Request Expert

52100 steel is the primary material used for standard bearings and automotive products that act as raceway materials. It is also common to use the material for bearing balls. The expert has extensive experience grinding the hardened form of this material in it's martensitic state with hardness values in the 58 to 62 HRc range. The expert has developed computer models predicting incipient burn when abusive grinding practices have been used with this material. This medium carbon steel falls into the category of "easy-to-grind" materials and the expert has applied a variety of abrasives to successfully grind this material.

The expert has experience in material handling equipment linked to and from grinding machines. This material handling equipment is controlled by the machine plc and there maybe de-magnetiziers and post process gauge systems included.This equipment ensures a hands off approach for loading and un-loading workpieces.

Manufacturing specifications applied to bearings help ensure that the "book" performance of a given bearing in an application is achieved. The theoretical performance can be enhanced dramatically by the grinding and super-finishing processes by changing the surface topography of the machined surface. The expert understands fully the required process parameters to produce specific surface properties using the process kinematic parameters and the influence of the grinding wheel specification and coolant type. Surface properties include integrity and topography.

The Expert has "hands-on" experience with this type of grinding equipment from his apprenticeship years. He has used this type of equipment in manual and CNC modes to produce full form products that include internal and external surfaces. He is most familiar with Jones and Shipman machines. Materials ground include soft and hardened metals, hard chrome plate, tool steels and carbide.

High-rate center less grinding was the subject of the experts PhD thesis. The Expert is fully familiar with plunge and through feed center less grinding modes. He has extensive knowledge regarding setup parameters to produce optimally round parts with no thermal damage. The Expert has produced kinematic models that predict the idealized undeformed chip thickness for given geometric and kinematic conditions. He also understand the geometric and kinematic conditions that cause work piece waviness often referred to as "chatter". Part sizes ground vary from micron size up to 14" in diameter. He was responsible for instrumenting the machine to measure grinding forces and was able to build a data base that reflected material characteristics based on steel composition and hardness from the grinding forces.The Expert used diaphragm compensated hydrostatic bearings for both grinding and control wheel spindles and experimented with grinding wheel speeds up to 24,000 sfpm.

From research experiences both in academia and industry the expert quickly identified properties in machine tools that produced accurate quality parts in the shortest cycle times - important for high volume commodity markets. The expert can work with designers to produce optimal features to produce machines that exhibit high stiffness, long life in moving parts and if necessary a wide variety of sensor technology. The expert advocates hydrostatics where ever possible. He has a solid understanding of dressing systems and high frequency spindle technology. The expert worked with CGRD at UCONN and Bryant Grinder Corporation to design and build an outside diameter grinding machine that runs at 50,000 sfpm. This is a documented NSF project.

To achieve the required part quality in grinding process it is important to have precision balanced rotating elements. Some balance can be achieved through manufacturing rotating elements to tight specification. However, after the components are put into assemblies there will be a residual unbalance. Dynamic balancing is necessary to deliver the final balance level tolerable. The expert has used manual balancing techniques using vibration sensing equipment and has used automatic balancing equipment that becomes integral with the spindle design. Mass addition and subtraction techniques have been used.

Characteristics required in grinding equipment are also required in other types of machinery. Here the expert has directed machine designers for wood working equipment, through feed bar heat treating machines, multi-axes machining centers in addition to grinding equipment.

Machine tool qualification includes testing the assembled machine tool against a set of accuracy, repeatability and physical characteristics against machine tool specification and the actual part run-off. The Expert has written numerous machine tool specifications for several companies that include mechanical and performance requirements. He has worked closely with quality engineers to develop the statistical requirements for part dimensions and surface properties of the machined or ground workpiece.

Although a significant portion of the expert's experience has been in the bearing industry he has worked for several years in the consumer products industry. Here he was heavily involved with stamping operations, assembly, quality and broaching and forging. Throughout his industrial experience he has been exposed to TQM, TPM, Kaizens, 5S, Lean, and OPEX that embraces all of the above but includes Break Through Deployment. As a major contributor to the many programs he has been involved with, the expert has developed strong working relationships with several universities and countless vendors.

The Expert has developed grinding processes to capitalize on the use of vitrified bonded CBN wheels in a significant number of applications. More than 80% of these applications required the use of water based grinding fluids. The expert worked with the researchers a GE Super-abrasives to develop grain and bond characteristics to produce G-ratios in excess of 4000 when grinding 52100 steel in synthetic coolants. Along with developing the wheel specifications, diamond dressing systems and dressing techniques were created to extract the most from the carat cost based abrasive grain. The Expert has applied CBN to 52100, Stain-less steel, tool steels and special tool steels such as Rex 20.

Plated CBN wheel have been used where appropriate. These applications maybe short run or long small diameter bores. The excellent results obtained in applying CBN were made possible by instrumenting grinding machines and through the application of DOE.

The Expert worked for 15 plus years for The Torrington Company, America's largest broadline bearing manufacturer. Torrington is now owned by The Timken Company. During this time, the Expert was involved with all aspects of ball bearing manufacture. However, the bulk of the experience was with the actual grinding processes and associated equipment and metrology. His experience covers a wide range of product types, sizes and materials. Raceway grinding of super precision bearings requires accurate machine tools and an understanding of the super finishing process to achieve the final product specification. The Expert has worked with all classes of bearings and has even used CBN abrasives on bearing races.

The expert has recently helped build a taper roller bearing manufacturing plant from a green field site to a fully operational facility. The expert provided technical support in the following areas:- machine tool specifications, acceptance specifications, acceptance of equipment at the machine tool plant, machine tool acceptance and problem solving at the bearing factory, metrology and metallurgy training and support, the use of instrumentation to improve cycle times and grinding burn avoidance, machine health monitoring and training in grinding process and technology in the class room and on the shop floor. The expert has experience in the manufacture of taper, spherical, needle, and large diameter roller bearings. This experience encompasses both simple rollers, and optimised profile rollers.

The requirements to produce quality needle roller races are similar to those for ball bearing races. However, typically, needle roller races are not super finished. This means that the grinding process has to impart the topography required. The Expert has experience in specifying abrasives, process and machine cycles to achieve the required bearing ratio and topography through the manufacturing process.

Worked with Client to build a taper roller bearing plant from "green field" to full production. Areas of support include machinery specification, purchase, acceptance and factory install. Metrology and metallurgy equipment were identified, the purchase supported and laboratory setup completed. Cycle time reduction, burn and "chatter" elimination solutions were developed. Grinding and metrology training were provided on the shop floor and in the classroom.Resolved manufacturing issues between a supplier and their customer, Was able to suggest alternative manufacturing techniques to the supplier to avoid the discourse between them and their customer.

Trained a maintenance team to use vibration analysis equipment to identify incipient bearing failure and thus avoid scrap work on turning and machining centers.Provided 1 week seminars to a machine tool builder to advance the level of technology in his machines. 50 design engineers attend the week long program. This work was conducted off shore.Performed a factory review for a tap and die manufacturer and was able to identify multiple opportunities to reduce scrap, reduce cycle time, improve the use of MRO and implement some basic lean engineering principles, 5S and Kaisens.Currently working with an offshore bearing manufacturing company to develop their process development team, solve manufacturing issues and give technical direction to the global machine tool design team.Provided expert witness technical support in resolving several personal injury cases that involved grinding equipment.