Maximum torque

This is the maximum torque that can be developed by the rotor during a run, but the useful torque will be in accordance to output, i.e. 

Since the maximum torque is measured by line AM, it is known as the torque line. 

Pull-out or breakdown torque (maximum torque) Rated torque... 

Maximum torque occurs at the locked rotor condition, i.e. when S = I (Figure 7.11). 

It is therefore necessary to take precautions during the test to avoid a excessive temperature rise and consequent damage to the windings. For wound rotor motors, speed-torque and speed-current tests may be taken between synchronous speed and the speed at which the maximum torque occurs. 

Adequate sizing of shafts, couplings, and bearings for maximum torque conditions... 

The damper and field windings each produce an effect on accelerating torque. The resistance of the damper winding is usually selected to produce its maximum torque during the first part of the starting period and a field-discharge resistor is selected so that the field-circuit torque peaks near pull-in speed. 

Breakdown torque For an alternating current motor, this is the maximum torque that it will develop with rated voltage applied at rated frequency, without an abrupt drop in speed. 

The pull-out or breakdown torque must be greater than the maximum torque required by the driven equipment to prevent stalling, usually 150% of full load torque for unity-power fector motors and 220-225% for 0.8 leading power factor motors. ... 

Torque. Specify NEMA design (A, B, C, or D) or manufacturer s designation if known. For special applications, advise when load peaks occur and severity, starting, pull-in, and maximum torques. For fractional hp, some manufacturers give you the choice of capacitor-split phase, reactance-split phase, or repulsion-start. 

Torque. Specify required starting, pull-in, pull-out, and maximum torques. 

It is usually good practice to apply motors at momentary loads at least 20% below the values given for maximum torque in order to offset that much torque drop caused by an allowable 10% voltage drop. 

The maximum torque will be at the maximum differential pressure Ap which is... 

Circulation Rate (9Pm) Speed (rpm) Maximum Differential Pressure (psi) Maximum Torque (ft-lbs) Maximum Horsepower... 

The maximum torque to be measured is 20,000 ft-lb. Using the same type of gages, properly placed on the sub, show that with two gages conveniently oriented the differential pressure strain and weight-on-bit strain do not register on the bridge. 

Torque requirements are a primary concern during the selection process. In all applications where variable or high torque is transmitted from the driver to the driven unit, a flexible coupling rated for the maximum torque requirement must be used. Rigid couplings are not designed to absorb variations in torque and should not be used. 

Flexible couplings rated for the maximum torque requirement... 

Although not a design that guarantees positive power transmission, a satisfactorily performing friction clutch will transmit the maximum torque output of the driver to the driven shaft without slip when fully engaged. The automobile clutch is the most common example, transmitting the maximum motor torque to the wheels. 

In order to test this concept a series of compounds was prepared in a 5 L Shaw Intermix (rubber internal mixer, Mark IV, Kl) with EPDM (Keltan 720 ex-DSM elastomers an amorphous EPDM containing 4.5 wt% of dicyclopentadiene and having a Mooney viscosity ML(1 +4) 125°C of 64 MU 100 phr), N550 carbon black (50 phr), diisododecyl phthalate (10 phr), stearic acid (2 phr), and l,3-bis(tert-butylperoxy-isopropyl)benzene (Perkadox 14/40 MB ex Akzo Nobel 40% active material 6 or 10 phr). A polar co-agent (15 phr) was admixed to the masterbatch on an open mill and compounds were cured for 20 min at 180°C in a rheometer (MDR2000, Alpha Technologies). The maximum torque difference obtained in the rheometer experiments was used as a measure of... 

The torque continues to increase, until there is no more signihcant rise. At this point the compound is vulcanized, and this maximum torque value is designated by the symbol Mh- The last major piece of data to be extracted is the time it takes to complete the cure, known as the cure time (t x). 

Influence of the ZnCFO contents (3,0 5,0 7,0 phr) on crosslink kinetics of the modelling unfilled rubber mixes from NBR-26 of sulfur, thiuram and peroxide vulcanization of recipe, phr NBR-26 - 100,0 sulfur - 1,5 2-mercaptobenzthiazole - 0,8 stearic acid - 1,5 tetramethylthiuramdisulfide - 3,0 peroximon F-40 - 3,0, is possible to estimate on the data of fig. 7. As it is shown, the increase of ZnCFO concentration results in increase of the maximum torque and, accordingly, crosslink degree of elastomeric compositions, decrease of optimum cure time, that, in turn, causes increase of cure rate, confirmed by counted constants of speed in the main period (k2). The analysis of vulcanizates physical-mechanical properties testifies, that with the increase of ZnCFO contents increase the tensile strength, hardness, resilience elongation at break and residual deformation at compression on 20 %. That is, ZnCFO is effective component of given vulcanization systems, as at equal-mass replacement of known zinc oxide (5,0 phr) the cure rate, the concentration of crosslink bonds are increased and general properties complex of rubber mixes and their vulcanizates is improved. 

The material of construction for the screw is critical in order to provide the proper strength in the event of an improper startup procedure such as a cold start and to minimize cost. The choice of the material of construction depends on the motor size, the maximum screw speed at the base motor speed, and the depth of the feed section. The maximum torque that the motor and gearbox combination can supply to the screw, (Nm) is computed as follows ... 

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