GB2134594A

GB2134594A - I.C. engine coolant pumping system

Info

Publication number: GB2134594A
Application number: GB08302413A
Authority: GB
Inventors: Frederick Stanley Johnson
Original assignee: Rover Co Ltd
Current assignee: Rover Co Ltd
Priority date: 1983-01-28
Filing date: 1983-01-28
Publication date: 1984-08-15
Also published as: GB8302413D0; GB2134594B

Abstract

The cooling liquid pump 18 is driven from the camshaft 26 and located in the cylinder block 11 to pump coolant from passages in the block to passages 28 in the head 12 or vice versa. <IMAGE>

Description

SPECIFICATION Improvements relating to internal combustion engines This invention relates to internal combustion engines, and in particular to engines including liquid cooling systems.

It is conventional for liquid cooling systems of internal combustion engines to incorporate a pump to ensure circulation of liquid through the system. Typically, the systems included interconnecting passages in the cylinder block and the cylinder head and a cooling radiator, the pump being located between the cooling radiator and the passages in the engine.

The present invention proposes locating the liquid cooling pump between the passages in the cylinder block and the passages in the cylinder hecd.

Preferably, the flow is arranged to passfrom the cylinder block to the pump and then into the cylinder head, although flow in the reverse direction is possible.

Internal combusion engines incorporating cooling systems, constructed in accordance with the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a schematic view of a first form of internal combustion engine and cooling system; and Figure 2 is a section through a second form of internal combustion engine and cooling system, taken through a plane containing the axes of the engine cylinders and of the liquid cooling pump.

Like parts have been given like reference numerals throughout each of the drawings.

In Figure 1 of the drawings there is shown an internal combustion engine having a cylinder block 11, a cylinder head 12 and a cooling radiator 13.

A series of cooling passages in the cylinder block and cylinder head are represented by dashed lines 14 and 1 5 respectively, the passages in the block and head being connected to the cooling radiator 13 by way of pipes 16 and 17. Water is circulated through the cooling system in the direction shown by the arrow D by means of a centrifugal pump 18.

Pump 1 8 receives coolant from the passages 14 in the cylinder block and pumps it to the passages 1 5 in the cylinder head, assisted to some extent by the natural convection current within the system.

The illustrated arrangement provides several advantages over a conventional system wherein the pump is located up-stream of both the passages in the cylinder block and in the cylinder head. Firstly, it is easier to design for optimum flow into the pump impeller, which is to say to arrange that substantially axial flow impinges upon the centrifugal impeller customarily used in cooling system pumps.Secondly, the illustrated arrangement provides for a higher coolant pressure in the cylinder head than in the cylinder block: whereas previously it has been desired to achieve a high pressure throughout the engine cooling passages, the applicants have appreciated that a higher pressure is required in the cylinder head than in the cylinder block since the head is generally significantly hotter than the block and is therefore more prone to the problem of boiling coolant and thus a differential is not only acceptable but preferable.

A further advantage is that the wafer inlet from the radiator to the engine need not be restricted in size by its proximity to drive belt lines, such as the belt used to transmit drive from the engine crank shaft to the electrical generator and water pump.

In order to take advantage of this, the water inlet would probably be relocated to another part of the cylinder block so that the pipe 1 6 would be replaced by a pipe 1 6', as shown in the drawing A still further advantage is that the engine unit can be made more compact by removing the necessity to provide an inlet pipe to the pump from outside the engine: such a pipe would normally fit between the drive pulley and the impeller of the coolant pump thus increasing the spindle length and consequently the length of the engine.

Referring to Figure 2, the cooling passages in the block 11 and the head 12 cannot be seen, because they surround the periphery of the cylinder 19 and the inlet and exhaust valves 20.

The flow is from left to right in the block as seen in Figure 2 and from right to left in the head as seen in Figure 2.

The pump 18 consists of a casing 21 formed integrally with the block 11 and an impeller 22 provided with veins 23 and secured to a shaft 24.

The shaft 24 is friction driven by means of a toothed belt 25 from a camshaft 26.

It will be seen that the cooling liquid passes through the cooling passages surrounding the cylinders into the chamber 27, and is driven by impeller 22 into chamber 28 in the head. The advantages noted for the Figure 1 embodiment apply to the Figure 2 embodiment. In particular, the axial entry of fluid to the impeller can be seen from Figure 2.

