Field of the Invention
[01] The present invention relates to a blower unit of an air conditioner for a vehicle, and more particularly, to a blower unit of an air conditioner for a vehicle, which can forcedly transfer indoor air or outdoor air into an air-conditioning case of the vehicle.
Background Art
[02] In general, an air conditioner for a vehicle is a device for heating or cooling the interior of the vehicle by introducing outdoor air to the interior of the vehicle or circulating indoor air to heat or cool. The air conditioner for a vehicle includes a blower unit for blowing indoor air or outdoor air into an air-conditioning case, an evaporator disposed inside the air-conditioning case for a cooling action, and a heater core for a heating action. Air cooled or heated by the evaporator or the heater core is selectively blown to each part of the interior of the vehicle.
[03] FIG. 1 is a sectional view showing a conventional blower unit of an air conditioner for a vehicle. As shown in FIG. 1, a blower unit (20) includes a blower case 22, an indoor and

outdoor air door 25, and a blower wheel 26. An indoor air inlet 24 and an outdoor air inlet 23 are formed at an upper portion of the blower case 22, and the indoor and outdoor air door 25 selectively opens and closes the indoor air inlet 24 and the outdoor air inlet 23. The blower wheel 26 blows the introduced indoor air or outdoor air toward an air-conditioning case.
[04] FIG. 2 illustrates a driving part for actuating a conventional indoor and outdoor air door of a manual operation type. Referring to FIG. 2, the indoor and outdoor air door 25 is a means for converting inflow of the indoor air and the outdoor air, and is a rotary type door of a dome shape. Moreover, the indoor and outdoor air door 25 controls operation by manual operation.
[05] An arm 31 is connected to a rotary shaft of the indoor and outdoor air door 25, and is slidably connected to a slot 33 formed in a lever 32 through a pin. One side of the lever 32 is connected to a controller mounted on a vehicle panel through a cable 34, and the lever 32 rotates on the rotary shaft while the cable 34 is pushed and pulled according to operation of the controller. When the lever 32 is rotated, the arm 31 slides along the slot 33 so that the indoor and outdoor air door 25 is rotated on the rotary shaft.
[06] When the indoor and outdoor air door 25 rotates in the clockwise direction to the maximum, an indoor air mode to close

the outdoor air inlet 23 and introduce the indoor air is carried out. When the indoor and outdoor air door 25 rotates in the counterclockwise direction to the maximum, an outdoor air mode to close the indoor air inlet 24 and introduce the outdoor air is carried out.
[07] Conventional indoor and outdoor air doors 25 of the manual operation type and a rotary type are heavier than doors of a flat type and may cause free fall by self-weight of the door. Furthermore, a lever structure of a slot type is difficult to control with uniform power at the moment of conversion of the indoor and outdoor air modes. Additionally, the indoor and outdoor air door 25 may cause a noise with a thud when touching a case sealing surface at the points, “A”, “B”, and “C”.
[08] In addition, the conventional indoor and outdoor air door 25 is deteriorated in durability and may cause malfunction since dust or foreign matters permeate into a door driving shaft or a power transfer means when the vehicle travels in dusty areas.
[09] In the meantime, in case that the conventional blower unit of an air conditioner for a vehicle has a cover for preventing inflow of foreign matters from the outside, the blower unit has a disadvantage in that the number of working processes and expenses are increased due to application of the cover.
[10] Moreover, because the conventional air conditioner for a vehicle has the power transfer means (an arm, a lever, a cam,

and so on) disposed outside the air-conditioning case, if foreign matters are induced, the foreign matters are inserted into the driving part of the power transfer means, and it causes malfunction and deterioration in durability. In order to solve the problems, if a cover for covering the outside of the power transfer means is attached, the air conditioner has several problems in that it may cause misassembly since it is impossible to check an assembled state with naked eyes when the power transfer means is assembled, and in that it is difficult to discriminate misassembly since the power transfer means may operate in some sections even though the power transfer means has been misassembled.
SUMMARY OF THE INVENTION
[11] Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior arts, and it is an object of the present invention to provide a blower unit of an air conditioner for a vehicle with an improved door operation structure, which can solve a noise problem since controlling a door with uniform power and prevent inflow of dust and foreign matters.
[12] Moreover, it is another object of the present invention to provide a blower unit of an air conditioner for a vehicle, which can show a stable door operation and improve

