190柴油机水泵机械密封的改进

Improvement of mechanical seal of water pump on 190 diesel engines

190系列柴油机水泵采用的SB-28型机械密封，因其动环和静环的配合是面接触，而且是单道密封，经高速运转后配合面磨损，橡胶件老化，最终导致密封失效而产生泄漏。频繁更换密封也难彻底排除故障。据此，将原密封改进成为机械式双密封，即由夹布胶木封水环与水泵衬座的配合面，以及油封与水泵轴的配合面，形成两道密封线，有效地提高了水泵的密封性能。密封平均寿命由原来的不足3000／小时提高到10000多小时。只要将水泵壳体座52^(+0.03)mm孔按水泵衬座外径尺寸镗至55^(+0.06)mm，即可换装改进后的密封。

The mechanical seal of water prmp on a 190 diesel engine failed and leakage is resulted owing to sealing surface abrasion and rubber elements ageing. The problem cannot be solved completely by frequent change of seal. Thereby the seal is modified into a mechanical dual seal. Having two sealing lines formed by the fitting suffoces of water sealing ring and pump liner seat, and the oil seal and prmp shaft, the new seal can improve the sealing performance of the water pump effectively. The mean life of the seal is improved from 3000h less to 10000h more. The water pump liner seat of 55^+(0.06) mm outside diameter should be bored to install the modified seal.