Design is generally rack or gear, hardness?
Personally think, mainly depends on the frequency of use of single teeth, which wear faster, there is another production cost.
2. small gear than large gear, tooth surface contact strength is low, sliding rate is high, more prone to failure.The gear tooth surface hardness is slightly bigger than the big gear tooth surface hardness, is for lets the big and small gear wear evenly, equates the life.We can see the rack as a gear with infinite radius.
In the transmission of two gears of unequal size1. at the same time the pinion rotates more often than the big gear. Each tooth has more work and more wear.
In gears and racks used in conjunction with each other, the hardness of the gear is usually slightly greater than the hardness of the rack.