durability since effectively preventing inflow of foreign matters without increase of the number of working processes and manufacturing costs.
[13] Furthermore, it is a further object of the present invention to provide a blower unit of an air conditioner for a vehicle, which can effectively prevent misassembly even if a foreign matter inflow preventing means is formed and easily detect misassembly even though there is misassembly.
[14] To accomplish the above object, according to the present invention, there is provided a blower unit of an air conditioner for a vehicle including: a case having an indoor air inlet for introducing indoor air and an outdoor air inlet for introducing outdoor air; and an indoor and outdoor air door disposed on the case to selectively open and close the indoor air inlet and the outdoor air inlet, wherein the indoor and outdoor air door is a rotary type door of a dome shape, and a power transfer means for connecting a power source and a rotary shaft of the indoor and outdoor air door with each other has a gear structure.
[15] According to the present invention, the blower unit of an air conditioner for a vehicle can control the indoor and outdoor air door with uniform power, and reduce noise since the indoor and outdoor air door does not do free fall by self-weight of the indoor and outdoor air door. Moreover, the blower unit of

an air conditioner for a vehicle can reduce the noise generated by collision against the case of the door at a contact surface between the indoor and outdoor air door and the case through the rotation action of the gear structure.
[16] Furthermore, the blower unit of an air conditioner for a vehicle can prevent deterioration in workability due to penetration of foreign matters between gears and enhance durability since preventing inflow of foreign matters when the vehicle travels under dusty environment. Additionally, the blower unit of an air conditioner for a vehicle can effectively prevent inflow of foreign matters from the outside without increase of the number of working processes and manufacturing costs, thereby providing stable operation of the door and enhancing durability.
[17] Additionally, the blower unit of an air conditioner for a vehicle can effectively prevent misassembly even if a foreign matter inflow preventing means is formed, easily detect misassembly even if the door is misassembled, and can detect misassembly regardless of the rotation direction of the gear part when there is misassembly.
BRIEF DESCRIPTION OF THE DRAWINGS [18] The above and other objects, features and advantages of the present invention will be apparent from the following

detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings, in which:
[19] FIG. 1 is a sectional view of a conventional blower unit of an air conditioner for a vehicle;
[20] FIG. 2 is a view of a driving part for driving a conventional indoor and outdoor air door of a manual operation type;
[21] FIG. 3 is a sectional view of a blower unit of an air conditioner for a vehicle according to a first preferred embodiment of the present invention;
[22] FIG. 4 is a view of a driving part for driving an indoor and outdoor air door of a manual operation type according to the first preferred embodiment of the present invention;
[23] FIG. 5 is an exploded perspective view of the indoor and outdoor air door and a power transfer means according to the first preferred embodiment of the present invention;
[24] FIG. 6 is a rear perspective view showing a lever and an arm according to the first preferred embodiment of the present invention;
[25] FIG. 7 is a sectional view of FIG. 6;
[26] FIG. 8 is a perspective view showing a state where a lever and an arm according to a second preferred embodiment of the present invention are separated;

[27] FIG. 9 is a perspective view showing a state where a lever and an arm according to a second preferred embodiment of the present invention are combined;
[28] FIG. 10 is a sectional view showing a state where a lever and an arm according to a second preferred embodiment of the present invention are separated;
[29] FIG. 11 is a perspective view showing a part of a blower unit of an air conditioner for a vehicle according to a third preferred embodiment of the present invention;
[30] FIG. 12 is a perspective view showing a state where a lever is assembled in FIG. 11;
[31] FIG. 13 is a perspective view showing the lever and an arm according to the third preferred embodiment of the present invention;
[32] FIG. 14 is a partially enlarged perspective view of FIG. 13;
[33] FIG. 15 is a side view of the lever according to the third preferred embodiment of the present invention;
[34] FIG. 16 is a side view of the arm according to the third preferred embodiment of the present invention;
[35] FIG. 17 is a view showing a misassembled state of the arm and lever according to the third preferred embodiment of the present invention; and

