JPS6336434B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Marine drives having water-cooled engines utilize a water pump mounted on the drive shaft within the drive shaft housing to cool the engine.

Some conventional water pumps used to cool outboard engines utilize cast metal housings. This cast metal housing requires machining and is expensive to make. In addition, when water pumps made of solid or aluminum castings are used in water containing sand or silt, their moving parts wear out and have a relatively short lifespan.

Another type of conventional water pump uses a molded plastic housing. A metal liner is placed within the plastic housing to provide wear resistance. Without a metal liner, the plastic would wear quickly, causing failure. A water pump failure is also an engine failure.

The present invention provides an improved water pump for marine drives that is simply and economically constructed through the use of stamped metal parts. These parts are used without machining.

The improved water pump of the present invention is installed in a marine drive and has a base plate having an eccentric drive shaft opening and a water inlet communicating with a cooling water intake, an end wall and a peripheral wall, the end wall A cup-shaped impeller housing formed of deformed sheet metal has an eccentric drive shaft opening and a water outlet, and is installed within the impeller housing to propel water from the water inlet to the water outlet and to the drive shaft. an impeller having an articulated central portion and a plurality of flexible impeller blades projecting outwardly from the central portion and contacting a peripheral wall of the impeller housing; and includes an impeller housing and a shroud forming a water collection chamber connecting the water outlet to the drain.

The water pump of the present invention has a long service life, excellent silt resistance and dry operation. Stamping the metal work hardens the wear surface and provides silt resistance, while the long flexible blades of the impeller reduce wear on the impeller housing and extend the life of the impeller. The water pump of the present invention has all the features necessary for a marine drive. These features include wear resistance, dry running durability, reduced diachronic pressure loss, long life, corrosion resistance, relatively low cost, and excellent long-term bonding of the impeller rubber to the non-metallic insert. It is gender. In this water pump, long flexible vanes reduce radial pressure,
Reduces impeller housing wear, while increasing blade life, reducing pressure loss over time, and lowering friction. This low friction means that
Reduces heat stored in the blades and improves drying operation.

The marine drive is shown as an outboard engine 10 in FIG. This outboard engine 10 has a drive shaft 14
It includes a liquid-cooled power head 12 that drives the. The engine is cooled with water supplied by pump 16. The propulsion unit 18 of the engine 10 has a water intake 20 which is submerged when the propulsion unit 18 is in the operating position. The water pump 16 may also be mounted within the outboard engine 10, in which case it is also submerged when the propulsion unit 18 is submerged.

Water pump 16 includes a base plate 22 that is mounted within outboard engine 10 above water intake conduit 24 and within the gearcase housing. This base plate 22 is preferably made of stainless steel plate. The base plate 22 has an eccentric drive shaft aperture 26 and is spaced apart from the aperture 26 .
Includes a water inlet 28 that communicates with water intake conduit 24 .

A cup-shaped impeller housing 30 is installed on the base plate 22 and has a water inlet 28.
is connected to. In the preferred embodiment, the impeller housing 30 is constructed from sheet stainless steel, providing economy in manufacturing the water pump 16 as well as corrosion resistance and allowing for hardening in desired areas. Impeller housing 30 has a peripheral wall 32 . The end wall 34 of the impeller housing 30 also includes an eccentrically located drive shaft aperture 36. End wall 3
4 also includes a water outlet 38 spaced from the opening 36;
This water outlet is approximately on the opposite side in the figure from the water inlet 28 after the water pump 16 is assembled.

An impeller 40 is contained within the impeller housing 30.
The impeller 40 is made of a flexible material such as a heat-resistant synthetic rubber compound. Preferred materials include nitrile elastomers. The impeller 40 has a boss 42,
The boss is partially formed of fiber-reinforced plastic to increase the corrosion resistance of the water pump 16 by avoiding metal-to-metal contact between the impeller 40 and the drive shaft 14. The boss 42 is keyed to the drive shaft 14 by a key 44. A plurality of long and flexible impeller blades 46 extend from the boss 42.
stands out. In the preferred embodiment, six such vanes are provided, as shown in FIG. There are seal rings 4 on both sides of the boss 42.
8,50 are provided to seal the impeller housing 30 when the impeller 40 is installed within the impeller housing 30 as shown in FIG. The length and flexibility of the vanes 46 and the outer diameter of the impeller housing 30 are selected such that the radial pressure exerted by each vane 46 on the peripheral wall 32 is low and the deflection stress created in the vanes 46 is low. In a preferred embodiment, the vane length is approximately 0.64 inches (16.3 mm), the vane width at boss 42 is approximately 0.2 inches (5.1 mm), and the vane length-to-width ratio is approximately
The ratio is 3.2:1. The outside diameter of the boss is approximately 1.04 inches (26.4 mm) and the impeller housing 3
The inside diameter of impeller housing 30 is approximately 2 inches (50.8 mm), which is the inside diameter of impeller housing 30 versus impeller boss 4.
The ratio of the outer diameters of the two is greater than 1.9:1.
The height of the vanes can be adjusted to obtain the desired capacity or flow rate of the water pump. In another embodiment,
The length of the blade is approximately 0.85 inches (21.6 mm),
The width of the vane at boss 42 is approximately 0.26 inches (6.6 mm), and the length-to-width ratio of the vane is approximately
The ratio is 3.3:1. The outside diameter of the boss is approximately 1.2 inches (30.5 mm), the inside diameter of the impeller housing 30 is approximately 2.5 inches (63.5 mm), and the ratio of outside boss diameter to inside diameter of the impeller is approximately 2.1:1.

