Internal-combustion engines – Cooling – With liquid coolant circulating means
Reexamination Certificate
1999-10-18
2001-01-23
Wolfe, Willis R. (Department: 3747)
Internal-combustion engines
Cooling
With liquid coolant circulating means
C417S423110, C417S423120, C417S423140
Reexamination Certificate
active
06176204
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a cooling water pump for an internal combustion engine, having a flow conducting housing in which an impeller is arranged and a bearing part which is arranged separate from the flow conducting housing and is provided with a bearing for the impeller.
Cooling water pumps of internal combustion engines are usually arranged as radial or axial-radial pumps. The flow conducting housing of such pumps is generally a cast part made of aluminium or an other metallic material.
DESCRIPTION OF THE PRIOR ART
A cooling water circulating pump is known from EP 0 208 074 A in which individual parts are made of plastic. Such a cooling water circulating pump comes with the considerable advantage of easy and cost-effective production and generally has a lower weight than a cooling water circulating pump made of a metallic material. The lower strength of plastic, however, leads to relatively serious constructional limitations and to difficulties in achieving the required service life. Moreover, as a result of the lower stiffness of the plastic material it is necessary to provide higher tolerances between the impeller and the flow conducting housing, which leads to a reduction of the efficiency and thus to an increase of the required drive output.
A coolant pump is known from WO 96/03574 in which a bearing part and a flow conducting housing are arranged as separate components. However, since the flow conducting housing is required to absorb the forces acting on the bearing part, there are narrow limits concerning the dimensioning and the choice of material. The same applies to the solution shown in EP-A 651 141.
Furthermore, it is known from U.S. Pat. No. 5,040,494 A or GB 1 456 938 A to integrally arrange the bearing part and the flow conducting housing. It is necessary to make compromises in the shaping and the choice of materials, so that an optimal arrangement of the individual functional parts is not possible.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a cooling water pump with which it is possible to combine the advantages of the use of plastic materials with a simple arrangement and a high efficiency.
It is provided in accordance with the invention that the flow conducting housing is arranged between an anchoring part and a bearing part, and that the bearing part encompasses the flow conducting housing and is fastened to the anchoring part. The relevant aspect in the present invention is that the flow conducting housing, which is relatively complex in its shape, can be produced simply and at low cost. In particular, this flow conducting housing may be made of plastic, e.g. by injection moulding. The motor unit or the cylinder head of the internal combustion engine is used as an anchoring part for example, to which the cooling water pump is directly attached. The supply of cooling water for the internal combustion engine is thus particularly simple. Since the bearing part is directly connected with the anchoring part, i.e. the internal combustion engine or any other fixed component, the bearing of the impeller can occur in a particularly stiff and stable manner. The bearing part can be arranged as a simple cast part made of gray cast iron or cast aluminium which is worked in merely one single chucking on a lathe. In this arrangement, the flow conducting housing merely needs to absorb the forces required for sealing. Accordingly, a considerable reduction in weight can be achieved.
In a particularly preferable embodiment of the invention it is provided that the flow conducting housing is provided with a first and second sealing surface. The first sealing surface rests in a sealing manner on the anchoring part, whereas the second sealing surface rests in a sealing manner on the bearing part. Generally, the first and the second sealing surface will be arranged parallel with respect to one another at opposite sides of the flow conducting housing. In this way separate fastening of the flow conducting housing is not required, since the same is held between the anchoring part and the bearing part.
It is particularly favorable when grooves are provided in the flow conducting housing for receiving sealing elements so as to provide sealing towards the anchoring part and/or the bearing part. This allows a further simplification during the production.
REFERENCES:
patent: 4961404 (1990-10-01), Itakura et al.
patent: 5040494 (1991-08-01), Okita et al.
patent: 5226787 (1993-07-01), Freeman
patent: 0208074 (1987-01-01), None
patent: 1456938 (1976-12-01), None
patent: 0651141 (1995-05-01), None
patent: 9603574 (1996-02-01), None
Dykema Gossett PLLC
Harris Katrina B.
TCG Unitech Aktiengesellschaft
Wolfe Willis R.
LandOfFree
Cooling water pump for an internal combustion engine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cooling water pump for an internal combustion engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cooling water pump for an internal combustion engine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2512640