Arrangement for driving a fluid-circulating pump

Abstract

An arrangement for driving a fluid-circulating pump includes a drive pulley which serves as means for tensioning the driving means, such as for example, a belt, associated therewith. The pump is mounted so as to be pivotable about the axis of a tubular element defining a fluid orifice of the pump, such axis being offset from the axis of the pulley. The adjustment of the tension of the pump drive belt is thus effected by pivoting the pump, through a limited arc, about the orifice axis whereby the pulley is pivoted about the same axis thereby tensioning the belt. The assembly further includes a cover plate integrally formed with the tubular element both of which are formed of molded plastic so as to serve as gasket means, and a circular sealing element is disposed upon the tubular element so as to prevent leakage between the element and the system through which the fluid is circulated.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an arrangement for driving a fluid-circulating pump, and more particularly to a water pump of an internal combustion engine, the source tensioning the drive means, which may be for example an endless chain or preferably a belt, serving to drive the pump as well as the camshaft of the engine.

2. Description of the Prior Art

A known practice, within internal combustion engines, is that of utilizing the water pump as the source of tensioning the pump drive means by linearly translating the pump along its mounting surface. In order to facilitate this practice, the pump is fastened to the cylinder block by means of straight slotted holes provided within the pump body.

Although this practice does not normally pose a problem during assembly of the engine when the parts are new, after some time in use, the component parts begin to stick due to the infiltration of deposits within the region between the pump and the cylinder block. This sticking phenomena hinders removal of the water pump as well as the adjustment of the amount of tension within the drive means, and additionally results in the scoring of the pump and block mating surfaces which leads to cooling system leakage when the pump is remounted or readjusted upon the block.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide an arrangement for driving a fluid circulating pump wherein the pump drive pulley is the source of tensioning the pulley driving means in a manner which is intended to overcome the aforenoted defects.

Another object of the present invention is to provide an arrangement which mounts the pump so as to be pivotable about the axis of one of its fluid circulation orifices whereby the drive pulley, the axis of which is offset from the orifice axis, is likewise pivoted through a limited arc thus tensioning the driving means.

Still another object of the present invention is to provide an arrangement wherein a rigid tubular element defines the fluid circulating orifice, the element fitting within a corresponding orifice of the fluid-circulation system and being provided with a circular sealing element seated within an external peripheral groove thereof thus allowing the pump to pivot without deterioration of the fluid seal.

Yet another object of the present invention is to provide an arrangement wherein the sealing element is seated within a groove defined upon the supporting surface of the pump and located at the junction between the rigid tubular element and the pump cover plate abutted against the cylinder block in order to produce an optimal seal.

A further object of the present invention is to provide an arrangement wherein the rigid tubular element is integral with the pump cover plate thus resulting in a solid assembly which is economical to produce and which also contributes to the fluid tightness of the assembly.

A still further object of the present invention is to provide an arrangement wherein the pump cover plate and tubular element abutting the cylinder block is made of molded plastic and thus serves as the pump gasket.

The foregoing objectives are achieved according to the present invention through the provision of an arrangement for driving a fluid-circulating pump which permits the easy attainment, with the aid of simple and inexpensive means, and in a durable manner, of the adjustment of the tension of the pump driving means while substantially eliminating the risk of sticking due to deposits infiltrating the region between the pump cover plate and the surface to which it is attached. Moreover, in the instance of slight sticking of the circular sealing element, such is more easily overcome due to the couple or moment produced as a result of the pivoting movement of the pump.

