五年来,变速箱的设计发生了巨大的变化。过去,在小客车和货车变速箱的设计和制造中曾用过滚珠轴承、滚针轴承和滚柱轴承。几年前,有增大变速箱的功率与重量之比的趋势并要求它有更大的可靠性和更长的寿命。那时使用着的变速箱多半是约30年前设计的。由于要求它有更大的容量和更好的性能,变速箱的结构也在不断地改进。后来,这一发展过程逐 Over the past five years, the gearbox design has undergone tremendous changes. In the past, ball bearings, needle roller bearings, and roller bearings have been used in the design and manufacture of passenger cars and freight car transmissions. A few years ago there was a trend towards increasing the power to weight ratio of a transmission and required greater reliability and longer life. Most of the gearboxes used at that time were designed about 30 years ago. Due to its greater capacity and better performance, the gearbox structure is constantly being improved. Later, this development process by