COOLANT PUMP
A coolant pump includes a housing having an internal axis; a bearing disposed on an outside surface of the housing; a shaft disposed along the internal axis of the housing, wherein the shaft is journaled by the bearing so as to be rotatable; an impeller disposed on the shaft so as to rotate with the shaft; and a seal disposed on the shaft at least partially inside of the bearing so that the bearing overlaps the seal along the internal axis of the housing, wherein the bearing has an inner diameter, the seal has an outer diameter, and the inner diameter of the bearing is greater than the outer diameter of the seal. An internal combustion engine incorporating a cooling system connected to a coolant pump in accordance with the invention is also disclosed.
This application claims priority from U.S. Provisional Patent Application No. 60/915,300, filed May 1, 2007, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTIONThe present invention relates to a coolant pump such as may be employed to pump coolant for an internal combustion engine. More particularly, the invention relates to a coolant pump that has its seal located at least partially within the bearing for the pulley actuating the coolant pump.
BACKGROUND OF THE INVENTIONIn the art of coolant pumps used for industrial applications, especially water pumps for cooling internal combustion engines for automobiles and like vehicles, a conventional water pump 10 having the features shown in
To prevent coolant from leaking out of the coolant system, the water pump 10 includes a seal 40 that is separated axially from the bearing 25 by a space 45. As is known in the art, the seal 40 is not 100% effective so that some small amount of coolant leaks from the coolant system and contaminates the bearing 25. The conventional water pump 10 has the drawback that the leaked coolant contaminating the bearing 25 collects in space 45 and eventually causes damage to the bearing 25, which shortens the operating life of the bearing 25 and of the pump 10. Bearing contamination occurs despite the fact that space 45 is contiguous with one or more holes or channels for draining out leaked coolant. However, coolant contamination of the bearing still occurs, especially if there is a significant leakage of coolant.
One recent improvement over the conventional water pump 10 is a so-called external bearing water pump 50 such as shown in
As shown in
However, both the conventional water pump 10 and the external bearing pump 50 suffer from the following drawbacks. First, these water pumps are not space efficient. More particularly, the spaces 45 and 85 of pumps 10 and 50, respectively, are underutilized spaces that add to the axial dimension of the pump. Second, with respect to the external bearing pump 50, the pulley 60 located at one end of the pump 50 not only rotates the shaft 55, but due to imperfections in axial alignment may also introduce some degree of runout or wobble of the shaft about its axial axis. Such runout of the shaft 55 about its axial axis creates potential damage of the seal 80 of the pump 50 and the seal 80 does not work under ideal conditions. The farther the seal 80 is located from the point of attachment of the pulley 60 with its shaft 55 the more pronounced the effects to the seal will be due to the misalignment the pulley imparts along the shaft.
The present invention endeavors to provide an improved coolant pump that maintains the advantages of the external bearing coolant pump while overcoming the disadvantages of the external bearing and conventional coolant pumps. Accordingly, a primary object of the present invention is to overcome the disadvantages of prior art coolant pumps.
Another object of the present invention is to provide a coolant pump that is practical and cost effective to manufacture, and that is space efficient and compact.
Another object of the present invention is to provide a coolant pump that is both durable and reliable, and that is less prone to bearing failure due to damage from coolant leakage.
Another object of the present invention is to provide a coolant pump that is both durable and reliable, and that is less prone to excessive damage to its coolant seal due to the effect of runout about the axial axis of the shaft of the coolant pump.
SUMMARY OF THE INVENTIONIn accordance with the above objectives, one embodiment of the present invention provides a coolant pump that includes (1) a housing having an internal axis; (2) a bearing disposed on an outside of the housing; (3) a shaft disposed along the internal axis of the housing, wherein the shaft is journaled by the bearing so as to be rotatable; (4) an impeller disposed on the shaft so as to rotate with the shaft; and (5) a seal disposed on the shaft at least partially inside of the bearing so that the bearing overlaps the seal along the internal axis of the housing, wherein the bearing has an inner diameter, the seal has an outer diameter, and the inner diameter of the bearing is greater than the outer diameter of the seal.
In accordance with another embodiment of the invention, the coolant pump may be further modified so that the seal is a dynamic seal. In accordance with still other embodiments of the present invention, the coolant pump may be modified so that the seal is a lip seal. In accordance with another embodiment of the present invention, the seal prevents leakage of coolant when the impeller is in contact with coolant from a cooling system of an internal combustion engine.
In accordance with another embodiment of the present invention, the coolant pump is modified so that the bearing comprises an inner ring defining said inner diameter and an outer ring disposed to rotate on the inner ring, wherein the inner ring is fixed to the housing. In accordance with still another embodiment of the invention, the coolant pump further includes a pulley having an inner surface connected to the outer ring of the bearing so that the outer ring is rotatable with the pulley, wherein the pulley also has a central portion attached to the shaft so that when the pulley is rotated, the pulley, the outer ring of the bearing, the shaft and the impeller rotate together. In accordance with still another embodiment of the present invention, the bearing further comprises one or more tracks of rolling elements sandwiched between the inner ring and the outer ring of the bearing. In accordance with still another embodiment of the present invention, the pulley further comprises a belt engaging portion adapted to engage an actuator belt to rotate the pulley and actuate the coolant pump.
In accordance with another embodiment of the present invention, the coolant pump further comprises a support member connected to the outer ring of the bearing so that the support member is rotatable with the outer ring, wherein the support member also has a central portion attached to the shaft so that when the outer ring is rotated, the outer ring of the bearing, the support member, the shaft and the impeller rotate together. In accordance with still another embodiment of the present invention, the outer ring of the bearing defines a belt engaging portion adapted to engage an actuator belt to rotate the outer ring and actuate the coolant pump. In accordance with yet another embodiment of the invention, the bearing further comprises one or more tracks of rolling elements sandwiched between the inner ring and the outer ring of the bearing.
