In hydrodynamic bearings, the shaft and the bearing shell are separated from each other during operation by a supporting lubricating film. The position of the shaft in relation to the speed and the load is important for an analysis of the tribological process in the bearing shell of a journal bearing. The pressure in the lubricating film in hydrodynamic journal bearings is generated by the relative motion between bearing shell and shaft.
Features:
Pressure distribution in the journal bearing
Locus of the shaft under different loads and speeds
Frictional moment under different bearing clearances and loads.
Learning Objectives And Experiments:
Influence of speed, bearing clearance and bearing load on the displacement of the shaft
Influence of speed, bearing clearance, bearing load and lubricant on the frictional moment
Determine the coefficients of friction at various loads and speeds, compare with Stribeck curves
Locus of the shaft.
The apparatus consists of a sturdy tubular steel frame on which is carried a counter shaft mounted in ball bearings having an overhung mandrel at the front. The Journal Friction Apparatus is the basic item in the Hydrodynamic Lubrication Unit which enables the friction in a journal bearing to be measured under various conditions of load and speed, including boundary lubrication conditions, and the comparison of the results with the friction torque predicted by the Petroff equation. The bearing system, which is to be the subject of the investigation, is assembled around the mandrel. The shaft is driven by a variable speed DC motor via a toothed belt and pulleys.
Features:
Uses automotive thin wall main bearing shells of various widths.
Variable speeds up to 1000 rev/min.
Horizontal 50 mm shaft and journal bearing;.
Three alternative shaft sleeves provide variable bearing clearance.
Air cylinder driven reciprocating oil pump and accumulator.
High quality oil filtration and pressure regulation.
Indication of oil film thickness and detection of metal to metal contact based on electrical resistance between journal and housing.
Radial loading of the bearing of up to 500N is applied vertically by weights via an hydrostatic pad.
Direct measurement of bearing friction torque.
Instrumented for oil pressure and temperature, and drive motor current.
Material: Polypropylene, autoclavable.
Jug, measuring, with handle and indelible embossed graduation for each 50ml.
Capacity: 1000ml.
It is used to squeeze juice and consists of lever press disc, filter plate, juice container. Manual plastic.
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Dully Hardened & Tempered. Heavy Duty
....-lab-344333951.jpg "JUNIOR HACKSAW(PLASTIC)")
JUNIOR HACKSAW(PLASTIC)
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Brass sheet, matches, candles, scissors, solder, carbon rods, wires, light bulbs, batteries, bulbs, wood, sand etc..
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The product is a magnetic absorption electrical demonstration experiment. Component module on the front screen printed circuit symbols and values, closed module bottom using transparent plastic production, visible internal components, equipment components should include: a digital ammeter, the range is not less than 5A, precision 0.01A, a digital voltmeter is not less than 20V, precision 0.1V, battery box two groups, the maximum series Combined 12V, three lamp holder and light bulb (4 3.8V/6V each), single knife and double throw switch two, single knife switch three, resistance 5 Omega /5W, 15 Omega /5W, 20 Omega /5W each, 10 Omega /5W two, connection cylinder six, sliding rheostat 20 /2A one, nickel chrome wire, copper wire, wire each 2 meters, connecting wire not less than 40 root, digital current The meter and voltmeter are displayed with high brightness digital tube. The bottom of all parts is composed of magnetic absorption independent component module. The modules can be directly adsorbed on the blackboard at the time of experiment. It has greater visibility, strong three-dimensional sense and convenient teaching demonstration experiment. The module should be placed in the hand-held plastic box for convenience. The size is not less than 0.8 inches. The size of each module is not less than 85mm*35mm*35mm.
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Junior High School Mechanics Experiment Box
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It is maily used for the following experiments: The rectilinear propagation of light, pinhole, light reverse, refraction, convex imaging etc.
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This instrument is an adjustable DC stabilized source, with standard voltage: 1.5V-9V six grades, rated output current: 1.5A, voltage stability: each grade less than 350mV, current stability: each grade less than 350mA, ripple voltage: each grade less than 15mV, over-current protection, current limiting in the range of 1.8A~2.4A.
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The circumference ratio demonstration consists of a circle wheel (100mm diameter) and a scale below the tray.
The circle area demonstration consists of a 200mm diameter circle divided into 16 equal parts of the fan-shaped small pieces, and each one be divided into two small pieces.
Junior Middle School Teaching Power
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Junior Scene Demonstrator
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It is used to combined demonstrate more than twenty basic experiment of junior school mechanics.
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The calorific value is obtained by utilizing a heat exchanger where the products of combustion are cooled by a measured flow of water. Junkers Boys Calorimeter apparatus allows for the accurate determination of the calorific value of the main fuel gases which are used in the industry, such as butane, propane and methane. The system is supplied with manuals which describe all parts of the trainer, the installation and utilization procedures, as well as some exercises with the relative results. The burner is supplied with a complete set of interchangeable nozzles for the different types of gases.
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