a person who does a lot of work, especially of a type that is necessary but not interesting

a willing/reliable workhorse 甘愿挑重担的人／可靠的老黄牛

She's a work horse - you have to be on top of things when you work with her.

a machine that operates without failing for long periods, although it might not be very interesting or exciting

The steam engine was the workhorse of the Industrial Revolution. 蒸汽机是工业革命中经久耐用的重负荷机器。

In the convoy were heavy equipment transporters - 48-wheeled Army work horses designed to carry tanks.