JP2015036510A - Fan motor with bypass for centrifugal flow - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axial fan motor that prevents counter flow of centrifugal flow, reduces noise and has high efficiency.SOLUTION: An axial fan motor comprises: a casing; a motor part that is molded integrally with the casing; and a fan that includes a plurality of blades arranged radially, and whose shaft is rotatably held to the motor part. In the axial fan motor, a fan motor with a bypass for centrifugal flow is configured such that an annular partition wall is provided between the inner peripheral surface of the casing and the tip of the blade; a bypass port flowing centrifugal flow generated in the centrifugal direction of the blade is included; and a bypass flowing the centrifugal flow is a gap between the inner peripheral surface and the partition wall.

Description

  The present invention relates to a fan motor with a bypass for a centrifugal flow that prevents a reverse flow of a centrifugal flow and is low in noise and highly efficient in an axial flow fan motor.

  As shown in FIG. 8, the axial fan type conventional fan motor 21 includes a casing 22, a motor unit 3 integrally formed on a bottom surface 22 a held by a support shaft 22 c extending from an end of the casing 22, and a motor unit. 3 and a fan 4 on which a shaft 4c is rotatably held. As shown in FIGS. 9B and 9C, when the fan 4 rotates, the air flows in the direction of the axis 4c of the fan 4, that is, from the suction port 22d side of the casing 22 toward the air outlet 22e (main flow 5). ).

  On the other hand, as shown in FIGS. 9B and 9C, apart from the main flow 5, an air flow (centrifugal flow 5a) is also generated from the root of the blade 4a toward the tip 4b, that is, in the horizontal direction (centrifugal direction). To do. Then, as shown in FIG. 10, the centrifugal flow 5a collides with the inner peripheral surface 22b of the casing 22, and becomes a flow (both arrows) in both directions of the suction port 22d side and the air outlet 22e of the casing 22, and the upstream side ( The flow toward the suction port 22d) is a flow opposite to the main flow 5 (reverse flow 5b), and the centrifugal flow 5a causes a vortex. This centrifugal flow 5a increases the pressure at the tip 4b of the blade 4a, and is known as a cause of noise in the conventional fan motor 21 (Patent Document 1, paragraph 0005, etc.).

  Patent Document 2 discloses an axial fan motor that allows turbulent flow (centrifugal flow) to escape from the pores on the side of the casing in order to prevent noise.

  However, if the centrifugal flow 5a is missed from the side surface, the noise is reduced and the blowing efficiency is lowered.

  The ventilation efficiency of the axial fan motor is strongly influenced by the width of the chip clearance 21a. As shown in FIG. 11, the tip clearance 21 a is a gap between the tip 4 b of the blade 4 a of the fan 4 and the inner peripheral surface 22 b of the casing 22. The narrower the chip clearance 21a, the higher the blowing efficiency.

  However, it is not easy to narrow the tip clearance 21a. This is because it depends on molding errors of parts and assembly accuracy.

  In the conventional fan motor 21, as shown in FIG. 12, the chip clearance 21a is designed to be wide so that the blade 4a of the fan 4 does not hit in consideration of component errors and assembly accuracy (FIG. 12). (A)). As a result, the width of the chip clearance becomes nonuniform as shown in FIG.

JP 2009-197658 A JP 2007-218150 A

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an axial fan motor that prevents a reverse flow of a centrifugal flow and is low noise and highly efficient.

