Abstract: A linear friction welding system includes a processing circuit configured to execute program instructions stored in a memory to control a first motor using one of a torque and speed control, placing a plurality of timing gears in a configuration wherein a fixed projection of one of the timing gears is at a trail position of a slot of another timing gear such that two power shafts of a cam assembly are rotating in phase and a ram is motionless. The processing circuit further controls a hydraulic press to generate a pressure between two components to be welded with the power shafts rotating in phase, and controls the second motor using the one of the torque and speed control to place the timing gears in a second configuration whereat the fixed projection is at a lead position of the slot thereby forcing the ram to oscillate.

Abstract: A method of operating a linear friction welding system in one embodiment includes establishing a ram vibration amplitude by positioning a stop of a phase change assembly and positioning the phase change assembly in different configurations to establish different phase relationships between two eccentrically engaged power shafts while one of the power shafts is driven by a timing component and the other power shaft is driven by the timing component through the phase change assembly. In one phase change assembly configuration a ram operably connected to one of two components to be welded does not vibrate when the first power shaft and the second power shaft rotate while in another phase change assembly configuration the ram vibrates. Pressure between the two components is controlled to provide scrub pressure when the ram vibrates and forge pressure when the ram is no longer vibrating.

Abstract: A cam assembly in a linear friction welding system includes two power shafts. Each of the shafts have two timing gears mounted thereupon. For one of the shafts, one of the timing gears includes a slot extending within the timing gear which is formed as an arc about a center of rotation of the power shaft. The other timing gear on that shaft includes a fixed pin which extends into the slot. A cross-over shaft is operably connected to both power shafts.

Abstract: A linear friction welding system in one embodiment includes a welding control system operably connected to a hydraulic press and a ram, the welding control system including a processing circuit operably connected to a memory and configured to execute program instructions stored in the memory to bring a shaped charge portion of a first component to be welded into contact with a second component to be welded, and establish an initial scrub load pressure between the two components based upon a ratio between initial surface area of a contact initiation portion of the shaped charge portion and a final surface area of the first component. The processing circuit increases pressure between the components from the initial scrub load pressure to a target scrub load pressure before terminating oscillation of the ram and establishing or maintaining a weld load pressure.

Abstract: A linear friction welding system in one embodiment includes a ram configured to oscillate along a welding axis, and a first and second power shaft operably connectable to the ram through a vibrating assembly. Respective motors are configured to drive respective power timing gears fixedly connected to the first and second power shafts. A slave timing gear is operably connected to the first power shaft in variable rotational relationship and to the second power shaft in fixed rotational relationship. The first slave timing gear is configured to be driven by one power shaft to force oscillation of the ram and by the other power shaft to stop oscillation of the ram.

Abstract: A method of operating a linear friction welding system in one embodiment includes positioning a phase change assembly driven by a motor in different configurations to establish different phase relationships between two eccentrically engaged power shafts while one of the power shafts is driven by the motor and the other power shaft is driven by the phase change assembly. In one phase change assembly configuration a ram operably connected to one of two components to be welded does not vibrate when the first power shaft and the second power shaft rotate while in another phase change assembly configuration the ram vibrates. Pressure between the two components is controlled to provide scrub pressure when the ram vibrates and forge pressure when the ram is no longer vibrating.

Abstract: A linear friction welding system in one embodiment includes a ram configured to vibrate along a welding axis, a cam follower operably connected to the ram, an eccentric including an eccentric outer periphery operably engaged with the cam follower, and an inner periphery, a first power shaft slidingly engaged with the eccentric, a second power shaft eccentrically engaged with the inner periphery, a timing component operably connected to the first power shaft and the second power shaft, a motor configured to drive the timing component, and a phase change mechanism engaged with the timing component and movable between a first position defining a first phase relationship between the first power shaft and the second power shaft, and a second position defining a second phase relationship between the first power shaft and the second power shaft.

Abstract: A method of operating a linear friction welding apparatus includes supporting a first work piece with a first fixture, supporting a second work piece with a second fixture, establishing a load between the first work piece and the second work piece along a press axis with a press assembly while the first fixture and the second fixture are in a fixed position relative to one another, simultaneously moving, with a vibrating assembly spaced apart from the press axis, the first fixture and the second fixture along a single weld axis so that both the first work piece and the second work piece are moved with respect to one another along the single weld axis after establishing the load, and heating at least a portion of the first work piece while simultaneously moving the first fixture and the second fixture under the load.

Abstract: The apparatus and method allows multiple components to be simultaneously bonded to a central shaft or tube using linear friction welding in a single welding process. The method involves simultaneously pressing the work pieces radially against the central shaft or tube at the desired locations while the shaft is vibrated axially. The weld is facilitated by the use of a linear friction welding machine, which includes a number of fixtures and press assemblies to hold and press the various work pieces against the central shaft or tube and a vibrating assembly for vibrating the central shaft or tube.

