齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)面(mian)(mian)(mian)的(de)承載(zai)能力應該(gai)與齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)面(mian)(mian)(mian)的(de)硬度(du)有關。硬度(du)越高，承載(zai)能力越高。根據齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)面(mian)(mian)(mian)的(de)硬度(du)，人們通(tong)常將齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)輪傳(chuan)動(dong)分為(wei)兩種類型，即硬齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)面(mian)(mian)(mian)齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)輪傳(chuan)動(dong)和軟齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)面(mian)(mian)(mian)齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)輪傳(chuan)動(dong)。通(tong)常，一(yi)對嚙合齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)輪的(de)齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)面(mian)(mian)(mian)硬度(du)大于350HBW，稱為(wei)硬齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)面(mian)(mian)(mian)齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)輪，否(fou)則稱為(wei)軟齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)面(mian)(mian)(mian)齒(chi)(chi)(chi)(chi)(chi)(chi)(chi)輪。