[36] FIG. 18 is a view showing a correctly assembled state of the arm and the lever according to the third preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [37] Hereinafter, with reference to the attached drawings, technical structure and configuration of an air conditioner for a vehicle according to a preferred embodiment of the present invention will be described in detail.
[38] FIG. 3 is a sectional view of a blower unit of an air conditioner for a vehicle according to a first preferred embodiment of the present invention, FIG. 4 is a view of a driving part for driving an indoor and outdoor air door of a manual operation type according to the first preferred embodiment of the present invention, FIG. 5 is an exploded perspective view of the indoor and outdoor air door and a power transfer means according to the first preferred embodiment of the present invention, FIG. 6 is a rear perspective view showing a lever and an arm according to the first preferred embodiment of the present invention, and FIG. 7 is a sectional view of FIG. 6.
[39] As illustrated in FIGS. 3 to 7, the blower unit 100 of an air conditioner for a vehicle according to a preferred embodiment of the present invention includes a case 110, an

indoor and outdoor air door 125, a blower motor 127, and a blower wheel 126.
[40] At an upper portion of the case 110, formed are an indoor air inlet 111 for introducing indoor air and an outdoor air inlet 112 for introducing outdoor air. The indoor and outdoor air door 125 is disposed on the case 110 to selectively open and close the indoor air inlet 111 and the outdoor air inlet 112. The blower wheel 26 blows introduced indoor air or outdoor air toward an air-conditioning case.
[41] The blower wheel 126 is combined with a rotary shaft of the blower motor 127 to be rotated, and blows indoor air or outdoor air into the air-conditioning case located in the interior of the vehicle. An air filter 130 is disposed above the blower wheel 126 in order to filter foreign matters of the air passing through the air filter 130.
[42] The indoor and outdoor air door 125 is a means for converting inflow of indoor air and outdoor air, and is a rotary type door of a dome shape. Moreover, an indoor and outdoor air door operation mechanism of the blower unit 100 is actuated by a manual operation type connected to a controller mounted on a vehicle panel through a cable 134.
[43] The blower unit 100 according to the preferred embodiment of the present invention has a power transfer means of a gear structure. The power transfer means connects a power

source for rotating the indoor and outdoor air door 125 with a rotary shaft of the indoor and outdoor air door 125.
[44] That is, the blower unit 100 includes a lever 140 and an arm 150. One side of the lever 140 is connected to the power source so that the lever 140 is rotated on a rotary shaft 146. The arm 150 is connected to the lever 140 to rotate, and is connected to the rotary shaft 128 of the indoor and outdoor air door 125. The lever 140 and the arm 150 are connected with each other through a gear structure.
[45] As described above, due to the lever 140 and the arm 150 of the gear structure, it can control the indoor and outdoor air door 125 with uniform power, and reduce noise since there is no free fall by self-weight of the indoor and outdoor air door 125. Furthermore, the indoor and outdoor air door 125 of the gear structure can remarkably reduce the noise generated by collision against the case of the door at a contact surface between the indoor and outdoor air door 125 and the case 110.
[46] In more detail, a first gear part 143 is formed on the outer circumferential surface of the rotary shaft 146 of the lever 140, and a second gear part 153 geared with the first gear part 143 is formed on the outer circumferential surface of the arm 150.
[47] The lever 140 includes a flat plate part 144 and a cover part 145. The flat plate part 144 has a flat plate shape,

