US2542902A - Water pump - Google Patents

Description

Feb. 20, 1951 H. A. CHUBBUCK 2,542,902

' WATER PUMP Filed Jan. 31, 1946 3 Sheets-Sheet 1 l g HORACA.CIIUBBUCK.

INVENTOR. efe ix? by A? ,4 M

f a? s ant-4A 77/)? (24 ATTORMEKQ Patented Feb. 20, 1951 WATER PUMP Home A. Chubbuck, Deal-born,

Mich., assignor to Ford Motor Company, Deal-horn, Mich, a corporation of Delaware Application January 31, 1946, Serial No. 644,560

1 Claim. 1

This invention is directed to a liquid pump, and more particularly to a centrifugal water pump. This invention will be particularly described in connection with a coolant circulating pump on an internal combustion engine, but is by no means so limited and is capable of use in any application requiring a pump of similar characteristics.

An object of this invention is to provide a pump the discharge of which is free from pulsations and oscillations.

Another object of this invention is to provide a pump 01' high efliciency particularly at high speeds and when pumping water the temperature 01' which closely approximates the boiling point.

With these and other objects in view, the invention consists in the arrangement, combination and construction of the various parts of m improved device, as described in the accompanying specification, claimed in the claim and illustrated in the accompanying drawings, in which:

Figure 1 is a plan view with parts broken away of the pump housing.

Figure 2 is an elevation of the pump housing.

Figure 3 is a central longitudinal vertical section oi a completed pump.

Figure 4 is a plan view of the pump impeller.

Figure 5 is a perspective view partially broken away of the pump housing.

Figure 6 is a section taken in Figure 4.

The overall efilciency of the single stage centrifugal pumps previously employed to circulate the coolant in internal combustion engines has been quite low. This inefficiency, per se, has not been a serious consideration since the total power requirements of the pumps are relatively small. The chief difliculty encountered in the operation of the usual coolant pumps has been a sharp decline in delivery at high speeds. Since it is at high speeds that a large volume of coolant is required, it is readily seen that a pump characterized by a drooping delivery curve at high speeds must be designed on a much larger scale than one without such a drooping curve.

The solution of this problem proposed by applicant is readily understandable from a conalong the line 6-8 sideration of the drawings and more particularly from simultaneous consideration of Figures 1, 2, 3 and 5. Turning first to Figure 3, there is shown a vertical section of the pump and the associated driving mechanism. The pump casing is generall indicated by In. This casing is usually an iron casting and is provided with an impeller cavity I 3, an inlet I, an inlet cavity IS, a separator l6 and separator opening I! leading into discharge cavity [8. This casing is further provided with a heater connection 24 threaded to receive a hot water heater fitting, a seal opening 34 which accommodates a seal 21 and an opening l2 into which is pressed ball bearing 26 which carries shaft 25. This shaft 25 carries on one end an impeller 2| and on the other end hub 3 I! and pulley 32 secured by retainer ring 33. The pump seal is generally indicated at 21 and is pressed into seal opening 34. This seal comprises a metal seal casing 35 which is pressed into seal opening 34 and which carries elastomer seal bellows 28. Graphite sealing ring is attached to elastomer seal bellows 29 and urged towards the left by coil seal spring 28. This seal cooperates with face 31 of impeller hub 36 (Figures 4 and 6).

The general relations of the various parts of the pump are shown in Figure 3. However, in the interest of clarity, Figures 1, 2 and 5 show only the pump housing, the seal and all moving parts having been omitted. An important distinction between this pump and those of the prior art is the provision of ramp 20 in inlet cavity IS. The structure of this ramp is best seen in Figure 5 although it is also shown in Figures 1 and 3. The flow oi coolant through the pump is illustrated by the arrows in Figures 2, 3 and 5 as entering through inlet I 4 flowing into inlet cavity l5 past separator I6 and impeller 2| into discharge cavity 18.