BRIEF DESCRIPTION OF THE DRAWINGS

Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description when considered in connection with the accompanying drawings, in which like reference characters designate like or corresponding parts throughout the several views, and wherein:

FIG. 1 is a plan view of a water pump of an internal combustion engine constructed according to the present invention and showing its cooperative parts, specifically the pulley and pulley driving means;

FIG. 2 is a cross-section view of the pump of FIG. 1 taken along the line II--II of FIG. 1; and

FIG. 3 is a view similar to that of FIG. 2 showing however another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, and more particularly to FIG. 1 thereof, there is shown the water pump assembly of the present invention which is secured to the engine by means of a suitable rear supporting surface, the pump including a main housing body 1 and a drive pulley 2, only a portion of the drive belt 3 associated with pulley 2 being shown, the belt 3 also performing the function of a notched camshaft-drive belt through means of its notched surface portion disposed opposite the surface which is in contact with pulley 2. The body 1 of the pump includes two arcuate, elongated apertures 4 of equal radii, both of which are disposed concentrically with the axis of the rigid tubular element 18 (see FIG. 2) which is associated with the pump outlet and is disposed within the cylindrical orifice entrance 5 to the cooling circuit which is of course disposed internally of the cylinder block 6.

Such apertures 4 are diametrically opposed with respect to each other about such axis and orifice, there also being provided suitable means, not shown, adapted to be inserted within such apertures, for fastening the pump 1 to the cylinder block 6. Consequently, as the drive pulley 2, the axis of which is offset from the common axis of the rigid tubular element 18 of the pump outlet and the orifice entrance 5 to the cooling circuit, is driven by means of the outer unnotched surface of the drive belt 3, it is then possible by pivoting the water pump about the common axis, to suitably adjust the tension within the drive belt 3, the distance between the outlet orifice and the axis of pulley 2 forming a lever arm permitting the body 1 of the pump to act as stretching means for tensioning the belt.

Referring now to FIG. 2, there is shown the inlet cylindrical orifice 5 associated with the internal cooling circuit of the cylinder block 6 as associated with the pump body 1 and the drive pulley 2 thereof. Also disclosed within this Figure is the turbine wheel assembly coaxially arranged with respect to pulley 2 and including a turbine wheel 7 fixedly mounted upon a turbine wheel hub 8, the latter of which is rotatably mounted upon a pump shaft 12. An annular pump shaft seal 9 is also disposed about shaft 12 for preventing leakage therealong, and a ball bearing 10 of the pulley assembly, as well as a retaining ring 11 are further provided in order to prevent axial shifting of the pulley assembly relative to body 1, the pump shaft 12 being formed as an integral assembly with the pulley wheel 2 in a manner similar to that of the tubular inlet orifice 13 of the pump being molded moded with the pump body 1.

The cover plate 15 of the water pump, which may be made, for example, of molded plastic, is provided with three centering pins 16 which fit into corresponding holes provided within three bosses 17 equidistantly disposed upon and about the pump body 1 whereby the rigid tubular element 18 is able to be tightly and properly fitted within the cylindrical orifice entrance 5 of the internal cooling circuit of the cylinder block 6. Element 18 is made integral with the cover plate 15 and connected therewith by means of an annular flange 19, the insertion of the tubular element into the cylinder block 6 being facilitated by means of an inlet chamfer 20 associated with the cylindrical bore 5. Tube 18 is also provided with a radially inwardly extending rib 21 which serves as a reinforcement means therefor, the outer surface of tube 18 which corresponds to the axial location of rib 21 also including a circular groove which serves to retain an elastomeric O-ring 22 therewithin.

The water pump cover plate 15 thus centered upon the body 1 by means of the centering pins 16 and disposed within the cylindrical entrance bore 5 of the internal cooling circuit of the cylinder block 6 by means of the rigid tubular element 18, thus permits the realization of pivoting movement of the water pump assembly upon the cylinder block 6, the fastening of the pump at a particular position after suitable adjustment of the tension within the belt 3 being effected by means of tightening of the bolts which pass through the elongated slots 4, the sealing of the pump assembly with respect to the inlet to the cylinder block 6 being of course assured by means of the O-ring 22.

Furthermore, due to the fact that the cover plate 15 is made of molded plastic and forms an integral assembly along with the rigid tubular element 18, it is apparent that in addition to its low cost and ease of manufacture in large quantities by utilizing processes which mold the same under pressure, the plastic composition inherently imparts to such components advantageous sealing surface properties thereby avoiding the need for gaskets to be interposed between the pump body 1 and cover plate 15, and/or between the cover plate 15 and the cylinder block 6, thereby lowering the cost of the assembly still further.