In accordance with another embodiment of the present invention, an internal combustion engine comprises a cooling system connected to a coolant pump, wherein the coolant pump includes: (1) a housing having an internal axis; (2) a bearing disposed on an outside of the housing; (3) a shaft disposed along the internal axis of the housing, wherein the shaft is journaled by the bearing so as to be rotatable; (4) an impeller disposed on the shaft so as to rotate with the shaft; and (5) a seal disposed on the shaft at least partially inside the bearing so that the bearing overlaps the seal along the internal axis of the housing, wherein the bearing has an inner diameter and the seal has an outer diameter, and the inner diameter of the bearing is greater than the outer diameter of the seal.
Further objects, features and advantages of the present invention will become apparent from the Detailed Description of Illustrative Embodiments, which follows, when considered with the attached drawings.
The apparatus of the present invention is a coolant pump as shown in
An inner surface of a pulley 110 is mounted on the outer ring 104 of the bearing 100 so that the pulley 110 rotates with the outer ring 104. The pulley 110 includes the inner surface and an outer surface and may have a cup-shape. The outer surface of the pulley 110 includes a belt engaging portion 112 and an end portion 114. The belt engaging portion 112 engages a drive or actuator belt connected to a motor or engine (not shown), which rotates the pulley 110 and actuates the pump 90. The end portion includes a plurality of holes 116 formed therein, and one central lipped portion 117 providing a surface for attaching to the shaft 120. As shown in
The shaft 120 is fixedly attached, at one end, to the pulley 110 so that the shaft and pulley rotate together as a unit as evident from
As shown in
The seal 140 provides a seal to prevent coolant 201, such as water, radiator fluid, anti-freeze, and the like, from leaking from the cooling system 200, in which the impeller 130 of the pump 90 is disposed. The cooling system 200 may be that of an internal combustion engine E as indicated by
The present invention may be employed without a separate designated pulley structure as shown in
A support 190 is provided to connect the outer ring 180 to the shaft 120. In this way, the bearing 170 functions as both a bearing ring and a pulley. As shown in
As shown in
In
While the present invention has been described with reference to certain illustrative embodiments, one of ordinary skill in the art will recognize, that additions, deletions, substitutions and improvements can be made while remaining within the scope and spirit of the invention as defined by the appended claims.
Claims
1. A coolant pump comprising:
- a housing having an internal axis;
- a bearing disposed on an outside of the housing;
- a shaft disposed along the internal axis of the housing, wherein the shaft is journaled by the bearing so as to be rotatable;
- an impeller disposed on the shaft so as to rotate with the shaft; and
- a seal disposed on the shaft at least partially inside of the bearing so that the bearing overlaps the seal along the internal axis of the housing, wherein the bearing has an inner diameter, the seal has an outer diameter, and the inner diameter of the bearing is greater than the outer diameter of the seal.
2. A coolant pump as recited in claim 1, wherein the seal is a dynamic seal.
3. A coolant pump as recited in claim 1, wherein the seal is a lip seal.
4. A coolant pump as recited in claim 1, wherein the seal prevents leakage of coolant when the impeller is in contact with coolant from a cooling system of an internal combustion engine.
5. A coolant pump as recited in claim 3, wherein the seal prevents leakage of coolant when the impeller is in contact with coolant from a cooling system of an internal combustion engine.
6. A coolant pump as recited in claim 1, wherein the bearing comprises an inner ring defining said inner diameter and an outer ring disposed to rotate on the inner ring, wherein the inner ring is fixed to the housing.
7. A coolant pump as recited in claim 6, further comprising a pulley having an inner surface connected to the outer ring of the bearing so that the outer ring is rotatable with the pulley, wherein the pulley also has a central portion attached to the shaft so that when the pulley is rotated, the pulley, the outer ring of the bearing, the shaft and the impeller rotate together.
8. A coolant pump as recited in claim 7, wherein the bearing further comprises one or more tracks of rolling elements sandwiched between the inner ring and the outer ring of the bearing.
9. A coolant pump as recited in claim 7, wherein the pulley further comprises a belt engaging portion adapted to engage an actuator belt to rotate the pulley and actuate the coolant pump.
10. A coolant pump as recited in claim 6, further comprising a support member connected to the outer ring of the bearing so that the support member is rotatable with the outer ring, wherein the support member also has a central portion attached to the shaft so that when the ring portion is rotated, the outer ring of the bearing, the support member, the shaft and the impeller rotate together.
11. A coolant pump as recited in claim 10, wherein the outer ring of the bearing defines a belt engaging portion adapted to engage an actuator belt to rotate the outer ring and actuate the coolant pump.
12. A coolant pump as recited in claim 10, wherein the bearing further comprises one or more tracks of rolling elements sandwiched between the inner ring and the outer ring of the bearing.
13. An internal combustion engine comprising a cooling system connected to a coolant pump, the coolant pump comprising:
- a housing having an internal axis;
- a bearing disposed on an outside of the housing;
- a shaft disposed along the internal axis of the housing, wherein the shaft is journaled by the bearing so as to be rotatable;
- an impeller disposed on the shaft so as to rotate with the shaft; and
- a seal disposed on the shaft at least partially inside the bearing so that the bearing overlaps the seal along the internal axis of the housing, wherein the bearing has an inner diameter and the seal has an outer diameter, and the inner diameter of the bearing is greater than the outer diameter of the seal.
Type: Application
Filed: Jul 23, 2007
Publication Date: Nov 6, 2008
Inventor: Jerome Maffeis (Southfield, MI)
Application Number: 11/781,366
International Classification: F01D 11/00 (20060101);