Fig.1 The side sketch of rotary tiller
2.1 Universal coupling assy
The universal coupling consists of universal joint head, universal joint head for male shaft, the universal joint head for female shaft and joint cross. There are
rings on the both ends of joint cross to avoid the movement of joint cross, and there is also a grease hole on the joint cross and the needle bearing can be
well lubricated if you inject grease into it frequently. The universal joint head for male shaft and the universal joint head for female shaft are sliding joint and it
can be pulled back and forth freely when the rotary tiller rises or falls. It must be noted that the interval between socket and shaft is in the shortest situation
but the socket and the shaft can not contact each other during operating, and if the interval between the socket and the shaft is in the biggest situation, the
overlap of socket and shaft must be longer or equal 1/2 length of the shaft.
2.2 Headstock
The upper hitch point on the headstock must be connected with the control link of the tractor and the lower coupling pin of headstock must be connected with
the tension link of the tractor to make the rotary tiller from the stable three-point hitch linkage.
2.3 Central gearbox assy
The central gearbox assy consists of gearbox, front cap, rear cap, first shaft, second shaft and a helical bevel gear pair that transmits the power to side chain
box, etc. And there is an oil hole for adding oil on the top of the gearbox. And there is a stopper for draining oil at the bottom of the gearbox. The helical bevel
gear is splined with the shaft. The gears are tightened with elastic collar, washer and locknut to prevent axial moving.
In using, the bearing clearance and the gear backlash will be changed because of wearing of bearings and gears, so you must adjust them (if necessary).
Adjustment of helical bevel gear backlash:
A proper backlash is the one of the condition for working normally. If the backlash is too small, result in the gear wearing rapidly or even biting one another. If
the backlash is to large, result in the gear making strong collision and loud noise.
Precaution:
Helical bevel gear backlash must be adjusted after the clearance of bearing on the first shaft has been adjusted. For retaining the clearance of bearing in
which have been adjusted, for pinion, the total thickness of adjusted shims of the front and the hind bearing seat on the first shaft must keep up. For example,
when moving the pinion forward, the decrease--the adjusted shims of the hind-bearing seat on the first shaft must added to the front bearing seat on the first
shaft, vice versa. For large helical bevel gear, when moving it rightward, you must decrease the shims of the bearing seat of the large bevel gear. In general,