In order to solve the above problems, the present invention
(1)
In an axial fan motor comprising a casing, a motor unit integrally formed with the casing, and a fan having a plurality of blades arranged radially and having a shaft rotatably held by the motor unit,
An annular partition is provided between the inner peripheral surface of the casing and the tip of the blade, and a bypass port is provided for flowing a centrifugal flow generated in the centrifugal direction of the blade, and the inner peripheral surface of the casing and the partition The gap is a bypass for flowing the centrifugal flow, and the fan motor with bypass for centrifugal flow is configured.
(2)
The bypass for the centrifugal flow according to (1), wherein the bypass port opens from a substantially center of the blade to a position before the blade end in a cross section orthogonal to an axial direction of the fan blade. The fan motor configuration was used.
(3)
The discharge outlet of the bypass flow that flows through the bypass is provided in the direction of the main flow outlet, and the discharged bypass flow covers the outer periphery of the main flow and suppresses the diffusion of the main flow (1) or ( It was set as the structure of the fan motor with a bypass for centrifugal flows as described in 2).
(4)
The bypass has a substantially L-shaped cross section from the bypass port to the discharge port, and a bent portion of the inner peripheral surface of the casing that the centrifugal flow collides with protrudes outward in a sectional view in the axial direction. It is set as the structure of the fan motor with a bypass for centrifugal flows as described in any one of (1)-(3) characterized by these.
(5)
The inner diameter of the casing from the bypass port end to the vicinity of the suction port is the same diameter as the inner peripheral surface of the partition wall, for centrifugal flow according to any one of (1) to (4) The fan motor with bypass is configured.
(6)
The material of the casing and the blades is made of carbon fiber-containing resin, and has the configuration of the centrifugal flow bypass motor according to any one of (1) to (5).
(7)
An axial flow comprising a casing, an annular partition fitted to the casing, a motor part held by the annular partition, and a fan having a plurality of radially arranged blades and a shaft rotatably held by the motor part In the fan motor,
A bypass flow fan motor having a centrifugal flow is provided between the inner peripheral surface of the casing and the annular partition so as to bypass the centrifugal flow generated in the centrifugal direction of the blades.
(8)
Manufacture of a fan motor with a bypass for centrifugal flow in which a groove is provided on the inner surface of the casing of the fan motor for bypass with centrifugal flow according to (7) and a protrusion inserted into the groove is provided on the outer periphery of the annular partition wall A method,
A play space is provided between the groove and the protrusion, the annular partition holding the fan is positioned, an adhesive is poured into the play air, the casing and the annular partition are fixed, and the fan The chip clearance accuracy between the tip and the casing is increased, and the manufacturing method of the centrifugal flow bypass fan motor is provided.
(9)
The positioning is performed using a tubular jig having a desired chip clearance thickness, and after fitting the tubular jig between the casing and the fan, the groove of the casing and the protrusion of the annular partition wall are formed by the adhesive. The structure of the manufacturing method of the fan motor with a centrifugal flow bypass according to (7), characterized in that is fixed.

  Since this invention is the said structure, the following effects are exhibited. That is, by providing a bypass that allows the centrifugal flow to flow separately from the main flow on the inner peripheral surface of the casing, it is possible to reduce the turbulent flow at the blade tip and reduce the noise of the fan motor. Furthermore, by circulating the centrifugal flow from the main flow and flowing in the main flow direction from the outer periphery of the main flow, diffusion of the main flow can be prevented and the air blowing efficiency can be improved.

  By identifying the bypass port of the centrifugal flow from the approximate center of the fan to the position just before the end of the fan in the cross section in the axial direction of the fan blades, the centrifugal flow can be bypassed efficiently, and the noise of the fan motor Can be further suppressed.

  Further, the bypass has a substantially L-shaped cross section, and the bent portion of the inner peripheral surface of the casing that the centrifugal flow collides with has a curved shape that is convex outward in a cross-sectional view in the axial direction, thereby reducing the flow of the bypass flow. It is possible to further smooth the flow of the centrifugal flow efficiently and to further suppress the noise of the fan motor.

  The assembly accuracy can be easily improved by separating the motor unit from the casing and integrating the motor unit and the partition wall.

  Specifically, by positioning the annular partition, the motor unit and the fan separately from the casing and the annular partition fitted to the casing and the motor part held by the annular partition, the assembly accuracy is improved and the chip clearance width is increased. Can be made closer to the design width, the chip clearance can be narrowed, and as a result, noise can be reduced and blowing efficiency can be increased. At that time, by using a tubular jig with a designed chip clearance width, the positioning is easy, and after positioning with the tubular jig, the casing and the annular partition wall are fixed, so that the accuracy of the chip clearance, the fan motor Assembly accuracy can be increased. As a result, a motor fan with low noise and high blowing efficiency can be provided.

