EP0067884B1

EP0067884B1 - A fluid deflecting arrangement

Info

Publication number: EP0067884B1
Application number: EP82900133A
Authority: EP
Inventors: Motoyuki Nawa; Norio Sugawara; Yutaka Takahashi
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1980-12-23
Filing date: 1981-12-21
Publication date: 1986-04-16
Also published as: CA1207725A; AU7937182A; EP0067884A4; WO1982002228A1; EP0067884A1; AU550478B2

Description

This invention relates to control of the direction of flow of a fluid discharged from a cross-flow fan.
There is known a technology of controlling the direction of flow of a fluid discharged from a cross-flow fan, such as the provision of a guide plate at the discharge outlet of the fan as taught by British Patent No. 983,901. However, the range of the control of flow as obtainable by such an arrangement is limited to the region where the guide plate is positioned. That is to say, deflection of a fluid over the entire circumferential direction of the fan cannot be accomplished. Moreover, because the guide plate as a deflecting means is positioned externally of the fan, the entire apparatus cannot be constructed in a compact layout. Japanese Utility Model Laid-Open Patent Kokai Sho 55-161087 discloses an apparatus wherein a guide plate is disposed within a cross-flow fan. However, such guide plate is intended to improve the efficiency of the fan and, moreover, because it is fixed in position, the guide plate does not have a function of controlling the direction of flow.
US-A-3,263,910, proposes a method of controlling the entry and discharge regions and the direction of a jet generated by the rotation of a cross-flow fan by using a guide element arranged inside the fan.
However, since the guide element is arranged at the center axis of the cross-flow fan, the concave area formed by this guide element is so large that the low pressure vortex formed within the concave area is unstable. Moreover, because of the position of the guide element, the width of the outer flow provided by the cross-flow fan is small.
Furthermore, in this case, the guide element is arranged with only one end being secured. With such a construction, the guide element cannot be in a rigid condition. Accordingly, the formed low pressure vortex becomes more unstable.
Accordingly, the present invention provides a fluid deflecting arrangement comprising a fan having a cross-flow impellor and electric motor and a rotational control vane arranged inside said impellor said rotational control vane having a substantially arcuate cross-section with such an included angle as to cause restriction of a low pressure vortex produced by said impellor inside a concave space formed by said control vane and to control the position of said vortex whereby to control the direction of flow through said impellor in response to the rotational position of said control vane, characterised in that the impellor is rotatably mounted at each end thereof by means of shafts and the control vane is displaced from the axis of rotation of the impellor by means of support members.
Features and advantages of the present invention will become apparent from the following description of embodiments thereof given by way of example with reference to the accompanying drawings, in which:

Figure 1 is a perspective view showing a fluid deflecting fan;
Figure 2 is a sectional view along the line A-A' of Figure 1;
Figures 3 and 4 are sectional views taken along the line B-B' of Figure 2, showing the states of flow at the cross-flow fan according to different positions of the control vane;
Figure 5 is a perspective view of the control vane according to this invention; and
Figure 6 is a sectional view showing the flow within the cross-flow fan which is obtainable with the control vane illustrated in Figure 5.

