The invention provides an overlap ratio improving method for external-gearing cycloid gears. In an engaging-out period when a driving external gear and a driven external gear are meshed, the diameter of the mesh circle in the engaging-out period is set to be larger than the diameter of the pitch circle of the driven external gear and smaller than or equal to the sum of the diameter of the pitch circle of the driven external gear and the radius of the pitch circle of the driving external gear. Thus, the addendum of the driving external gear is meshed with the addendum of the driven external gear. In an engaging-in period when the driving external gear and the driven external gear are meshed, the diameter of the mesh circle in the engaging-in period is set as the diameter of the mesh circle in the engaging-out period minus the diameter of the pitch circle of the driven external gear. Thus, the dedendum of the driving external gear is meshed with the addendum of the driven external gear.

Overlap ratio improving method for external-gearing cycloid gears

The invention discloses an inside engaged gear tooth form design method based on a B-spline engaging line. According to the method, an inside engaged gear engaging line is constructed by using b-splines according to the freedom and flexibility of b-spline curves constructing complex curves; according to the gear engagement principle, an inside engaged internal and external gear conjugate tooth profile curve satisfying the engaging line is constructed, and the engagement performance of the inside engaged internal and external gear conjugate tooth profile curve is analyzed; with the goal of the smoothness of the engaging line and the engagement performance of the conjugate tooth profile, optimized design of the conjugate tooth profile is carried out; and a tooth root transition circular curve from the tooth profile curve to a root circle is constructed, and the overall tooth design of an inside engaged gear is completed. Through the engaging line designed through the method, the engagement performance of the constructed conjugate tooth profile can be solved before construction of the conjugate tooth profile. According to the method, the engaging line constructed by the B-splines is utilized, and the shape of the engaging line can be adjusted conveniently by changing position coordinates of a control vortex. Thus, the method has great freedom in geometrical shape design and the engagement performance design of the inside engaged gear conjugate tooth profile.

Inside engaged gear tooth form design method based on B-spline engaging line

The utility model provides an oil pump rotor, aiming to solve the problems of easy jamming of the rotor, large noise and the like in gear cutting interference and tooth profile intersection of an internal meshing cycloid gear which is universally adopted at present. The oil pump rotor comprises an inner rotor and an outer rotor, which are meshed with each other, wherein the quantity of teeth of the inner rotor is n; the quantity of the teeth of the outer rotor is n+1; the distance between the center of the inner rotor and the center of the outer rotor is equal to the difference between the pitch radius of the inner rotor and the pitch radius of the outer rotor; the radial clearance delta between the inner rotor and the outer rotor is equal to 0.1-0.2mm; the tip cone clearance delta of the inner rotor and the outer rotor is equal to 0.03-0.18mm; the tooth profile of the inner rotor comprises a tip cone line, a tooth root line, and a transition connecting line which is smoothly connected with the tip cone line and the tooth root line; the tooth profile of the outer rotor comprises a tip cone line, a tooth root line, and a transition connecting line which is smoothly connected with the tip cone line and the tooth root line; and the tip cone line of the outer rotor is a curve conjugated with the tooth root line of the inner rotor.

Oil pump rotor

The invention discloses cycloid-like gears and a cycloid-like gear speed reducer. The tooth profile of the cycloid-like gears is formed by compound splicing of the cycloid and the involute. The gearscombine advantage of an involute gear and a cycloid gear, and the problems of gear strength and transmission stability in the inner meshing transmission process can be solved. The cycloid-like gear speed reducer adopts the two cycloid-like gears which make eccentric motion to form a 2K-H-type combined wheel train so as to achieve speed reduction, the two cycloid-like gears are meshed with a shelland a movable disc respectively, speed-reduction output is achieved through the movable disc, and then in combination with tooth number distribution, a large transmission ratio is achieved. By means of the cycloid-like gears and the cycloid-like gear speed reducer, the over-location problem that three crankshafts in an existing RV speed reducer planetary transmission structure jointly act on cycloid gears is solved, and the interference problem in the small-tooth-difference transmission process is also solved; the cycloid-like gears are adopted as transmission gears of the speed reducer to achieve a tooth-needle-free structure, so that the overall processing and assembling difficulty of the speed reducer is greatly lowered, and the transmission performance and transmission characteristic of the high-speed-ratio speed reducer are further improved.