Turning now to FIG. 3, another embodiment of a water pump assembly, conforming to the present invention, is shown wherein the configuration of the rigid tubular element 18 integral with the pump cover plate 15, as well as the disposition of the O-ring 22 has been modified, all the other details of the pump remaining unchanged. Within this embodiment, the cover plate 23 is similarly provided with the centering pins 16, however the rigid tubular element 24 no longer includes the radially inwardly extending rib 21 and the constriction produced thereby which risks throttling of the flow of the cooling water, nor the external grooved seat for the sealing O-ring 22.

In contrast thereto, an O-ring 25 is seated within an annular groove formed within the upper surface of the cover plate 23 at a position surrounding orifice 5 so as to rest against the undersurface of cylinder block 6 at the juncture of the tube 24 with the cover plate 23, an annular rib or bead 26 being formed within the lower surface of the cover plate 23 at a location corresponding to that of ring 25 so as to embrace the same and protrude in the axial direction into the interior of the pump body 1. This embodiment, while assuring optimal sealing of the cooling circuit and reinforcement of the cover plate 23 near its juncture with tube 24, also provides a better flow pattern of cooling liquid through the pump and into the circuit than the preceding embodiment, due to the presence of a vertically disposed deflector element 27 which is axially aligned within tubular element 24 so as to divide the same into two equal halves, such component thereby serving to form a nozzle thereof while providing reinforcement therefor. Moreover, such component renders unnecessary and even deleterious, for good contact of the O-ring seal 25 within the groove within member 26 and between the cover plate 23 and block 6, the chamfer upon inlet 20 thereby permitting the elimination of a machining operation upon the cylinder block 6, the seal 25, by simply pressing against the surface of block 6 with which it is in contacts, thus removing all risk of scoring of the component parts.

Thus, it may be seen that the fluid circulating pump of the present invention has important advantages over the prior art structures in that the arrangement for driving the fluid-circulating pump thus permits the realization, in a practical and durable manner and by simple and economical means which may be easily mass-produced, of tension adjustment of the pump driving means. In addition, it should be further appreciated that the application of such an arrangement is not limited to the realm of water pumps for internal combustion engines as described above, but can extend to any use of a fluid-circulating pump, such as for example, pumps for the hydraulic actuation of, or for the circulation of cutting oil within, a machine tool, pumps for domestic or industrial washing machines, or the like.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood therefore that within the scope of the appended claims the present invention may be practiced otherwise than as specifically described herein.

Claims

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An arrangement for driving a fluid-circulating pump comprising:

a housing;

a pulley wheel associated with said housing and being rotatable about a first axis;

tensionable means for driving said pulley wheel about said first axis;

said housing having associated therewith means defining a fluid orifice the axis of which is offset and parallel to said first axis of said pulley; and

means for permitting said housing to be pivoted about said orifice axis,

whereupon said pulley is likewise pivoted about said orifice axis so as to adjust the tension within said tensionable driving means.

2. A driving arrangement as set forth in claim 1, wherein said means defining said fluid orifice comprises a rigid tubular element which is adapted to be fitted within a corresponding orifice of a circulation system through which said fluid is to be pumped.

3. A driving arrangement as set forth in claim 2 wherein said rigid tubular element is provided with a groove disposed upon the external periphery thereof within which a sealing element may be seated.

4. A driving arrangement as set forth in claim 3, wherein said sealing element is an O-ring.

5. A driving arrangement as set forth in claim 3, wherein said groove for seating said sealing element is disposed at the junction between said tubular element and said housing.

6. A driving arrangement as set forth in claim 2, further comprising:

a cover plate disposed over said housing; and

said rigid tubular element is integrally formed with said cover plate.

7. A driving arrangement as set forth in claim 6, wherein said cover plate and said tubular element are made of molded plastic so as to serve as gasket means for said pump.