Zenith C-30HDG manual Drive Chain Lubrication, Chain-Link Cross Section

C-30HDG PUMP — MAINTENANCE (PUMP)

Drive Chain Lubrication

As a chain articulates in entering and leaving a sprocket, there is relative movement between pin and bushing surfaces. These surfaces wear causing chain elongation. If a lubricant film can be maintained between the pin and bushing, the wear rate is very slow and the chain wear life very long. Maintaining the oil film is relatively simple at low speeds but becomes increasingly difficult as the speed increases.

It is recognized that good lubrication is not possible in many applications, so shorter wear life must be accepted in these situations.

In general, chain wear leads to rough or unsatisfactory service prior to actual chain breakage. Good lubrication can help to prevent chain failure by providing protection against rust or corrosion. Rusting can allow pits to form in the surfaces of the chain parts causing stress concentration points.This can lead to chain failure at relatively low loads.

The clearance between pin and bushings is very small (Figure 30), on the order of .003 to .005 inches. A lubricant must be thin enough to flow into the chain. SAE 30 weight oil is about right for room temperature. Lighter oil should be used for lower ambients and heavier for higher operating temperatures. Grease should not be used as it cannot penetrate chain clearances.

Figure 30. Chain-Link Cross Section

PAGE 46 — MAYCO C-30HDG PUMP — OPERATION AND PARTS MANUAL — REV. #6 (04/02/12)