select a mechanical component from part 3 of this book (roller bearings, springs, etc.), go to the internet, and, using a search engine, report on the information obtained on five manufacturers or suppliers.
please see the attached.
please see the attached.
review design equations (stress calculation) on mechanics of materials.
please check the attached.
please see the attached ducument (ppt version)
please check the attached documents.
please see the attached document
please check the attached document
please compare belt drive, chain drive and gear drvie.
the sewing machine is . a．double-rocker mechani b．double crank mechani c．crank-rocker mechani
the life of ball rolling bearing is fl = constant,, for roller bearings, α= . a．1 b．3 c．1/3 d．10/3
the condition of continuous tranission of a pair of involute gears is that contact ratio ε should be . a. ε≥1 b. ε≥2 c. ε≤1 d. ε≥1.3
in belt drive, the tension stress of the belt is as follows . a. invariant b. regularly changing c. irregular d. equal to zero
condition of self-lock for screw is . a. lead angle ≤ equivalent frication angle b. lead angle ≤ frication angle c. lead angle ≥ frication angle d. lead angle ≥ equivalent frication angle
the pressure angle at locked point for four-link mechani is . a. 0 b. 90° c. 0~45° d. 45°~90°
pressure angle at each point of involute curve is . a．= b．≠ c．≠ 0 d．= 0
pressure angle at the base circle is . a．= b．≠ c．≠ 0 d．= 0
the place of the maximum stress of belt is . a. small pulley--slack side b. small pulley--tight side c. big pulley--slack side d. big pulley--tight side
the considerations of design have . a .cost b. reliability c. quality d. cover a.b and c
the meshing conditions of gears are . a. modules are same b. pressure angles are same c.both modules and pressure angles are same d. numbers of teeth are same
for a single bearing, the probability of reaching or exceeding its expected life is only . a.70% b. 80% c. 90% d. 100%
the design is an innovative and highly iterative process.
the gear train can change speed and direction.
the tension pulley of v-belt should be placed in the inner of the slack side and close to the all pulley as far as possible.
when the belt drive works normally, the accurate tranission ratio can not be guaranteed because the belt is easy to slip on the pulley.
the internal and external threads used together have the same helix.