Axial Positioning Methods for Camshafts in Diesel Generator Sets

The camshaft is a component in piston engines that controls the opening and closing of valves. While camshaft structures and installation methods are generally similar across engine models, axial positioning is critical to restrict axial movement during operation and counteract axial forces generated by helical gear transmission. Excessive axial movement can disrupt valve timing (especially in gear-driven camshafts) and degrade diesel generator set performance. To prevent such issues and ensure proper valve train operation, camshafts require specific axial positioning measures.

Two Quick Axial Positioning Methods for Diesel Generator Set Camshafts

The following two methods are commonly used for camshaft axial positioning in diesel generator sets:

1. Thrust Plate Axial Positioning

The camshaft thrust plate is fixed to the cylinder block with screws. A proper gap (typically 0.05~0.20mm) must be maintained between the thrust plate and the timing gear to accommodate thermal expansion of components. This gap can be adjusted by replacing the spacer ring.

2. Thrust Bearing Axial Positioning

The first bearing of the camshaft serves as a thrust bearing, which is installed in the bearing bore and fixed to the engine block with screws. A suitable gap is reserved between its end face and the camshaft’s flange spacer ring. When axial movement occurs, the camshaft flange contacts the spacer ring and is blocked by the thrust bearing. The 6135 diesel engine employs this type of camshaft axial positioning device.

Camshafts are typically driven by gears mounted on their front ends, which mesh directly or indirectly with the crankshaft gear (known as the timing gear). For four-stroke diesel engines, the crankshaft rotates twice to complete one working cycle, while the camshaft rotates once (achieving a 2:1 transmission ratio), ensuring each cylinder’s intake and exhaust valves open once per cycle. The crankshaft timing gear drives the camshaft timing gear via one or two intermediate gears. During camshaft assembly, timing marks on all gears must be aligned to ensure valves open/close and the fuel injection pump operates at the specified timing.

Since 1982, Dingbo Generator has been a generator set manufacturer qualified by the "National Internal Combustion Engine Quality Supervision and Inspection Center". The product quality has passed the IS09001 quality system standard certification. And obtained the qualification certificate for self-operated import and export. Over the years, Dingbo units have been widely used in all walks of life, and have won the network access qualification of the Ministry of Information Industry, the network access qualification of the Ministry of Radio and Television, the network access qualification of CNPC, the network access qualification of China Mobile, and the manufacturing qualification of marine units. In 2016, Dingbo was awarded the Certificate of Qualified Supplier of China Nuclear Power Group. Dingbo Generator has been cooperating with Shangchai Power for many years. In 2009, it became the OEM partner of Shangchai Power in China. Dingbo generator VOLVO unit ranks the top three in the Asia-Pacific sales volume, and is the core OEM partner of Sweden Volvo in the Asia-Pacific region. If any question please feel free to visit our website https://www.dieselgeneratortech.com/ or send email to [email protected].