为解决三臂液压凿岩台车油箱改造问题，使液压油箱在改造后能够满足设备使用要求，并保证液压油箱容量及系统散热性能，需计算油箱容量是否满足使用需求，验证液压系统热平衡是否合理。对于液压油箱容量方面，分别从液压油泵排量，油缸及油管的储油量，使用过程中油箱液面的变化量3个方面计算分析了液压油箱的容量问题，验证了改造后液压油箱容量满足使用要求；对于系统热平衡方面，分别计算了液压系统的动力机构发热功率、液压油箱散热功率及水冷散热功率，结合理论计算得到了解决散热问题的方法。液压凿岩台车改造后经过工厂及工业性试验，并通过实践检验了其理论计算的合理性，以期为其他设备的升级改造提供一定的借鉴。

The hydraulic oil tank of a 3boom rockdrilling jumbo needs to be reformed. Calculations should be made to verify whether the capacity of the hydraulic oil tank meets relevant requirements and whether the heat balance of the hydraulic system is rational, so as to ensure that the reformed hydraulic oil tank can meet the operation requirements of the rockdrilling jumbo. In the paper, the capacity of the hydraulic oil tank is calculated in terms of the displacement of the hydraulic pump, the quantity of the oil reserved in the hydraulic cylinders and pipes and the variation of the oil level of the hydraulic oil tank during operation, which shows that the reformed hydraulic oil tank can meet the operation requirements; the heat emission power of the actuating unit of the hydraulic system, the heat emission power of the hydraulic oil tank and the heat emission power of the water cooling system are calculated and solutions are proposed for the heat emission problem. The reformed hydraulic rockdrilling jumbo has passed the workshop test and the field test, which proves that the theoretical calculation made is rational. The paper can provide reference for the reform of other equipment in the future.