Abstract: A method of operating a linear friction welding apparatus includes holding a first work piece with a first fixture, holding a second work piece with a second fixture, pressing the first work piece toward the second work piece along a press axis with a press assembly, establishing a selective load between the first work piece and the second work piece with the press assembly while the first fixture and the second fixture are in a fixed position relative to one another, and simultaneously vibrating, with a vibrating assembly spaced apart from the press axis, the first fixture and the second fixture along a single weld axis so that both the first work piece and the second work piece are moved with respect to one another along the single weld axis after establishing the selective load.

Abstract: The linear friction welding apparatus of this invention includes two vibrating assemblies, which simultaneously vibrate both work pieces along different weld axis within the plane of the weld interface during the weld process. The LFW apparatus allows one or both work pieces to be independently vibrated against one another along different weld axis to control and concentrate the application of thermal energy across the weld surfaces caused by friction in certain areas of the weld surface and certain times during the weld process.

Abstract: The linear friction welding (LFW) apparatus of this invention, in various embodiments includes a vibrating assembly or assemblies, which simultaneously vibrates both work pieces along the weld axis during the weld process. In one embodiment, separate vibrating assemblies are used to vibrate each work piece along the weld axis relative to each other. Each vibrating assembly has its own oscillator mechanism with motors and cams that can be moved into and out of phase with that of the other vibrating mechanism to generate the relative movement between the work pieces. In another embodiment, the apparatus includes a vibrating assembly that uses a single oscillator and two sets of rocker arms supporting carriages operatively connected by a linkage mechanism to simultaneously vibrate both work pieces along the weld axis.

Abstract: A linear friction welding system includes a power shaft defining a power shaft axis and including a first eccentric portion and a first power transfer portion, a power transfer rod engaged with the first power transfer portion, an actuator assembly operably coupled with the power transfer rod and configured to move the power transfer rod axially along the power shaft axis, a crank including a second eccentric portion operably coupled with the first eccentric portion, and a second power transfer portion engaged with the power transfer rod, the linear friction welding system configured such that axial movement of the power transfer rod causes rotational movement of the crank with respect to the power shaft about the power shaft axis, a cam follower operably connected to an outer surface of the second eccentric portion, and a ram operably connected to the cam follower and configured to vibrate along a welding axis.

Abstract: A linear friction welding system includes a power shaft defining a power shaft axis and including a first eccentric portion and a first power transfer portion, a power transfer rod engaged with the first power transfer portion, an actuator assembly operably coupled with the power transfer rod and configured to move the power transfer rod axially along the power shaft axis, a crank including a second eccentric portion operably coupled with the first eccentric portion, and a second power transfer portion engaged with the power transfer rod, the linear friction welding system configured such that axial movement of the power transfer rod causes rotational movement of the crank with respect to the power shaft about the power shaft axis, a cam follower operably connected to an outer surface of the second eccentric portion, and a ram operably connected to the cam follower and configured to vibrate along a welding axis.

Abstract: A linear friction welding system and method in one embodiment includes a first motor configured to rotate a first power shaft, a second motor configured to rotate a second power shaft, a memory including program instructions, and a controller operably connected to the first motor, the second motor, and the memory, and configured to execute the program instructions to identify a first current oscillation amplitude of a ram operably connected to the first power shaft and the second power shaft, determine a second desired oscillation amplitude for the ram, determine a minimum shift in relative angle between the first motor and the second motor to achieve the second desired oscillation amplitude, allocate the minimum shift in relative angle between the first motor and the second motor, and control the first motor and the second motor based upon the allocated minimum shift in relative angle.

Abstract: A linear friction welding system and method in one embodiment includes a first motor configured to rotate a first power shaft, a second motor configured to rotate a second power shaft, a memory including program instructions, and a controller operably connected to the first motor, the second motor, and the memory, and configured to execute the program instructions to identify a first current oscillation amplitude of a ram operably connected to the first power shaft and the second power shaft, determine a second desired oscillation amplitude for the ram, determine a minimum shift in relative angle between the first motor and the second motor to achieve the second desired oscillation amplitude, allocate the minimum shift in relative angle between the first motor and the second motor, and control the first motor and the second motor based upon the allocated minimum shift in relative angle.

Abstract: A linear friction welding system in one embodiment includes a ram configured to vibrate along a welding axis, at least one rocker arm with a first end portion spaced apart from the welding axis and constrained against movement along the welding axis, and a second end portion which is movable along the welding axis, and a first welding component support member configured to hold a first welding component, the first welding component support member operably connected to the ram and supported by the second end portion of the at least one rocker arm, such that vibration of the ram along the welding axis causes the location of the first welding component support member along an axis orthogonal to the welding axis to vary.