FR2569245A1 - CENTRIFUGAL FAN WITH ADJUSTABLE CAPABILITY, SET OF ADJUSTMENT FINS FOR SUCH FAN AND SERIES OF SUCH ASSEMBLIES - Google Patents

Abstract

THE INVENTION RELATES TO A CENTRIFUGAL FAN. IT INCLUDES AN AIR INLET 3, A WHEEL 5 WHICH TURNS IN THE BOX 1 AND AN AIR OUTLET (NOT SHOWN). ACCORDING TO THE INVENTION, A SET OF FIXED FINS 9 IS MOUNTED ON THE INPUT CONE 2, THE FINS BEING FIXED WITH RESPECT TO A SUPPORT RING 10. THE VENTILATION CAPACITY CAN THEREFORE BE CHANGED BY USING A SET OF '9 FINS WITH DIFFERENT INCLINATION AND OR DIMENSION. APPLICATION TO THE MANUFACTURING OF CENTRIFUGAL FANS.

Description

69245

  The present invention relates to a central fan

  trifuge with adjustable capacity, as well as a set of fins

  for a fan and a series of assemblies.

  More specifically, it concerns a central fan

  trifuge comprising a chassis housing having an air inlet and an air outlet, a wheel which can rotate in the stacker and which is driven directly by a motor, and a device supported by the housing and intended to regulate the ventilation capacity of the engine. fan, this device comprising a number of fins protruding at the air inlet. The invention is essentially intended for small direct drive fans, working at low pressure and with a constant capacity, for example in

  air conditioning installations.

  The operating characteristics of a Venti-

  centrifugal mass, for example the volumetric flow rate

  Fan pressure, referred to as "ventilation capacity" in the remainder of this specification, depends on the speed of rotation of the wheel. When it is directly mounted

  on the axis of a drive motor, the ventilation capacity

  lation is thus determined by the rotational speed of the

  engine. Where another deventilation capability is desirable

  table, with the same fan, using a

  directly by a motor, the latter must be replaced by another motor whose rotation speed corresponds

  to the new desired ventilation capacity.

  It has been suggested to drive the fan wheel by a belt drive so that the manufacturer can avoid storing a large number of different engines. The rotational speed of the fan wheel can then

  to be modified so that it corresponds to the ability to

  buyer's request, in each particular case, by changing the pulleys of the belt without having to change the engine. The fan can therefore have different ventilation capacities, although the engine used always has the same size. When such a fan has

  a belt drive is only used with a

  constant quotient, the belt drive represents, however,

  at an additional cost since it is not

  to change the transmission ratio after the initial fundamental adjustment. The fact is that the transmission requires its own shaft and bearings for the wheel, belts, pulleys, a protective cover, a separate base for the engine support and

power on.

  Fans in which the ventilation capacity

  must be continuously adjustable have a device

  particular for adjusting fins having a certain number of

  a plurality of vanes mounted to form a circle of vanes at the fan air inlet, and a set or set of adjustment levers connected to the vanes and allowing the angular position of the vanes to be adjusted in the air inlet so that the ventilation capacity is changed. This requires flanging of the fins in the inlet or intake cone of the fan. When such a fan having a fin adjustment device is used only at a constant capacity, the adjustment device is a considerable additional cost, since the setting should not be changed when the adjustment

initial has been made.

  The invention relates to a centrifugal fan which does not have the aforementioned drawbacks and makes it possible to adjust a direct drive fan designed to work with a constant capacity, in a simple manner, for the desired ventilation capacity in each particular case, without changing the rotation speed of the fan. This characteristic is obtained by means of a fan according to the invention in which the adjusting device comprises a fixed and removable set of fins, fins being permanently placed with respect to the air inlet and having dimensions and angular position

  corresponding to a certain constant ability to ventilate

  tion. The invention is based on the fact that, during or after assembly, the fan is provided with a special set of adjustment vanes which are fixed (that is, non-pivoting) and which are placed at the air inlet of the fan with an angular position which exactly matches

  to the ventilation capacity for which the ventilation

  The light is supplied. The manufacture and assembly of such a set of adjustment fins are very simple. Matching sets or sets of control fins can be manufactured for different ventilation capabilities, so that the range of use of a direct drive fan

  can be significantly enlarged without

  pleated belt or fin adjustment device

are necessary.

  Thus, the invention also relates to such a set of control fins for a fan, and a series of control fins corresponding to various ventilation capabilities. The fin assembly has fins formed of separate elements, the fin adjusting portion being rigidly positioned relative to a portion for attachment to the fan casing, the blade adjusting portion having dimensions and an angular position corresponding to a certain ventilation capacity. A series of fins has fin assemblies of the type

  mentioned above, corresponding to different ventilation capacities

  each set being of the aforementioned type. The fins of an assembly according to the invention can be made simply of a metal sheet or sheet, folded

  with the desired angular position. The selection of

  and angular positions of these fins for obtaining a particular ventilation capacity

  with a particular fan is well known.

  Other features and advantages of the invention

  will be better understood by reading the following description

  Embodiments 1 and 2 are respectively an axial section and an axial elevation of an advantageous embodiment of a centrifugal fan according to the invention; FIG. 3 is an axial section of another mode of

  embodiment of the inlet cone of a fan according to the invention

  tion; Figures 4 and 5 show a third embodiment of the fan according to the invention, in axial section and in axial elevation respectively; and Figure 6 is a perspective of a series of fins

  adjusting members forming sets of control fins.