1. An internal combustion engine wherein the liquid cooling pump is located between cooling passages in the cylinder block and cooling passages in the cylinder head.

2. An internal combustion engine as claimed in claim 1, wherein the pump is so arranged that the flow passes from the block to the head.

3. An internal combustion engine as claimed in claim 1 or claim 2, wherein the pump is driven from a camshaft of the engine.

4. An internal combustion engine as claimed in

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements relating to internal combustion engines This invention relates to internal combustion engines, and in particular to engines including liquid cooling systems. It is conventional for liquid cooling systems of internal combustion engines to incorporate a pump to ensure circulation of liquid through the system. Typically, the systems included interconnecting passages in the cylinder block and the cylinder head and a cooling radiator, the pump being located between the cooling radiator and the passages in the engine. The present invention proposes locating the liquid cooling pump between the passages in the cylinder block and the passages in the cylinder hecd. Preferably, the flow is arranged to passfrom the cylinder block to the pump and then into the cylinder head, although flow in the reverse direction is possible. Internal combusion engines incorporating cooling systems, constructed in accordance with the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a schematic view of a first form of internal combustion engine and cooling system; and Figure 2 is a section through a second form of internal combustion engine and cooling system, taken through a plane containing the axes of the engine cylinders and of the liquid cooling pump. Like parts have been given like reference numerals throughout each of the drawings. In Figure 1 of the drawings there is shown an internal combustion engine having a cylinder block 11, a cylinder head 12 and a cooling radiator 13. A series of cooling passages in the cylinder block and cylinder head are represented by dashed lines 14 and 1 5 respectively, the passages in the block and head being connected to the cooling radiator 13 by way of pipes 16 and 17. Water is circulated through the cooling system in the direction shown by the arrow D by means of a centrifugal pump 18. Pump 1 8 receives coolant from the passages 14 in the cylinder block and pumps it to the passages 1 5 in the cylinder head, assisted to some extent by the natural convection current within the system. The illustrated arrangement provides several advantages over a conventional system wherein the pump is located up-stream of both the passages in the cylinder block and in the cylinder head. Firstly, it is easier to design for optimum flow into the pump impeller, which is to say to arrange that substantially axial flow impinges upon the centrifugal impeller customarily used in cooling system pumps.Secondly, the illustrated arrangement provides for a higher coolant pressure in the cylinder head than in the cylinder block: whereas previously it has been desired to achieve a high pressure throughout the engine cooling passages, the applicants have appreciated that a higher pressure is required in the cylinder head than in the cylinder block since the head is generally significantly hotter than the block and is therefore more prone to the problem of boiling coolant and thus a differential is not only acceptable but preferable. A further advantage is that the wafer inlet from the radiator to the engine need not be restricted in size by its proximity to drive belt lines, such as the belt used to transmit drive from the engine crank shaft to the electrical generator and water pump. In order to take advantage of this, the water inlet would probably be relocated to another part of the cylinder block so that the pipe 1 6 would be replaced by a pipe 1 6', as shown in the drawing A still further advantage is that the engine unit can be made more compact by removing the necessity to provide an inlet pipe to the pump from outside the engine: such a pipe would normally fit between the drive pulley and the impeller of the coolant pump thus increasing the spindle length and consequently the length of the engine. Referring to Figure 2, the cooling passages in the block 11 and the head 12 cannot be seen, because they surround the periphery of the cylinder 19 and the inlet and exhaust valves 20. The flow is from left to right in the block as seen in Figure 2 and from right to left in the head as seen in Figure 2. The pump 18 consists of a casing 21 formed integrally with the block 11 and an impeller 22 provided with veins 23 and secured to a shaft 24. The shaft 24 is friction driven by means of a toothed belt 25 from a camshaft 26. It will be seen that the cooling liquid passes through the cooling passages surrounding the cylinders into the chamber 27, and is driven by impeller 22 into chamber 28 in the head. The advantages noted for the Figure 1 embodiment apply to the Figure 2 embodiment. In particular, the axial entry of fluid to the impeller can be seen from Figure 2. CLAIMS

4. An internal combustion engine as claimed in any one of claims 1 to 3, wherein at least a part of the pump is formed integrally with the cylinder block.

5. An internal combustion engine substantially as hereinbefore described with reference to and as shown in the accompanying drawings.