Gear Finishing with a Nylon Lap

Gear Finishing with a Masahiko Nakae Kazunori Hidaka Yasutsune Ariura Toshinori Matsunami Masao Kohara Dr. Masahiko Nakae is a pressor in the department mechanical engineering, Sasebo National College Technology, Nagasaki, Japan. In the field gear manufacturing, he specializes in the study finish hobbing with CBN-tipped hobs finish with nylon gears. Dr. Kazunori Hidaka was a pressor in the mechanical engineering department Sasebo National College Technology until March 2005. His research interests include corner wear on hobs finish gears with a nylon gear. Dr. Yasutsune Ariura is a pressor emeritus who worked in the department intelligent machinery systems, Kyushu University, Fukuoka, Japan, from 1983 to 2005. His gear manufacturing research involved finish hobbing with cermet- CBN-tipped hobs, manufacturing performance austempered ductile iron gears, load carrying capacity hardened tempered surface hardened cylindrical gears. Toshinori Matsunami is the president Gifu Gear Manufacturing Co. Ltd, Gifu, Japan. His company manufactures highly accurate gears for various industries via its gear manufacturing measuring equipment. The objective this research is to develop a new process that can efficiently make tooth flanks hardened steel gears smooth as a mirror. The is carried out using a nylon helical gear as a lap using a simple mechanical device. This paper first shows the machine designed manufactured by the authors the procedure principle the. As a result the tests, it becomes clear that the process can make tooth flanks hardened steel gears smooth in a short time that it is important to carry out the using a nylon gear with a large helix angle high teeth (teeth with addendums larger than their modules) under a condition high rotating speed light load in order to prevent increasing tooth prile errors. Moreover, the process was varied to include microvibrations the nylon gear. From the result, it is found that the addition microvibrations enables this process to also reduce tooth prile errors the work gears. The lapped gears running noise load carrying capacity are considered, too. Masao Kohara is the deputy general manager the technical center in Yushiro Chemical Industry Co. Ltd., Kanagawa, Japan. The company supplies metalworking oils fluids to industry, as well as fering building maintenance products textile 3 8 S E P T E M B E R / O C T O B E R 2 0 0 5 G E A R T E C H N O L O G Y w w w. g e a r t e c h n o l o g y. c o m w w w. p o w e r t r a n s m i s s i o n. c o m

Introduction It is known that the tooth flank roughness a gear influences its performance in power transmission that is, the load carrying capacity gears is improved, the running noise vibration are reduced by making the tooth flanks smooth (Refs. 1 2). Gear finishing methods such as shaving, hobbing with a carbide hob, grinding honing are used in the gear industry. However, they generally require a highly accurate machine tool, advanced technical skills a lot time, or they require the hardness the work gear be restricted. Furthermore, it is next to impossible to make tooth flanks smooth as a mirror by these methods. We propose a new process that can productively make tooth flanks hardened gears smooth as a mirror. The process is carried out using a nylon helical gear as a lap on a simple mechanical device. This paper will first show the mechanism the machine designed manufactured by the authors the procedure principle the. Next, the tests were performed on highly accurate ground gears. The test results showed that: 1.) the process could improve tooth flank roughness hardened gears in a short time 2.) the conditions to prevent increases in tooth prile errors were clarified. Therefore, we could get highly accurate gears with smooth tooth flanks, as shown in Figure 1, the lapped gear on page 38. Also, by vibrating the nylon gear, the process could improve the tooth prile the tooth flank roughness hobbed gears. Running noise load carrying capacity the lapped gears were investigated as well. Lapping Machine Procedure Lapping Process Figure 2 shows the machine that was designed manufactured by the authors. A work gear is meshed with the lap, a nylon helical gear, they are rotated at high