Worlds largest roundness system, with 2.5m Column!
Taylor Hobson has produced the world’s largest roundness system for use in the heavy duty truck engine market. Talyrond 450 with its 2.5 metre column, new high precision air bearing spindle and 1000Kg load capacity provides full inspection of engine blocks, cranks, heads…
The Talyrond 450 with an incredible 2.5 metre tall column represents a new milestone in roundness measurement here at Taylor Hobson.
In 2006 Taylor Hobson were approached by two leading manufacturers of heavy duty truck engines hoping we could find a solution to the measurement of their latest engines, these being litre and litre engines for the Chinese truck market.
To meet emission criteria these new engines require tighter form tolerances, creating a challenge for the inspector and stretching the capabilities of the measuring room. Co-ordinate measuring instruments although capable of measuring the cylinder bores and other parts of the engine, struggle to meet the specifications applied to the crankshaft and camshaft bores and are certainly not capable of measuring the crankshaft.
The main reason for this problem is the length of the measuring probes. These probes have to reach depths of greater than 1.2 metres and still maintain accuracies in and around the micron mark.
This is where we came in; the first problem for our engineers was the instruments spindle stiffness. Current technology involves our world renowned hydro-dynamic oil spindle. These spindles are accurate to nanometre level and have been in use for over 55 years with well over 1000 spindles installed worldwide. However these new engines required probe depths and lengths of greater than 1.2 metres; at these depths the greatest challenge is the stiffness of the spindle.
Take the example shown here, the crankshaft bore of this litre engine requires precision measurement of its main bearings for roundness and concentricity. In this particular application an 1100 mm drop arm made from carbon fibre is suspended from the spindles rotating arm, the gauge head is connected to the end of the drop arm and the stylus tip placed in contact with the part. For standard systems suspending 1100mm drop arms from the spindle creates problems due to lack of spindle stiffness.
1360mm “Cobra” Drop Arm
However this was not a problem for our current spindle technology, the bigger problem was the measurement of the crankshaft. This crankshaft provided two challenges, the first challenge was the sheer length of the crankshaft and the second was designing a drop arm that could rotate without fouling on the crankshafts counterweights yet still reach the pins and main bearings to
measure roundness and cylindricity.
Using finite element analysis and previous design experience a crankshaft arm was developed that ensured access to crankshaft bearings while maintaining the stiffness and stability required for high accuracy form measurement.
New Air Bearing Spindle
To avoid “coning error”, whereby rotation of the large drop arm causes an ovality effect during measurement, and to prevent vibration from the spindle being amplified at the probe tip, a new spindle design was required.
Our engineers took this challenge on and with extensive knowledge gained from our experience in diamond turning machines and our mid range roundness systems, all of which use air bearings; we set to work on designing a new
spindle with higher stiffness and greater accuracy.
New Radial Arm with counterbalance mechanism
To enhance accuracy even further and again drawing from experience gained during development of our Talyrond 1600 large diameter roundness system a new radial arm was created. The key change to this radial arm was the new counterbalance system. When rotating large drop arms that are offset from the main axis of the spindle (see crankshaft inset) any out of balance effect can cause a coning error. This error will give false roundness readings from the measurement often appearing as an oval effect. The new counterbalance system has a mechanism that shifts weight in an equal and opposite radial direction to the probe and drop arm thus ensuring equilibrium resulting in high accuracy roundness measurement.
New Automated centre and level with follow mode
A tilted part placed on the table top of the roundness system requires centring and levelling to the systems spindle axis prior to measurement. As parts get taller then the effects of tilt become greater; often resulting in the tilt exceeding the range of the probe. For example a 1 metre component is placed on the systems table with a tilt error of 0.5 degree, this is no problem for the levelling process but it means that the part has a 9mm tilt that lies outside the gauge range. To overcome this and to prevent the need for expensive fixturing the TR450 has the ability to follow the tilted part using the radial arm, thus keeping the gauge in range and allowing the user to carry out rapid alignment.
New 2.5 metre column
The question is often asked why we need a 2.5 metre vertical column to measure a 1200mm engine. The answer to this is fairly simple but not obvious at first glance. In order to measure the crankshaft bores of this particular engine we needed 1200mm of travel using a vertical straightness datum provided by the system's precision guides.
