Northwestern University

Shanghai Jiaotong University

Korea Institute of Machinery & Materials

Council of Scientific & Industrial Research

Irwin-industrial Tool Company

Kornel F Ehmann

Jian Cao

Qiang Zeng

Jun Chen

Huan Yun Zhang

Jong-Kweon Park

Seung Kook Ro

Byung-Sub Kim

Sung Cheul Lee

Rajiv Malhotra

Rui Zhou

Kumar Pallav

Ishan Saxena

Yip-Wah Chung

Qian Jane Wang

Iqbal Singh

Jaegu Kim

Xingliang He

Jennifer Lynn Bennett

Zhong Liu

Peidong Han

Man Kwan Ng

Jiaxi Xie

Huaqing Ren

Shuheng Liao

Dohyun Leem

Abhijit Mahapatra

Yi Shi

Samik Dutta

A three degrees of freedom (3DoFs) Wedge Air Bearing Translational Stage System (WABSS) for positioning of miniature components using a parallel kinematic mechanism. The system has three kinematic sub-chains situated at 120° apart from each other, where each sub-chain has one prismatic joint and one planar joint guided by air bearings. One central stage assembly (CSA) having three wedges with wedge planes oriented 45° to the horizontal plane is capable of translations along the X-, Y- and Z-axes for precision positioning of the targeted workpiece material held on the CSA. Following the parallel kinematic principle, the coordinated translations of the three slide bars produce 3DoFs translations to position CSA in each sub-chain. The linear geometric error along the Z-axis is independent from the angular tolerances due to its unique vertical structure.

Three degrees of freedom (3DoFs) precision positioning wedge air bearing stage system (WABSS)

Novel systems and methods for an incremental forming process to manufacture a product are disclosed herein. The system and method generally involves continuously modifying the toolpath in real-time based upon the forming force of the forming tool compared to a predicted springback error established offline from a series of simplified simulations. The system and method disclosed herein are effective to form products with complex geometries and minimizes the costs and time requirements associated with prior art techniques.

In-situ springback compensation in incremental sheet forming

A system for making a build using directed energy deposition is provided. The system includes a primary heat source; a processing nozzle movable relative to the build for delivering a metal powder, a carrier gas for the metal powder, and a shield gas to the build; a melt pool sensor for providing information regarding a temperature of a melt pool of the build; a secondary heat source separate from the primary heat source positionable relative to the build for delivering heat to a selected area of the build; a cooling source positionable relative to the build for delivering a cooling fluid to a selected area of the build; and a control system for operating the primary heat source, the secondary heat source and the cooling source to maintain a desired temperature profile for the build. The system preferably includes a temperature sensor for providing a temperature profile of the build. The temperature control system preferably includes a programmable controller configured to control the secondary heat source and the cooling source to conform the temperature of the build to the desired temperature profile. In one embodiment, the programmable controller is pre-programmed with a dynamic thermal model of a thermal history of the build for each time step.

Systems and methods for global thermal control of additive manufacturing

Flanges formed on sheet metal parts to increase the part stiffness or create mating surface for further assembly are created in an incremental sheet forming process using forming tool and supporting tool that move along a specified tool path so as to gradually deform a peripherally-clamped sheet metal work piece into the desired geometry. With two universal tools moving along the designed toolpath on the both sides of the part, the process is very flexible. Process time is can also be reduced by utilizing an accumulative double-sided incremental hole-flanging strategy, in which the flange is formed in only one step.

Method and apparatus for double-sided incremental flanging

In an embodiment, a method of hardening a surface of a substrate comprises directing a waterjet having a transition flow region, the waterjet comprising water and particles, at a surface of a substrate such that the waterjet impacts the surface within the transition flow region to provide a layer of embedded particles underneath the surface of the substrate, thereby forming a hardened substrate. The hardened substrates are also provided.

Surface hardening of substrates by a particle-containing cavitating waterjet

A rolling mill system for Incremental rotary shaping of an elongated workpiece is provided that includes first and second workpiece holders. A support frame has a track with the first and second workpiece holders being movably associated with the track, the workpiece holders and an associated workpiece being movable in unison along the track. A radial chuck is mounted to the frame that includes a plurality of jaws that are movable radially inwardly and outwardly. Each jaw has a tool mounted thereto that is rotatable about an axis of rotation, with the axis of rotation of each tool being oriented at a skew angle relative to the longitudinal axis of a workpiece. A source of electric current and an electrically conductive flow path are provided for flowing electrical current through a workpiece. A controller is provided that is configured to control the operation of each of the first motor, second motor and third motor, and to control the flow of current flowing through the tools to the workpiece.

