GB2033979A - Coolant Pump for Liquid-cooled Internal Combustion Engines - Google Patents

Abstract

The shaft (5) of a coolant pump impeller passes through a bearing (4) and a seal (8) and any coolant which seeps past the seal (8) enters an annular chamber (9) from where it drains into a reservoir chamber (11) having an overflow. Leaked coolant is retained in the reservoir chamber until it evaporates and any residues collect in the reservoir chamber so as to remain invisible from the exterior of the pump, thereby obviating unwarranted replacement of the pump such as occurs with prior pumps when residues appear at the drain opening thereof. <IMAGE>

Description

SPECIFICATION Coolant Pump for Liquid-cooled Internal Combustion Engines This invention relates to a coolant pump for liquid-cooled internal combustion engines which comprises a sealing ring disposed between the coolant-containing interior of the pump and an adjacent bearing of the pump, and an annular chamber disposed between the sealing ring and the bearing so as to receive any coolant which leaks past the seal.

Coolant pumps of this construction are generally known in which the annular chamber of such a pump has a drainage bore leading from the lowermost zone thereof. Leaking coolant escapes through the drainage bore and evaporates. Since the cooling liquid usually contains anti-freeze mixture and possibly other constituents which leave residues upon evaporation, deposits of striated form are often formed in the zone of the drainage bore. These deposits occur even when the seals are very tight, since it is almost impossible to avoid leakage losses by slight seepage, these losses occurring when coolant pumps of this kind have been switched off.

Therefore, coolant pumps still capable of operating are often replaced, since because of the presence of the deposits, undesirable leakiness is incorrectly thought to have developed, so that high costs are incurred.

An aim of the present invention is to design a coolant pump of the construction specified in the opening paragraph in such a manner that no residual matter can be seen at the outside of the pump housing, so that replacement of coolant pumps that are still capable of functioning does not take place.

According to the invention, this aim is achieved by providing a chamber disposed generally beneath and in communication with the annular chamber to act as a reservoir for any coolant which leaks past the seal, a coolant overflow opening leading from an upper zone of the chamber to atmosphere.

Coolant seeping through the seal is collected in the reservoir chamber, e.g. when the pump is first switched off, the chamber having a relatively large surface from which the coolant can evaporate. The coolant vapour passed into the atmosphere, whereas the coolant constituents that form the deposit are retained in the reservoir chamber and are not visible from the exterior. Of course, should a serious leak develop, then fairly large quantities of leaked liquid can be discharged through the overflow opening without damage occurring to the bearings.

The reservoir chamber preferably intersects the annular chamber and thus communicates therewith, in which case a separate connection between the annular chamber and the reservoir chamber is unnecessary. The reservoir chamber, preferably formed by a blind bore or other hole, can extend horizontally.

A preferred embodiment coolant pump according to the invention is illustrated by way of example in the accompanying drawing, in which: Figure 1 is a section along the axis of the coolant pump for liquid-cooled internal combustion engines; and Figure 2 is a cross-section taken on the line Il-Il in Figure 1.

The drawing shows a coolant pump 1 for a liquid-cooled internal combustion engine (not illustrated), the pump having a pump housing 2, a shaft 5 mounted on two bearings 3 and 4 in the housing, and a pump impeller 6 secured to the shaft 5. Between the liquid-transmitting interior 7 of the pump 1 and the adjacent bearing 4 there is arranged a sealing ring 8 in the form of an axial slide-ring seal. Located between the sealing ring 8 and the bearing 4 is an annular chamber 9 which is provided at its top with a ventilation duct 10. In a plane perpendicular to the shaft 5, and below the annular chamber 9, is formed a horizontal blind hole 11 which cuts into the annular chamber 9 and forms a reservoir chamber. The blind hole 11 is closed by a plug 12 which is cut away at its top to form an overflow 13.The overflow 13 is disposed at a lower level than the bearing 4 adjacent the annular chamber 9.

When leaking liquid passes through the sealing ring 8 and finds its way into the annular chamber 9 between the sealing ring 8 and the bearing 4, it flows into the blind hole 11 which acts as a reservoir chamber until the coolant evaporates.

The vapour passes into the atmosphere by way of the overflow 13 and the ventilation duct 10, and residues from the coolant that form a layer remain unseen in the interior of the chamber.

Claims

1. A coolant pump for liquid-cooled internal combustion engines which comprises a sealing ring disposed between the coolant-containing interior of the pump and an adjacent bearing of the pump, and an annular chamber disposed between the sealing ring and the bearing so as to receive any coolant which leaks past the seal, in which a chamber is disposed generally beneath and in communication with the annular chamber to act as a reservoir for any coolant which leaks past the seal, a coolant overflow opening leading from an upper zone of the chamber to atmosphere.

2. A coolant pump according to claim 1, in which the reservoir chamber intersects the annular chamber and thus communicates therewith.

