Zhè wèi lǎo yuángōng rènláorènyuàn, shì gōngsī de dǐngliángzhù.
This veteran employee works hard and never complains — he's a pillar of the company.
Tips
history
Traced to Huan Kuan's Han-dynasty 《盐铁论·刺权》: 夫食万人之力者,蒙其忧,任其怨劳 — 'one who draws on the labor of ten thousand must bear their worries and shoulder their toil and resentment.' The phrase crystallized from this.
usage
任 here means 'to shoulder/bear' — bear the labor (劳) and bear the complaints (怨). Strong praise; usually applied to dedicated workers, mothers, caretakers, long-serving officials.