Due to the rigid space and weight limitations inherent in automotive design, all dimensions of this pump must be kept as small as possible. This causes the impeller hub 36 diameter to be a substantial fraction of the diameter of inlet cavity 15 and separator opening IT. The impeller hub rotation tends in previous designs to cause a corresponding rotation of the water in inlet cavity l5. This rotation in inlet cavity I5 is highly un desirable inasmuch as it causes inlet cavit l5 to act as the first stage of a two stage pump, the second stage being in impeller cavity 13. These two stages are of course pumping in opposite directions and it is this opposition which results in a drop in efilciency at high speed. These opposing actions also give rise to an oscillating or pulsating delivery in which the variations in pressure amount to as much as five inches of mercury.

Applicant has efiectively cured this defect and greatly enhanced the efficiency of this: type of pump by the simple expedient depicted in Figures 1, 2 and 5. Ordinarily inlet cavity I5 is an nular or doughnut shaped. Applicant has modified the configuration of inlet cavity I 5 by inserting ramp 2!! as shown most clearly in Figure 5 The exterior outline of ramp 2!! is shown in Figure 2. This deflecting ramp covers about one hundred twenty degrees around the periphery of inlet cavity 15 and in this one hundred twenty degrees slopes from the rear to the front of inlet cavity l5. Any tendency of the water to rotate in inlet cavity l5 causes a flow along the slope of ramp 20 and directly into impeller cavity l3. 5

Figures 1, 2 and 5 show face H which is bolted tightly against a mating face on the engine block (not shown) by bolts placed in bolt holes 38. In Figure 1 is shown bypass l9 leading directly from inlet cavity IE to the engine block. The object of this bypass is to prevent the development of hot spots in the engine during the warming-up period while normal circulation through the radiator is cut off by the engine thermostats. During normal operation circulation through bypass I9 is prevented by a valve action of the thermostats and all circulation is through the radiator.

Figures 4 and 6 depict in detail a preferred form of impeller. Figure 4 is a plan view showing full blades 22, half blades 23 and impeller hub face 31. Figure 6 is a sectional view taken along the line 8-6 of Figure 4. This figure shows full blades 22, impeller hub 36 and impeller hub face 31.

with standard pumps, a test set up was established in which the pumps to be tested were caused to pump hot water in a circuit containing a number 11 orifice having a diameter of eleven-sixteenths of an inch. Pumping 200 F. water, the

vmaximum pressure drop across the orifice with the modified pump was found to be 17.8 pounds per square inch at 5425 R. P. M. A standard pump with the same impeller also working on 200 F. water reached a maximum pressure of 11.1 pounds per square inch at 4900 R. P. M., and

To test this pump so modified and compare it I at 5425 R. P. M. the pressure was only 10.7 pounds per square inch. At 210 F., the modified pump generated 5.05 pounds per square inch at 3100 R. P. M. and the standard pump 3.6 pounds per square inch at 2600 R. P. M. and 2.9 pounds per square inch at 3100 R. P. M.

Some changes may be madein. the arrangement, construction and combination of the various parts of my improved device, and it is intended to cover by the claim such changes as may be reasonably included within the scope thereof.

I claim as my invention:

A centrifugal coolant pump for internal combustion engines comprising an impeller chamber, an intake cavity, a rotating member in the intake cavity whose diameter is a substantial fraction of the intake cavity diameter and which is exposed directly to the coolant therein, a ramp in the intake cavity, and a separator disposed between the impeller chamber and the intake cavity, the direction of the slope of said ramp being such that coolant rotating with the shaft in the intake cavity will be given an axial component of motion towards the impeller chamber, the separator be-,- ing so arranged that no axial flow is possible from said ramp into the impeller chamber except by passing around the inner periphery of the separator.

HORACE A. CHUBBUCK.

REFERENCES CITED The following references are of record in the ills of this patent:

UNITED STATES PATENTS Number Name Date 1,817,169 Schwitzer et a1. Aug. 4, 1931 2,001,369 Ruesenberg May 14, 1935

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