3. A coolant pump according to claim 1 or claim 2, in which the reservoir chamber extends horizontally and is closed by a plug which in its upper zone has the said overflow opening.

4. A coolant pump according to any preceding claim in which the reservoir chamber consists of a blind hole.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Coolant Pump for Liquid-cooled Internal Combustion Engines This invention relates to a coolant pump for liquid-cooled internal combustion engines which comprises a sealing ring disposed between the coolant-containing interior of the pump and an adjacent bearing of the pump, and an annular chamber disposed between the sealing ring and the bearing so as to receive any coolant which leaks past the seal. Coolant pumps of this construction are generally known in which the annular chamber of such a pump has a drainage bore leading from the lowermost zone thereof. Leaking coolant escapes through the drainage bore and evaporates. Since the cooling liquid usually contains anti-freeze mixture and possibly other constituents which leave residues upon evaporation, deposits of striated form are often formed in the zone of the drainage bore. These deposits occur even when the seals are very tight, since it is almost impossible to avoid leakage losses by slight seepage, these losses occurring when coolant pumps of this kind have been switched off. Therefore, coolant pumps still capable of operating are often replaced, since because of the presence of the deposits, undesirable leakiness is incorrectly thought to have developed, so that high costs are incurred. An aim of the present invention is to design a coolant pump of the construction specified in the opening paragraph in such a manner that no residual matter can be seen at the outside of the pump housing, so that replacement of coolant pumps that are still capable of functioning does not take place. According to the invention, this aim is achieved by providing a chamber disposed generally beneath and in communication with the annular chamber to act as a reservoir for any coolant which leaks past the seal, a coolant overflow opening leading from an upper zone of the chamber to atmosphere. Coolant seeping through the seal is collected in the reservoir chamber, e.g. when the pump is first switched off, the chamber having a relatively large surface from which the coolant can evaporate. The coolant vapour passed into the atmosphere, whereas the coolant constituents that form the deposit are retained in the reservoir chamber and are not visible from the exterior. Of course, should a serious leak develop, then fairly large quantities of leaked liquid can be discharged through the overflow opening without damage occurring to the bearings. The reservoir chamber preferably intersects the annular chamber and thus communicates therewith, in which case a separate connection between the annular chamber and the reservoir chamber is unnecessary. The reservoir chamber, preferably formed by a blind bore or other hole, can extend horizontally. A preferred embodiment coolant pump according to the invention is illustrated by way of example in the accompanying drawing, in which: Figure 1 is a section along the axis of the coolant pump for liquid-cooled internal combustion engines; and Figure 2 is a cross-section taken on the line Il-Il in Figure 1. The drawing shows a coolant pump 1 for a liquid-cooled internal combustion engine (not illustrated), the pump having a pump housing 2, a shaft 5 mounted on two bearings 3 and 4 in the housing, and a pump impeller 6 secured to the shaft 5. Between the liquid-transmitting interior 7 of the pump 1 and the adjacent bearing 4 there is arranged a sealing ring 8 in the form of an axial slide-ring seal. Located between the sealing ring 8 and the bearing 4 is an annular chamber 9 which is provided at its top with a ventilation duct 10. In a plane perpendicular to the shaft 5, and below the annular chamber 9, is formed a horizontal blind hole 11 which cuts into the annular chamber 9 and forms a reservoir chamber. The blind hole 11 is closed by a plug 12 which is cut away at its top to form an overflow 13.The overflow 13 is disposed at a lower level than the bearing 4 adjacent the annular chamber 9. When leaking liquid passes through the sealing ring 8 and finds its way into the annular chamber 9 between the sealing ring 8 and the bearing 4, it flows into the blind hole 11 which acts as a reservoir chamber until the coolant evaporates. The vapour passes into the atmosphere by way of the overflow 13 and the ventilation duct 10, and residues from the coolant that form a layer remain unseen in the interior of the chamber. Claims

1. A coolant pump for liquid-cooled internal combustion engines which comprises a sealing ring disposed between the coolant-containing interior of the pump and an adjacent bearing of the pump, and an annular chamber disposed between the sealing ring and the bearing so as to receive any coolant which leaks past the seal, in which a chamber is disposed generally beneath and in communication with the annular chamber to act as a reservoir for any coolant which leaks past the seal, a coolant overflow opening leading from an upper zone of the chamber to atmosphere.

2. A coolant pump according to claim 1, in which the reservoir chamber intersects the annular chamber and thus communicates therewith.

3. A coolant pump according to claim 1 or claim 2, in which the reservoir chamber extends horizontally and is closed by a plug which in its upper zone has the said overflow opening.

4. A coolant pump according to any preceding claim in which the reservoir chamber consists of a blind hole.

5. A coolant pump for liquid-cooled internal combustion engines substantially as described herein with reference to the accompanying drawing.