It is explanatory drawing of 1st embodiment of the fan motor with a bypass for centrifugal flows which is this invention. (A) is a front perspective view, (B) is a front perspective partial sectional view, and (C) is a partial longitudinal sectional view. It is an enlarged vertical sectional view of the bypass part at the time of use of this invention of FIG. It is explanatory drawing of 2nd embodiment of the fan motor with a bypass for centrifugal flows which is this invention. (A) is a rear perspective view exploded view, (B) is a rear perspective view, (C) is an exploded partial longitudinal sectional view, (D) is a partial longitudinal sectional view, and (E) is an enlarged view in a (D) broken line frame. It is. It is explanatory drawing of the motor part with an annular partition which hold | maintains a fan rotatably. (A) is a rear perspective view, (B) is a front perspective view, and (C) is a partial longitudinal sectional view. It is explanatory drawing of 2nd embodiment of the fan motor with a bypass for centrifugal flows which is this invention. (A) is a rear view, (B) is an enlarged view in a broken line frame of (A), and (C) is an explanatory view of an assembly error. It is explanatory drawing of the assembly method of 2nd embodiment of the fan motor with a bypass for centrifugal flows which is this invention. (A) is a perspective view of the assembly of the motor part with an annular partition which supported the casing and the fan, and a tubular jig. (B) is a perspective view when a tubular jig is fitted into the tip clearance of the assembly of the motor unit with an annular partition that supports the casing and the fan, and the motor unit with the annular partition that supports the fan is positioned in the casing. FIG. 4C is a partial longitudinal sectional view of FIG. It is explanatory drawing of the assembly method of 2nd embodiment of the fan motor with a bypass for centrifugal flows which is this invention. (A) is a back perspective partial longitudinal cross-sectional view at the time of FIG. 6 (B). (B) is a rear perspective view of a second embodiment of the fan motor with bypass for centrifugal flow according to the present invention. It is explanatory drawing of the conventional fan motor. (A) is a front perspective view, (B) is a front perspective partial longitudinal sectional view, and (C) is a longitudinal sectional view. It is explanatory drawing of the main flow in a fan motor and the centrifugal flow of a centrifugal direction accompanying rotation of a fan. (A) is a front view of the fan, (B) is a rear perspective view of the fan, and (C) is a side view of the fan. It is explanatory drawing (enlarged longitudinal cross-section) of the mainstream and centrifugal flow in the use condition in the conventional fan motor of FIG.8 (C). It is explanatory drawing of the chip clearance of the conventional fan motor. (A) is a front view of a conventional fan motor, and (B) is an enlarged view in a broken line frame of (A). It is explanatory drawing of the fluctuation | variation of the chip clearance by an assembly error. (A) shows the chip clearance at the time of design, and (B) shows the component error and the state of the chip clearance due to assembly.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited to the following Example.

  As shown in FIGS. 1 and 2, the centrifugal flow bypass fan motor 1 according to the first embodiment includes a casing 2, a motor unit 3, a fan 4, and a bypass 7, and is based on a centrifugal flow 5 a. Reduces backflow and turbulence, and achieves low noise and high efficiency of the motor fan.

  The casing 2 is a box-type case having an air suction port 2d and an air outlet 2e, and the fan 4 is located in the internal space. A bottom surface 2a is connected to a support shaft 2c extending from the end on the outlet 2e side to the center, and the motor portion 3 is integrally formed on the bottom surface 2a.

  The inner diameter of the casing 2 from the end of the bypass port 7 a to the vicinity of the suction port 2 d is the same as that of the inner peripheral surface 6 b of the partition wall 6.

  The motor unit 3 is integrally formed with the casing 2 and rotatably holds the shaft 4c of the fan 4.