Before describing an embodiment of the invention it is considered helpful to describe a basic form of fan with reference to Figures 1 to 4. The reference numeral 11 indicates a fluid deflecting arrangement, the numeral 12 a cross-flow impellor, and the numeral 13 a motor. The cross-flow impellor 12 has end plates 14A and 14B which are rotatably supported by bearings 17 and 18 at side plates 15 and 16, respectively. The end plate 14B is rigidly secured to a shaft 20 of the motor 13, whereby the cross-flow impellor 12 revolves together with the shaft 20 of motor 13. The motor 13 is rigidly mounted on the side plate 16 by means of a motor support 21. The side plate 15 is secured in position with three posts 22 projecting from the side plate 16. The reference numeral 23 indicates a casing which secures the side plate 16 in position. The casing 23 is provided with a dial 24 for turning the motor 13 on and off and a dial 25 for controlling the number of revolutions thereof. The casing 23 is further provided with an opening 26 for cooling the motor 13 with natural ventilation. Disposed within the cross-flow impellor 12 is a control vane 27. One rotary shaft 28 affixed to this control vane 27 extends through a bore of the end plate 14A and is rotatably supported by a retaining plate 29 fixedly secured to the side plate 15. Another rotary shaft 30 affixed to the other end of the control vane 27 is rotatably supported by a recess 31 formed at the end of shaft 20 of the motor 13. Thus, the two rotary shafts 28 and 30 are capable of revolving about m which is the axis of revolution of shaft 20 of motor 13 and the center of rotation of the cross-flow fan 12. This revolution is effected with a lever 32 affixed to the rotary shaft 28. The lever 32 is so designed that it can be set in a desired position with an engaging means 33 which is secured thereto and engageable with the side plate 15.
The cross-flow fan which is conventionally employed for an air conditioner has a stabilizer and a rear guider, and a low-pressure vortex is generated in the vicinity of the stabilizer. Referring to the cross-flow impeller 12 illustrated in Fig. 3, the addition of said stabilizer and rear guider thereto generates a low-pressure vortex with a radius of r. The control vane 27 disposed within the cross-flow impellor has a substantially arcuate cross-section and its radius R is defined as R>r. The control vane 27 is disposed in such a manner that ends of its arc will be located near an inner circumference 36 of the cross-flow impellor 12 and has an angle 8 such that the low-pressure vortex V will be confined on the inner side of the arc of the control vane 27. Where the radius of the inner circumference 36 of cross-flow fan is defined as r_a, the value of r is approximately 1/2 r_a-r_a.
The operation of the fluid deflecting arrangement will be described below.
Referring to Figs. 1 and 2, as the dial 24 is turned on, the shaft 20 of the motor 13 starts revolving, whereupon the end plate 14B affixed to this shaft 20 is rotated to drive the cross-flow impellor 12. When the control vane 27 is in the position shown in Fig. 3, if the direction of rotation of the cross-flow impellor 12 is clockwise as indicated by the arrow-mark C, the low-pressure vortex V will also have a clockwise direction of flow and the flow on the outside of the control vane 27 is directed substantially in the direction indicated by the arrow-mark X. As aforesaid, the radius R of the control vane 27 is larger than the radius r of the low-pressure vortex in the case of existence of the stabilizer and rear guider for the cross-flow fan and the ends 34, 35 of the arc of control vane 27 are located near the inner circumference 36 of cross-flow impellor 12 with the angle A of the control vane 27 being such that the low-pressure vortex V will be confined within the inner side thereof. Therefore, despite the fact that there is no restricting member other than the control vane 27, such as a guider, the low-pressure vortex V is stabilized on the inner side of the control vane 27 and the external flow X on the other side of the control vane 27 is also stabilized accordingly.
Let it be assumed that the lever 32 is rotated to bring the control vane 27 into the position illustrated in Fig. 4. Then, because of the absence of a restricting member other than the control vane 27, the low-pressure vortex V spins, as it remains confined on the inner side of the control vane 27 and is stabilized in the position indicated in Fig. 4. The flow external of the control vane 27 is as indicated by the arrow-mark Y.
Thus, because the only restricting member for the low-pressure vortex V is the control vane 27, the position of the low-pressure vortex V can be shifted to an optional position on the circumference of the cross-flow impellor 12 by nothing other than the rotation of the control vane 27. Thus, the flow on the outer side of the control vane 27 can be directed in an optional direction on the circumference so that the fluid can be deflected over the entire circumferential range of 360 degrees. Since, in this arrangement, there is no obstruction such as a casing outside of the fan, fluid deflection control can be accomplished in a compact arrangement and there also is the advantage that changing the direction of the vane does not cause changes in the volume of wind, noise or characteristics.
An embodiment of this invention will now be described with reference to Figs. 5 and 6. The reference numeral 37 indicates a control vane, supporting members 38A and 38B thereof being displaced from rotary shafts 39A and 39B by the length /. This control vane 37 is disposed in place of the control vane 27 of Fig. 2 and the rotary shafts 39A and 39B are in place of the rotary shafts 28 and 30, respectively. As in Figs. 1 to 4 the control vane 37 can be rotated and set in a desired position about the axis of rotation of the cross-flow fan by means of a lever 32.
As before, the control vane 37 has a substantially arcuate cross-section and its radius R' is larger than the radius r of the low-pressure vortex of the conventional cross-flow fan equipped with a guider. However, the control vane 37 is so designed that ends of its arc 40A and 40B are located near the inner circumference 36 of the cross-flow impellor 12 has an angle 8' such that the low-pressure vortex V is confined on the inner side of the arc of control vane 37. The operation of this fluid deflecting fan is similar to that described above.
Thus, by rotating the control vane 37, the low-pressure vortex V can be shifted to any optional position on the circumference of the cross-flow impellor 12, whereby the flow Z on the outer side of the control vane 37 can be directed in an optional direction. In this fan, since the support members 38A and 38B of the control vane 37 are displaced from the center of rotation of the cross-flow impellor 12, the width of flow Z on the outer side of the control vane 37 can be increased.
In the above two fluid deflecting arrangements, the control vanes 27 and 37 are rotated manually with use of the lever 32. However, by connecting the rotary shaft 28 of the control vane 27 or the shaft 39A of the vane 37 directly to the shaft of a small-sized motor, the deflection of a fluid over the range of 360 degrees can be automatically accomplished. When the motor is of reversible rotation, the desired air swing action can be accomplished without resort to a complicated linkage mechanism.
It will be apparent from the foregoing description that since the fluid deflecting arrangement according to this invention is such that the low-pressure vortex of the cross-flow fan can be controlled only with a control vane disposed within the fan, deflection control over the range of 360 degrees can be accomplished in a compact arrangement without inducing changes in wind volume, noise and other characteristics.

Claims

A fluid deflecting arrangement comprising a fan (11) having a cross-flow impellor (12), an electric motor (13) and a rotational control vane (37) arranged inside said impellor (12), said rotational control vane (37) having a substantially arcuate cross-section with such an included angle as to cause restriction of a low pressure vortex produced by said impellor (12) inside a concave space formed by said control vane (37) and to control the position of said vortex whereby to control the direction of flow through said impellor (12) in response to the rotational position of said control vane (37), characterised in that the impellor (12) is rotatably mounted at each end thereof by means of shaft (39A and 39B) and the control vane is displaced from the axis of rotation of the impellor (12) by means of support members (38A and 38B).