  The fan shown in Figures 1 and 2 comprises a housing 1 having an air inlet 3 delimited by a cone 2 inlet or intake and an air outlet 4, with a wheel 5 mounted in the casing and fixed to a shaft 7 of an electric motor 6 carried by the housing. An assembly 8 of control fins according to the invention is fixed to the cone

  fan inlet. This set includes four

  9 cut in a metal sheet and a support ring 10 to which the fins are fixed at regular distance around the axis of the support ring. Each

  fin has a folded adjustment portion 9a with an inclination

  particular, with respect to a fin attachment portion 9b, so that when the set of vanes has been attached to the fan inlet cone, the vanes change the operating characteristics of the fan to correspond to the ventilation capacity that must

have the fan.

  The set of control fins is preferably attached to the inlet cone when mounting the fan. Being

  given the rigid fixing of the fins, the parts

  keep their angular position firmly in relation to the fan inlet cone. The position of the fins should not normally be changed, and the fan is

  normally used with a constant capacity, permanently

vance.

  The operating characteristics of the fan

  can be modified by the angular position of

  the fin adjustment part. When a same fan

  must be provided for another blowing capacity, the set of control fins consists of fins having

  control parts having another angular position

  corresponding to this other ventilation capacity.

  It should be noted that a centrifugal fan with

  Direct operation can be set to be used at a particular constant capacity using simple shaped fins

  of a metal sheet and fixed rigidly. The construction

  a set of control fins is thus very simple

and inexpensive.

  The ventilator embodiment shown in FIG. 4 differs from the preceding one only because the

  support of the fin assembly 18 is removed and the

  19 are directly attached to the wall of the input cone, with a shape corresponding to that of the previous embodiment. In the embodiment of the fan shown in FIGS. 4 and 5, the fins 29 of the assembly 28 form a plate-like adjustment part 29a, and an attachment pin 29b which is integral with it, allowing the fins to be fixed. on a support ring 20, in the desired angular position in each particular case by

  relative to the axis of the support ring, the axes being

  rigidly on the support ring after adjustment.

  The support ring is fixed in front of the entry cone.

  Figure 6 shows a series of sets of

  control units for a centrifugal fan, this series comprising 8 ', 8 ", 8"' fin assemblies

  9 ', 9 ", 9"' having dimensions and / or angular positions

  different sets, the sets being intended to give different ventilation capabilities to a fan of a particular type. Each set of fins thus comprises several similar fins. A fan manufacturer must keep such simple fins formed of sheet metal

  metal, from which he chooses a suitable set of

  setting fins allowing the ventilation capacity

  wanted by the buyer in each particular case.

  Of course, various modifications can be

  provided by those skilled in the art to fans, games of

  series and series of sets of fins which have just been described as non-limiting examples without

depart from the scope of the invention.

Claims (10)

  1. Centrifugal fan comprising: - a casing (1) forming a chassis having an air inlet (3) and an air outlet (4), - a wheel (5) can journal in the housing and driven directly by a motor (6), and - a device carried by the housing and intended for   adjust the ventilation capacity of the ventilation   the device comprising a number of fins (9; 19; 29) protruding into the air inlet,   characterized in that the adjuster   carries a set (8; 18; 28) of fixed but   vices, the fins (9; 19; 29) having a fixed position with respect to the air inlet (3) and having dimensions and   an angular position corresponding to a particular capacity   constant fan ventilation.   2. Fan according to claim 1, characterized in that the set (18) of adjusting fins comprises a number of separate fins (19) in the form of a plate, fixed separately and permanently to the inlet cone ( 2) around of the axis of the air inlet (3).   Fan according to Claim 1, characterized   in that the assembly (8; 28) of the adjusting vanes   takes a number of separate plate-shaped fins (9; 29) permanently attached to a common support ring (10; 20) around the axis of the support ring;   this being fixed to the entry cone (2) permanently.   4. Fan according to one of claims 2 and 3,   characterized in that the fins (9; 19; 29) are   elements cut from a metal sheet.   5. Set of adjustment vanes for ventilation   centrifugal device, said assembly (8; 18; 28) comprising fins (9; 19; 29) intended to be fixed to a housing (1) of the fan, the fins forming parts   adjusting member (9a; 29a) protruding at the air inlet (3) of the   characterized in that the fins (9; 19; 29) are formed of separate elements, the adjusting portion (9a; 29a) of the fin being rigidly disposed with respect to a fixing portion (9b; 29b) intended to be permanently fixed to the housing (1) of the fan, the setting position of the fin having dimensions and an angular position corresponding to a certain ventilation capacity fan.   6. Set of control fins for a fan   centrifugal device, this series comprising fins (9) intended to be fixed to a housing (1) of the fan, the fins forming adjustment portions protruding at the air inlet (3) of the fan, characterized in that the series includes sets (8 ', 8 ", 8"') of control fins   corresponding to different ventilation capacities of the   tilator, each assembly comprising fins (9 ', 9 ", 9"'), formed of separate elements, and the adjusting portion (9a) of the fin is rigidly disposed with respect to a fixing portion (9b) intended to be permanently attached to   fan housing, the dimensions and the position of the   of the fin adjustment parts of the different   corresponding to different fan capacities fan.   7. Set of vanes according to claim 5,   characterized in that the fins (9; 19; 29) of the   (8; 18; 28; 38 ') have the plate shape, and the adjustment portion (9a) of each fin is folded so that it has a fixed angular position relative to the   fixing part (9b) of the fin.   8. set of fins according to claim 7, characterized in that the fins (9; 29) of the set (8; 28) are permanently fixed to a common support ring, and are   spaced around the axis of the support ring.   9. Set of fins according to one of the claims   7 and 8, characterized in that the fins (9; 19; 29) are   elements cut from a metal sheet.   10. Series of vanes according to claim 6, characterized   characterized in that the fin assemblies are made   according to any one of claims 7 to 9.