圈上海文通大华 Worms and worm Gears ▣Disadvantage: >Relatively low efficiency compared to other gear sets. The relative motion at the teeth is sliding rather than rolling > Generates significant heat. Heat transfer from the gearbox,rather than the stresses in the teeth,can limit a worm set's life. The oil temperature in the mesh should be kept below about 200 degree Fahrenheit for long tooth life. 圈上泽夫通大学 Common Types of Gears Type Shaft Orientation Advantages Disadvantages Spur Parallel,Non-Intersecting High efficiency Noisy Parallel,Non-Intersecting Helical Non-Parallel,Non- Lower Noise More expensive Intersecting Bevel Shaft Any angle,intersecting or Greater Thrust and non-intersecting Orientation Loads Hypoid change Worm Perpendicular,non- High Gear Ratio,not Low Efficiency intersecting back drivable 99  Disadvantage:  Relatively low efficiency compared to other gear sets.  The relative motion at the teeth is sliding rather than rolling  Generates significant heat.  Heat transfer from the gearbox, rather than the stresses in the teeth, can limit a worm set’s life.  The oil temperature in the mesh should be kept below about 200 degree Fahrenheit for long tooth life. Worms and worm Gears Common Types of Gears Type Shaft Orientation Advantages Disadvantages Spur Parallel, Non-Intersecting High efficiency Noisy Helical  Parallel, Non-Intersecting  Non-Parallel, Non￾Intersecting Lower Noise More expensive Bevel and Hypoid Any angle, intersecting or non-intersecting Shaft Orientation change Greater Thrust Loads Worm Perpendicular, non￾intersecting High Gear Ratio, not back drivable Low Efficiency