High Efficiency Finish Hobbing of High Accurate Gears with cermet or CBN Hobs
Grant-in-Aid for General Scientific Research (B)
|Allocation Type||Single-year Grants|
|Research Institution||KYUSHU UNIVERSITY|
ARIURA Yasutune Kyushu Univ.Faculty of Eng.Professor, 工学部, 教授 (10038044)
ISHIMARU Ryohei Kyushu Univ.Faculty of Eng.Research Associate, 工学部, 助手 (10264061)
UMEZAKI Yoji Kyushu Univ.Faculty of Eng.Research Associate, 工学部, 助手 (70038066)
KUROKAWA Shuhei Kyushu Univ.Faculty of Eng.Associate Professor, 工学部, 助教授 (90243899)
NAKANISHI Tsutomu Miyazaki Univ.Faculty of Eng.Professor, 工学部, 教授 (40038055)
ONIKURA Hiromiti Kyushu Univ.Faculty of Eng.Professor, 工学部, 教授 (90108655)
|Project Period (FY)
1993 – 1994
Completed(Fiscal Year 1994)
|Budget Amount *help
¥6,200,000 (Direct Cost : ¥6,200,000)
Fiscal Year 1994 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1993 : ¥5,500,000 (Direct Cost : ¥5,500,000)
|Keywords||Cutting / CBN / Cermet / Hobbing / Gear / Accurate Gear / Load-Carrying Capacity / Tooth Surface Roughness / サーメット|
This research aim at development of cermet- and CBN-hobs, there is possibility of finish hobbings of high hardness gears with accurate tooth profile, and describes the surface durability of those gears.
1. Summary for the efficiency manufacturing of accurate gears ; The development of the finishing hob made with cermets and/or CBNs which can finish the tooth profile of high hardness gears accurately and smoothly is carried out.
The fundamental tests using the fly-tool shows as follows.
(1) The cermet tools are suitable for life in low cutting speed of about 85 m/min.
(2) The CBN tools have good wear resistance and are possibility of high speed cutting of about 400 m/min.
Hobbing tests of the high hardness gear with the CBN finishing hob that is made with the new CBN selected in the fly-tool tests shows as follows ;
(1) The hob wear is very small. The average flank wear is about 0.03 mm after 15 times finishing of high hardness tooth surfaces. In many hob teeth, the chippings after grinding tool edges are kept after hobbing.
(2) The surface roughness is about 1-3 micro-meter in maximum, and this value is constant in the beginning and the ending of hobbings.
(3) The accuracy of the tooth profile is JIS 0 class and this profile is attributable to the accuracy of hob teeth. It is very important to grind the hob teeth accurately and smoothly to improve the tooth surface roughness and the profile accuracy and to prevent chippings of hob teeth.
2. Summary for the tooth surface durability of gears ; The surface durability of the gears manufactured with the cermet finishing hob are investigated by using a power circulating-type gear testing machine.
(1) The cermet-hobbed gears that are modified 40 micro-meter have the same load-carrying capacities as the non-modified ground gears.
(2) The load carrying capacity increases with smaller surface roughness.
Research Output (13results)