BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from the following detailed description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts, in which:
FIG. 1 is a sectional view of a conventional U-shaped tangential element of a shroud.
FIG. 2 is a sectional view of a conventional thin tangential element of a shroud.
FIG. 3 shows a fan module having motor mount arms or connecting elements provided in accordance with an embodiment of the present invention.
FIG. 4 shows a portion of a connecting element of FIG. 3 and axes thereof.
FIG. 5 shows a cross section of the connecting element of FIG. 4.
FIG. 6 is a sectional view of a connecting element of another embodiment of the invention shown in an air flow path.
FIG. 7 is a plan view of a portion of the fan module in accordance with another embodiment of the invention.
FIG. 8 is a view of a connecting element as viewed from the line 8-8 of FIG. 7.
FIG. 9A is a sectional view taken along the line 9A-9A in FIG. 8.
FIG. 9B is a sectional view taken along the line 9B-9B in FIG. 8.
FIG. 9C is a sectional view taken along the line 8C-8C in FIG. 8.
FIG. 10 is a view of a connecting element as viewed from the line 10-10 of FIG. 7.
FIG. 11A is a sectional view taken along the line 11A-11A in FIG. 10.
FIG. 11B is a sectional view taken along the line 11B-11B in FIG. 10.
FIG. 11C is a sectional view taken along the line 11C-11C in FIG. 10.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
A fan has the purpose to move a substance of gaseous state. A multiple number of fan blades fixed rigidly to a fan hub and surrounded by a ring produces air flow when rotating. The fan produces air at very high flow rates even when the wake of the fan is highly restricted by obstacles. Therefore, such a fan is highly suited for automotive engine cooling applications where the wake of the fan is blocked by the automotive engine or other components.
The fan is coupled to a shaft of a motor. The motor (not shown) is mounted to a fan module or shroud 10 (FIG. 3). The module 10 includes a generally rectangular base 12, a motor mount 14, for mounting the motor thereto, and a plurality of motor mount arms or connecting elements 16 connecting the motor mount 14 to the base 12. The base 12 includes an opening for receiving a fan (not shown) in the conventional manner. A member 17 between the base 12 and motor mount 14 includes a trough 19 for receiving the wires for powering the motor. Each connecting element 16 has a radial axis A and an axis B generally transverse with respect to axis A.
With reference to FIGS. 3-5 the geometry of the connecting elements 16 is adapted to the spiral-shaped air path in the wake of a fan, such that the aerodynamic disturbance is reduced and the connecting elements 16 pose a nearly neutral acoustic effect. The arrows in FIG. 3 show the air flow direction. As shown in FIG. 5, each connecting element 16 of the embodiment of FIGS. 3 and 4 is generally triangular in section and is solid. However, to reduce material and ensuring good plastic flow during molding, cavities (not shown) can be provided in an underside of the element 16.
In a vehicle, air velocity is not symmetric due to blockage of various underhood components and upstream parts such as the bumper, unequal radiator resistance, etc. Thus, the connecting elements 16 are also adapted to the vehicle geometry such that the elements 16 are adjusted to the air flow according to their tangential positions to generally reduce interference with in-vehicle air flow patterns or match in-vehicle velocity conditions. Each connecting element 16 is oriented (rotated) about a radial axis A (FIG. 5) thereof in a manner different from an orientation of at least one other connecting element 16 with respect to its radial axis. In the embodiment, each connecting element 16 is oriented differently with respect to each other connecting element 16. Thus, the connecting elements 16 around the electric motor drive can be non-identically oriented and adapted to the un-symmetric flow.
With reference to FIG. 6, the main angle of orientation θ of the connection elements 16 aligns with the average oncoming air flow velocity vector V. In other words, axis B is generally parallel to V. To determine the oncoming flow angle θ for each connecting element 16, the velocity vector V is either measured or simulated using computational fluid dynamics.
The shape of the connecting element 16 of FIG. 5 fulfills three major functions: aerodynamic, acoustic, and structural (rigidity) performance. However, a disadvantage of the solid shape of the connecting element 16 is that is expensive to manufacture because it needs high pressure in the plastic injection molding process. Thus, FIG. 6 shows a section of another embodiment of a connecting element 16″ that can be molded with reduced pressure in the plastic injection molding process. This is possible since the connecting element 16″ is generally a non-symmetrical elliptical shape having cavities 20 therein to reduce material. Furthermore, when injected out of plastic, there is a maximum allowable thickness to the element. If the element is fully solid (as in FIG. 5), the plastic may not fill properly during injection. Providing the cavities 20 permits proper plastic filling and has been found not to deteriorate the acoustic, aerodynamic or structural performance of the connecting element 16″. The connecting element 16″ has a height h and a width w of maximum values defined by the U-shaped elements 100 of FIG. 1.
FIG. 7 shows a plan view of a portion of a fan module 10′ in accordance with another embodiment of the invention. In accordance with the embodiment, and with reference to FIGS. 7, 8, 9A, 9B, 9C, 10, 11A, 11B and 11C, as a function of their radial position, the shape of each connecting element 16″ changes to reflect the prevalent flow condition so as to be aerodynamically as well as structurally optimized. The air flow direction is indicated by arrows F in FIGS. 8A, 8B, 8C and 11A, 11B and 11C. Aerodynamically, the connecting elements 16′ should be as thin as possible to reduce interference with air; however, thin parts reduce the structural stability and can cause breakage of the part. Thus, an optimized configuration is preferable. Furthermore, the configuration of the connecting elements must be manufacturable, preferably made using an “off-the-shelf” state-of-art-linear injection tool.
Thus, the fan module 10, 10′ of the embodiment when employed with a fan (not shown) minimizes the acoustic disturbance associated with the installation of fan modules in tight, complicated engine compartments with the connecting elements 16, 16″ providing structural integrity.
The foregoing preferred embodiments have been shown and described for the purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments and are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the spirit of the following claims.
Patent Application
20080078340
