(1) For a tight bolted connection with transverse load, the bolt is carried by . V\{@c%xW
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(2) For a tight bolted connection with axial tensile load F and preload , the resultant tensile force in the bolt is . U]vUa^nG
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(3) If the performance grade of a bolt is 6.8, then the yield limit stress of the bolt material is MPa. Z$KyK.FUU
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A. 600 B. 800 C. 680 D. 480 ]?D$n
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(4) The lubricating method of a journal bearing is dependent on . %%?}db1n
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(5) For a hydrodynamic radial journal bearing, the valid method for increasing is to . 3!gz^[!?EN
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(6) For a hydrodynamic radial journal bearing, the relative clearance is the ratio of . `Kf@<=
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D. minimal clearance and journal diameter XA;PWl5!
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(7) The axial preloading for rolling bearings is for _______. Nh^I{%.x
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A. increasing loading capacity B. decreasing noise 4vG-d)"M2
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C. improving running precision D. avoiding shaft displacement iZdl0;16[
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(8) The inner ring and outer ring of the bearing are separable. 6 *S
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(9) In an important application, if the reliability of rolling bearings is increased to 95%, then the relation between the dynamic load rating relative to 95% reliability to the basic dynamic load rating C is _______. "A~dt5GJ
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A. B. C. D. uncertain i7h^L)M
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(10) For a cylindrical helical compressive spring, the maximal shear stress on spring wire happens at the ______. @aUNyyVP
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(11) For a cylindrical helical compressive spring with working coils being 12, if the number of working coils is decreased by 3, then spring stiffness is _____. C/N;4
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C. not changed D. increased to 4/3 of the original value ^vG<Ma.yk
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(12) For a static balanced rigid rotor, its mass center is located at the rotating axis. %4x0^<k~
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(13) Shown in the figure is a cylindrical cam with uniform material, accurate manufacture and installation. When it rotates round the axis A-A, the cam is under the state of _________. `g1?Q4h
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