speed by the driving motor. Lapping load is applied by means braking the driven spindle. Lapping fluid that contains abrasive grains is splashed between the tooth flanks nylon work gears as they rotate. The work gear is given a traverse motion at low speed along the axis in order to finish the whole flank. The specifications the work gear the nylon gear are shown in Table 1. The work gears are spur gears with modules 4, 25 teeth, face widths 10 mm. The work gears tooth flanks were accurately ground after carburizing hardening or induction hardening. The carburized gears induction-hardened gears are made chromium-molybdenum alloy steel JIS SCM415 JIS SCM435, respectively. The hardness the tooth flanks are 860 HV 640 HV, respectively. Also, their tooth priles, tooth traces tooth flank roughnesses are similar Nylon helical gear Figure 2 Lapping machine. accuracy. An example is shown in Figure 3. The tooth prile measuring position is at the center the face width. The tooth trace was measured on the pitch circle. The roughness was measured along the tooth prile near the pitch circle. The tooth prile tooth trace are highly accurate. The tooth flank roughness has a maximum peakto-valley height (R y ) 1.5 2 µm, which can translate to an average surface roughness (R a ) 0.24 0.31 µm. The test gears were ground using a Reishauer RZ300 E. This machine is a fairly common gear grinder in the United States can achieve the above R a. It may Table 1 Specifications Work Nylon Gears. Work Gear Nylon Gear Module 4 4 Pressure Angle (deg.) 20 20 Helix Angle (deg.) 0 30 (R, L) Number Teeth 25 19 Face Width (mm) 10 34 Materials Work gear Driving motor SCM435 (640 HV) SCM415 (860 HV) Nylon Tooth Flank Condition Ground Hobbed Tooth prile Tooth trace Roughness Figure 3 Tooth prile roughness ground gear. 2 µm 0.2 mm w w w. p o w e r t r a n s m i s s i o n. c o m w w w. g e a r t e c h n o l o g y. c o m G E A R T E C H N O L O G Y S E P T E M B E R / O C T O B E R 2 0 0 5 3 9

with a Figure 4 Tooth prile nylon gear. Table 2 Nylon Properties. Specific Gravity Tensile Strength Elastic Modulus 1.15 1.17 78 96 MPa 2.9 3.4 GPa Table 3 Lapping Conditions. Abrasive Grain WA1000, GC6000 Rotating Speed Work Gear (rpm) 610; 1,210; 2,290; 3,420 Traverse Feed Rate (mm/min) 300 Stroke (mm) 11 Load (N) 3.8, 7.6, 15.2 a) Roughing (WA500) b) Finishing (WA2000) Figure 5 Lapped tooth flanks. Figure 6 Tooth flank nylon gear. 40 µm Figure 7 Abrasive grains embedded in nylon gear. Masahiko Nakae be difficult to achieve it in a normal production Kazunori environment, Hidaka though. An average roughness (R a ) 0.4 0.5 µm may be more Yasutsune Ariura easily obtained in regular production with a Toshinori threaded wheel Matsunami grinding machine, like the Masao Reishauer Kohara machine. However, this slightly rougher finish would not affect time, cost, or other results presented in Dr. Masahiko Nakae is a pressor in the department mechanical engineering, Sasebo National this College paper. Technology, Nagasaki, Japan. In the field The gear nylon manufacturing, helical gears he were specializes hobbed. the study Their finish tooth hobbing priles with were CBN-tipped not highly hobs accurate, as shown with in nylon Figure gears. 4. The nylon gears finish are easily machined. The nylon s properties are Dr. shown Kazunori in Table Hidaka 2. is a pressor in the in the Table mechanical 3 shows engineering the department conditions Sasebo used National in the College experiments. Technology. This process His research consistests include a roughing the corner by coarse wear abrasive on hobs grains the finish inter- a finishing gears by with fine a abrasive nylon gear. grains. A helical gear with right-h teeth is used in the Dr. roughing, Yasutsune Ariura a helical is a gear pressor with lefth worked teeth in is the used department in the finishing. intelligent Sincemachinery each direction systems, Kyushu the University, crosses Fukuoka, the Japan, emeritus who other from as 1983 shown to 2005. in Figure Gear 5, manufacturing the time for research finishing involved becomes finish hobbing shortened. with Lapping cermet- fluid CBNtipped roughing hobs, consists manufacturing 200 cc performance min- for eral austempered oil 5 g ductile