Incremental rotary rolling mill and method

A system for laser-induced plasma micromachining of a work-piece includes a dielectric fluid, a dielectric fluid supply device, a laser, a processor, and a memory. The dielectric fluid supply device is arranged to hold a work-piece in the dielectric fluid or to direct the dielectric fluid onto the work-piece. The laser is arranged to emit a pulsed laser-beam. The processor is in electronic communication with the laser. The memory is in electronic communication with the processor. The memory includes programming code for execution by the processor. The programming code is programmed to direct the laser to deliver the pulsed laser-beam into the dielectric fluid to create a plasma generated at a focal point of the pulsed laser-beam in the dielectric fluid to micromachine, using the plasma, the work-piece disposed adjacent to the focal point.

Laser induced plasma micromachining (LIPMM)

In one aspect, a translational parallel manipulator is provided and includes a fixed platform including three guide members. The three guide members include first ends and second ends, and the first ends of the three guide members are all coupled to each other and the second ends of the three guide members are all spaced-apart from each other. The manipulator also includes a movable platform spaced-apart from the fixed platform and three serial subchains coupled between the three guide members and the movable platform. In one aspect, a translational parallel manipulator is provided and includes a fixed platform, a movable platform spaced-apart from the fixed platform, and a plurality of subchains coupled between the fixed platform and the movable platform. At least one of the plurality of subchains includes no more than four one degree-of-freedom joints.

Translational parallel manipulators and methods of operating the same

According to an exemplary embodiment of the present invention, a trocar is provided. The trocar includes: a sharp end; at least three concave cutting edges extended from the sharp end; and at least three concave cutting surfaces forming the sharp end and the at least three cutting edges.

Trocar, method for manufacturing the same, and method for continuously manufacturing the same

An apparatus for processing the surface of a workpiece includes: a first rotating body connected to a first rotating shaft and including a first protruding portion connected to a part of the outer circumference thereof; a second rotating body connected to a second rotating shaft and including a second protruding portion connected to a part of the outer circumference thereof; and a third rotating body connected to a third rotating shaft and including a third protruding portion connected to a part of the outer circumference thereof, wherein the first to third rotating shafts are in the same plane, a first angle between the first and second rotating shafts, a second angle between the first and third rotating shafts, and a third angle between the second and third rotating shafts are identical, outer circumferences of the first to third rotating shafts adjacent to one another form a pathway through which a workpiece can pass, and the size of the pathway is adjusted by moving the first rotating body.

Apparatus for processing surface of workpiece

A compact deformation-based micro-texturing apparatus and method employ flexure bearing houses for rotatably supporting opposite ends of each of a first (e.g. upper) roll and a second (e.g. lower) roll to provide a working roll gap between the rolls, wherein at least one of the rolls has one or more micro surface features to plastically deform a surface of a workpiece deformed by rolling action in the roll gap. An electrical current may be passed through the workpiece to assist micro deformation. A roll gap adjusting device is operably associated with the first and second flexure bearing houses for adjusting the roll gap dimension to the final depth of the micro surface features to be imparted to the surface of the workpiece by the rolling action. A sheet material or antifriction element (e.g. journal bearing or bushing) is produced having at least one surface that includes rolled-in micro surface depressions wherein depressions have a lateral dimension of about 1 &#x3bc;m to about 10 mm and a depth of about 1 &#x3bc;m to about 10 mm, typically a lateral dimension of about 1 &#x3bc;m to about 100 &#x3bc;m and a depth of about 1 &#x3bc;m to about 100 &#x3bc;m.

Deformation-based micro surface texturing system

A compact deformation-based micro-texturing apparatus and method employ flexure bearing houses for rotatably supporting opposite ends of each of a first (e.g. upper) roll and a second (e.g. lower) roll to provide a working roll gap between the rolls, wherein at least one of the rolls has one or more micro surface features to plastically deform a surface of a workpiece deformed by rolling action in the roll gap. An electrical current may be passed through the workpiece to assist micro deformation. A roll gap adjusting device is operably associated with the first and second flexure bearing houses for adjusting the roll gap dimension to the final depth of the micro surface features to be imparted to the surface of the workpiece by the rolling action.

Growing community of inventors

Evanston, IL, United States of America

Kornel F Ehmann