Engine Water Pump Construction

Car’s water pump is creating forced cooling fluid circulation in the cooling system of the engine. Some water pumps are structurally combine with fans and have a common drive. So the engine water pump installs on the front end of the cylinder block.

The water pump housing 3 consists of two parts: one part of the housing is cast from iron and attach to another, which is made together with the cover of the block of distribution gears of aluminum alloy. The water pump shaft 2 and the fan hub 1 rotate on two ball bearings 14 install into the housing 3. Special snap rings and spacer sleeve keep ball bearings from shifting. There are seals to hold lubricant and to protect against contamination.

Engine Water Pump Construction

Engine Water Pump Construction

1 – fan and pulley hub; 2 – shaft; 3 – housing; 4 – inspection hole for the release of lubricant from the housing; 5 – lubricator; 6 – water pump impeller; 7 – a control aperture for an exit of a cooling liquid at stuffing box leak; 8 – spring; 9 and 10 – stuffing box clips; 11 – stuffing box cuff; 12 – stuffing box washer; 13 – stuffing box locking ring; 14 – ball bearings.

A fan hub and a pump pulley and a generator pulley are press on at one end of the shaft. The hub is protecting against axial displacement with a washer and a toothed nut, which is neatly split. Water pump impeller 6 is install on the second shaft end.

The impeller of the water pump is kept from displacement by the washer and bolt. The shaft in the housing is sealing with a self-locking stuffing boxes consisting of a graphitiz-textolite washer 12, rubber sleeve 11, so two cages 9 and 10 and a spring 8. A spring 8 presses the washer through a rubber sleeve 12 to the plane of the housing 3, which prevents fluid from escaping from the pump.

In addition the leakage of fluid through the control hole 7 indicates a malfunction of the self-locking stuffing box. In this case, you have to remove the pump and repair it.

Water pump drive
The drive of the water pump and fan is carry out from the crankshaft pulley using a V-belt drive (consisting of one belt). The belt covers the pulley of the water pump and fan, also the pulley of the tension roller and the crankshaft pulley.
The fan pulley is double-rack. The second belt from the fan pulley is thrown onto the generator pulley. The belt tension of the water pump should not be very weak and not very tight for normal operation. So the tension of the belt of the water pump is regulated by the movement of the tension roller.

Also with proper belt tension, the deflection under the action of a force of 40 Nm in the middle of the branch should be 10-15 mm.