Pump drive cam 8,0

The cam angle is a design parameter that directly determines the piston stroke of the pump. Cam 4005580 with an angle of 8.0° is a drive component of the Kranzle piston chamber – its geometry is fixed and cannot be adjusted during operation.

Application

The cam is mounted on the main shaft in the pump drive chamber. The 8.0° angle determines the piston stroke with each shaft revolution – the greater the angle, the greater the stroke and the higher the volumetric output at the same rotational speed. A roller bearing operates on the outer raceway of the cam and transfers the drive movement to the piston heads. The 8.0° parameter identifies a specific cam variant in the Kranzle range – other angles are separate catalogue parts and are not interchangeable with one another.

Symptoms – When to Replace

• Drop in pump volumetric output with valves and seals in good condition – a worn cam alters the effective piston stroke.
• Rhythmic pressure pulsations synchronised with shaft rotation.
• Visible wear or pitting on the outer raceway at the roller bearing contact zone.
• Cam play on the shaft – worn seating bore or damaged key that positions the cam.
• Irregular knocking from the drive chamber that does not resolve after replacing the roller bearing and washers.

How to Select the Correct Part

The 8.0° angle is the identifying parameter – Kranzle cams with other angles carry different reference numbers and are not substitutes. Before ordering, confirm the angle of the removed cam or select by the full reference number 4005580. If the angle of the removed cam is unknown, verify using the service diagram for the specific washer model. The seating bore dimension alone is not sufficient for selection – two cams with the same bore but different angles will produce a different piston stroke.

Compatibility

Kranzle catalogue part. Used among others in Kranzle pressure washers with a piston pump featuring an 8.0° cam angle. Cooperates in the drive assembly with the cam roller bearing, cam washer 40039, and bearing washer 40041. Verify model compatibility using reference number 4005580 or the pump service diagram.

[faq]

How does the 8.0° cam angle translate into pump operation in practice?|The cam angle determines the linear piston stroke – at a given shaft diameter and rotational speed, the 8.0° angle sets a specific volume displaced by the pump per revolution. Increasing the angle raises the stroke and output but also increases the load on the system. Using a cam with an angle other than that specified by the manufacturer shifts the pump's operating parameters outside the design range.

What does it mean that the cam "sits with play on the shaft", and does this always mean the cam must be replaced?|Cam play on the shaft can result from a worn seating bore in the cam or a damaged key on the shaft. If the cam bore is worn – the cam requires replacement. If the key is damaged on the main shaft side, replacing the cam alone will not resolve the problem. Before ordering a new cam, check the condition of the key on the main shaft.

Can contamination in the chamber oil damage the cam faster than the bearing?|The cam is a steel component with a hardened raceway surface – it is more resistant to abrasion than the roller bearing. In practice, contaminated oil destroys the bearing first, and through it secondarily damages the cam raceway. Regular oil changes in the drive chamber protect both components simultaneously and are a cheaper preventive measure than replacing the cam after bearing seizure.

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