Does a motorcycle crankcase have the function of fixing moving parts?

The motorcycle crankcase has the function of fixing moving parts. It is not only one of the outer shell structures of the engine, but also plays a role in installing, positioning, and supporting various internal moving parts. The following is a point by point introduction:

1、 Function of fixing moving parts in the crankcase
Fixed crankshaft
The crankshaft is the core moving component of the engine, and the crankcase provides bearing seats and mounting holes for precise positioning and firm support of the crankshaft's rotational motion.
Install the lower end of the connecting rod and piston system
The piston is connected to the crankshaft through a connecting rod, and during its movement, the small end of the connecting rod swings up and down, while the large end rotates with the crankshaft in the crankcase.
Fixed lubrication system components such as oil pump
An oil pump, oil filter, and other moving parts are often installed inside the crankcase, which are driven by the crankshaft during operation. The crankcase provides stable support and mounting base.
Supporting the primary shaft and clutch of the transmission (some models)
For integrated engine transmission structures (such as scooters or some small displacement motorcycles), the primary shaft, clutch, and other components of the transmission are also installed in the crankcase and supported for operation.
Maintain the accuracy of the relative position of moving parts
The manufacturing accuracy of the crankcase is high, ensuring the positional relationship between internal moving parts such as the crankshaft, connecting rod, and bearings, maintaining motion balance, and reducing vibration and wear.
Integrated flywheel/ignition device bracket
The magnetic motor flywheel or ignition coil of some car models is also installed at the end of the crankcase, driven by the crankshaft, and the crankcase also plays a supporting and positioning role.

2、 Why is the crankcase capable of performing fixed functions
Strong rigidity: usually made of aluminum alloy die-casting or alloy steel structure, with strong deformation resistance.
High processing accuracy: precise processing of shaft holes, bearing seats, and other parts ensures smooth operation of moving parts.
Sealed and intact structure: ensuring the normal operation of lubrication and cooling systems, preventing impurities from entering.