A Practical Guide to Shaft Alignment phần 6 pdf

... 59 Laser shaft alignment - Case study Laser shaft alignment reduces vibration alarms During the period from 1987 to 2000 a major UK petroleum renery adopted laser shaft alignment as a standard ... eliminated altogether. © 2002 PRUFTECHNIK LTD. 51 Laser shaft alignment To be able to measure an offset a system detector range has to be twice the offset. As with...

Ngày tải lên: 08/08/2014, 11:21

... LTD. 3 Shaft Alignment Page Number What is shaft alignment 6 A denition 6 Machine catenary 7 Operation above critical speed 8 Expressing alignment 10 Alignment parameters 10 Angularity, ... LTD. 10 Expressing alignment Alignment parameters Since shaft alignment needs to be measured and subsequently corrected, a method of quantifying and describing alignmen...

Ngày tải lên: 08/08/2014, 11:21

... LTD. 15 Expressing alignment Spacer Shafts Spacer shafts are usually installed when signicant alignment changes are anticipated during operation of the machine, for example due to thermal growth. ... spacer shaft, the angular change at the spacer shaft end remains small even when larger machine positional changes occur. The alignment precision for machines tted with spacer s...

Ngày tải lên: 08/08/2014, 11:21

... always easy to detect misalignment on machinery that is running. The radial forces that are transmitted from shaft to shaft are difcult to measure externally. Using vibration analysis or infrared ... miss minor damage to the bearing that will progessively worsen after re-tting. Mechanical Seals Seal wear increases due to shaft loading when shafts are misaligned. Pump se...

Ngày tải lên: 08/08/2014, 11:21

... before embarking on a dial indicator alignment task. Indicator bracket sag: This should always be measured before actual alignment readings are taken - no matter how solid the bracket appears. ... perpendicular to the measurement surface so that part of the displacement reading is lost. Axial shaft play: This will affect face readings taken to measure angularity unless two a...

Ngày tải lên: 08/08/2014, 11:21

... analysis of alignment accuracy. Having identied some of the benets and advantages that can be obtained by using a laser alignment system to carry out shaft alignment, it is important to establish ... have the following capabilities: • Certied calibration to a traceable standard. There is no point purchasing a system for accurate shaft alignment that cannot hav...

Ngày tải lên: 08/08/2014, 11:21

... before embarking on a dial indicator alignment task. Indicator bracket sag: This should always be measured before actual alignment readings are taken - no matter how solid the bracket appears. ... referred to as parallel offset or rim misalignment, the shaft rotation axes are however rarely parallel and the coupling or shaft rim has an unknown relationship to the shaft r...

Ngày tải lên: 27/06/2014, 14:20

... Diebold and Labys (2001) and Taylor, J. (2004). With the increased availability of intraday data, we can expect to see research on the realized volatility variant of the historical model to intensify ... is a latent variable. Before high-frequency data became widely available, many researchers have resorted to using daily squared returns, calculated from market daily closing prices,...

Ngày tải lên: 22/03/2014, 23:20

... mentioned is Section A, the smallest particle that can be reliably measured must produce a signal amplitude at least twice that of the noise, or a 2 to 1 signal- to- noise ratio. C. RESOLUTION ... detected and measured if it produces a signal with a minimum 2 to 1 signal -to- noise ratio. B. SIGNAL -TO- NOISE RATIO All electronic instruments are subject to various forms...

Ngày tải lên: 18/06/2014, 19:20

... động h a)  NHỮNG KHÁI NIỆM CƠ BẢN(sóng mang dữ liệu, phương thức truyền, điện thoại cung cấp thiết bị hỗ trợ kết nối) 1. Tổng quan về DBA  DBA là viết tắt c a Desktop Browser Automation.  Có ... với các ứng dụng trên desktop.  Bộ nhớ đệm c a trình duyệt  Các bộ công cụ c a AJAX (chẳng hạn Google’s Web Toolkit).  Việc rút gọn và mã giã h a nội dung file JavaScript.  Cung cấp c...

Ngày tải lên: 28/07/2014, 12:13