Cycloid-like gears and cycloid-like gear speed reducer

The invention provides a double-stage nested closed root-cut cycloid movable tooth transmission unit. The transmission unit comprises an inner ring transmission wheel, inner ring movable teeth, an intermediate transmission wheel, outer ring movable teeth and an outer ring transmission wheel. On the basis of a single-stage root-cut cycloid movable tooth transmission unit, the other single-stage root-cut cycloid movable tooth transmission unit is added, and the relationship between the two is not a simple series relationship, but the input and output of the first-stage single-stage root-cut movable tooth transmission unit are simultaneously used as the input of the second-stage single-stage root-cut movable tooth transmission unit. The whole mechanism can be equivalent to a double-stage differential gear train, the combined form of the transmission unit is flexible and diverse, the single-stage root-cut outer cycloid transmission unit can be all adopted, the single-stage root-cut inner cycloid transmission unit can be all adopted, the single-stage root-cut outer cycloid transmission unit and the single-stage root-cut inner cycloid transmission unit can be adopted at the same time, and each unit may also have two choices of forward placement and reverse placement. Therefore there are sixteen combinations, and different combinations have different formulas for calculating the reduction ratio.

Double-stage nested closed root-cut cycloid movable tooth transmission unit

The invention provides a cycloid gear with high-speed transmission, heavy load and low abrasion, comprising a hypocycloid gear, an epicycloid gear and a flat cycloid rack which can be combined to form transmission pairs including an outer engagement, an inner engagement, a gear and rack engagement and the like. The cycloid gear completely complies with natural laws, has no interferences and does not need correction; compared with an involute gear, the engagement sliding rate of the cycloid gear is only about 20%, the thickness of a tooth root is much thicker and the loading capability is improved by more than one time; the anti-agglutination capability is strong, the cycloid gear is not easy to abrade, the noise is small and the temperature rise is low; the cycloid gear is particularly suitable for high-speed and heavy-load transmission; the cycloid gear is machined by gear hobbing and gear shaping and the minimum teeth number reaches six teeth without undercutting; under the conditions of same output power and an approximate transmission ratio, the modulus can be decreased and the gear ratio is decreased to corresponding fewer teeth, so that the volume of a transmission system is reduced by about 30%; and the service life is improved by more than 3 times.

Cycloid gear with high-speed transmission, heavy load and low abrasion

The utility model provides a high-speed and heavy-load extensive cycloid gear which comprises an extensive cycloid gear and an extensive flat cycloid spline. The extensive cycloid gear and the extensive flat cycloid spline can be combined into various transmission pairs such as an inner gearing, an outer gearing, a gear and a spline meshing. The extensive cycloid gear completely conforms to natural laws, involvement does not exist, and amendment is not required. Compared with an involute gear, the meshing sliding rate of the extensive cycloid gear is only about 20% and is close to pure rolling. The high-speed and heavy-load extensive cycloid gear is strong in anti-gluing capacity, not prone to abrasion, small in noise, low in temperature rising, and large in root thickness, and loading capacity is about 1.5 times of the involute gear. The high-speed and heavy-load extensive cycloid gear is especially suitable for high-speed and heavy-load transmission. Hobbing and gear shaping machining is adopted, so that the minimum teeth number is five rootless undercutting. Under the condition that output power is equal and transmission ratio is approximate, modulus can be reduced, and gear ratio is reduced to corresponding less teeth number, so that the size of a transmission system is reduced by about 40%, and service life is prolonged by more than three times.

Li Yuanqing

Papers

Cycloid gear with high-speed transmission, heavy load and low abrasion

High-speed and heavy-load extensive cycloid gear