mount the damper actuator pointing in different directions, some have a gear release that is triggered by a magnet or a mechanical push button (se e.g., W02005090831 , and US10295215). However, a gear release with magnets results in the consumption of large amounts of rare earth/precious metal, and there is a risk of erasing the microcontroller's programming, if the magnet is held in the wrong place by accident or ignorance. This fault will be hard to detect in the quality assurance because it can also result in a periodic error, resulting in a complex fault-finding procedure. A mechanical push button takes up significant space and is therefore difficult to implement in thin damper actuators, which many customers prefer. Moreover, this is an expensive solution as it requires many parts to manufacture and assemble.
Other solutions are provided with an input to a cog in the middle of the gear chain, which can be turned manually, e.g., with a screwdriver. However, having to turn the gears with a screwdriver is considered a hassle, is difficult to adjust properly, and increases the mounting time considerably. The technician also needs more space to handle the proper tools for this kind of operation inside e.g., an HVAC unit.
Again, other solutions use a universal clamping and mounting method (see e.g., WO201 3013334, W02007006162, and CN103282677), where the clamp is tightened around the damper shaft after the damper actuator has been mounted,
such that said damper actuator is pointing in the intended direction. However, if using a universal hole, one will have to wait with the tightening operation of the damper actuator on the damper shaft before screwing the damper actuator onto the damper, which is a hassle as it requires three hands to keep it all in place while mounting. The technician also needs more space to handle the proper tools for this kind of operation inside e.g., an HVAC unit.
Many damper actuators come in clockwise and counterclockwise versions. Some have a dial that switches between the direction of rotation (WO2013013334). Selling the same damper actuator in different versions is the most expensive solution of all as it requires a larger product range and stock, and the production costs are markedly increased relative to the other solutions. This also forces customers to purchase smaller quantities, thereby obtaining smaller discounts.
A rotary knob that changes the direction of rotation is an expensive solution as it requires many parts to manufacture. Furthermore, there is a risk of turning too far which damages the damper actuator.
The damper actuator can also be reversed electrically by switching around the signal wires. Switching around the signal wires is not always an acceptable solution as it increases the risk of product failure, as the installer who performs monotonous work risks connecting the cables incorrectly if it is not following a fixed color code system that further requires extra documentation work. This extra documentation work forces a customer to have more wiring/electrical diagrams for their systems to track and update. Further, as most damper actuators are not symmetrical, this strategy is not an option for many customers due to mounting space restrictions.
US2017241560 discloses a valve actuator assembly that include an actuator and an actuator mounting assembly. The actuator mounting assembly may be secured to a valve shaft without the actuator present, and the actuator may be secured to the actuator mounting assembly later. This can make it easier to mount the actuator mounting assembly, especially in cramped spaces. In some
cases, the actuator may be wired where it is convenient, and then moved to the actuator mounting assembly and secured to the mounted actuator mounting assembly, sometimes with a simple snap attachment. In some cases, a button, lever, or other mechanism may release the actuator from the actuator mounting assembly for easy removal.
Description of the invention
It is an object of the present invention to overcome the above-mentioned problems. The present invention provides a smarter way to mount an actuator to a rotatable shaft by providing a novel mounting system.
One aspect relates to an actuator comprising:
- a housing or mounting plate;
- a ring- or tube-shaped drive shaft rotatably mounted in/on said housing or mounting plate; said drive shaft having a toothed channel;
- an electric motor unit positioned within said housing or on said mounting plate, and indirectly or directly adapted to transfer a torque to said drive shaft;
- a ring- or tube-shaped first insert comprising a) a channel adapted for receiving a rotatable shaft of a fluid flow controller; and b) a toothed outer face complementary in shape to said toothed channel; wherein said first insert is adapted for insertion into and for releasably or non-releasably engagement with said toothed channel; and
- a mechanism adapted for preventing said first insert from passing through said toothed channel.
A method for mounting the actuator of the present invention may comprise the steps of:
- determining the profile of said rotatable shaft;
- selecting a ring- or tube-shaped first insert having a channel adapted for receiving said rotatable shaft, said channel being complementary in shape to
said profile of said rotatable shaft; said first insert having a toothed outer face;
- mounting said first insert over said rotatable shaft such that the shaft extends through said channel of said first insert;
- providing a housing or mounting plate with a ring- or tube-shaped drive shaft rotatably mounted in/on a housing or mounting plate; said drive shaft having a toothed channel complementary in shape to said toothed outer face of said insert;
- mounting said drive shaft onto said first insert, such that said drive shaft enters said toothed channel, wherein a mechanism is adapted for preventing said first insert from passing through said toothed channel; and
- fastening said housing or mounting plate to a substrate that does not rotate with said rotatable shaft.
