Speed control fluid couplings

Figure 8.7(a) Variable-speed scoop control fluid coupling (Courtesy Fluidomat)... 

There is special coverage of fluid couplings for soft starting and speed control, A comparison between static drives and variable-speed fluid couplings is inade. 

The problem of wear when the fluid film lubricant is no longer intact is associated with the asperity contact of structured surfaces. The contact behavior of such surfaces was discussed in Chapter 12 wear models governed by asperity contact were described in Chapter 13. Theoretically the laws controlling fluid film thickness can be coupled with asperity contact models to yield quantitative descriptions of the course of wear. In this section we shall deal with those cases in which the function of the lubricant is only to provide a fluid film separating the two rubbing bodies, and the events at the contact, once it is established, are determined by the interaction of mechanical parameters such as load and rubbing speed with the properties of the contacting interface. 

Figure 3. Examples of the NESS, (a) An electric current / flowing through a resistance R and maintained by a voltage source or control parameter V. (b) A fluid sheared between two plates that move at speed v (the control parameter) relative to each other, (c) A chemical reaction A — B coupled to ATP hydrolysis. The control parameters here are the concentrations of ATP and ADP.

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