Blower unit

• US 20090180868A1
• Filed: 12/10/2008
• Published: 07/16/2009
• Est. Priority Date: 12/18/2007
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Nakamura, Takahito, Ito, Koji, Sakai, Masaharu
• Granted Patent: US 8,167,550 B2
• Time in Patent Office: Days
• US Class Current: 415/204
• CPC Class Codes: F04D 29/162 of a centrifugal flow wheel
• CPC Class Codes: F04D 29/703 specially for fans, e.g. fan guards

Abstract

A blower unit includes a rotation shaft, a centrifugal fan and a casing. The centrifugal fan has blades arranged around the rotation shaft. The casing has a wall part defining an opening. The ring part has a ring shape having a center coinciding with an axis of the rotation shaft. The ring part is provided at first axial ends of the blades and support the blades. The ring part includes an arcuate wall curved in a radially inward of the centrifugal fan. The centrifugal fan is housed in the casing such that the arcuate wall of the ring part is located radially inside of the opening of the wall part.

Claims

1. A blower unit comprising:

a rotation shaft;

a centrifugal fan supported by the rotation shaft, the centrifugal fan including a plurality of blades and a ring part, the blades being arranged around an axis of the rotation shaft, the ring part being provided at first axial ends of the blades and supporting the blades, the ring part having a ring shape defining a center coincident with the axis of the rotation shaft; and

a casing housing the centrifugal fan therein, the casing including a wall part extending in a radial direction of the centrifugal fan adjacent to the ring part, the wall part having an opening portion defining an opening, wherein

the ring part includes an arcuate wall having an outside diameter portion at which a diameter of the arcuate wall is the largest and an inside diameter portion at which the diameter of the arcuate wall is the smallest, the outside diameter portion being further than the inside diameter portion from second axial ends of the blades with respect to an axial direction of the centrifugal fan,

the arcuate wall is curved radially inside of the centrifugal fan, and

the arcuate wall is located inside of the opening portion of the wall part with respect to the radial direction.

2. The blower unit according to claim 1, wherein

the centrifugal fan is disposed such that a ring end of the ring part coincides with a wall end of the opening portion with respect to the axial direction, the ring end being the furthest portion in the ring part from the second axial end of the blade with respect to the axial direction, the wall end being the furthest portion in the opening portion from the second axial end of the blade with respect to the axial direction.

3. The blower unit according to claim 1, wherein

the centrifugal fan is disposed such that a ring end of the ring part is closer to the second end of the blade than a wall end of the opening portion with respect to the axial direction, the ring end being the furthest portion in the ring part from the second axial end of the blade with respect to the axial direction, the wall end being the furthest portion in the opening portion from the second axial end of the blade with respect to the axial direction.

4. The blower unit according to claim 1, wherein

the centrifugal fan is disposed such that a wall end of the opening portion is located closer to the second end of the blade than a ring end of the ring part with respect to the axial direction, the ring end being the furthest portion in the ring part from the second axial end of the blade with respect to the axial direction, the wall end being the furthest portion in the opening portion from the second axial end of the blade with respect to the axial direction.

5. The blower unit according to claim 1, wherein

the opening portion includes a small diameter portion at which a cross-sectional area of the opening is the smallest and a large diameter portion at which a cross-sectional area of the opening is the largest,

the small diameter portion is displaced from the large diameter portion in the axial direction, and

the arcuate wall of the ring part is located inside of the small diameter portion with respect to the radial direction.

6. The blower unit according to claim 1, wherein

the casing has an air outlet through which air blown by the centrifugal fan is discharged to an outside of the casing, and

the casing and the centrifugal fan have a throttle structure therebetween, the throttle structure being configured to reduce air from flowing to the outside of the casing through a clearance provided between the wall part and the ring part while bypassing the air outlet of the casing.

7. The blower unit according to claim 6, wherein

one of the wall part and the ring part has a projection projecting toward the other, and

the projection constitutes the throttle structure with the other.

8. The blower unit according to claim 6, wherein

the wall part has a projection projecting in the axial direction, and

the projection constitutes the throttle structure with radially outer edges of the blades.

9. The blower unit according to claim 6, wherein

the casing has a first projection,

the ring part has a second projection, and

the first projection and the second projection constitute the throttle structure.

10. The blower unit according to claim 1, wherein

the centrifugal fan includes a boss part connected to the rotation shaft and supporting the blades,

the boss part, the blades and the ring part are integrally formed with each other.