and faces the side of the case 110 in a longitudinal direction of the rotary shaft. The cover part 145 is formed along an edge of the flat plate part 144, and extends toward the case 110. The arm 150 is received in the flat plate part 144 and the cover part 145.
[48] The cover part 145 in the longitudinal direction of the rotary shaft is extended longer than thickness of the arm 150 to completely cover the arm 150. The rotary shaft 146 of the lever 140 has a boss protruding toward the case 110, and is rotatably connected to a rotary shaft part 141 formed on the case 110. A through hole 147 to which the rotary shaft part 141 of the case 110 is inserted is formed in the rotary shaft 146. The first gear part 143 is formed on the outer circumferential surface of the rotary shaft 146. The cover part 145 is formed integrally with the flat plate part 144.
[49] The flat plate part 144 of the lever 140 has a flat plate shape having a predetermined thickness, and is opposite to the side of the case 110 to be spaced apart from the side of the case 110 at a predetermined interval. A cover part 145 of a side wall shape is protrudingly formed along the edge on one side facing the case 110. Therefore, the lever 140 has an approximately hexahedral shape of which one side (facing the case) is open. In this instance, since the flat plate part 144 may not be a rectangular shape, the lever 140 may be an

octahedral shape or other polygonal shape or a streamlined cylindrical shape as well as the hexahedral shape.
[50] The rotary shaft 146 of the boss shape is protrudingly formed on one side of the flat plate part 144, and the rotary shaft part 141 is rotatably inserted and combined into the through hole 147 formed in the rotary shaft 146. The lever 140 is rotated relative to the case 110 because the rotary shaft 146 is rotated on the rotary shaft part 141, and the cable 134 is connected to one side 142 of the lever 140. The lever 140 has one side connected to the controller mounted on the vehicle panel through the cable 134, and the lever 32 rotates on the rotary shaft part 141 since the cable 134 is pushed and pulled by operation of the controller.
[51] The first gear part 143 is formed on the rotary shaft 146. The arm 150 is arranged adjacent to the rotary shaft 146 in parallel, and the rotary shaft 146 of the lever 140 and the rotary shaft of the arm 150 are spaced apart from each other at a predetermined interval. The second gear part 153 is formed on the outer circumferential surface of the arm 150 to be geared with the first gear part 143.
[52] A joining part 155 to be joined with the rotary shaft 128 of the door 125 is formed on the rotary shaft of the arm 150. The joining part 155 provides stable joining power and also provides the merits of the above mentioned gear structure, namely,

door control with uniform power and noise reduction effect) since having the gear structure.
[53] When the lever 140 rotates, the arm 150 rotates by receiving driving power by the first and second gear parts 143 and 153, and rotates the indoor and outdoor air door 125 on the rotary shaft 128. When the indoor and outdoor air door 125 rotates in the clockwise direction to the maximum, the outdoor air inlet 112 is closed and the indoor air mode to introduce indoor air is carried out. When the indoor and outdoor air door 125 rotates in the counterclockwise direction to the maximum, the indoor air inlet 111 is closed and the outdoor air mode to introduce outdoor air is carried out.
[54] When a vehicle travels under dusty environment in India or Southeast Asia, installation structure of the cover part 145 of the lever 140 and the arm 150 can prevent deterioration in workability due to penetration of foreign matters between gears and enhance durability since preventing inflow of foreign matters.
[55] FIG. 8 is a perspective view showing a state where a lever and an arm according to a second preferred embodiment of the present invention are separated, FIG. 9 is a perspective view showing a state where a lever and an arm according to a second preferred embodiment of the present invention are combined, and

