JPS5936117B2 - thin plate fan assembly - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet fan assembly particularly suitable for use in the cooling system of an internal combustion engine installed in a motor vehicle.

A typical example of the utility of a fan assembly according to the present invention is between a motor vehicle's radiator and engine.

The fan draws air from the surrounding area through the radiator.
This helps cool the fluid that has transferred heat from inside the engine to the radiator.

Such fans are well known and come in a variety of formats, and are of interest to many skilled in the art.

One common type of fan structure as described above consists of a laminar bub or spider with radially outwardly projecting arms.

Each of the arms supports a vane which may be attached to it by welding, riveting or the like.

Either or both of each blade and the arm to which it is attached can be twisted to change the pitch of the fan.

The spider bub is attached to a pulley or other rotating member driven by the engine.

Some examples of such prior art thin plate fan structures are shown in the following patents: US Pat.

U.S. Patent No. 295,449 (Sm i th), U.S. Patent No. LO 41,913 ('1.”yson), U.S. Patent No.
Ti No. 7,103 (Ste 1nbach),
Same 1st. ．． No. 255,346 (Sp-arks), No. 1.404,298 (Jacobs), No. 1. ．． 5
No. 97,175 (Boening), No. 1, . 868
, No. 528 (G-ardner), No. 2,681, 7
No. 08 (M i x ), No. 2,906,349 (
Hans), No. 3,147,811 (Klonos
ki), No. 3,147,958 (Stifflo
r), No. 3,827,842 ('Pope), British Patent No. 417,232, West German Patent No. 762,625 and British Patent No. 908,586.

However, these patents do not necessarily represent all of the prior art.

In accordance with the practice of the present invention, a fan assembly is constructed in which each blade is bent outward from the plane of rotation of the fan assembly to assist in radially outward flow.

Here, the radial direction refers to a direction extending outward from the rotation axis.

By directing the flow radially outward, the amount of exhaust space required directly behind the fan can be reduced.

In the fan assembly of the present invention, relatively thin sheet steel blades are provided with reinforcing rib elements.

This rib element increases the strength of the blade, thereby allowing the thickness and weight of the metal plate to be reduced.

Furthermore, according to the practice of the present invention, damage to the vanes is prevented.

Typically, blade failure occurs due to resonance of each spider arm, but this is reduced by the novel reinforcing rib structure on each fan blade.

Each spider arm also includes a rib on the radially outer portion of each spider arm that matches a complementary rib formed on the radially inner portion of each fan blade.

Additionally, according to practice of the invention, a novel connection is created between each vane and the arm to which it is attached.

This is done, for example, by forming point connections in the form of rivets, spot welds or similar forms in a particular manner with respect to the reinforcing ribs on the fan blades.

The present invention will now be described in detail with reference to the accompanying drawings.

In the accompanying drawings, the number 10 generally indicates the thin plate fan assembly of the present invention.

The assembly is formed from a thin plate hub 12 having a plurality of angularly spaced arms 14.

Hub 12 is sometimes referred to as a spider and arm 14 is referred to as a spider arm.

Number 16 indicates a typical fan blade according to this configuration.

The radially outer portion 18 of this fan blade is bent away from the rest of the fan blade.

Each of the fan blades 16 is generally in the form of a portion of a cylindrical surface, with a curved portion 18 extending forward or toward the radiator from the generally minor portion of the blade across the width of the blade.

Number 20 indicates one of the reinforcing channels and number 22 indicates a similar channel.

The two channels 20 and 22 extend in substantially parallel radial directions to form arms.

A channel 24 extends generally transversely to the radial direction from the radially inner ends of the channels 20 and 22 and forms a generally U-shape with the channels 20 and 22.

Ribs 30 extend from the radially inner portion of each fan blade 16 and intersect the channel 24 forming the radially inner portion of the U-shape.

Both the reinforcing channels 20, 22, 24 and the reinforcing ribs 30 bulge outward from the front side of the fan blade, ie, the side facing the radiator, and are both of the same depth.

Number 32 indicates the rivet used to fasten each fan blade 16 to each spider arm 14.

One of these rivets is on the inside of the branched reinforcing channel and the other two are on the outside of the reinforcing channel, i.e. one on one side of the reinforcing rib 30 and one on the other side.
There is one.

The spider or hub 12 is provided with a side wall 40 connecting an edge flange 46 and an inner portion 41 .

As shown in Figures 3 and 5, each datum is 14 degrees.
45 has a forward or radiator facing mounting extending radially outwardly from the hub 12 and having a generally triangular shape.
is formed.

This attachment is flat-faced and twisted from the face of the edge flange 46, as shown at 46'.
It merges smoothly with 6.

The inner end of each vane 16 is likewise formed with a flat, generally triangular region 47, the rear surface of which is secured to a mounting surface 45.

Each arm 14 is formed with a groove 44 which interrupts the side wall 40 and merges smoothly with the front surface of the inner portion 41 of the hub, as shown in FIG. It extends radially from section 41 inside mounting surface 45 and terminates just short of the outermost rivet area, as shown in phantom in FIG.

The groove 44 bulges toward the rear of the arm 14, that is, toward the engine, and forms a reinforcing rib 44' extending in the radial direction.

The two ribs 44' and 30 align to form a tubular reinforcing structure as shown in FIGS. 5 and 6.

The surface of the fan blade 16 and the surface of the arm 14 are flat in the area of the rivet 32, except in the area of the reinforcing ribs 30 and 44', respectively.

