Refrigeration – Gas controller or director
Reexamination Certificate
1999-02-18
2001-03-06
McDermott, Corrine (Department: 3744)
Refrigeration
Gas controller or director
C062S262000, C454S313000, C454S315000
Reexamination Certificate
active
06196018
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an air conditioner, and more particularly, to the structure of a wind-directing-plate driving means attached in a large ceiling-mounted type of an indoor unit which is installed, for example, on the ceiling of a room, and to a wind directing plate which is preferable for a large indoor unit.
2. Description of the Related Art
Air conditioners are broadly divided into three types, that is, wall-mounted, floorstanding, and ceiling-mounted types, according to the ways they are mounted. Of these three types, the ceiling-mounted type of an air conditioner is mainly used in a larger space such as an office, and a store, to be placed on the ceiling. This type of an air conditioner is larger than, for example, a wall-mounted, or floorstanding type in structure, but has an advantage of effectively utilizing the space of a wall and a floor of a room.
Usually, a wind vertically directing plate (hereinafter, referred to as a flap) vertically rotatable around a horizontal axis of rotation, and a wind laterally directing plate (hereinafter, referred to as a louver) laterally rotatable around an axis of rotation almost perpendicular to the horizontal axis of rotation are disposed in an air outlet of an air conditioner. In the case of a ceiling-mounted type of a larger unit, its flap is , for example, 1500 mm in length, and 90 mm in width.
A flap and a louver are respectively driven by different motors, and the ways to drive them are broadly divided into two ways described below. One of them is to use a synchronous motor. With a synchronous motor, greater torque is obtained at a low cost, but there is a disadvantage of requiring a complicated link mechanism and a limit switch in order to control the position where its rotation stops and its rotational direction.
The other way is to use a stepping motor. A stepping motor with a gear reducer being incorporated therein is used for driving a wind directing plate, and usually its reduction gear ratio is about 1/40. A stepping motor allows complicated rotation control or the like without requiring a link mechanism or a limit switch.
However, a stepping motor has small output torque even with the aforementioned reduction gear ratio, therefore it has a disadvantage of insufficient torque for enduring external force when stopped without electric current, that is, insufficient detent torque, when the stepping motor is used for a large-sized flap applied especially to a ceiling-mounted type.
In order to compensate the aforementioned disadvantage, it is necessary to additionally carry out gear reduction outside.
FIG. 17
shows the conventional example of the case in which gear reduction is additionally conducted outside. Based on this drawing, the configuration of a flap driving means will be explained. It should be mentioned that
FIG. 17
is a cross-sectional view when a side plate portion of an air outlet is seen from the top of a housing.
According to the drawing, a flap driving means
1
is attached on a side plate
3
forming a part of an air outlet
2
, and by this flap driving means
1
, a flap
4
in the air outlet
2
is vertically driven rotatively around a horizontal axis of rotation X. Incidentally, the entire body of the flap driving means
1
is covered with a side cover
5
of the housing.
The flap driving means
1
includes a motor base
6
attached on the side plate
3
. The motor base
6
has a first supporting base plate
6
a
in a size blocking an opening, which is for attaching the motor base, and which is formed on the side plate
3
, a second supporting base plate
6
b
made almost vertical from the first supporting base plate
6
a
towards the outside surface of the side plate
3
, specifically, the side cover
5
side, up to a predetermined height, and a third support base plate
6
C bent to be parallel to the aforementioned first supporting base plate
6
a
from the upper end of the second supporting base plate
6
b
, all of which are made of synthetic resin.
The second supporting base plate
6
b
has a motor attaching frame
7
formed to be parallel to the aforementioned first supporting base plate
6
a
, and a stepping motor
8
having a gear reducer incorporated therein is secured to the frame
7
with screws with a driving shaft
8
a
thereof facing the third supporting base plate
6
c
side. A pinion gear
8
b
is secured to the driving shaft
8
a
with screws, and the third supporting base plate
6
c
is provided with a bush
9
a
serving as a bearing for the pinion gear
8
b.
An output gear
10
meshed with the pinion gear
8
b
is provided between the first supporting base plate
6
a
and the third supporting base plate
6
c
of the motor base
6
. An output shaft
10
a
is secured to the output gear
10
with screws. The output shaft
10
a
is located on the horizontal axis of rotation X of the flap
4
, extending through the first supporting base plate
6
a
into the air outlet
2
, and is coupled with the flap
4
.
In this case, in order to keep the axis of the output gear
10
parallel to the axis of the pinion gear
8
b
, the third supporting base plate
6
c
is provided with a bearing bush
9
b
, and the first supporting base plate
6
a
is coaxially provided with a bearing hole
11
for the output shaft
10
a
. Incidentally, an E-ring (retaining ring)
12
is fitted onto the output shaft
10
a
at the position close to the bearing hole
11
in order to prevent rattling in the axial direction.
According to the flap driving means
1
, the output from the stepping motor
8
is further reduced by the output gear
10
, and is transmitted to the flap
4
, thereby obtaining predetermined detent torque. However there are disadvantages described below.
First of all, due to a large number of components required, there is a disadvantage in assembling operability. Specifically, in the prior art, when coupling the pinion gear
8
b
to the driving shaft
8
a
of the stepping motor
8
, and when coupling the output shaft
10
a
to the output gear
10
, they are fastened with screws. Further, the third supporting base plate
6
c
of the motor base
6
needs to be provided with two of the bearing bushes
9
a
and
9
b
for the pinion gear
8
b
and the output gear
10
.
Next, since the stepping motor
8
is held in the motor base
6
, the motor base
6
itself needs to have a large size. Therefore, the flap driving means
1
becomes larger in size, and a larger space for attaching the same must be secured.
Further, the backlash of the inner gear of the stepping motor
8
, the pinion gear
8
b
, and the output gear
10
appears as rattling of the flap
4
. Especially when the flap
4
is rotated and its center of gravity is located above the horizontal axis of rotation X, the center of gravity is deviated according to the angle of the flap
4
, therefore it seems that rattling occurs to the flap
4
.
Meanwhile, in a larger unit like a ceiling-mounted type, its flap
4
needs to have for example, a length of 1500 mm and a width of 90 mm as described in the above. However, in order to obtain such a flap
4
by molding resin, slimmer molding die must be used, therefore it is difficult to secure the rigidity of the die. Accordingly, a larger-sized molding die compared to the molded flap
4
is used, therefore a large-sized injection machine must be used.
A slim cavity in a molding die doesn't allow smooth flow of resin material, thereby easily causing warp, sink, flow mark, weld, or the like. The aforementioned disadvantage is eliminated when using the flap
4
made of metal plate, but moisture condensation easily occurs to the flap
4
due to high thermal conductivity of the metal plate. Therefore, piled cloth or the like is set thereon, but in addition to high cost required, it is difficult to clean it when dust or the like is settled thereon. Further, metal plate is not preferable, since it is heavier than resin and gives an additional load to the motor.
SUMMARY OF THE INVENTION
The present invention is made to eliminate the aforementioned
Kawai Yoshimi
Mori Nobuyuki
Nakamura Osamu
Fujitsu General Limited
Jiang Chen-Wen
Kanesaka & Takeuchi
McDermott Corrine
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