arm according to a second preferred embodiment of the present invention are separated.
[56] Hereinafter, just different contents from the first preferred embodiment will be described in detail.
[57] Referring to FIGS. 8 to 10, the blower unit of an air conditioner for a vehicle according to the second preferred embodiment includes a case 110, an indoor and outdoor air door, a blower motor, and a blower wheel. The blower unit has a power transfer means of a gear structure. The power transfer means connects a power source for rotating the indoor and outdoor air door with a rotary shaft of the indoor and outdoor air door.
[58] The blower unit has a lever 140 and an arm 150. The lever 140 has one side 142 connected to the power source to rotate on a rotary shaft 146. The arm 150 is connected to the lever 140 to rotate, and is connected to a rotary shaft 128 of the door 125. The lever 140 and the arm 150 are connected with each other through the gear structure.
[59] A first gear part 143 is formed on the outer circumferential surface of the rotary shaft 146 of the lever 140, and a second gear part 153 geared with the first gear part 143 is formed on the outer circumferential surface of the arm 150. The rotary shaft 146 of the lever 140 has a boss shape protruding toward the case 110, and is rotatably connected to a rotary shaft part 141 formed on the case 110. The rotary shaft 146 has a

through hole 147 formed to insert the rotary shaft part 141 of the case 110 thereinto. A joining part 155 of a gear structure for joining with the rotary shaft 128 of the door 125 is formed on the rotary shaft of the arm 150.
[60] The blower unit of an air conditioner for a vehicle according to another embodiment of the present invention includes a cover wall 119 and a cover lid 149.
[61] The cover wall 119 protrudingly extends from the case 110 and surrounds the lever 140 and the arm 150. The cover wall 119 extends integrally in an axial direction from the case 110. The cover wall 119 forms a fence in the form of a circle, an oval or other closed curve line along the rim of the arm 150 and the lever 140 to perfectly cover the sides of the arm 150 and the lever 140.
[62] The cover lid 149 is disposed on the lever 140 and covers a space part surrounded by the cover wall 119. The cover lid 149 is extended integrally from the lever 140 in a radial direction of the rotary shaft. When the lever 140 rotates on the rotary shaft 146, the cover lid 149 is large enough to always cover the space part surrounded by the cover wall 119.
[63] FIG. 11 is a perspective view showing a part of a blower unit of an air conditioner for a vehicle according to a third preferred embodiment of the present invention, FIG. 12 is a perspective view showing a state where a lever is assembled in

FIG. 11, and FIG. 13 is a perspective view showing the lever and an arm according to the third preferred embodiment of the present invention.
[64] Referring to FIGS. 11 to 13, the blower unit of an air conditioner for a vehicle according to a third preferred embodiment of the present invention includes a plurality of power transfer means. The power transfer means are disposed outside the case 110, and connect a door with a power source to transfer driving power. The power source may be an actuator. In this embodiment, one of the power transfer means is a lever 300, and the other one is an arm 200.
[65] The lever 300 has a first gear part 320. The first gear part 320 is formed on the outer circumferential surface of a rotary shaft 310. The rotary shaft 310 protrudes toward the outer face of the case 110 from one side of the lever 300 facing the case 110. The rotary shaft 310 has a rotary hole 301 to which a rotary shaft part 190 formed on the case 110 is inserted rotatably.
[66] The arm 200 has a second gear part 230. The second gear part 230 is formed on the outer circumferential surface of the rotary shaft of the arm 200. The second gear part 230 is geared with the first gear part 320 so that the arm 200 and the lever 300 are connected with each other. The arm 200 is rotatably disposed on the outer surface of the case 110. A door

connection shaft 210 extends from the rotary shaft 220 of the arm 200 toward the case 110. A joining part 211 is formed on the outer circumferential surface of the door connection shaft 210 and is joined with the rotary shaft of the door.
[67] The lever 300 is connected to a cam or is directly connected to an actuator to carry out a rotating action. When the lever 300 receives rotary power from the power source, the lever 300 rotates on the rotary shaft part 130 of the case 110. The arm 200 engaging with the lever 300 rotates on the door connection shaft 210 depending on rotation of the lever 300. The door joined to the door connection shaft 210 rotates together with the arm 200. The arm 200 is rotated integrally with the door outside the case 110 and the door is rotated integrally with the arm 200 inside the case 110.
[68] A cover 180 is protrudingly formed on the outer surface of the case 110. The cover 180 is formed on at least one among the case 110 and the power transfer means, and in this embodiment, the cover 180 is formed on the case 110. The cover 180 may be formed integrally with the lever 300, which is the power transfer means. The cover 180 extends to surround sides of the lever 300 and the arm 200 to prevent inflow of foreign matters. When the lever 300 is assembled to the case 110, the lever 300 and the gear driving part of the arm 200 are completely covered by the cover 180 so as to prevent inflow of foreign