For best deflection life of the vanes 46, their length to width ratio is greater than or equal to 3:1 and the impeller housing 3
The ratio of the inner diameter of 0 to the outer diameter of the impeller boss 42 is
Must be greater than 1.9:1. The impeller 40 is eccentric to the inner diameter of the housing 30 as described above and shown in FIG.
Because it is located within the housing 30, the outer diameter of the impeller 40 is larger than the inner diameter of the impeller housing 30. The ratio of the outer diameter of impeller 40 to the inner diameter of impeller housing 30 is between 1.10:1 and 1.16:1.
within the range of This is necessary to form a seal between the end of the vane and the peripheral wall 32.

Also, the width of the tip of the blade should be as small as possible. In a preferred embodiment, the tip width is about 0.12 inches (3.0 mm), and in another embodiment, the tip width is about 0.15 inches (3.8 mm). To obtain this tip width, the vane is tapered from its width at its boss to its distal width at an angle of about 8 to 9 degrees.

The impeller housing 30 has a shroud 52.
are fitted. In the preferred embodiment, the shroud 52 is formed from stainless steel sheet. Shroud 52 includes a flange 54 that contacts base plate 22. Shroud 52
and base plate 22 is attached to propulsion unit 18 by bolts 56. bolt 56
It is also made of stainless steel to prevent corrosion. A non-metallic sleeve 58 is installed between the bolt 56 and the flange 54 to improve corrosion resistance. Shroud 52 has a peripheral wall 60 that is press fit to peripheral wall 32 of impeller housing 30 . An O-ring 62 on the edge of this peripheral wall 60 seals the base plate 22 from the impeller housing 30, and another gasket between the base plate 22 and the shroud 52 seals the base plate 22 outboard. It is sealed from engine 10. The transition between peripheral sidewall 60 and flange 54 may be suitably shaped to accommodate O-ring 62. The shroud 52 has an eccentric opening 66 for inserting the drive shaft 14.
It has an end wall 64 including. A rotating slinger 68 is installed at the top of the water pump 16 over the drive shaft to prevent mud and sand from entering. When press-fit, the end wall 34 of the impeller housing 30 and the end wall 64 of the shroud 52 define a water collection chamber in the form of a spiral passage 70, which collects water in the impeller housing 30. The outlet 38 is connected to a drain pipe 72 via a connector 74. A drain pipe 72 runs from the water pump 16 to the outboard engine 10.
Cooling water is sent to the heat generating parts of the

In operation, the impeller housing 30
Water is received through water inlet 28 in plate 22. As shown in FIG.
4 causes each revolution of the impeller 40 to deflect sequentially against the peripheral side wall 32 of the impeller housing 30, first to a greater degree and then to a lesser degree. The deflection of the vanes 46 and the resulting volume reduction between the vanes and the peripheral wall of the impeller housing 30
The water therein is directed to the water outlet 38 and through the spiral passage 70 to the drain pipe 72.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of an outboard engine showing the water pump of the present invention, FIG. 2 is a cross-sectional view of the water pump of FIG. 1, and FIG. 3 shows the components of the water pump of FIG. 1. FIG. 4 is a top view of the impeller of the water pump of FIG. 1, and FIG. 5 is a bottom view of the impeller within the impeller housing. 10... Outboard engine, 12... Power head, 14... Drive shaft, 16... Pump, 18...
Propulsion unit, 20... Water intake, 22... Base plate, 26... Eccentric drive shaft opening, 28...
...Water inlet, 30...Impeller housing, 34
... End wall, 36 ... Eccentric drive shaft opening, 40 ... Impeller, 42 ... Boss, 46 ... Vane, 52 ...
Shroud, 64... End wall, 32... Surrounding side wall,
38... Water outlet, 48, 50... Seal ring, 60... Surrounding side wall, 64... End wall, 68...
Rotating slinger.

Claims (1)

[Scope of Claims] 1. A water pump for a marine drive machine having a water-cooled engine that rotates a drive shaft and a cooling water intake, the water pump comprising: (a) being installed in the marine drive machine and having an eccentric position drive; a base plate having a shaft opening and a water inlet leading to a cooling water intake; (b) an end wall and a peripheral side wall, the end wall having an eccentrically located drive shaft opening and a water outlet; (c) an impeller disposed within the impeller housing and capable of propelling water to be received at the water inlet and discharged at the water outlet; an impeller having a central boss connected to a shaft and a plurality of flexible impeller blades extending outwardly from the central boss and contacting a peripheral sidewall of the impeller housing; (d) the impeller housing; and is mounted on the base plate to abut against the end wall and peripheral side wall of the impeller housing, forming an arcuate water collection chamber together with the impeller housing, and connecting the water outlet to the drive shaft. a shroud made of deformed sheet metal connected to a pump discharge opening angularly displaced from said water outlet about an axis of the pump, said base plate, impeller housing and shroud being made of stainless steel; A water pump, wherein the impeller housing has a work-hardened peripheral wall. 2. A water pump according to claim 1, wherein the shroud abuts the base plate, and there is a sealing device between the shroud and the base plate. 3. In the water pump according to claim 1, the length and width dimensions of the impeller blades themselves produce a low deflection stress, and the length dimensions are arranged in a radial direction with respect to the drive shaft. , the width dimension is perpendicular to the length dimension and the drive axis, the blade length-to-width ratio is greater than 3:1, and the impeller housing inner diameter to impeller boss outer diameter ratio A water pump characterized in that the ratio is greater than 1.9:1.