11. The blower unit according to claim 1, wherein

the blades are arranged at predetermined intervals in a circumferential direction of the rotation shaft such that air passages are provided between adjacent blades,

the blades are capable of blowing air suctioned from the opening in the radial direction through the air passages,

the centrifugal fan further includes an air blocking part,

the air blocking part has a ring shape defining a center coincident with the axis of the rotation shaft, and

the air blocking part is provided on radially outer sides of the blades and is configured to restrict the air blown by the blades from flowing back into the air passages.

12. The blower unit according to claim 11, wherein

the air blocking part is disposed along radially outer edges of the blades.

13. The blower unit according to claim 11, wherein

the air blocking part extends from the ring part toward the second ends of the blades.

14. The blower unit according to claim 11, wherein

the air blocking part has a first end adjacent to the ring part and a second end opposite to the first end,

the second end of the air blocking part includes a curved wall curved radially inside of the centrifugal fan and toward the second axial ends of the blades, and

the curved wall is capable of adjusting a flow of air blown by the blades to be inclined toward the second ends of the blades relative to the radial direction.

15. The blower unit according to claim 11, wherein

the casing has an air outlet through which air blown by the centrifugal fan is discharged to an outside of the casing,

the casing and the centrifugal fan have a throttle structure therebetween, the throttle structure being configured to reduce air from flowing to the outside of the casing through a clearance between the air blocking part and the opening portion while bypassing the air outlet.

16. The blower unit according to claim 15, wherein

the wall part of the casing includes a third projection projecting toward the air blocking part,

the air blocking part includes a fourth projection projecting toward the wall part,

the third projection and the fourth projection are displaced from each other with respect to the axial direction, and

the third projection and the fourth projection constitute the throttle structure.

17. The blower unit according to claim 1, further comprising:

an electric motor including a motor body, wherein

the rotation shaft includes a first shaft portion extending from a first side of the motor body and a second shaft portion extending from a second side of the motor body,

the centrifugal fan is one of a first centrifugal fan supported by the first shaft portion and a second centrifugal fan supported by the second shaft portion, and

the casing is one of a first casing housing the first centrifugal fan therein and a second casing housing the second centrifugal fan therein.

18. A blower unit comprising:

an electric motor having a motor body and a rotation shaft capable of being rotated by the motor body, the rotation shaft including a first shaft portion and a second shaft portion, the first shaft portion and the second shaft portion extending from opposite sides of the motor body;

a first centrifugal fan supported by the first shaft portion, the first centrifugal fan including a plurality of first blades and a first ring part, the first blades being arranged around an axis of the first shaft portion, the first ring part being disposed at first axial ends of the first blades and supporting the first blades, the first ring part having a ring shape having a center coinciding with an axis of the first rotation shaft;

a first casing housing the first centrifugal fan therein, the first casing including a first wall part extending in a radial direction of the first centrifugal fan, the first wall part defining a first opening;

a second centrifugal fan supported by the second shaft portion, the second centrifugal fan including a plurality of second blades and a second ring part, the second blades being arranged around an axis of the second shaft portion, the second ring part provided at first axial ends of the second blades and supporting the second blades, the second ring part having a ring shape having a center coinciding with an axis of the second rotation shaft; and

a second casing housing the second centrifugal fan therein, the second casing including a second wall part extending in a radial direction of the second centrifugal fan, the second wall part defining a second opening, wherein

the first ring part includes a first arcuate wall,

the second ring part includes a second arcuate wall,

the first arcuate wall has a first outside diameter portion at which a diameter of the first arcuate wall is the largest and a first inside diameter portion at which the diameter of the first arcuate wall is the smallest, the first outside diameter portion is further than the first inside diameter portion from second axial ends of the first blades in an axial direction of the first shaft portion,

the second arcuate wall has a second outside diameter portion at which a diameter of the second arcuate wall is the largest and a second inside diameter portion at which the diameter of the second arcuate wall is the smallest, the second outside diameter portion is further than the second inside diameter portion from second axial ends of the second blades in an axial direction of the second shaft portion, and

the first arcuate wall is curved radially inside of the first centrifugal fan,

the second arcuate wall is curved radially inside of the second centrifugal fan

the first arcuate wall is located inside of the first opening of the first wall part with respect to the radial direction of the first centrifugal fan,

the second arcuate wall is located inside of the second opening of the second wall part with respect to the radial direction of the second centrifugal fan.