matters into the gear driving parts of the lever 300 and the arm 200.
[69] FIG. 14 is a partially enlarged perspective view of FIG. 13, FIG. 15 is a side view of the lever according to the third preferred embodiment of the present invention, and FIG. 16 is a side view of the arm according to the third preferred embodiment of the present invention.
[70] Referring to FIGS. 14 to 16, at least one among the first gear part 320 of the lever 300 and the second gear part 230 of the arm 200 has gear teeth formed with different sizes. That is, the first gear part 320 of the lever 300 has neighboring gear teeth having different sizes. Furthermore, gear teeth of the second gear part 230 of the arm 200 correspond with the gear teeth of the first gear part 320.
[71] In more detail, gear teeth of at least one among the first gear part 320 of the lever 300 and the second gear part 230 of the arm 200 are different in thickness in an axial direction. In this instance, the other one among the first gear part 320 and the second gear part 230 forms a groove in the axial direction corresponding to the gear teeth having different thickness to form a misassembly detection part.
[72] When the first gear part 320 and the second gear part 230 are assembled correctly, the gear teeth with different thicknesses engage with grooves of the opposite side.

Additionally, when the first gear part 320 and the second gear part 230 are misassembled, since the gear teeth with different thicknesses do not engage with grooves of the opposite side, misassembly can be detected. A misassembly detection part is located in the middle in a circumferential direction, which is an assembly direction of the first gear part 320 and the second gear part 230.
[73] The gear teeth having grooves formed in the axial direction have ribs for connecting the gear teeth with each other. Moreover, the gear teeth located in the middle in the circumferential direction among the gear teeth with different thicknesses in the axial direction are thicker than neighboring gear teeth. The gear part having grooves is formed such that the groove located in the middle in the circumferential direction is the deepest in the axial direction. In the meantime, the first gear part 320 and the second gear part 230 are formed to have gear teeth with uniform shape and ridges and valleys formed at uniform intervals.
[74] Referring to the drawings, the first gear part 320 and the second gear part 230 according to the third preferred embodiment of the present invention will be described in more detail.
[75] The first gear part 320 formed on the outer circumferential surface of the rotary shaft 310 of the lever 300

has a plurality of gear teeth, namely, a first gear tooth 321, a second gear tooth 322 and a third gear tooth 323 formed in order in the circumferential direction. Non-actuated gear teeth 325 and 326 are formed at the front of the first gear tooth 321 and the rear of the third gear tooth 323 in the circumferential direction.
[76] All of the first gear tooth 321, the second gear tooth 322 and the third gear tooth 323 have the same shape, ridges and valleys formed at uniform intervals, so the gear teeth are formed uniformly. At least one of the first gear tooth 321, the second gear tooth 322 and the third gear tooth 323 has an axial thickness different from that of the other gear teeth.
[77] That is, a thickness t2 of the second gear tooth 322 is larger than a thickness t3 of the first gear tooth 321 and a thickness t1 of the third gear tooth 323. It is possible that the thickness t3 of the first gear tooth 321 and the thickness t1 of the third gear tooth 323 are identical to each other or different from each other. If the number of the gear teeth is more than three, the gear tooth located in the middle in the circumferential direction is the thickest. In this instance, the second gear tooth 322, which is located in the middle in the circumferential direction, functions as the misassembly detection part.

