Torque ratios

As a vehicle is accelerated from rest, the initially stationary turbine accelerates toward impeller (engine) speed, and torque multiplication falls steadily. In a typical automotive converter, by the time the turbine has reached about 85 percent of the impeller speed, the torque ratio across the converter has dropped to unity and the one-way clutch allows the reactor to rotate. The speed ratio at which this occurs is known as the coupling point. Beyond the coupling... 

Per-unit reactances and starting-to-fnII-Ioad torque ratio for LV two-pole... 

An important factor in the construction of the composite waveform is the setting of the maximum strain and torque ratio for each harmonic of the fundamental. As the strain applied to the sample is the sum of the individual strains associated with each harmonic, care must be taken not to exceed the linear visco-elastic limit. For strain sensitive systems this can severely restrict the munber of frequencies used. 

A viscous material (power-law rheology) is to be processed in a mixing vessel under laminar conditions. A sample of the material is tested using a laboratory scale mixer. If the mixing time is to be the same in the small and large-scale equipments, estimate the torque ratio for a scale-up factor of 5 for the range 1 > n > 0.2. 

The calculations indicated that the losses in the motors have been reduced by around 23% due to an improved pejikto rated torque ratio through the cycle. This leads to ui overall power saving of around 4.5% for this rock hoisting system. 

Figure 7.24. Morphology changes as function of Brabender torque ratio and composition. The numbers show the mean domain diameter in jxm and the length-to-diameter ratio (in parentheses). V, E3/HV2 E2/HV3 0, E4/HV1 O, E1/HV4 , E1/MV2 O, E2/HV1 A,...

F Double-cage, low-torque Uneconomical for most industrial loads because of their high starting-torque to breakdown-torque ratio. 

Generally, the range of cocontinuity is dependent on the viscosity (torque) ratio. In blends with a viscosity ratio near unity, a fully cocontinuous structure appears around 50 50 composition otherwise, the component vhth a lower viscosity tends to form a continuous phase and the range of cocontinuity is shifted to the lower amounts of less-viscous component (Figure 3.11). A second important parameter determining the formation of cocontinuous structure is the interfacial tension. With increasing interfacial tension, the minor phase forms more spherical... 

Figure 3.11 Type of final morphology of EPDM/PB blends with different torque ratios. Reproduced with permission from Ref. [54] 1976, American Chemical Society.

Extmsion accounts for about 30% of nylon produced and is used in various processes (24). Nylons can be extmded on conventional equipment having the following characteristics. The extmder drive should be capable of continuous variation over a range of screw speeds. Nylon often requires a high torque at low screw speeds typical power requirements would be a 7.5-kW motor for a 30-mm machine or 25-kW for 60-mm. A nylon screw is necessary and should not be cooled. Recommended compression ratios ate between 3.5 1 and 4 1 for nylon-6,6 and nylon-6 between 3 1 and 3.5 1 for nylon-11 and nylon-12. The length-to-diameter ratio, T/D should be greater than 15 1 at least 20 1 is recommended for nylon-6,6, and 25 1 for nylon-12. 

Tlocciilant addition rate can be regulated in proportion to the thickener oliirnetric feed rate or solids mass How in a feed-fonvard mode, or in a feed-back mode on either rake torque, iindertlow density, settling solids (sludge) bed le el, or solids settling rate. Of these, feed-fonvard on mass How or feed-back on bed le el are probably the most common. In some feed-fonvard schemes, the ratio multiplier is trimmed by one of the other parameters. 

The machine now operates in a constant torque region (see Figure 6.7(b)). The frequency is reduced as is the voltage to maintain the same ratio of V f. At lower voltages, / and therefore /, will diminish, while and / , will rise, so that 0, I s a constant. 

Ki = mean load factor, i.e. the ratio of the average load torque to the motor torque which depends upon the loading on the motor during start-up. 

Figure 8-11 shows the effleieney variation with the tip speed ratio. This eurve also shows the runaway speed. Runaway speed is aehieved when turbine torque falls to zero at blade speeds higher than the design speed. If failure oeeurs above the tip speed, the rotor ean be defined as a fail-safe rotor design. 

Figure 2.8 shows a reduetion gearbox being driven by a motor that develops a torque T tn(t). It has a gear reduetion ratio of and the moments of inertia on the motor and output shafts are and /q, and the respeetive damping eoeffieients Cm and Cq. Find the differential equation relating the motor torque CmfO and the output angular position 6a t). 

The appropriate drive ratio is selected for each motor so that it is fully loaded when in operation- a distinct advantage over two speed, variable torque motors where the available horsepower is proportional to the square of fan speed while the required fan horsepower varies as to the cube of fan speed (from the fan law). As an example, a fan motor that can produce 40 hp at high speed can produce 10 hp at low speed while a fan that requires 40 hp at high speed only requires 5 hp at half speed. As a result, 1800/900 rpm motors are always 100 % oversized at low speed. And, since the motor usually operates at low speed most of the time, the... 

In a toroidal traction drive, toroidal input and output disks face one another, separated by a number of rollers that contact the toroid surfaces. The rollers are mounted so that they can he tilted to vaiy the radius from the centerline of the disks where they contact the toroids, and therefore determine the input/output speed ratio of the rotating disks. A substantial axial force must be applied to the disks to prevent the rollers from slipping on the disk surfaces. To avoid excessive losses when the torque transmitted is low, this force needs to he modulated in proportion to the torque transmitted. 

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