Turbo fan and ceiling type air conditioner using thereof

Abstract

A turbo fan includes a main plate rotated by power provided from a fan motor, blades each having one end connected to the main plate to perform rotation movement, and a shroud having an inner circumferential part and an outer circumferential part, an other end of each of the blades connected to the shroud. The shroud includes a plurality of curved parts each having one side connected to the inner circumferential part and an other side connected to the outer circumferential part, the plurality of curved parts each having a predetermined curvature.

What is claimed is: 
     
         1 . A turbo fan comprising:
 a main plate rotated by power provided from a fan motor;   a plurality of blades, each blade having one end connected to the main plate to perform rotation movement; and   a shroud having an inner circumferential part and an outer circumferential part, an other end of each of the blades connected to the shroud,   wherein the shroud comprises:   a plurality of curved parts, each curved part having one side connected to the inner circumferential part and an other side connected to the outer circumferential part, the plurality of curved parts each having a predetermined curvature.   
     
     
         2 . The turbo fan according to  claim 1 , wherein at least one of the plurality of curved parts comprises a mountain part spaced away from the main plate. 
     
     
         3 . The turbo fan according to  claim 2 , wherein the plurality of curved parts comprise a first curved part and a second curved part disposed adjacent to the first curved part,
 a valley part disposed on a boundary surface between the first curved part and the second curved part, the valley part being disposed spaced closer to the main plate than the mountain part; and   an inclined part connecting the mountain part to the valley part, the inclined part having the predetermined curvature.   
     
     
         4 . The turbo fan according to  claim 3 , wherein each of the plurality of curved parts comprises the mountain part, and the mountain part and the valley part are alternately disposed with respect to each other along a circumferential direction of the shroud. 
     
     
         5 . The turbo fan according to  claim 2 , further comprising:
 a rotation shaft providing a rotation center of the main plate, and   a central line that is a virtual line defined when the rotation shaft and the virtual line extending through mountain part extend in parallel, wherein a distance between the mountain part and the inner circumferential part is greater than a distance between the mountain part and the outer circumferential part with respect to the central line.   
     
     
         6 . The turbo fan according to  claim 2 , wherein an angle of a slope of a surface connecting the mountain part to the inner circumferential part is less than a slope of a surface connecting the mountain part to the outer circumferential part. 
     
     
         7 . The turbo fan according to  claim 1 , wherein a first contact is a point at which the outer circumferential part and a blade meet, and a second contact is a point at which the outer circumferential part and an adjacent blade meet, the extension part defined as a virtual line connecting the first contact point and the second contact point. and a protrusion is a point at the outer circumferential part disposed spaced furthest away from the main plate,
 wherein when a distance between the protrusion and the extension part is a, and a distance between the extension part and the main plate is b, a value a/b is set according to a predetermined ratio.   
     
     
         8 . The turbo fan according to  claim 7 , wherein when a length of the extension part is c, a value of a/c is set according to a predetermined ratio. 
     
     
         9 . The turbo fan according to  claim 7 , further comprising an exhaust part disposed between the plurality of blades to provide a moving path of the air,
 wherein the exhaust part comprises:   a first exhaust part disposed at an upper side of the extension part; and   a second exhaust part communicating with the first exhaust part, the second exhaust part disposed at a lower side of the extension part.   
     
     
         10 . The turbo fan according to  claim 9 , wherein at least one of the first and second exhaust parts is defined as a space in which the outer circumferential part and the extension part are disposed. 
     
     
         11 . The turbo fan according to  claim 3 , wherein the valley part has a length greater than a length of a surface at which the blade meets the shroud. 
     
     
         12 . The turbo fan according to  claim 3 , wherein the valley part has a curvature radius greater than a curvature radius of a surface at which the blade meets the shroud. 
     
     
         13 . A ceiling type air conditioner comprising:
 a case defining an outer appearance, the case having a suction hole;   a fan motor disposed within the case;   a turbo fan disposed within the case to change a moving direction of air passing through the suction hole; and   a heat exchanger disposed outside the turbo fan,   wherein the turbo fan comprising:   a main plate rotated by power provided from the fan motor;   a plurality of blades, each blade having one end connected to the main plate to perform rotation movement; and   a shroud having an inner circumferential part and an outer circumferential part, an other end of each of the blades connected to the shroud,   wherein the shroud comprises:   a plurality of curved parts, each curved part having one side connected to the inner circumferential part and an other side connected to the outer circumferential part, the plurality of curved parts each having a predetermined curvature.   
     
     
         14 . The ceiling type air conditioner according to  claim 13 , wherein at least one of the plurality of curved parts comprises a mountain part spaced away from the main plate. 
     
     
         15 . The ceiling type air conditioner according to  claim 14 , wherein the plurality of curved parts comprise a first curved part and a second curved part disposed adjacent to the first curved part,
 a valley part disposed on a boundary surface between the first curved part and the second curved part, the valley part being disposed spaced closer to the main plate than the mountain part; and   an inclined part connecting the mountain part to the valley part, the inclined part having the predetermined curvature.   
     
     
         16 . The ceiling type air conditioner according to  claim 13 , wherein a first contact is a point at which the outer circumferential part and a blade meet, and a second contact is a point at which the outer circumferential part and an adjacent blade meet, the extension part defined as a virtual line connecting the first contact point and the second contact point. and a protrusion is a point at the outer circumferential part disposed spaced furthest away from the main plate,
 wherein when a distance between the protrusion and the extension part is a, and a distance between the extension part and the main plate is b, a value a/b is set according to a predetermined ratio.   
     
     
         17 . The ceiling type air conditioner according to  claim 16 , further comprising an exhaust part disposed between the plurality of blades to provide a moving path of the air,
 wherein the exhaust part comprises:   a first exhaust part disposed at an upper side of the extension part; and   a second exhaust part communicating with the first exhaust part, the second exhaust part disposed at a lower side of the extension part.   
     
     
         18 . The ceiling type air conditioner according to  claim 14 , further comprising:
 a rotation shaft providing a rotation center of the main plate, and   a central line that is a virtual line defined when the rotation shaft and the virtual line extending through mountain part extend in parallel, wherein a distance between the mountain part and the inner circumferential part is greater than a distance between the mountain part and the outer circumferential part with respect to the central line.