[78] As described above, since the gear tooth located in the middle in the circumferential direction is the thickest, in case of misassembly, if a user tries to rotate the gears in the clockwise direction and in the counterclockwise direction after the lever and the arm are assembled with each other, the gears are not rotated, so misassembly can be detected. On the contrary, if the misassembly detection part is arranged at a start position in the assembly direction, that is, if the first gear tooth 321 is the thickest, since the gears rotate only in one direction among the clockwise direction and the counterclockwise direction, misassembly can be detected when the gears are rotated not in both directions but in one direction. Additionally, if the misassembly detection part is arranged at an end position in the assembly direction, that is, if the third gear tooth 323 is the thickest, since the gears rotate only in one direction among the clockwise direction and the counterclockwise direction, misassembly can be detected when the gears are rotated not in both directions but in one direction.
[79] The second gear part 230 formed on the outer circumferential surface of the rotary shaft 220 of the arm 200 includes a plurality of gear teeth 236. A plurality of grooves engaging with gear teeth of the lever 300 are formed between the gear teeth 236 of the arm 200. That is, a first groove 231, a second groove 232, and a third groove 233 are formed to engage

with the first gear tooth 321, the second gear tooth 322 and the third gear tooth 323 in order.
[80] All of the gear teeth 236 of the arm 200 have the same shape, ridges and valleys formed at uniform intervals, so the gear teeth are formed uniformly. Furthermore, the gear teeth 236 of the arm 200 have the same thickness in the axial direction. The first groove 231, one among the second groove 232, and the third groove 233 has different axial depth to correspond with the first gear tooth 321, the second gear tooth 322 and the third gear tooth 323.
[81] In other words, a depth w2 of the second groove 232 is larger than a depth w1 of the first groove 231 and a depth w3 of the third groove 233. It is possible that the depth w1 of the first groove 231 and the depth w3 of the third groove 233 are identical to each other or different from each other. If the number of the grooves is more than three, the groove located in the middle in the circumferential direction is the deepest. In this instance, the second groove, which is located in the middle in the circumferential direction, functions as the misassembly detection part.
[82] The grooves formed in the arm 200 may be formed by a plurality of ribs, which traverse and connect the gear teeth 236 in a transverse direction, namely, in a vertical direction to the axial direction. That is, the first groove 231 is formed by a

first rib 241, the second groove 232 is formed by a second rib 242, and the third groove 233 is formed by a third rib 243. The grooves are dented in the axial direction from one side facing the lever 300, of which the bottom surface is defined by the ribs. Finally, when the formation position of the ribs is adjusted, the depth of the grooves can be adjusted. Moreover, the ribs may serve to reinforced the gear part.
[83] FIG. 17 is a view showing a misassembled state of the arm and lever according to the third preferred embodiment of the present invention. Referring to FIG. 17, if the lever 300 and the arm 200 are misassembled with each other, the gear teeth of the lever 300 indicated by dotted lines do not engage with the grooves and are not operated not only in the clockwise direction but also in the counterclockwise direction, so misassembly can be detected easily.
[84] FIG. 18 is a view showing a correctly assembled state of the arm and the lever according to the third preferred embodiment of the present invention. Referring to FIG. 18, if the lever 300 and the arm 200 are assembled correctly, the gear teeth of the lever 300 indicated by dotted lines engage with the grooves of the arm, so that rotary power of the lever 300 is transferred to the arm 200 to rotate the door.
[85] As previously described, in the detailed description of the invention, having described the detailed exemplary

embodiments of the invention, it should be apparent that modifications and variations can be made by persons skilled without deviating from the spirit or scope of the invention. Therefore, it is to be understood that the technical protective scope of the present invention should be defined by the technical idea of the attached claims.

