Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K3/00—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing
  • F16K3/02—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing with flat sealing faces; Packings therefor
  • F16K3/03—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing with flat sealing faces; Packings therefor with a closure member in the form of an iris-diaphragm
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
  • F24F13/08—Air-flow control members, e.g. louvres, grilles, flaps or guide plates
  • F24F13/10—Air-flow control members, e.g. louvres, grilles, flaps or guide plates movable, e.g. dampers
  • F24F13/105—Air-flow control members, e.g. louvres, grilles, flaps or guide plates movable, e.g. dampers composed of diaphragms or segments

Definitions

• the present invention relates to a flow control device for ducts, said control device operating based on the iris-diaphragm principle and includ-ing an annular housing with pivotally rotatable control leaves mounted therein and a rotating control ring adapted to control the position of said control leaves, and said flow control device further having a motor mounted thereon capable of moving said control ring and therethrough, said control leaves.
• the controlled flow may be, e.g., a gaseous fluid such as air.
• a gaseous fluid such as air.
• Different types of control devices can be employed for air flow rate measurement and control.
• a simple control device comprises a rotatable damper placed inside a duct, whereby the rotation of the damper serves to control the cross-sectional flow area of duct and thus the air flow rate through the duct.
• One drawback of this kind of damper is that the air flow rate control also changes the direction of the air flow.
• FI patent publication no. 50,184 discloses a different type of air flow con- troi device known as an iris damper comprising an annular housing formed by two adjacently mounted halves.
• a rotatable con-trol ring and the control leaves of the iris diaphragm are adapted between said halves.
• the control leaves are rotatably mounted by their one ends on pivot pins attached to one half of the annular damper housing.
• the other ends of the control leaves have pegs adapted to slidably move in radially expanding slots made on the control ring.
• the rotation of the control ring forces the iris orifice formed by the shaped control leaves to constrict or open as required.
• the air flow control device is characterized in that
• the accuracy of flow rate control is improved be- cause the prior-art linkage mechanisms can be disposed with. Resulting- ly, mechanical play is reduced and calibration accuracy of flow rate is improved.
• the flow rate adjuster i.e., the control shaft end nut in prior-art constructions
• the retaining friction of the control shaft can be smaller, thus permitting the use of a control motor of lower output rating. Also this feature is one of those imparting the device a longer service life.
• a preferred embodiment of the invention in characterized in that there is mounted a potentiometer on the drive shaft of the gear wheel to the end of sensing the position of the gear wheel.
• the potentiometer serves to provide a realtime indication of the actual control position of the damper.
• control motor, reduction gear, control gear wheel and position-indicating potentiometer are integrated into a compact unit which is adapted into a casing, whereby said unit with its casing can be mounted detachably on the housing of the flow control device.
• the benefit of the integrated actuator construction is a smaller size. Additionally, the serviceability of the device is improved as said integrated actuator motor unit can be readily dismounted from the damper housing and replaced by a new set.
• Figure 1 shows a side view of a flow duct iris damper equipped with a control motor unit according to the invention
• Figure 2 shows a section on lines A-A of Fig. 1;
• Figure 3 shows a top view of the structure of Fig. 1 ;
• Figure 4 shows a top view of the control ring and control leaves of the iris damper.
• Fig. 1 denoted by reference numeral 1 a portion of a flow duct, particularly an air flow duct.
• the duct is provided with an iris-diaphragm type flow control device, whose housing is denoted by reference numeral 8 in the diagram.
• the internal con-struc-tion of the flow control device may be, e.g., similar to the iris damper dis-closed in FI Pat. No. 50,184 with the exception of the damper control technique employed herein.
• the iris damper according to the in-ven-tion is namely equipped with a control motor unit 2 comprising a motor 3, reduc-tion gear 4, a gear wheel 5 and a position-indicating poten-tiometer 6.
• the control motor unit 2 is detachably mounted on the iris damper housing 8 as shown in the sectional view of Fig. 2 taken on lines A-A and is ex-ter-nally protected by a casing 7. A more detailed illustration of the control motor unit is also shown in Fig. 2.
• the outer perimeter of the iris damper housing 8 is provided with an opening at the gear wheel 5 thus per-mitting the gear wheel teeth to mesh with toothing 10 made on the outer pehm-eter of the iris damper control ring 9 (cf. Fig. 4).
• the gear wheel 5 is located chiefly outside the damper housing as can be seen from Fig. 2.
• the flow rate control by means of the iris damper is implemented according to the invention so that the output shaft of the motor 3 rotates via the output shaft 11 of the reduction gear 4 the meshing gear wheel 5 that in turn rotates the control ring 9.
• the control leaves 12 of the iris damper are moved in a conventional manner so as to increase or constrict the orifice 13 of the iris damper, depending on the direction of rotation of the control ring.
• the potentiometer mounted on the shaft of the gear wheel (which may be the output shaft of the reduction gear, as well), indicates the actual posi- tion of the iris damper control ring thus facilitating an extremely accurate control of the damper orifice.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Electrically Driven Valve-Operating Means (AREA)
• Air-Flow Control Members (AREA)
• Flow Control (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8551249

Family Applications (1)

Country Status (6)

Cited By (13)

Citations (3)

• 1998
  • 1998-03-13 FI FI980564A patent/FI980564A/fi unknown
• 1999
  • 1999-03-02 WO PCT/FI1999/000160 patent/WO1999047839A1/en active Application Filing
  • 1999-03-02 AU AU26274/99A patent/AU2627499A/en not_active Abandoned
• 2000
  • 2000-08-03 SE SE0002817A patent/SE520548C2/sv not_active IP Right Cessation
  • 2000-09-01 DK DK200001299A patent/DK174380B1/da not_active IP Right Cessation
  • 2000-09-07 NO NO20004462A patent/NO319828B1/no not_active IP Right Cessation

Patent Citations (3)

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