Industrial Technology Research Institute

Tsann-Huei Chang

Kuan-Wen Chen

Jih-Jong Hsu

Shang-Liang Chen

Tung-Chuan Wu

Ching-Yuan Lin

Chen-Chung Du

Yeou-Bin Guu

Jinn-Fa Wu

Shao-Yu Hsu

Yaw-Der Hwang

Chao-An Kang

Zhi-Ming Chen

Cheng-Chang Lin

Method and apparatus for automatically dynamically adjusting prestressed bearings of shaft are provided. The apparatus comprises a sleeve assembly having outer and inner sleeves sandwiched between the bearings. An inner diameter of outer sleeve is smaller than an outer diameter of inner sleeve. Hence, outer and inner sleeves are fitted together after cooling. Further, inner sleeve is compressed by the outer sleeve to extend axially. During rotation of shaft, the axial extension of inner sleeve is reduced because the radial expansion of outer sleeve is larger than that of inner sleeve due to an thermal expansion coefficient of outer sleeve larger than that of inner sleeve. This can reduce prestress of bearings without degrading a rigidity thereof.

Method and apparatus for automatically dynamically adjusting prestressed bearings of shaft

Disclosed herein is a gantry type hybrid parallel linkage five-axis machine tool composed of a machine framework a parallel spatial linkage mechanism, a feeding shaft mechanism, and a controller unit. The parallel spatial linkage mechanism is formed of three straight feeding molding dies rotatably hinged together with a base so that enabling this rotatable base to perform uni-dimensional linear motion and two-dimensional swiveling. Besides by controlling the operation of the feeding shaft mechanism with the controller unit, the parallel spatial linkage mechanism fixed to the machine framework is able to perform two-dimensional planar motion so as to operate the machine tools more accurately and efficiently in refining work.

Gantry type hybrid parallel linkage five-axis machine tool

An active piezoelectric spindle bearing preload adjustment mechanism includes a preload adjustment assembly located between an inner ring and an outer ring of two bearings, and an internal generator mounted at a selected location in a spindle. The preload adjustment assembly includes a spacer ring set and a piezoelectric actuator located in the spacer ring set. The rotation speed of the spindle is changeable to enable the internal generator generating selected amount of power and voltage for controlling extension or contraction length of the piezoelectric actuator whereby to change slide distance between the inner and outer ring for controlling bearing preload value.

Active piezoelectric spindle bearing preload adjustment mechanism

A shaft having thermal expansion, thermal pre-load yielding and dynamic pre-load adjusting systems. The shaft is made by the zero expansion or very low expansion materials. The shaft has two bearing assemblies. Each bearing assembly has two parallel bearings. A partition ring set is disposed between them. The partition ring set is made of multiple low and negative thermal expansion materials. It includes an inner partition ring and an outer partition ring. The inner partition ring is tightly contacting with corresponding sides of inner annular seats of the bearing. The outer partition ring is disposed outside of the inner partition ring without any contact. And, the outer partition ring is tightly contacting with corresponding sides of outer annular seats of the bearings.

Shaft having thermal expansion, thermal pre-load yielding and dynamic pre-load adjusting systems

A motor main shaft has a plurality of rolling bearings, a plurality of spacing rings, and a sleeve, which are all provided with a plurality of microfins to prevent the overheating of the main shaft in motion. The microfins serve to promote the heat convection.

Motor main shaft provided with fast cooling means

A composite mechanism multi-axis machine tool includes an orthogonal coordinate feeding axis mechanism and a parallel type spatial linkage mechanism. The orthogonal coordinate feeding axis mechanism has two orthogonal platforms to provide two dimensional motion vectors. The parallel type spatial linkage mechanism has three sets of linear feeding modules engaging with a base frame for holding a main spindle which further holds a tool cutter. The parallel type spatial linkage mechanism provides one dimensional motion and two dimensional rotation for the tool cutter. A controller is provided to control and coordinate the movements of the orthogonal coordinate feeding axis mechanism and the parallel type spatial linkage mechanism. It reduces accumulation of inertia and tolerance effect, and rigidity deficiency of conventional orthogonal coordinate multi-axis machine tool, and overcomes the problems of conventional hexapod parallel type spatial linkage mechanism such as difficult for position tuning, small working space, complex control system and high cost.

Composite mechanism multi-axis machine tool

A tool magazine for use with an automatic machine tool comprising a housing for removably storing tools, a rotatable tool holding disk for rotatingly switching one of the tools between a first position and a second position, the tool holding disk being rotatably supported inside the housing by a shaft about a first axis, and a cam type tool magazine mechanism disposed inside the housing for indexingly rotating the tool holding disk. The cam type tool magazine mechanism is characterized in that it comprises: (1) a follower member having a disk mounted to the shaft so as to be rotatable in unison therewith, the follower member disk having a first surface and a second surface, each of which are rotatably mounted with a plurality of first and second rollers, respectively, in an equally-spaced manner around the first axis; and (2) a drive member comprising a first plate cam and a second plate cam, each being rotatable about a second axis, which is substantially parallel to the first axis and spaced apart therefrom at an axis-to-axis distance, each of the first and second plate cam having at least a camming tooth contactingly engageable with the first and second rollers, respectively, so as to drive the follower member about the first axis in an indexing way, in both clockwise and counterclockwise directions. An eccentric offset adjustment member can be provided for adjusting the axis-to-axis distance so as to provide a tight contact engagement between the plate cam and the corresponding rollers.

Parallel conjugate cam type tool magazine mechanism

A coolant through spindle device is disclosed, including a rotating joint member secured to the rear end of the spindle for conducting coolant into the spindle, the coolant being conducted through a separate coolant passage inside the spindle to the nozzles formed on a cutting tool to be sprayed out thereof so as to fully cool down and lubricate the cutting point thereof, increase machining precision and cutting rate, and prolong service life of the cutting tool. Moreover, by using a switching collar to provide separated coolant passage and pressurized air passage, no residual coolant can follow the pressurized air jet into the tapper hole of the spindle to contaminate the tapper hole.

Growing community of inventors

Hsinchu, Taiwan

Tsann-Huei Chang