However when using a 1200mm drop arm to reach in the bores, we need to raise the spindle 1200mm from the table top to allow withdrawing of the stylus tip and gauge from the engine block. This means we required a riser block of 1 metre and a vertical travel of 1200mm, resulting in a 2.2 metre column requirement. However, to future proof the system for larger engine blocks we have developed a 2500mm column, making it the largest roundness gauge in the world.
Other Large Capacity Systems
Talyrond 450
Designed for the powertrain and machine tool industries this instrument utilises a rotating gauge head mounted on a vertical straightness unit, the rotating head allows manufacturers to measure roundness of prismatic or non rotationally symmetric components such as engine blocks, crankshafts,cylinder heads and many more. The solid cast iron base frame and column surround ensure stability during measurement while the high precision spindle and vertical straightness unit ensure repeatable and reliable measurement of roundness, cylindricity and straightness. A high load capacity X,Y table with fully automated centre and level ensures precise set up and repeatability between operators. The entire system is completely automated utilising Taylor Hobson's Ultra software, this software has many features ensuring measurement and analysis to national and international standards. • Fully Automated Centre and level capability
• 1000kg load X,Y table with high accuracy position control
• High accuracy spindle with large load capacity for special deep bore drop arms
• Straightness, parallelism and cylindricity measurement up to 1.5 metres
• Column heights of up to 2000mm
• Windows based Ultra software with measurement traceable to national and international standards
Download Overview
More Information
Talyrond 440
This instrument utilises a high load capacity rotating table with fully automated centre and level ensuring fast and reliable part alignment. The vertical straightness unit is contained within a cast iron structure and consists of a precision ground column with up to 1500mm of straightness movement and measurement. The instruments load capacity and column height make it ideally suited for large crankshafts and precision spindles however its arm orientation mechanism and precision radial arm make it extremely versatile allowing measurement of both small to large components. The Instrument is completely automated and is driven by Taylor Hobson's intuitive and programmable Ultra software.
- Fully Automated Centre and level capability
- 225Kg High load capacity spindle with +/- 0.05um roundness uncertainty
- Straightness and cylindricity measurement up to 1.5 metres
- Fully Automated gauge attitude/orientation mechanism
- Windows based Ultra software with measurement traceable to national and international standards
| Download Overview | More Information |
Talyrond 365/385 XL
These systems are extremely popular in the measurement of lage diameter bearings and non-rotationally symmetric components. The system is based around Taylor Hobson's popular Talyrond 365 range and utilises a frictionless air bearing spindle and high accuracy column with adjustable positioning to allow measurement of bearings up to 1 meter in diameter. The system has features such as fully automated centre and level and automatic gauge calibration, these features greatly reduce measurement and set up time thus increasing throughput. The systems come in two types, either with fully automated arm attitude/orientation or a manually operated version, in both cases these patented mechanisms provide access to the most difficult of components.
- Fully automated centre and level capability with radial follow mode
- Automatic gauge calibration
- Patented arm attitude/orientation mechanism with choice of automated or manual modes
- Vertical straightness units of up to 900mm
- Large diameter range with adjustable column and 300mm radial arm
- Windows based Ultra software with measurement traceable to national and international standards
| Download Overview | More Information |
Talyrond 1600
The Talyrond 1600 is the most accurate system of its type, utilising an air bearing spindle with a rotating arm this instrument is unique in its capacity and accuracy. Components of up to 1000Kg with diameters of up to a considerable 1.6 metres can be measured yet still maintains accuracies normally associated with laboratory type equipment. This system is ideal for manufactures of large diameter bearings and gears such as those found in the wind turbine, mining and excavation industries. Like all Taylor Hobson's roundness systems the rotating arm of the Talyrond 1600 has been designed using Finite Element Analysis techniques, constructed from carbon fibre this arm can measure roundness from speeds of 0.2rpm to 6rpm. Despite the size of this system centering is fully automated while the sturdy base frame contains coarse and fine adjustment levelling mechanisms making set up fast and simple.
- Fully automated centering capability with targets to less than 0.8um
- High load capacity base frame with up to 1000kg load
- Carbon fibre radial arm with 1600mm diameter capability
- High precision air bearing spindle with +/- 0.1um roundness uncertainty
- Windows based Ultra software with full harmonic and velocity analysis capability
| Download Overview | More Information |
