Journal Bearing Friction Apparatus | FrixoDynamics FX-528

Key Features

Key Features

• Three interchangeable bearing shells, sintered bronze, cast iron, and PTFE, on a common 40 mm stainless steel shaft journal for direct material pairing comparison under identical speed and load conditions
• Three-phase AC motor (750 W) with VFD provides continuously variable shaft speed with digital display up to 9,999 rpm, enabling systematic speed-dependent friction investigation
• Inductive speed sensor ensures accurate, real-time shaft speed measurement independent of the VFD control setting
• Friction moment measured via lever arm and spring balance (30–750 Nmm range), load and friction moment measurable simultaneously using two supplied spring balances
• Digital display of both lubricant temperature and shaft speed on the control panel for continuous monitoring throughout the experiment
• Drip-feed lubricator with dedicated lubrication channel delivers consistent, controllable oil supply to the bearing, ISO VG 100 or alternative viscosity grades
• Drip tray collects escaping lubricant, maintaining a clean working environment and allowing lubricant consumption observation
• Both lubricating gap and shaft journal surface visible during operation for direct observation of hydrodynamic film condition

Applications

• Experimental investigation of hydrodynamic lubrication principles in radial journal bearings
• Determination of friction moment as a function of shaft speed for a given bearing load and material pairing
• Investigation of the effect of bearing load on friction moment at constant speed
• Comparison of friction behaviour across sintered bronze, cast iron, and PTFE bearing shell materials
• Study of the effect of lubricant temperature on friction moment and lubricant viscosity
• Investigation of the Stribeck curve, the relationship between friction coefficient and the ratio of speed to bearing load, using the FX-528 experimental data
• Undergraduate and postgraduate laboratory practicals in tribology, machine elements, mechanical engineering design, and lubrication engineering
• Supplementary demonstration for courses covering hydrodynamic bearing theory, lubricant selection, and bearing material choice

Construction and System Design

The FX-528 is built on a rigid base panel that houses the motor, VFD control electronics, digital display, and lubrication system. The three-phase AC motor is coupled to the stainless steel shaft journal through a suitable drive connection. The shaft runs in the free-moving bearing housing, which is constrained from rotating by the lever arm connected to the friction moment spring balance. The lever arm extends from the bearing housing at a known radius, so the spring balance reading on the lever directly gives the friction moment when multiplied by the arm length.

Bearing load is applied to the top of the bearing housing through a separate lever and weight hanger system, confirmed by the load spring balance. The knurled screw at the top of the housing allows fine adjustment of the applied load. The interchangeable bearing shells, sintered bronze, cast iron, and PTFE, are seated in the housing bore and clamped in position before the experiment begins. Changing shells requires only the removal and replacement of the shell in the housing, with no modification to the shaft, lever, or lubrication system.

The drip-feed lubricator is mounted above the bearing and delivers oil at a controlled drop rate through the lubrication channel to the bearing clearance gap. Two lubricators are supplied, allowing different oil types or viscosity grades to be prepared and switched between experiments without refilling. Oil escaping the bearing clearance falls into the drip tray below the housing, keeping the base panel clean. The temperature sensor is positioned to monitor the lubricant temperature continuously, and the digital display updates in real time alongside the speed reading, allowing students to observe temperature-related changes in friction during extended running conditions.

Export and Supply Capability

The SCIENTICO FrixoDynamics FX-528 is available for supply to engineering colleges, technical universities, mechanical engineering departments, research institutions, and industrial training centres. SCIENTICO manufactures and exports laboratory equipment to institutions and distributors across multiple regions. Standard packaging is suitable for international shipment. Bulk orders, customised configurations, and institutional procurement enquiries are welcomed. Please contact SCIENTICO directly for pricing, lead times, and shipping terms.

Standards & Compliance

• Manufactured under ISO 9001:2015 Quality Management System
• CE Marking - European Conformity where applicable
• Supplied with calibration certificate, operation manual, and experiment guide
• 12-month manufacturer's warranty (parts & labour from installation)

Ordering & Delivery

• Incoterms: CIF to destination seaport, FOB Mundra/Nhava Sheva, or Ex-Works Ambala
• Lead time: 3–5 weeks production + sea transit to destination
• Payment: LC (Letter of Credit) or T/T bank transfer against proforma invoice
• Documentation: commercial invoice, packing list, bill of lading, certificate of origin, insurance certificate

Frequently Asked Questions

Q1: What is the journal bearing friction apparatus used for in engineering education?

The FX-528 is used to investigate the friction phenomena in radial journal bearings under controlled conditions of speed, bearing load, lubrication, and material pairing. Students measure the friction moment generated in the bearing using a lever arm and spring balance, observe how it varies with shaft speed, applied load, lubricant temperature, and bearing shell material, and relate the results to hydrodynamic lubrication theory, including the Stribeck curve relationship between friction coefficient and the ratio of speed to bearing pressure.

Q2: What is hydrodynamic lubrication, and how does the FX-528 demonstrate it?

Hydrodynamic lubrication occurs when a rotating shaft journal generates sufficient pressure in the lubricant film to completely separate the shaft and bearing surfaces, eliminating direct metal-to-metal contact. The friction force in this regime is determined by the viscous shear of the lubricant film rather than by surface asperity contact. The FX-528 demonstrates this by showing that friction moment decreases as shaft speed increases from rest, where boundary lubrication dominates, toward the full hydrodynamic regime at higher speeds, producing the characteristic Stribeck curve shape.

Q3: How does bearing shell material affect friction in the FX-528?

The three bearing shell materials, sintered bronze, cast iron, and PTFE, have different surface hardness, thermal conductivity, and compatibility with the steel shaft journal. Under boundary or mixed lubrication conditions, where the lubricant film is thin and surface contact occurs, the material pairing significantly affects the friction coefficient and wear rate. PTFE has the lowest boundary friction coefficient; sintered bronze offers good load capacity and compatibility with oil lubrication; cast iron provides high hardness and wear resistance. The FX-528 allows direct measurement of friction moment for each shell under identical speed and load conditions.

Q4: What role does lubricant temperature play in journal bearing friction?

Lubricant viscosity decreases with increasing temperature. Lower viscosity reduces the hydrodynamic pressure developed in the lubricant film, which can shift the lubrication regime from fully hydrodynamic toward mixed lubrication, increasing friction and wear risk. The FX-528 monitors lubricant temperature continuously on the digital display, allowing students to observe how friction moment changes as the bearing warms up during operation, and to investigate the importance of lubricant viscosity grade selection for a given bearing speed and load condition.

Q5: What is included in the scope of delivery for the FX-528?

The FX-528 is supplied as a complete experimental kit including: one journal bearing experimental module with stainless steel shaft, free-moving bearing housing, lever arm, VFD-controlled three-phase motor, inductive speed sensor, and digital speed and temperature display; one set of bearing shells (sintered bronze, cast iron, PTFE); two spring balances for load and friction moment measurement; one set of calibrated weights (1 x 0.5 N hanger, 10 x 0.1 N, 3 x 0.5 N); one drip tray; two drip-feed lubricators; and one comprehensive instructional manual covering experimental procedures, lubrication theory, and data recording guidance.