GSU Series Universal Grinder
Shigiya (USA) Ltd.’s GSU Series of Universal Grinders are designed with a wheelhead NC swivel function that allows the operator to select from nine different installation patterns. Using the correct wheelhead installation pattern and specifications allow a variety of multi-grinding tasks to be performed and reduce the number of processes. For more flexibility, two grinding wheels can be mounted onto two wheel spindles of the GSU, contrasted with conventional machines where two grinding wheels are mounted onto one spindle. The wheelhead is swiveled at high speeds by a direct drive system, and provides high positioning accuracy without backlash.
Grinder speeds can be changed steplessly on the AC servo motor within a range of 15 to 600 rpm. A user-friendly and flexible interactive automatic programming system automatically determines the optimal rotational speed for each workpiece.
The GSU is designed with non-concentric bearings that use hydrodynamics to secure the optimal wedge angle, and provide high precision rotation of the wheel.
The GSU’s tailstock is mounted with a large diameter spindle to further ensure high precision heavy grinding. Heat expansion of the workpiece during grinding is offset by a helical compression spring.
To avoid thermal displacement in the machine caused by a rise in the lubrication oil’s temperature, wheel spindle lubrication oil is stored in an isolated tank.
Shigiya offers an optional closed type hydrostatic slide wheelhead feed and a work spindle rotation direct drive so operators can perform eccentric O.D. and non-concentric O.D. grinding (polygonal grinding) using the C-X axis control.
GPV-10 / GAV-10 Vertical Grinders
GPV-10 and GAV-10 vertical CNC grinders have compact footprints to accommodate a range of production line layouts: the main body of these machines is approximately 1m2, or about half the size a Shigiya GAC-20 Grinder.
The GPV-10 cylindrical grinder and the GAV-10 angular cylindrical grinder are designed for precision grinding of small workpieces. A novel gate structure ensures accurate grinding by counter measuring against vibration, thermal displacement and noise. A top beam connects the upper portion of the two columns securely, and the rigidity of these machines ensures precision after a cold start, and even during post-process grinding.
Also contributing to GPV-10 and GAV-10 accuracy is Shigiya’s non-concentric hydrodynamic bearing for the wheel spindle. Mounted on the wheel side of the wheelhead, this bearing maintains low processing heat by optimizing the bearing clearance and the wedge angle. Infeed is performed by the table moving toward the wheel.
These vertical grinders are designed for ease of use, including a wide machine opening that allows for flexible automation of loading/unloading and easy maintenance. An electrical control panel hinged on the rear of the machines swings open wide to ensure enough working space for easy wheel change.
The wheel changer of the GAV-10 enables for smooth wheel change, easier operation and reduced operator fatigue. Removal and attachment of the grinding wheel are performed by the vertical movement of the air cylinder. The arm can be manually moved back and forward easily. The grinding wheel of the GPV-10 is not angled and does not require a wheel changer to be changed.
Both the GPV-10 and the GAV-10 feature a ø100 mm swing-over table, and 150 or 200 mm distance between centers. Wheel sizes are ø305 (O.D.) x 25 (W) x 127 (I.D.) mm or ø355 (O.D.) x 25 (W) x 127 (I.D.) mm.
GPES-30 Series Eccentric Pin / Polygon Grinder
Shigiya will introduce its efficient, high-accuracy GPES-30 Series of CNC eccentric pin / polygon grinders. With a rigid base and thermal expansion control, the GPES-30 is designed for accuracy.
The GPES-30’s revolutionary process of grinding two different eccentric areas within the same chucking eliminates or drastically reduces setup time. Journal grinding and face grinding options are available. An innovative polygon grinding method also eliminates or reduces training and adjusting. Plunge, oscillation and traverse grinding are also available.
For smooth and stable movement, the GPES-30 has closed hydrostatic slideways for the wheelhead feed, which automatically adjust to maintain the position of the wheelhead. As a result, eccentric grinding can be performed to an accuracy of less than 1 micron.
A high-speed, non-circular wedge-type hydrodynamic spindle bearing contributes to accurate and efficient grinding, too.
The direct drive spindle has a high precision angular contact bearing with no backlash on movement. Located behind the workhead, the rotary diamond dresser’s spindle is supported by an ultra precise angular contact bearing and lubricated with Micro-fog. An AE sensor and wheel flatness sensor are included as standard. The GPES-30’s tailstock is mounted with a large diameter spindle to further ensure high precision heavy grinding.
The GPES-30 is controlled with Shigiya’s conversational programming system. With this system, eccentric pin grinding offset direction can be measured quickly with the OD gauge, and operators can choose among 13 polygon pre-programmed shapes. Other features of the system include shape compensation, automatic workhead speed override, automatic grinding conditions, a new wheel dressing cycle and an indicator for X-axis speed and acceleration.
The GPES-30 features a ø300 mm swing-over table, and 250- or 630-mm distance between centers. Wheel size is ø350 (O.D.) x 25 (W) x 127 (I.D.) mm.
GAE Series Angular Cylindrical Grinders
The GAE Series of CNC angular cylindrical grinders provides high accuracy for heavy-duty grinding at an affordable price – with rigid wheelheads, workheads, and tailstock units. Combined with an angled wheelhead, the GAE performs face grinding easily, similar to a plain cylindrical grinder.
For precision, efficiency, and productivity, the GAE wheelhead features a rigid main body, a heat-treated nitride steel wheel spindle, and a large ø510mm wheel. To maximize stability and load capacity, the GAE’s wheelhead and table feed include wide, V-flat guiding surfaces. The high damping performance and equalization of lubricant provided by the oil film’s squeezing effect ensure long-term smooth and precise grinding. Non-concentric hydrodynamic bearings secure an optimal wedge angle. Bearings are ground to high precision with Shigiya’s exclusively developed grinder for bearings.
The GAE is equipped with a non-swivel dead spindle workhead for further stability and low vibration. In addition, a highly rigid tailstock and a large diameter spindle enable high-precision, heavy grinding.
Shigiya’s new 250-mm center-distance model for short-length workpieces has a compact workhead and tailstock that allow for an approximately 20% reduction in machine width, versus previous models.
The GAE includes an interactive automatic programming system designed for easy operation, allowing a wide range of grinding and dressing patterns.
Due to a high-output servo motor, the grinder can change workpiece rotational speed steplessly within the range of 15 to 600 rpm in response to NC instructions.
Shigiya offers numerous options for the GAE, including an in-process O.D. gauge, a workpiece shoulder locator, an automatic loading/unloading system and more.
GAE-30B and GAE-40B types are available in the series. The GAE-30B features a ø300-mm swing-over table and 250- to 2,000-mm distance between centers.
The GAE-40B features a ø410 mm swing-over table and 220 to 1,970 mm distance between centers. Wheel size for both models is ø 510 (O.D.) x 50 (W) x 127 (I.D.) mm.