  The fan 4 includes a cylindrical portion 4d, a plurality of blades 4a radially provided on the cylindrical portion 4d, and a shaft 4c provided at the bottom of the central portion of the cylindrical portion 4d. The shaft 4c is rotatably held by the motor portion 3 at the shaft 4c portion so that the tip 4b of the blade 4a does not touch the partition wall 6 of the casing 2. As the fan 4 rotates, air flows from the suction port 2d of the casing 2 to the air outlet 2e as the main flow 5. The clearance between the tip 4b of the blade 4a of the fan 4 and the inner peripheral surface 2a of the casing 2 becomes the chip clearance 1a. In addition, it is preferable that the fan 4, especially the blade | wing 4a and the casing 2 are made into resin containing carbon fiber. The environment used by the fan motor often becomes high temperature, and if it is a resin containing carbon fiber, deformation due to thermal expansion of the casing 2 and the blades 4a can be prevented, and the accuracy of the chip clearance 1a can be stably maintained.

  The partition wall 6 is integrally connected (molded) to the casing 2 via a connecting portion 6 a, and a bypass 7 is formed by the partition wall 6 and the inner peripheral surface 2 b of the casing 2.

  The bypass 7 is formed by providing an annular partition wall 6 between the inner peripheral surface 2b of the casing 2 and the tip 4b of the blade 4a, and a centrifugal flow 5a is generated between the inner peripheral surface 2b of the casing 2 and the partition wall 6. Shed.

  The bypass 7 includes a bypass port 7a through which the centrifugal flow 5a generated in the centrifugal direction of the blade 4a and a discharge port 7b through which the centrifugal flow 5a is discharged. The detour port 7a is open all around the end of the partition wall 6 from the approximate center of the blade 4a to a position before the end of the blade 4a in a cross section orthogonal to the axis 4c of the blade 4a of the fan 4.

  The shape of the bypass 7 from the bypass port 7a to the discharge port 7b is substantially L-shaped in cross section, and the bent portion of the inner peripheral surface 2b of the casing 2 with which the centrifugal flow 5a collides is a cross-sectional view in the main flow 5 direction. An outwardly convex curve 2f.

  Further, the discharge port 7 b of the bypass flow 7 c flowing through the bypass 7 is provided in the direction of the outlet 2 e of the main flow 5, and the discharged bypass flow 7 c covers the outer periphery of the main flow 5 and suppresses the diffusion of the main flow 5.

  As shown in FIGS. 3 and 4, the centrifugal flow bypass fan motor 11 according to the second embodiment includes a casing 12, an annular partition wall 13 d, a motor unit 13 b, a fan 4, and a bypass 17. By reducing the backflow 5b and turbulence caused by the centrifugal flow 5a, the motor fan can be reduced in noise and increased in efficiency.

  The casing 12 is a box-type case having an air suction port 12d and an air outlet 12e, and the motor unit 13 with an annular partition that rotatably holds the fan 4 is located in the internal section 12f. A plurality of grooves 12a are formed in the inner peripheral surface 12b of the casing 12 in the axial direction (the direction connecting the suction port 12d and the outlet 12e).

  The inner diameter of the casing 12 from the end of the bypass port 17a to the vicinity of the suction port 12d is the same as the inner peripheral surface 13f of the annular partition wall 13d.

  The motor part 13 with an annular partition is composed of an annular partition 13d and a motor part 13b. The annular partition wall 13d and the motor part 13b are integrally formed.

  As shown in FIG. 4, the annular partition wall 13d includes an annular portion and an axial linear protrusion 13e on the outer periphery of the annular portion, and the protrusion 13e meshes with the groove 12a with a play 19 space.

  The motor unit 13 is held by the annular partition wall 13d and rotatably holds the shaft 4c of the fan 4. A bottom surface 13a is connected to a support shaft 13c extending from the end on the air outlet 12e side to the center, and a motor portion 13b is formed integrally with the bottom surface 13a.