It is contemplated that the drive shaft may be used to drive the rotatable shaft of any suitable fluid flow controller, including but not limited to water valves within hydronic heating and/or cooling systems, other fluid or gas valves, and/or any other actuatable valve as desired. The term “fluid flow controller” may encompass any actuatable valve, such as air dampers, water valves, gas valves, ventilation flaps, louvers, and/or other actuatable valves that help regulate or control the flow of fluid in e.g., an HVAC system.
In one or more embodiments, the actuator further comprises a kit of first inserts, each of said first inserts having a channel adapted for receiving a rotatable shaft of a fluid flow controller of a different profile than the other of said first inserts in said kit.
In one or more embodiments, the step of selecting said first insert comprises selecting said first insert from a kit of first inserts, each of said first inserts having a channel adapted for receiving a rotatable shaft of a fluid flow controller of a different profile than the other of said first inserts in said kit.
In one or more embodiments, one end of the first insert comprises a guide recess with a stop, and wherein the housing or mounting plate comprises a guide pin adapted for moving within said guide recess and to engage with said stop, thereby allowing said drive shaft to rotate a predefined number of degrees around its axis of rotation. This configuration allows the user or manufacturer to define the allowable degrees of rotation that the drive shaft can move the rotatable shaft of the fluid flow controller.
In one or more embodiments, the mechanism comprises that one end of said first insert comprises a stop pin or plate adapted for engaging with an end of said drive shaft.
In one or more embodiments, the mechanism comprises that said first insert and said toothed channel are both conical in shape. This configuration may be used in conjunction with one end of said first insert comprising a stop pin or plate adapted for engaging with an end of said drive shaft.
In one or more embodiments, the mechanism comprises that said first insert is conical in shape and of a length corresponding to maximum half of said toothed channel, and wherein said toothed channel is biconical in shape and adapted for receiving said first insert via one or both ends. This configuration may be used in conjunction with one end of said first insert comprising a stop pin or plate adapted for engaging with an end of said drive shaft.
In one or more embodiments, the mechanism comprises that said first insert is conical in shape and of a length corresponding to less than the total length of said toothed channel, and wherein said toothed channel is biconical in shape and adapted for receiving said first insert via one or both ends. This configuration may be used in conjunction with one end of said first insert comprising a stop pin or plate adapted for engaging with an end of said drive shaft. One part of the toothed biconical channel may have one type of teeth, while the other has a
second type of teeth. Similarly, the first insert may have teeth corresponding to the one or the other biconical part of the toothed biconical channel, while another component, such as the below mentioned second insert may have teeth corresponding to the opposite biconical part of the toothed biconical channel.
In one or more embodiments, the first insert is of a length corresponding to maximum half of said toothed channel or alternatively being of a length corresponding to less than the total length of said toothed channel. These configurations allow the user to decide if the insert should be inserted into one or the other end of the toothed channel and may be an advantage if the rotatable shaft should be worked in a clockwise direction or in a counter-clockwise direction. However, such a solution is primarily necessary when the first insert and toothed channel are conical in shape. The actuator may further comprise a ring- or tube-shaped second insert comprising a) a toothed outer face complementary in shape to said toothed channel, and adapted for insertion into and for releasably or non-releasably engagement with said toothed channel in the opposite end than said first insert, and b) a guide recess with a stop; wherein said housing or mounting plate comprises a guide pin adapted for moving within said guide recess and to engage with said stop, thereby allowing said drive shaft to rotate a predefined number of degrees around its axis of rotation. This configuration allows the user or manufacturer to define the allowable degrees of rotation that the drive shaft can move the rotatable shaft of the fluid flow controller.
In one or more embodiments, the method further comprises the step of inserting a second insert into the toothed channel in the opposite end than said first insert. Preferably, the second insert comprises a) a toothed outer face complementary in shape to said toothed channel, and adapted for insertion into said toothed channel, and b) a guide recess with a stop; wherein said housing or mounting plate comprises a guide pin adapted for moving within said guide recess and to engage with said stop, thereby allowing said drive shaft to rotate a predefined
number of degrees around its axis of rotation.
As used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" or "approximately" one particular value and/or to "about" or "approximately" another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about", it will be understood that the particular value forms another embodiment.
It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.
Brief description of the figures
Figure 1 shows a mounting system in accordance with various embodiments of the invention.
Figure 2 shows a drive shaft in accordance with various embodiments of the invention.
Figure 3 shows a cross-sectional view of a drive shaft in accordance with various embodiments of the invention.
Figures 4A and 4B show perspective views of an insert in accordance with various embodiments of the invention.
Figures 5A-5D show perspective views of an insert in accordance with various
embodiments of the invention.
Figures 6 shows a second insert in accordance with various embodiments of the invention.
Figure 7 shows an exploded view of the mounting system and second insert in accordance with various embodiments of the invention.
