JP2000161466A5

JP2000161466A5 -

Info

Publication number: JP2000161466A5
Application number: JP1998332223A
Authority: JP
Filing date: 1998-11-24
Publication date: 2005-07-21

Description

単に伝達効率を向上させる事だけを考えれば、上記第一、第二両転がり軸受８ａ、８ｂ、９ａ、９ｂを、円すいころ軸受に比べて摩擦抵抗が小さい玉軸受にすれば良いが、代わりに、運転時に発生する騒音や摩耗が著しくなる可能性がある。即ち、玉軸受は円すいころ軸受に比べて剛性が低い為、例えば両端軸部７ａ、７ｂを一般的な玉軸受により支持した場合には、運転時に加わる大きなトルクにより、これら両端軸部７ａ、７ｂが僅かとは言え、傾斜する可能性がある。図２に示す様に、ユニットフレーム６が、１対の第二転がり軸受９ａ´、９ｂ´の外輪１１、１１を内嵌支持している、ケーシングの保持孔の中心軸に対しθ（ラジアン）だけ傾斜した場合、大歯車５の噛み合い点のピッチ円直径をｄ_m とすると、この噛み合い点は、正規位置に対してｄ_m ・θ／２分移動する。ピッチ円直径ｄ_m は大きいので、上記ユニットフレーム６の傾斜角度が僅かであっても、上記大歯車５と小歯車４との噛み合い点の移動量は大きくなり、噛み合い部で生じる音が大きくなる。又、噛み合い部での摩耗も、噛み合い状態が正規の場合に比べて著しくなる可能性がある為、好ましくない。
Considering only to improve the transmission efficiency, the first and second rolling bearings 8a, 8b, 9a and 9b may be ball bearings having a smaller frictional resistance than the tapered roller bearings. , Noise and wear generated during operation may become significant. That is, since ball bearings have lower rigidity than tapered roller bearings, for example, when both end shafts 7a and 7b are supported by general ball bearings, the large torque applied during operation causes these both end shafts 7a and 7b. However, there is a possibility of tilting. As shown in FIG. 2, θ (radian) with respect to the central axis of the holding hole of the casing in which the unit frame 6 internally fits and supports the outer rings 11 and 11 of the pair of second rolling bearings 9a ′ and 9b ′. Assuming that the pitch circle diameter of the meshing point of the large gear 5 is d _m _{, this meshing point moves by d m} · θ / 2 with respect to the normal position. The pitch circle diameter d _m is large, even a small inclination angle of the unit frame 6, the movement amount of the engagement point of the pinion 4 and the gear wheel 5 is increased, the sound is large caused by the meshing portion .. Further, wear at the meshing portion is also not preferable because the meshing state may become more remarkable than when the meshing state is normal.