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A Y type planetary gearing consists basically of three central gears, a sun gear and two ring gears, and a number of identical planet gears. The three central gears have a common central axis and a number of teeth different from each other. Each planet gear has a uniform tooth profile in the longitu

A Y type planetary gearing consists basically of three central gears, a sun gear and two ring gears, and a number of identical planet gears. The three central gears have a common central axis and a number of teeth different from each other. Each planet gear has a uniform tooth profile in the longitudinal direction. The Y type planetary gearing of this invention has three important characteristics: (1) each planet gear is able to mesh simultaneously with the three central gears, (2) each pair of gears satisfy the law of conjugate gear-tooth action to provide uniform rotary motion, and (3) the planet gears are able to work properly without a carrier. Consequently, the disclosed Y type planetary gearing is compact in structure, small in size, low in cost, and capable of providing a high speed ratio.

대표청구항 ▼

A gear assembly, comprising: a housing having a bore extending therethrough, said bore including a rear opening substantially cylindrical chamber, a front opening substantially cylindrical chamber, and a middle opening substantially cylindrical chamber, between said front and rear chambers and havin

A gear assembly, comprising: a housing having a bore extending therethrough, said bore including a rear opening substantially cylindrical chamber, a front opening substantially cylindrical chamber, and a middle opening substantially cylindrical chamber, between said front and rear chambers and having a greater diameter than either said front chamber or said rear chamber; a first shaft extending through said front chamber and rotatably disposed in said front chamber and said middle chamber, said first shaft having a sun gear disposed thereon for unison rotation therewith within said middle chamber; a first ring gear fixedly secured to said housing in said middle chamber coaxial with said sun gear; a second shaft extending through said rear chamber and rotatably disposed in said rear chamber and said middle chamber; a second ring gear rotatably disposed within said middle chamber adjacent said first ring gear and coaxial with said sun gear; means rigidly securing said second ring gear to said second shaft for unison rotation therewith; a plurality of identical planet gears disposed in meshed, non-interfering engagement with said sun gear and both of said ring gears, in a common orbit around said sun gear equiangularly from each other, each of said planet gears having a substantially uniform tooth profile along a lengthwise direction thereof, a front end portion engaging said first ring gear and a rear end portion engaging said second ring gear; means spaced from said planet gears closely confining end faces of said planet gears to prevent axial movement thereof; and said sun gear, ring gears and planet gears configured according to the relation; wherein C is the common center distance, T1, T2, T3 and T4 are the numbers of teeth respectively of said sun gear, first ring gear, second ring gear and each of said planet gears, ff1 is the working pressure angle between said sun gear and each of said planet gears, f2 is the working pressure angle between said first ring gear and each of said planet gears, f3 is the working pressure angle between said second ring gear and each of said planet gears (T1+T4) Cos fP Cos f1)=(T2-T4). Cos fP Cos f2)=(T3-T4). Cos fP Cos f3)=2C.