  The fan 4 includes a cylindrical portion 4d, a plurality of blades 4a radially provided on the cylindrical portion 4d, and a shaft 4c provided at the bottom of the central portion of the cylindrical portion 4d. The shaft 4c is rotatably held by the motor portion 13 so that the tip 4b of the blade 4a does not touch the annular partition wall 13d. As the fan 4 rotates, air flows as a main flow 5 from the suction port 12d of the casing 2 to the blowout port 12e. A gap between the inner peripheral surface 12b of the casing 12 and the tip 4b of the blade 4a becomes a tip clearance 11a (FIG. 3E).

  The bypass 17 is formed between the outer peripheral surface 13g of the annular partition wall 13d and the inner peripheral surface of the casing 12, and flows the centrifugal flow 5a generated in the centrifugal direction of the blade 4a.

  The bypass 17 includes a bypass port 17a for taking in the centrifugal flow 5a generated in the centrifugal direction of the blade 4a and a discharge port 17b for discharging the centrifugal flow 5a as a bypass flow 17c. In the cross section orthogonal to the direction of the axis 4c of the blade 4a of the fan 4, the bypass port 17a opens to the end of the annular partition wall 13d from the approximate center of the blade 4a to a position before the end of the blade 4a. The annular partition wall 13d has a width that can form the bypass port 17a.

  The shape of the bypass 17 from the bypass port 17a to the discharge port 17b is substantially L-shaped in cross section, and the bent portion of the inner peripheral surface 12b of the casing 12 with which the centrifugal flow 5a collides is a cross-sectional view in the main flow direction 5 The curve 12c is convex outward.

  Further, the discharge port 17 b of the bypass flow 17 c flowing through the bypass 17 is provided in the direction of the outlet 12 e of the main flow 5, and the discharged bypass flow 17 c covers the outer periphery of the main flow 5 and suppresses the diffusion of the main flow 5.

  Next, a manufacturing method of the centrifugal flow bypass fan motor will be described in detail with reference to FIGS. If it is the said method, the assembly precision of the fan motor 11 with a bypass for centrifugal flows can be raised, and the chip clearance 11a can be manufactured stably narrowly unlike before.

  As shown in FIG. 5A, the motor unit 13 with an annular partition that holds the casing 12 and the fan 4 rotatably is engaged with the groove 12a of the casing 12 and the annular partition 13d. At this time, as shown in FIG. 5B, the groove 12a and the protrusion 13e are provided with a space (play 19). With such play 19, as shown in FIG. 5C, the fan 4 is not fixed, and the center of the locus (broken line) drawn by the tip 4b when the blade 4a rotates is the center of the casing space. Is not determined to match.

  Therefore, the tubular jig 18 shown in FIG. 6A is fitted to the suction port 12d side of the casing 12 as shown in FIGS. 6B and 6C, and the fan 4 is inserted into the hollow portion 18a of the tubular jig 18. Position.

  The inner diameter of the tubular jig 18 is the same as the locus drawn by the tip 4b of the blade 4a of the fan 4. The outer diameter of the tubular jig 18 is the same as the inner diameter of the casing 12. That is, the thickness 18b (FIG. 6C) of the tubular jig 18 becomes the chip clearance 11a.

  Therefore, by fitting the tubular jig 18 between the casing 12 and the fan 4, the center of the annular partition wall 13 d and the fan 4 can be matched with the center of the space of the casing 12. Then, if the annular partition 13d is bonded to the casing 12, the motor fan can be assembled with high accuracy. In order to bond the annular partition wall 13d and the casing 12, an adhesive may be poured into the space (play 19 portion) between the protrusion 13e of the annular partition wall 13d and the groove 12a of the casing 12.

  If the centrifugal flow bypass fan motor 11 is manufactured in this way, the assembly accuracy can be improved while the bypass 17 is formed, and the chip clearance 11a can be manufactured uniformly and stably. Therefore, the tip clearance 11a can be made narrower than before, for example, 0.1 mm (FIG. 7C). As a result, the noise of the motor fan can be easily and stably reduced. Furthermore, since the bypass 17 is provided, the air blowing efficiency can be made extremely high (FIG. 7B).