1. A blower unit of an air conditioner for a vehicle
comprising: a case (110) having an indoor air inlet (111) for
introducing indoor air and an outdoor air inlet (112) for
introducing outdoor air; and an indoor and outdoor air door (125)
disposed on the case to selectively open and close the indoor air
inlet (111) and the outdoor air inlet (112),
wherein the indoor and outdoor air door (125) is a rotary type door of a dome shape, and
wherein a power transfer means for connecting a power source and a rotary shaft (128) of the indoor and outdoor air door (125) with each other has a gear structure.
2. The blower unit according to claim 1, wherein the indoor and outdoor air door (125) is in a manual operation type to be connected to a controller through a cable (134).
3. The blower unit according to claim 1, comprising:
a lever (140) having one side connected to the power source to be rotated on a rotary shaft (146); and
an arm (150) connected to the lever (140) to be rotated and connected to the rotary shaft (128) of the indoor and outdoor air door (125),

wherein the lever (140) and the arm (150) are connected by a gear structure.
4. The blower unit according to claim 3, wherein a first gear part (143) is formed on the outer circumferential surface of the rotary shaft (146) of the lever (140), and a second gear part (153) gearing with the first gear part (143) is formed on the outer circumferential surface of the arm (150).
5. The blower unit according to claim 3, wherein the lever
(140) includes a flat plate part (144) facing the side of the
case (110) in a longitudinal direction of the rotary shaft (146),
and a cover part (145) extending toward the case (110) along an
edge of the flat plate part (144), and
wherein the arm (150) is received in the flat plate part (144)and the cover part (145).
6. The blower unit according to claim 4, wherein the rotary
shaft (146) of the lever (140) has a boss protruding toward the
case (110) to be rotatably connected to the rotary shaft part
(141) formed on the case (110), a through hole (147) to which the
rotary shaft part (141) is inserted is formed in the rotary shaft
(146), and the first gear part (143) is formed on the outer
circumferential surface of the rotary shaft (146).

7. The blower unit according to claim 3, further comprising:
a cover wall (119) protruding from the case (110) to
surround the lever (140) and the arm (150).
8. The blower unit according to claim 7, wherein the lever (140) has a cover lid (149) for covering a space part surrounded by the cover wall (119).
9. The blower unit according to claim 8, wherein the cover lid (149) extends integrally from the lever (140) in a radial direction of the rotary shaft.

10. The blower unit according to claim 7, wherein the cover wall (119) extends integrally from the case (110) in the axial direction.
11. The blower unit according to claim 1, wherein further comprising:
a first gear part formed on the rotary shaft of one of the power transfer means; and
a second gear part formed on the rotary shaft of the other power transfer means and geared with the first gear part,
wherein at least one among the first gear part and the second gear part has gear teeth with different sizes.

12. The blower unit according to claim 11, wherein the first gear part has neighboring gear teeth with different sizes from each other, and gear teeth of the second gear part are formed to correspond with gear teeth of the first gear part.
13. The blower unit according to claim 11 or 12, wherein one gear teeth among the first gear part and the second gear part has different thicknesses in the axial direction.
14. The blower unit according to claim 13, wherein the other one among the first gear part and the second gear part forms grooves in axial direction corresponding to the gear teeth having different thicknesses to form a misassembly detection part.
15. The blower unit according to claim 14, wherein the gear teeth with different thicknesses engage with the grooves of the opposite side when the first gear part and the second gear part are assembled correctly, and
wherein the gear teeth with different thicknesses do not engage with the grooves of the opposite side when the first gear part and the second gear part are misassembled, so that misassembly can be detected.

16. The blower unit according to claim 15, wherein the
misassembly detection part is located in the middle in the
circumferential direction, which is an assembly direction of the
first gear part and the second gear part.
17. The blower unit according to claim 14, wherein the gear teeth having the grooves formed in the axial direction have ribs for connecting the gear teeth.
18. The blower unit according to claim 13, wherein the gear tooth located in the middle in the circumferential direction among the gear teeth having different thicknesses in the axial direction is thicker than the neighboring gear teeth.
19. The blower unit according to claim 18, wherein the other one among the first gear part and the second gear part has grooves formed in the axial direction to correspond to the gear teeth having different thicknesses, and
wherein the groove formed in the middle in the circumferential direction among the grooves is the deepest in the axial direction.
20. The blower unit according to claim 13, wherein the first
gear part and the second gear part are formed to have gear teeth

with uniform shape and ridges and valleys formed at uniform intervals.