Tham khảo tài liệu 'advanced vehicle technology 2 episode 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Fig. Setting differential cage bearing preload using adjusting nuts pinion teeth when the transmission overruns the engine or the vehicle is being reversed. Crownwheel and pinion backlash The free clearance between meshing teeth is known as backlash. Checking crownwheel and pinion tooth contact Prepare crownwheel for examining tooth contact marks Fig. After setting the correct backlash the crownwheel and pinion tooth alignment should be checked for optimum contact. This may be achieved by applying a marking cream such as Prussian blue red lead chrome yellow red or yellow ochre etc. to three evenly spaced groups of about six teeth round the crownwheel on both drive coast sides of the teeth profiles. Apply a load to the meshing gears by holding the crownwheel and allowing it to slip round while the pinion is turned a few revolutions in both directions to secure a good impression around the crownwheel. Examine the tooth contact pattern and compare it to the recommended impression. Understanding tooth contact marks Fig. a-f If the crownwheel to pinion tooth contact pattern is incorrect there are two adjustments that can be made to change the position of tooth contact. These adjustments are of backlash and pinion depth. The adjustment ofbacklash moves the contact patch lengthwise back and forth between the toe heel of the tooth. Moving the crownwheel nearer the pinion decreases the backlash causing the contact patch to shift towards the toe portion of the tooth. Increasing backlash requires the crownwheel to be moved sideways and away from the pinion. This moves the contact patch nearer the heel portion of the tooth. When adjusting pinion depth the contact patch moves up and down the face-flank profile of the tooth. With insufficient pinion depth pinion too far out from crownwheel the contact patch will be concentrated at the top face zone of the tooth. Conversely too much pinion depth pinion too near crownwheel will move the contact patch to the lower
