Tham khảo tài liệu 'gear noise and vibration episode 1 part 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 100 Chapter 7 frequency divider Fig Block diagram of high speed . tester. Typically with a gear ratio of 19 31 and the standard 18 000 x 4 line encoders and 12 bit digital recording the resolution would be to about second of arc and more than adequate for automobile work. The detailed design of the electronics requires some care to get the high accuracy necessary for the final phase comparison. This approach unlike that in section the original pulse frequency multiplying system is not affected by torsional vibrations at the input so it can be used under industrial conditions in situ on machinery such as printing machines. The encoders can be mounted quite large distances apart 50 m on printing rolls to investigate dot synchronisation problems and the results show clearly when the gears start coming out of contact. Although intended originally for on site work at moderate speeds of the order of 200 rpm there seems to be no practical limit to operating speeds other than the requirement that for the simplest and most robust system the vibration should not be so severe that there is reversal of rotation. This is a requirement for most of the systems. Practical limitations of the double-divide high speed system arise from three sources a Since the system will operate over very large frequency ranges from roughly rpm to 6000 rpm the operator needs to dial tooth numbers roughly to zero the trace on the screen and to set a low-pass filter according to the conditions so the system is not completely automatic and idiot proof. This makes it suitable for development or consultancy work but less suitable for production monitoring using unskilled personnel when speeds and tooth numbers change frequently. Copyright Marcel Dekker Inc. All rights reserved. Marcel Dekker Inc. 270 Madison Avenue New York New York 10016 T. E. Measurement 101 If on the other hand a test rig is set up to test a particular drive the settings remain constant and the only requirement is