alumina iron gears, abrasive grains load carrying (WA1000). capacity That hardened for finishing & tempered is about 14% surface hardened cylindrical Carborundum abrasive gears. grains (GC6000). The rotating speeds the work spindle are Toshinori 610; 1,210; Matsunami 2,290; is 3,420 the president rpm. The Gifu Gear traverse Manufacturing speed Co. stroke Ltd, Gifu, a work Japan. gear are His company fixed manufactures at 300 mm/min highly accurate 11 mm, gears respectively. for various industries Consequently, via its gear manufacturing the takes measuring equipment. about four seconds per stroke. The loads on the pitch cylinder the work gear Masao Kohara is the deputy general manager are 3.8, 7.6 15.2 N. the technical center in Yushiro Chemical Industry Principle process. Figure Co. Ltd, Kanagawa, Japan. The company supplies 6 shows an example tooth flanks a metalworking oils fluids to industry, as well as nylon gear after six work gears with fering building maintenance products textile WA500. A section that became dark during the can be seen on the surface. 3Figure 8 S E7 P Tis E Ma Bphotograph E R / O C T O B E R 2the 0 0 5 darkened G E A R T E C H N O L section enlarged by SEM. It was found that the surface became rough, abrasive grains were embedded in it. Chips from are shown in Figure 8. They look like chips from grinding. These figures show abrasive grains embedded in the surface a nylon gear after they ve worked between the tooth flanks the work gear nylon 4 0 S E P T E M B E R / O C T O B E R 2 0 0 5 G E A R T E C H N O L O G Y w w w. g e a r t e c h n o l o g y. c o m w w w. p o w e r t r a n s m i s s i o n. c o m

with a gear. The nylon gear, in effect, acts like a grinding wheel. Masahiko Nakae Lapping Kazunori Tests Hidaka High Accuracy Yasutsune Ground Gears Ariura Increases in tooth Toshinori prile error. Matsunami Figure 9 shows the tooth Masao prile, tooth Kohara trace tooth flank roughness a carburized gear lapped using WA1000 Dr. Masahiko abrasive grains, Nakae ais a pressor in the department angle mechanical 30 degrees, engineering, Sasebo National nylon gear with a helix a work spindle speed College 1,210 Technology, rpm, a Nagasaki, Japan. In the field load 15.2 N. gear The manufacturing, roughness was he specializes the study Figure 8 Chips from. 50 µm reduced to an R y finish about hobbing 0.5 µm with through CBN-tipped hobs finish seven strokes, about with 30 nylon seconds. gears. However, a concavity is found near the pitch The objective point on the tooth prile. Dr. this Kazunori research It was supposed Hidaka is to develop is a a pressor new process a heavier that can load efficiently the mechanical the in The objective this research is to develop a new pro that caused the make concavity tooth engineering flanks near hardened department steel gears Sasebo Tooth prile National College Technology. His research interests include the corner wear on hobs the finish smooth as a mirror. The is carried out using a nylon helica cess that can efficiently make tooth flanks hardened steel gear the smooth pitch cylinder as a mirror. during The the engagement is carried out using a nylon helical one gear pair as a lap teeth. a simple mechanical gears with device. a nylon gear. gear as a lap a simple mechanical device. Therefore, This paper we first tried shows to lap the a carburized machine designed manufactured by the authors Dr. Yasutsune the procedure Ariura is a pressor principle emeritus the lap- who 0.2 mm Tooth trace gear with a load 3.8 N a This paper first shows the machine designed manu work spindle speed 2,290 rpm. The factured by the authors the procedure principle the lap ping. As a result worked the the tests, department it becomes intelligent clear that machinery the process through can make two tooth strokes flanks, hardened about steel gears 1,210 smooth rpm; in a 15.2 short roughness was reduced to an R y about 0.5 Roughness systems, Kyushu University, Fukuoka, Japan, ping. As a result the tests, it becomes clear that the pro µm from 1983 to 2005. Gear manufacturing research N; WA1000; cess 7 can strokes; make tooth SCM415 flanks (860 hardened HV) steel gears smooth in a shor eight time seconds. that The it is tooth involved important prile finish to