Figure 8 shows the second insert connected to the mounting system in accordance with various embodiments of the invention.
Figure 9 shows the mounting system, electric motor, and gearing relative to a rotatable shaft of a fluid flow controller.
Figure 10 shows a first side view of the actuator in accordance with various embodiments of the invention mounted on a rotatable shaft of a fluid flow controller.
Figure 11 shows a second side view of the actuator in accordance with various embodiments of the invention mounted on a rotatable shaft of a fluid flow controller.
Detailed description of the invention
The following description is to be seen as a non-limiting example of an actuator according to various embodiments of the present invention.
All actuators for fluid flow controllers, such as damper actuators, comprise an electric motor, a gearing, a motor driver circuit, a housing, and a mounting system fitted for the shaft of the fluid flow controller. The actuator 100 of the present invention comprises a mounting system comprising a ring- or tube shaped drive shaft 300 and a first insert 600 (Figure 1 , exploded view). The drive
shaft 300 (see also Figure 2) has a toothed channel 310 and is shown with a toothed outer face 320, here embodied as two rings delimiting a guide track 330 for the gearing 500 (only shown in Figure 9). In Figure 3, a cross-section of the drive shaft 300 is shown. The toothed channel 310 is biconical in shape and adapted for receiving the first insert 600 via both ends.
The first insert 600 is adapted for insertion into and for releasably engagement with the toothed channel 310. This is possible as its toothed outer face 620 is complementary in shape to the toothed channel 310. The first insert 600 also comprises a channel 610 adapted for receiving a rotatable shaft 10 of a fluid flow controller. This channel 610 can have any suitable form and is formed according to the profile of the rotatable shaft 10. The embodiment shown in Figure 1 is a square profile rotatable shaft 10 and a first insert 600 with a square channel 610. It is important that the channel 610 finish close around the rotatable shaft 10, as the forces from actuator’s motor 500 are transferred to the rotatable shaft 10 via said first insert 600. Flence, the channel walls will have to engage with the rotatable shaft 10 in order to rotate it. One exception from this is when the shaft must be moved in a circular path, as e.g., dragged in a circular guide recess. Flere, the shaft has a circular profile and the channel 610 (see Figure 5C) is positioned eccentrically, i.e., not symmetrically with respect to the center of the first insert 600. Examples of channel shapes are shown in Figures 4 and 5. The first insert 600 is to be mounted over the rotatable shaft 10 such that the shaft 10 extends through said channel 610. The multitude of teeth on both the first insert 600 and the toothed channel 310 allows a user to easily couple the two parts together.
Finally, the first insert 600 is shown with a stop plate/rim 630 adapted for engaging with an end of said drive shaft 300. Thereby, the first insert 600 will be held in place and cannot move through the toothed channel 310.
Figures 6 shows a second insert 700 in accordance with various embodiments of the invention. The second insert 700 is ring- or tube-shaped and adapted for insertion into and for releasably engagement with the toothed channel 310. The
second insert 700 is intended for insertion in the opposite end of the toothed channel 310 than the first insert 600 as seen in Figures 7-9, and 11. The second insert 700 comprises a) a toothed outer face 710 complementary in shape to said toothed channel 310, and b) a guide recess 720 with a stop 730. The main purpose of the second insert is to aid in a controlled rotation of the fluid flow controller within the piping or duct in which it is acting. This is done by restricting the drive shaft’s 300 possibility to rotate. Hence, the housing or mounting plate 200 is provided with a guide pin 210 (Figure 10 and 11 ) adapted for moving within said guide recess 720 and to engage with said stop 730, thereby allowing the drive shaft 300 to rotate a predefined number of degrees around its axis of rotation. The housing or mounting plate 200 is provided with a mounting hole 220.
Figure 10 shows a first side view of the actuator 100 in accordance with various embodiments of the invention mounted on a rotatable shaft 10 of a fluid flow controller. Figure 11 shows a second side view of the actuator 100 in accordance with various embodiments of the invention mounted on a rotatable shaft 10 of a fluid flow controller. As can be seen, the rotatable shaft 10 can be worked in a clockwise direction or in a counterclockwise direction depending on which side of the housing that is facing it. The first 600 and second 700 inserts should just be inserted accordingly. The features of the second insert may also be built into the first insert 600, but it will be more difficult for the user to see how the guide recess is positioned relative to the rotatable shaft.
References
10 Rotatable shaft
100 Actuator
200 Housing/mounting plate
210 Guide pin
220 Mounting hole
300 Drive shaft
310 Channel
320 Outer face
330 Guide channel
400 Motor unit
500 Gear
600 First insert
610 Channel
620 Outer face
630 Stop plate/rim
700 Second insert
710 Outer face
720 Guide recess
730 Stop