DESCRIPTION OF SYMBOLS 1 Fan motor 1a with a centrifugal flow bypass Tip clearance 2 Casing 2a Bottom surface 2b Inner peripheral surface 2c Support shaft 2d Suction port 2e Air outlet 2f Curve 3 Motor part 4 Fan 4a Blade 4b Tip 4c Shaft 4d Tube part 5 Main flow 5a Centrifugal flow 5b Reverse flow 6 Partition wall 6a Connecting portion 6b Inner peripheral surface 7 Bypass 7a Bypass port 7b Discharge port 7c Bypass flow
11 Centrifugal flow bypass fan motor 11a Chip clearance 12 Casing 12a Groove 12b Inner peripheral surface
12c Curved 12d Suction port 12e Air outlet 12f Space 13 Motor part 13a with annular partition wall 13b Motor part 13c Support shaft 13d Ring partition 13e Projection 13f Inner peripheral surface 13g Outer peripheral surface 17 Bypass port 17b Discharge port 17c Bypass port 18 Tubular Jig 18a Hollow portion 18b Thickness 19 Play 21 Conventional fan motor 21a Chip clearance 22 Casing 22a Bottom surface 22b Inner peripheral surface 22c Support shaft 22d Suction port 22e Air outlet

Claims (9)

In an axial fan motor comprising a casing, a motor unit integrally formed with the casing, and a fan having a plurality of blades arranged radially and having a shaft rotatably held by the motor unit,
An annular partition is provided between the inner peripheral surface of the casing and the tip of the blade, and a bypass port is provided for flowing a centrifugal flow generated in the centrifugal direction of the blade, and the inner peripheral surface of the casing and the partition A fan motor with a bypass for centrifugal flow, characterized in that the bypass is used to pass the centrifugal flow. 2. The bypass for centrifugal flow according to claim 1, wherein the bypass port opens from a substantial center of the blade to a position in front of the blade end in a cross section orthogonal to an axial direction of the blade of the fan. With fan motor. The discharge port of the bypass flow that flows through the bypass is provided in the direction of the main outlet, and the discharged bypass flow covers an outer periphery of the main flow to suppress diffusion of the main flow. Item 3. A fan motor with a bypass for centrifugal flow according to Item 2. The bypass has a substantially L-shaped cross section from the bypass port to the discharge port, and a bent portion of the inner peripheral surface of the casing that the centrifugal flow collides with protrudes outward in a sectional view in the axial direction. The fan motor with a bypass for centrifugal flow according to any one of claims 1 to 3, wherein the fan motor has a curved shape. 5. The centrifugal according to claim 1, wherein an inner diameter of the casing from the bypass port end to the vicinity of the suction port is the same as an inner peripheral surface of the partition wall. Fan motor with bypass for flow. 6. The fan motor with a bypass for centrifugal flow according to claim 1, wherein the casing and the blade are made of resin containing carbon fiber. An axial flow comprising a casing, an annular partition fitted to the casing, a motor part held by the annular partition, and a fan having a plurality of radially arranged blades and a shaft rotatably held by the motor part In the fan motor,
A fan motor with a bypass for centrifugal flow, characterized in that a bypass for flowing a centrifugal flow generated in the centrifugal direction of the blades is provided between the inner peripheral surface of the casing and the annular partition. The manufacture of a fan motor with a bypass for centrifugal flow in which a groove is provided on the inner surface of the casing of the bypass motor for centrifugal flow according to claim 7 and a protrusion inserted into the groove is provided on an outer periphery of the annular partition wall. A method,
A play space is provided between the groove and the protrusion, the annular partition holding the fan is positioned, an adhesive is poured into the play air, the casing and the annular partition are fixed, and the fan A method of manufacturing a fan motor with a bypass for centrifugal flow, wherein the tip clearance accuracy between the tip and the casing is increased. The positioning is performed using a tubular jig having a desired chip clearance thickness, and after fitting the tubular jig between the casing and the fan, the groove of the casing and the protrusion of the annular partition wall are formed by the adhesive. The method for manufacturing a fan motor with a bypass for centrifugal flow according to claim 8, wherein: