Elastic shafts (TM625)

investigation of the natural modes of various shafts with continuous mass distribution and of a Laval rotor

CodeTM625

Description:

  • The terms “critical speed” and “resonance” are often used when referring to rotating systems.
  • Resonance occurs when the natural frequency and the excitation frequency match.
  • The natural frequency of an oscillatory system is that frequency at which the system oscillates with the associated natural mode after a single excitation.
  • Operation at critical speed can damage the system because of the high vibration amplitudes.
  • In order to study the phenomenon of shaft vibration in more detail, there are two simplified calculation models.
  • In the first case, the mass of the elastic shaft is evenly distributed along its length.
  • In the second case, the shaft consists of massless, elastic shaft sections and the masses are combined into discrete mass disks.
  • The TM 625experimental unit can be used to study the natural modes of these different models.
  • Illustrative experiments are used to explain resonance and the supercritical or subcritical states of a vibrating system.
  • Six shafts of different lengths and diameters are available.
  • The shafts can be mounted on four self-aligning ball bearings and fitted with a mass disk to construct a Laval rotor.
  • The axial positions are read on a scale mounted parallel to the shaft.
  • A three-phase motor drives the shaft via a flexible coupling.
  • The electronically controlled speed can be selected via two potentiometers and is continuously variable.
  • It is displayed digitally.
  • A transparent protective cover and safety bearing ensure safe operation.
  • The measured values can be displayed and analysed on a PC using the optional TM 620.20unit for data acquisition.

Technical Details:

Specification:

  • experimental unit for determining critical speeds and investigating the natural modes of a shaft
  • 6 high-tensile steel shafts
  • up to 4 self-aligning ball bearings, each moveable to any point as a shaft bearing
  • 1 mass for constructing a Laval rotor
  • 3 safety bearings and transparent protective cover for safe operation
  • three-phase motor: 2 pre-selectable speed ranges; speed electronically controlled and continuously adjustable
  • digital speed display
  • system TM 620.20 for data acquisition available as an option

Technical Data:

  • 6 shafts
    • Ø 3mm, 6mm, 7mm
    • L: 600mm, 900mm
    • high-tensile steel
  • Mass, disk-shaped
    • Ø 80mm
    • m: 965g
    • high-tensile steel
  • Motor
    • power: 0,25kW
    • speed: 6000min-1
    • speed electronically controlled
  • Shaft bearing
  • 4x self-aligning ball bearings
  • 3x safety bearings
  • Measuring ranges
  • speed: 0…6000min-1
  • scale for clearance measurement: 0…1000mm
  • 230V, 50Hz, 1 phase
  • 230V, 60Hz, 1 phase; 120V, 60Hz, 1 phase
  • UL/CSA optional

Dimensions & Weight:

  • L x W x H: 1550x380x450mm
  • Weight: approx. 65kg

Learning Objectives/Experiments:

  • investigation of a Laval rotor:
    • critical speed
    • self-alignment
  • natural modes on a shaft with continuous mass distribution with:
    • different bearing clearances
    • different shaft diameters
    • different shaft lengths

Scope of Delivery:

  • 1 experimental unit
  • 6 shafts
  • 1 set of tools
  • 1 set of instructional material

Features:

  • optimal visibility and simultaneous protection thanks to transparent protective cover

Accessories:

Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on this Website.