is carry shown hobbing out the with Figure cermetusing 9 Tooth a nylon prile CBNtipped helix does hobs, angle not occur manufacturing high near teeth under a performance condition roughness time lapped gear. that it is important to carry out the using a nylo Figure gear that 10. has A concavity a large gear that has a large helix angle high teeth under a condition o the high pitch rotating point. speed austempered light load ductile in order iron to gears, prevent Figure 11 shows the tooth prile an increasing load carrying high rotating speed light load tooth prile errors. capacity hardened & tempered surface hardened gear cylindrical lapped under gears. the tooth prile errors. 2.5 in order mm to prevent increasing o induction-hardened Moreover, the process was varied to include microvibrations the tooth flanks the is nylon lower gear. than that From the result, it is found that same conditions as Figure 10. The hardness Moreover, the process was varied to include micro Toshinori Matsunami is the president 2,290 rpm; Gifu 3.8 Gear N; WA1000; vibrations 2 strokes; the SCM415 nylon gear. (860 From HV) the result, it is found tha carburized the addition ones. A Manufacturing concavity microvibrations occurs Co. on enables Ltd, the Gifu, this Japan. process His to company also dedendum flank near the root. The same Figure 10 Tooth prile lapped gear. the addition microvibrations enables this process to als reduce tooth prile manufactures errors the highly work accurate gears. The gears lapped for gears various reduce tooth prile errors the work gears. The lapped gears concavity running occurred noise industries on load the carburized carrying via its gear capacity gear manufacturing are considered, measuring too. lapped under a load 7.6 N. running noise load carrying capacity are considered, too equipment. Figure 12 shows the calculated sliding velocity at every degree Masao Kohara rotation is on the adeputy general manager tooth flank a work the gear technical meshing center with in ayushiro 2,290 Chemical rpm; Industry 3.8 N; WA1000; 2 strokes; SCM435 (640 HV) nylon gear under a Co. rotating Ltd, speed Kanagawa, 2,290 Japan. The company supplies rpm. The helix angles metalworking the nylon oils gear fluids Figure to industry, 11 Concavity as well on as dedendum flank. were 30 15 degrees. fering The building radius maintenance 50 products textile mm indicates the tip the tooth in the fig- w w. With g e a rthis t e c hfigure, n o l o git y. is c oclear m that w won w. pthe o w e r t r a n s m i s s i o n. c o m O G Y wure. 3 8 S E P T E M B E R / O C T O B E R 2 0 0 5 G E A R T E C H N O L O G Y w w w. g e a r t e c h n o l o g y. c o m w w w. p o w e r t r a n s m i s s i o n. c o dedendum flank near the root, the sliding velocity is higher the interval between the dots is smaller that is, the movement the contacting point is also slower than at other positions. Consequently, it was supposed that the removal amount near the root is larger so the concavity occurred there. With the smaller w w w. p o w e r t r a n s m i s s i o n. c o m w w w. g e a r t e c h n o l o g y. c o m G E A R T E C H N O L O G Y S E P T E M B E R / O C T O B E R 2 0 0 5 4 1 2 µm

with a Figure 12 Sliding velocity on a tooth flank a work gear. 2,290 rpm; 3.8 N; WA1000; 2 strokes; SCM435 (640 HV) Figure 13 Effect nylon gear with high teeth. Figure 14 Effect nylon gear with high teeth. helix Masahiko angle, the difference Nakae in sliding velocity along the tooth prile is larger. This Kazunori Hidaka resulted in the occurrence a concavity. The Yasutsune same concavity Ariura also occurred on the carburized Toshinori gear with Matsunami a longer time. Masao Prevention Kohara the concavity near the root. In order to prevent the concavity near Dr. Masahiko Nakae is a pressor in the department mechanical engineering, Sasebo National the root, we tried to lap an induction-hardened gear using a nylon gear with high teeth College Technology, Nagasaki, Japan. In the field under the same conditions as Figure 11. The gear manufacturing, he specializes the study tooth flank roughness was reduced through finish hobbing with CBN-tipped hobs finish two strokes. The tooth prile is with nylon gears. shown in Figure 13. A concavity was not found. Dr. Kazunori Hidaka is a pressor in the in the Figure mechanical 14 shows engineering changes department the prile Sasebo error National after College every four Technology. seconds His research interests as include compared the corner with the wear case on hobs using the finish time, a nylon gear gears with with full-depth a nylon teeth. gear. When with a nylon gear with full-depth teeth, Dr. prile Yasutsune error Ariura increases is rapidly a pressor because emeritus who worked the occurrence in the department a concavity intelligent near the machinery root. However, systems, Kyushu there is University, little change Fukuoka, until Japan, three from strokes 1983 to 2005. Gear (12 seconds) manufacturing the research case involved a nylon finish gear hobbing with high with teeth. cermet- When CBNtipped gear hobs, with manufacturing high teeth (see Fig. performance 15) is a nylon used, austempered the contact ductile ratio iron increases gears, three load carrying pair capacity teeth hardened contact, so & the tempered load near surface the hardened shown cylindrical Figure gears. 16 is decreased. This root decrease means the concavity does not occur Toshinori readily. Matsunami is the president Gifu Gear Manufacturing Figure 17 shows Co. the Ltd, tooth Gifu, prile Japan. His company the manufactures tooth flank roughness highly accurate a carburized gears for various gear industries after a via roughing its gear using manufacturing a nylon gear measuring with equipment. high teeth a finishing using a nylon gear with full-depth teeth. The roughness is Masao reduced Kohara in comparison the deputy with that general before manager, the technical no center concavity in Yushiro is found Chemical on the Industry tooth Co. prile Ltd, Kanagawa, after four strokes Japan. The roughing. company supplies In metalworking the finishing oils stage, it fluids took four to industry, strokes as well as to fering remove building roughing maintenance traces using products GC6000 textile abrasive grains under a load 7.6 3N. 8 The S Eroughness P T E M B E R is / Oreduced C T O B E R further 2 0 0 5 through G E A R T E C H N O L the finishing, but a small concavity is found near the root. Therefore, it is necessary to use a nylon gear with high teeth when finishing with fine grains. Figure 18 shows changes tooth flank roughness prile error carburized gears lapped using WA1000 abrasive grains under rotating speeds 610 3,420 rpm. 4 2 S E P T E M B E R / O C T O B E R 2 0 0 5 G E A R T E C H N O L O G Y w w w. g e a r t e c h n o l o g y. c o m w w w. p o w e r t r a n s m i s s i o n. c o m

Finishing with a It is clear in these figures that the roughness more rapidly decreases Masahiko the Nakae rotating speed increases, Kazunori the prile Hidaka error increases at low rotating Yasutsune speeds because Ariura long time. Toshinori Matsunami Lapping Process with Masao Kohara Microvibrations Added to the Nylon Gear Figure 15 High tooth. We next tried Dr. to Masahiko improve the Nakae toothis a pressor in the department roughness mechanical hobbed engineering, Sasebo National Nylon gear gears through this College process Technology, by addingnagasaki, Japan. In the field prile tooth flank microvibrations to the gear nylon manufacturing, gear. he specializes the study The tests finish were hobbing carried out with using CBN-tipped hobs finish a new machine with hobbed nylon gears. Rotating direction ion having the same dimensions as mentioned Work gear above. The The objective amplitude Dr. this Kazunori research frequency Hidaka is to develop is a a pressor new process microvibrations that can efficiently the were mechanical make fixed tooth at 0.2 engineering flanks mm the in Figure 16 Contact a work gear a The nylon objective gear with this research is to develop a new pro the high hardened department teeth. steel gears Sasebo 88 Hz, respectively. National The College Technology. was His research interests cess that can efficiently make tooth flanks hardened steel gear smooth as a mirror. The is carried out using a nylon helical carried out under a include load the corner 15.2 N. wear on hobs the finish smooth as a mirror. The is carried out using a nylon helica gear as a lap a simple mechanical gears with device. a nylon gear. The rotating speed the work spindle was gear as a lap a simple mechanical device. This paper first shows the machine designed manufactured by the authors Dr. Yasutsune the procedure Ariura is a pressor principle emeritus the lap- who 2,000 rpm. These work gears were finished Tooth prile This paper first shows the machine designed manu with a carbide hob after they were hardened factured by the authors the procedure principle the lap to ping. 350 HB. As a result worked the the tests, department it becomes intelligent clear that machinery the process New can make tooth machine. flanks The newly hardened devel- steel gears smooth in a short Roughness 0.2 mm systems, Kyushu University, Fukuoka, Japan, ping. As a result the tests, it becomes clear that the pro from 1983 to 2005. Gear manufacturing research cess can make tooth flanks hardened steel gears smooth in a shor oped time that machine it is is shown in Figure involved important finish to carry hobbing out the with a) cermet- After using roughing a nylon CBNtipped hobs, manufacturing teeth under a performance condition the one shown in Figure 2. Microvibrations gear that has a large helix angle high teeth under a condition o (3.8 N; WA1000; 2 strokes) time that it is important to carry out the using a nylo 19. gear It has that basically has a large the helix same angle mechanism high as high rotating speed austempered light load ductile in order iron to gears, prevent increasing load carrying can be added to the driven spindle along Tooth prile high rotating speed light load in order to prevent increasing o tooth prile errors. capacity hardened & tempered surface hardened an cylindrical eccentric cam gears. on tooth prile errors. the axis by means the new Moreover, the machine. And process the driving was varied to include microvibrations is located the above nylon the gear. driven From spindle the result, it is found that Roughness Moreover, the process was varied to include micro spindle Toshinori Matsunami is the president so that a work gear can easily be attached b) After finishing Gifu Gear (7.6 N; GC6000; vibrations 4 strokes) the nylon gear. From the result, it is found tha the addition Manufacturing microvibrations Co. enables Ltd, Gifu, this Japan. process His to company also the addition microvibrations enables this process to als or reduce removed. tooth prile manufactures errors the highly work accurate gears. Figure The gears 17 Effect lapped for gears various nylon gear with high teeth when made SCM435 (860 HV) Effect microvibrating nylon gear. reduce tooth prile errors the work gears. The lapped gears running noise industries load carrying via its gear capacity manufacturing rotating are considered, at a speed measuring too. 2,290 rpm. Figure 20 shows equipment. the comparison the running noise load carrying capacity are considered, too removal amounts based on the presence or absence microvibrations Masao Kohara during the is the lap-deputping process. The the removal technical amounts center were in Yushiro Chemical Industry general manager measured through the Co. weight Ltd, Kanagawa, the work Japan. The company supplies gears before after metalworking the oils process. fluids to industry, as well as It is clear from the fering figure that building the addition maintenance products textile microvibrations increases the removal O G Y wamount. w w. g e a r t e c h n o l o g y. c o m w w w. p o w e r t r a n s m i s s i o n. c o m Figure 21 shows 3 8 changes S E P T E M B Etooth R / O C Tpro- file tooth flank roughness via O B E R 2 0 0 5 G E A R T E C H N O L O G Y w w w. g e a r t e c h n o l o g y. c o m w w w. p o w e r t r a n s m i s s i o n. c o with microvibrations. The gear was rough lapped using abrasive grains WA1000 finish lapped using abrasive grains WA2000, respectively, for 16 seconds. It a) Tooth flank roughness b) Tooth prile error was found that the with microvibrations improves the tooth prile as well Figure 18 Effect rotating speed. as 5 5 w w w. p o w e r t r a n s m i s s i o n. c o m w w w. g e a r t e c h n o l o g y. c o m G E A R T E C H N O L O G Y S E P T E M B E R / O C T O B E R 2 0 0 5 4 3 2 µm

with a Figure 19 New machine. 30 µm Figure 21 Effect microvibrations. Eccentric cam Work gear Microvibrations Traverse feed Nylon gear Figure 20 Effect microvibrations on removal amounts. Tooth prile Before After roughing After finishing 3.5 mm 2,000 rpm; 15.2 N; SCM435 (350 HB) Roughness the tooth flank roughness. Effect. In addition, we investigated the running noise durability Kazunori Hidaka Yasutsune Ariura a pair gears lapped under the aforementioned Toshinori conditions. Matsunami The numbers teeth the Masao driving gear Kohara the driven gear were 23 25, respectively. The running tests were Dr. Masahiko Nakae is a pressor in the department mechanical engineering, Sasebo National carried out using a power-circulation-type gear testing machine with a driving gear College Technology, Nagasaki, Japan. In the field rotation speed 3,580 rpm. Applied pitchline gear manufacturing, he specializes the study finish load hobbing was 1,188 with N/cm, CBN-tipped which hobs gave a finish maximum with Hertzian nylon stress gears. 745 MPa. Figure 22 shows the spectral distributions Dr. Kazunori the running Hidaka noise is for a the pressor lapped in the in gears the compared mechanical with engineering that a pair department hobbed Sasebo gears. National The College sound pressure Technology. level His research the interests include gears is the lower corner at all wear frequencies. on hobs The the finish lapped difference is gears larger with at higher a nylon frequencies. gear. Figure 23 shows changes in the pitting area Dr. ratio. Yasutsune The pitting Ariura on is the a pressor lapped gears emeritus who occurs worked later in the increases department more slowly intelligent than machinery on hobbed systems, gears. Kyushu University, Fukuoka, Japan, from 1983 to 2005. Conclusions Gear manufacturing research involved We investigated finish hobbing the with cermet- process CBNtipped a nylon hobs, lap manufacturing a simple mechanical performance using device austempered for finishing ductile gear iron tooth gears, flanks. Based load carrying on capacity the results, hardened the following & tempered conclusions surface are hardened cylindrical gears. obtained: 1. In this process, abrasive grains embed Toshinori the surface Matsunami a nylon is gear the president when Gifu Gear Manufacturing they re injected Co. between Ltd, Gifu, the tooth Japan. flanks His company manufactures the work gear highly nylon accurate gear. gears The for various industries nylon gear, via in its effect, gear manufacturing works like a grind- measuring equipment. ing wheel. 2. The process can improve tooth flank Masao roughness Kohara hardened is the steel deputy gears general to an manager the R y technical less than center 0.5 µm in in Yushiro a short Chemical time Industry Co. Ltd, Kanagawa, Japan. The company supplies despite using an inaccurate lap. metalworking oils fluids to industry, as well as 3. In under a low rotating fering building maintenance products textile speed a heavy load, a concavity is apt to occur near the pitch cylinder during S Ethe P Tengagement E M B E R / O C T O Bone E R pair 2 0 0 5 teeth. G E A R T E C H N O L 3 8 As the rotating speed increases, the removal amount near the root is greater, so the concavity occurs there. 4. It is important to complete in a short time using a nylon gear with a large helix angle high teeth under a high rotating speed a light load in 4 4 S E P T E M B E R / O C T O B E R 2 0 0 5 G E A R T E C H N O L O G Y w w w. g e a r t e c h n o l o g y. c o m w w w. p o w e r t r a n s m i s s i o n. c o m 2 µm 0.2 mm Masahiko Nakae

Finishing with a order to prevent increases tooth prile errors. Masahiko Nakae 5. The addition microvibrations Kazunori Hidaka to the 110 process increases Yasutsune the removal amount Ariura Rotating speed: 3580 rpm enables the process Toshinori to improve Matsunami tooth Maximum Hertzian stress: 745 MPa prile errors. Masao Kohara 6. The running noise the pitting rate work gears are reduced Dr. Masahiko through Nakae the process. ment mechanical engineering, Sasebo National is a pressor in the depart- College Technology, Nagasaki, Japan. In the field This paper was presented gear manufacturing, at the ASME/ he specializes the study Hobbed gears AGMA 2003 International finish hobbing with Power CBN-tipped hobs finish Transmission Gearing with Conference, nylon gears. held Sept. 3 5, 2003, in Chicago, IL, The was objective published Dr. this in Kazunori research Proceedings Hidaka is to develop is a a pressor new process 2003 that can ASME efficiently the the in Lapped gears The objective this research is to develop a new pro the Design mechanical make Engineering tooth engineering flanks hardened department 30 steel gears Sasebo National College Technology. His research interests include the corner wear on hobs the finish smooth 10 as a mirror. The is carried 20out using a nylon helica cess that can efficiently make tooth flanks hardened steel gear Technical smooth as Conferences a mirror. The & Computers is carried out using 0 a nylon helical Information gear as a lap in Engineering a simple mechanical Conference. gears with device. a nylon gear. It s republished here with permission Frequency gear as khz a lap a simple mechanical device. This paper first shows the machine designed manufactured by the authors Dr. Yasutsune the procedure Ariura is a pressor principle emeritus the lap- who from ASME. Figure 22 Effect on running noise. This paper first shows the machine designed manu factured by the authors the procedure principle the lap References ping. As a result worked the the tests, department it becomes intelligent clear that machinery the process Ishibashi, can make A., tooth S. Ezoe, flanks hardened S. Tanaka. steel gears smooth in a short systems, Kyushu University, Fukuoka, Japan, ping. As a result the tests, it becomes clear that the pro 1. from 1983 to 2005. Gear manufacturing research cess can make tooth flanks hardened steel gears smooth in a shor Mirror time Finishing that it is involved important Tooth Surfaces finish to carry hobbing Using out the with cermetusing a nylon CBNtipped helix with hobs, angle Cubic-Boron- manufacturing high teeth under a performance condition time that it is important to carry out the using a nylo a gear Trial that Gear has a Grinder large gear that has a large helix angle high teeth under a condition o Nitride high rotating Wheel, speed Fourth austempered International light load ductile in Power order iron to gears, prevent increasing load carrying Transmission Gearing Conference, high rotating speed light load in order to prevent increasing o tooth prile errors. capacity hardened & tempered surface hardened cylindrical No. 84-DET-153, gears. tooth prile errors. Cambridge, MA. Paper October Moreover, 1984, pp. the 1 8. process was varied to include microvibrations Ishibashi, A., the S. nylon Hoyashita, gear. From S. Ezoe, the result, it is found that Moreover, the process was varied to include micro 2. Toshinori Matsunami is the president Gifu Gear vibrations the nylon gear. From the result, it is found tha Y. the Chen addition K. Manufacturing Sonoda. microvibrations Reduction Co. enables Ltd, in Gifu, this Japan. process His to company also the addition microvibrations enables this process to als Noise reduce tooth Vibration prile manufactures Levels errors Spur the highly work Gears accurate gears. The gears lapped for gears various reduce tooth prile errors the work gears. The lapped gears Achieved running noise by Mirror-like industries load carrying Grinding via its gear capacity manufacturing are considered, measuring too. Prile Modification equipment. Teeth, Transactions running noise load carrying capacity are considered, too Japan Society Mechanical Engineers (in Japanese), Vol. 56, No. 532, 1990, pp. 3410 3415. Sound pressure level db Masao Kohara is the deputy general manager the technical center in Yushiro Chemical Industry Co. Ltd, Kanagawa, Japan. The company supplies metalworking oils fluids to industry, as well as fering building maintenance products textile O G Y w w w. g e a r t e c h n o l o g y. c o m w w w. p o w e r t r a n s m i s s i o n. c o m 3 8 S E P T E M B E R / O C T O B E R 2 0 0 5 G E A R T E C H N O L O G Y w w w. g e a r t e c h n o l o g y. c o m w w w. p o w e r t r a n s m i s s i o n. c o Figure 23 Effect on pitting. w w w. p o w e r t r a n s m i s s i o n. c o m w w w. g e a r t e c h n o l o g y. c o m G E A R T E C H N O L O G Y S E P T E M B E R / O C T O B E R 2 0 0 5 4 5