The radially outer end of spider 12 terminates in a flange designated by numeral 46.

In particular, as seen in FIG. 2, the spider arm 14 is twisted relative to the plane of the spider hub 12 to define the pitch of the fan blades.

Note that if a straight line were drawn from the radially outermost rivet 32 inside the reinforcing channel to either of the other two rivets, that straight line would intersect the channel portion 24 at right angles.

Typical sheet fan blade failure is caused by spider arm resonance.

Typically, the bending will occur around the attachment point defined by the rivet 32.

In the configuration of the present invention, bending of the fan blade 16 (third
) occurs at right angles to the reinforcing channel portion 24 around a straight line drawn from the inner rivet 32 of the reinforcing channel to either of the other two outer reinforcing channel rivets 32, and therefore this geometry Because of this relationship, the fan blades 16 of the present invention are resistant to breakage.

It will also be appreciated that one of the strongest structural shapes is a triangle, which is the overall shape of the reinforcing channels 20, 22, 24.

That is, one of the sides 20° 22.24 cannot be easily twisted, preventing the other two sides from twisting.

Additionally, ribs 30 at the radially innermost portions of each fan blade 16 provide continuity and radial stiffness to the spider hub 12, with ribs 44' and ribs 30 facing each other to provide continuity and radial stiffness. is giving.

As can be seen in particular from FIG. 2, the hub 12 is generally dish-shaped.

This biases forward and creates a center hole with the minimum required distance between the mounting surface and the rear of the assembly.
(piercing) or offset the fan blades to the rear.

A typical fan blade assembly according to the present invention has a width of about 8
There are reinforcing channels 20, 22, 24 and reinforcing ribs 30 of approximately 5/16 inches in length and approximately 0.30 inches deep.

Typical reinforcing channels in the ribs of the prior art had a depth of about 3 mm (on the order of +2 inches).

This relatively large ratio between depth and width of the channels or ribs of the invention allows the use of thinner metal plates for the fan blades.

Another advantage brought about by the configuration of the invention is that
A greater radial airflow is created by the tip of each fan blade being bent toward the suction side of the fan assembly, ie, toward the radiator.

As previously discussed, greater radial airflow improves the cooling efficiency of the fan assembly.

In Figure 2, the tip of each blade is bent to the right,
Extending beyond the projected width of the fan assembly.

The projected width of the fan assembly is the width as viewed perpendicular to the axis of rotation of the fan assembly.

Number 19 indicates the extension of the tip extending beyond the remaining partial projected width PW of the fan blade.

Therefore, the tips of the fan blades form the widest projected width of the fan assembly.

The rear surface of the inner portion of the hub is used to attach the fan assembly to a member (not shown) that is driven by the engine.

The spacing T between the radiator and the engine block, represented respectively by lines P and B in FIG. 2, is often completely limited, and the spacing allocated for the fan assembly is correspondingly very small. .

The engine block is mounted directly behind the fan blades, so the air exhausted by the fan blades hits the engine block directly.

This not only restricts airflow, but also causes the fan to consume unnecessary power.

Accordingly, this type of fan blade has its tips bent forward to direct the airflow radially outwardly, thereby reducing the airflow impinging on the engine block.

In normal practice, the forward curved tips of the fan blades are notched generally along the lines indicated at 48 in FIG.
Then, the twist of the fan blade is adjusted so that it becomes equal to the projected width distance W of the fan blade.

However, as described above, the projected width PW of most fan blades is reduced, and the front edge portion 49 of the tip of each fan blade is
By maximizing the projected width of the fan, less power is consumed by the fan to obtain the airflow required through the radiator.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a representative thin plate fan blade structure in accordance with the practice of the present invention. FIG. 2 is a view taken along line 2--2 of FIG. FIG. 3 is an enlarged view of a part of the typical fan blade and spider shown in FIG. FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. FIG. 6 is a cross-sectional view taken along line 6--6 of FIG. 10... Thin plate fan assembly, 12...
Bub (spider) 14...Spider arm, 1
6...Fan blade, 18...Tip portion, 20, 22, 24...Reinforcement channel, 30
...Reinforcement rib, 32...Rivet

Claims (1)

Claims: 1. A laminar fan assembly comprising a laminar bub having a plurality of radially extending spider arms, each having a laminar fan blade, over each of the arms outwardly from its surface; a radially extending rib is provided, and a radially inner portion of each of the fan blades is provided with a rib extending radially along the fan blade and projecting outwardly from a surface of the fan blade; the fan blade is fixed to the spider arm such that the ribs on the fan blade are aligned with the ribs on the spider arm, each of the fan blades intersecting a radially outer end of a rib on the blade; and a reinforcing channel branching laterally from each side of the outer end, the channel projecting outwardly from the surface of the fan blade in the same direction as the ribs on the fan blade, the channel extending outwardly from the surface of the fan blade in the same direction as the ribs on the blade. A thin plate fan assembly comprising: a radially inner portion extending substantially transversely to the direction; and arms extending substantially parallel to the radial direction at both ends of the inner portion. Three-dimensional. 2. A laminar fan assembly comprising a laminar bub having a plurality of radially extending spider arms each having a laminar fan blade secured thereto, extending radially from a radially inner portion of each of the laminar fan blades; ribs projecting outwardly from a surface of the vanes; and reinforcing channels on each vane intersecting the radially outer ends of the ribs and branching laterally from opposite sides thereof. A thin plate fan assembly characterized by: