CN109681608A - Central cycloid differential mechanism - Google Patents

Abstract

The present invention relates to technical field of transmission, in particular to a kind of central cycloid differential mechanism that can be used for automobile.Central cycloid differential mechanism is made of planet carrier, at least two one end with A type planetary gear, at least two Type B planetary gears, at least one A type wobble gear, output gear A, the output gear B of crank axle；Each A type planetary gear rotation axle center is fixed on the planet carrier, each A type planetary gear rotation axial line and planet carrier rotation axis parallel, each A type planetary gear is at least engaged with a Type B planetary gear, crank axle with the axle journal axial line opposed gear rotation axis parallel of level-one crank throw and apart from identical on each A type planetary gear, crank axle phase on all A type planetary gears is identical, and the axle journal of the crank throw at the same level on each A type planetary gear is each passed through each axis hole on the same A type wobble gear.

Description

Central cycloid differential mechanism

Technical field

The present invention relates to technical field of transmission, in particular to a kind of central cycloid differential mechanism that can be used for automobile.

Background technique

Differential mechanism is a kind of mechanical transmission component, and the power transmission for being chiefly used in exporting automobile gearbox is to two or four Wheel is driven, the track for causing driving wheel to press through due to Uneven road and vehicle turning etc. is different, if keeping synchronized Rotation will result in the increased friction on wheel and road surface, increase vehicle travel resistance, so differential mechanism is needed according to each driving The different working orders of wheel export revolving speed to wheel, and traditional differential mechanism is mostly helical gear or crown gear structure.

Limited-slip differential, English entitled Limited Slip Differential, abbreviation LSD.Limited-slip differential cares for name Think justice be exactly limiting wheel slide a kind of modified differential mechanism, refer to driving wheel rotating speed difference be allowed in a certain range, with Guarantee the class differential mechanism of the driving performances such as normal turning, but when a certain driving wheel skid or it is hanging when can limit differential mechanism not again By whole power outputs to skidding or hanging wheel, facilitates vehicle and get rid of poverty and manipulation when fierce drive, for example work as vehicle As soon as wheel is fallen into pit-hole, this wheel, which has no any frictional force, to be sayed, the wheel that lands but has great resistance relatively, general at this time The effect of logical differential mechanism can allow all dynamic feedbacks to the wheel of low friction.Fall into pit-hole wheel can not stall it is dynamic, and Complete attonity, such wheel can not just travel land wheel instead, at this moment if vehicle assembly is that limited-slip differential would not go out Existing such case.Current limited-slip differential, which has using automatically controlled multiplate clutch, realizes locking, but reaction speed is relatively Slowly, also have through the worm and gear of Purely mechanical and realize, cost is relatively high, also inconvenient when as center differential Scores are not waited to match in the output torque of setting front and back wheel.

Summary of the invention

To solve the above-mentioned problems, the invention proposes a kind of central cycloid differential mechanism, specific technical solution is as follows.

Central cycloid differential mechanism is had A type planetary gear, at least two B of crank axle by planet carrier, at least two one end Type planetary gear, at least one A type wobble gear, output gear A, output gear B composition；Each A type planetary gear rotation Axle center is fixed on the planet carrier, each A type planetary gear rotation axial line and planet carrier rotation axis parallel, each A type Planetary gear is at least engaged with a Type B planetary gear, the journal shaft of the same level-one crank throw of crank axle on each A type planetary gear Heart line opposed gear rotation axis parallel and apart from identical, the crank axle phase on all A type planetary gears is identical, each A The axle journal of crank throw at the same level on type planetary gear is each passed through each axis hole on the same A type wobble gear, and output gear A is certainly Walk around axis and planet carrier rotation shaft it is coaxial, output gear A engaged respectively with each A type wobble gear simultaneously composition internal gear Pair, all A type wobble gear numbers of teeth are equal；Each Type B planetary gear rotation axle center is fixed on the planet carrier, each Type B Planetary gear rotation axial line and planet carrier rotation axis parallel, each Type B planetary gear at least with an A type planet tooth Wheel engagement, output gear B rotation shaft and planet carrier rotation shaft are coaxial, output gear B and meanwhile respectively with each Type B planet Gear engagement；Each A type planetary gear and Type B planetary gear meshed gears are than identical, planet carrier, output gear A and output Gear B is respectively provided with the tooth connecting with differential mechanism external world part or hole.The technical program selects planet carrier and planetary gear Description method be described, primarily to more accurately description part between connection relationship, because of technical side of the invention There might not be traditional sun wheel construction in case and have the intermeshing between planetary gear, so being not belonging to traditional planet Gear drive, with the part or component naming method of planetary gear and planet carrier simply facilitate vivider elaboration part or Relationship between component；It is also to be stressed that the part or component of above-mentioned composition cycloid differential mechanism can be selected and be integrally machined molding zero " the A planetary gear that one end has crank axle " is referred to as " A type planetary gear " herein by part or the component integrally moved, when When planetary gear crank axle has two-stage above crank throw, using excentric sleeve and non-circular shaft or the form covered with key fixed eccentric shaft Planetary gear members of the composition with crank axle are common method, and can cooperate other parts in differential mechanism assembling process Erection sequence setting-up eccentricity axle sleeve step by step；The axle journal of crank throw is exactly the axle journal of eccentric shaft on crank axle, and every level-one crank throw is exactly The eccentric shaft and the axis of rotation of crank axle upper level and adjacent crank throw all out-of-alignment eccentric shafts, above-mentioned all A type planetary gears On the identical spatial relation of crank axle phase can be understood as the same stages of any two A type planetary gear crank axle The axle journal axial line of crank throw remains parallel with the plane that gear rotation axial line determines.A type planetary gear and Type B planet tooth Wheel can be same gear, is also possible to number of teeth difference but can form the gear of external tooth wheel set；Output gear B is relative to Type B Planetary gear is that gear ring or sun gear depend on A type wobble gear and select interior toothed ring gear or select external tooth gear, when A type is put When moving gear selects interior toothed ring gear, output gear B is that external tooth sun gear is engaged with Type B planetary gear, when A type wobble gear is selected Output gear B is that interior toothed ring gear is engaged with Type B planetary gear when external tooth gear；There are many kinds of forms for tooth, and spline can also be at last One kind, the most commonly used is spline structure on differential mechanism, the tooth on planet carrier can be any list convenient for applying torque to planet carrier The structure of key or spline, and be used to the hole that extraneous part is connect be usually by part screw or pin and the differential mechanism external world zero The hole shape structure that part is connected and fixed.

Above-mentioned planet carrier is driven each A type planetary gear and each Type B planet tooth by external force rotation by the tooth or hole Wheel revolves with the rotation of planet carrier, and the crank axle on each A type planetary gear drives all A type wobble gears with planet Frame rotation, all A type wobble gears drive output gear A rotation, and each Type B planetary gear drives output gear B rotation, output Gear A and output gear B pass through tooth or hole output rotation respectively；The differential mechanism when output gear A is identical with output gear B revolving speed Interior all parts are stationary with respect to planet carrier；When the output loading imbalance of output gear A and output gear B cause revolving speed not Meanwhile output gear A and output gear B relatively rotate, both output gear A and output gear B occurred with planet carrier respectively Contrary relative rotation causes all A type wobble gears to occur respectively with planet carrier relative to planet carrier rotation axis Revolution, each A type wobble gear drive each A type planetary gear certainly by crank axle relative to the revolution of planet carrier rotation axis Turn, is limited to engaging for A type planetary gear and the engagement of Type B planetary gear and planetary gear B and output gear B, output gear With a fixed rotating ratio relationship contrary relative rotation can only occur relative to planet carrier for wheel A and output gear B.On State be cycloid differential mechanism rotational motion of the invention transitive relation in other words the transitive relation of torque and differential output realization Principle；Differential mechanism of the invention is explained further potentially limiting the realization principle of sliding mechanism is: output gear A and A type swings tooth The number of teeth of wheel determines each A type wobble gear of the output gear A with respect to drive in planet carrier rotation one week with planet carrier rotation axis Revolve circle number for axis relative to planet carrier, the revolution circle number of A type wobble gear and each A type planetary gear oneself turn-take several phases Together, the gear ratio between output gear B and Type B planetary gear determines what output gear B drove with respect to planet carrier rotation one week Each Type B planetary gear is from number of turn-taking, when the rotating ratio of the A type wobble gear revolution in output gear A rotation and gear pair When higher, when especially output gear A and A type wobble gear form few teeth difference internal gear pair, due to frictional force and lubrication oil stream Difference rotary resistance can be according to phase inside differential mechanism when the relative rotation of the presence of body resistance, output gear A and output gear B Difference rotary resistance to the proportional amplification of rotary rpm, while inside this differential mechanism also cause output gear A with engage A type wobble gear between engagement surface pressure increase, cause between output gear A and the A type wobble gear engaged gear pair to pass Dynamic resistance increases, and further increases difference rotary resistance inside the differential mechanism that output gear A and output gear B is relatively rotated, this The increase of a little resistances all causes the imbalance of output gear A and the extraneous output resistance of output gear B speed difference in balance, makes Output gear A and output gear B tends to export at the same speed, that is, plays the role of limit and slide；Locking can be specifically realized when skidding, Depending on the maximum value that difference rotary resistance inside differential mechanism increases, theoretically when the opposite of output gear A and output gear B is turned round It may be implemented when difference rotary resistance is more than or equal to the torque for being input to planet carrier inside differential mechanism caused by square or relative rotation speed Opposite locking between output gear A and output gear B, output loading refer to that output gear passes through keyway or hole and the external world zero Resistance when the extraneous parts turn that part needs to drive after circumferentially connecting；It can also be in difference if it is desired to further increasing the sliding effect of limit Fast device, which has, increases friction plate between the opposite part slided to improve frictional resistance.

The gear pair of above-mentioned A type wobble gear and output gear A composition is cycloid tooth wheel set.Cycloid tooth wheel set includes cycloid Pinwheel pair, when the less tooth difference of cycloid tooth wheel set, two gears are with respect to the corresponding gear of one weekly assembly of rotation around another tooth The rotation axial line revolution of wheel is mostly all, can amplify resistance when rotation, and cycloid gear can choose the less tooth of the number of teeth Wheel, it is interior in a limited space to increase gear endurance, it can be engaged additionally by the tooth form of adjustment cycloid gear with adjustment gear Rotary resistance and meshing torque between relationship, be more advantageous to and implement the different differential mechanisms for limiting sliding abilities out.

Above-mentioned A type planetary gear and Type B planetary gear are helical gear or worm screw.Bevel gear set at gear pair opposite Axial stress can be generated when rotation, this axial stress is conducive to increase the friction pressure of gear and axial other parts, Exactly increase the rotation resistance of gear；Worm screw belongs to a kind of gear, and the gear pair that worm screw and worm screw form is produced in relative rotation Raw axial stress, this axial stress increase the frictional force in worm tooth wheel set between worm screw and worm screw, increase worm screw rotation resistance Power, while this axial stress is conducive to increase the friction pressure of worm screw and axial other parts, also increases the rotation resistance of worm screw Power, the gear pair of worm screw and worm screw composition can be in certain opposing torque certainly after the lead angle of worm screw is less than certain angle Lock；It will cause the engagement rotation of planetary gear A and planetary gear B after the resistance of planetary gear rotation increases to some fixed value Resistance is more than the torque for causing planetary gear A and planetary gear B to relatively rotate, and the locking of differential mechanism may be implemented.

Above-mentioned central cycloid differential mechanism includes at least three A type planetary gear and at least three Type B planetary gear.3 with Upper A type planetary gear and 3 or more Type B planetary gear are just distinguished at least 3 crank axles and are connect with A type wobble gear, simultaneously Three Type B planetary gears are engaged with output gear B again, are more advantageous to the stabilization that wobble gear revolves around planet carrier axis of rotation heart line Property and share torque, 3 crank axles are more favorable to the torque that planet carrier rotation drives wobble gear and planet carrier synchronous rotary Load-carrying ability.

Above-mentioned central cycloid differential mechanism, the differential mechanism include that two A types of revolution phase phase difference 180 degree swing tooth Wheel.The phase difference of 180 degree ensure that two wobble gears to output gear when two wobble gears are engaged with the same output gear Radial pressure caused by wheel is offset, and the radial load of output gear is reduced, and similarly also reduces planetary gear and planetary gear crank The radial load of axis, while also assuring that the center of gravity of differential mechanism unitary rotation is placed in the middle.

Above-mentioned central cycloid differential mechanism, the planet carrier are equipped with position limiting structure at least one, and position limiting structure is to output Gear A and output gear B are radially limited, and position limiting structure is to output gear A and output gear B axle to limit, and position limiting structure is to A type Planetary gear and Type B planetary gear axially limit.Accurate output accuracy is not needed in differential mechanism, and with greater need for different Different difference device difference rotation internal drags is shown under the conditions of difference, then there is the part cloth of certain shake allowance in relative position Office advantageously reduces the rotation internal drag of the difference in normal driving process, and can guarantee to need to limit in the larger difference of appearance and slide When, compress that increase the rotation of differential mechanism difference internal when axial stress caused by the engagement between differential mechanism internal gear between part Resistance.

Above-mentioned central cycloid differential mechanism, the differential mechanism further includes shell, which, which is equipped at least one, limits knot Structure, position limiting structure radially limit planet carrier, output gear A and output gear B, and position limiting structure is to output gear A and output gear B axle is taken turns to limit.It needs to increase independent shell to differential mechanism in some cases, not necessarily there is circumferential direction between shell and planet carrier Fixed relationship in addition shell can be a part of gear box casing, shell can effectively provide some necessary parts Shell can also carry lubricating oil to the flowing offer preferably control of lubricating oil simultaneously for limit；A kind of above-mentioned cycloid differential Device, the planet carrier are diametrically fixed by two, part or the component composition of circumferentially opposed fixation.Two panels planet carrier is set respectively Set planetary gear shaft to both ends, this two panels planet carrier allows to have one in mutual limit or under being limited by other parts in axial direction Fixed mobile space, this has no effect on planet carrier and drives planetary gear revolution, and especially selection helical gear or worm screw are as planet When gear, planet carrier can move axially under the promotion of planetary gear axial stress, this is conducive to the row when differential mechanism skids Increase the friction inside differential mechanism between planet carrier and wobble gear when star gear mesh force square is larger, or even further increases Add the friction of wobble gear and other parts, difference rotary resistance inside differential mechanism can be increased, improves and limit sliding effect.

Above-mentioned central cycloid differential mechanism, the differential mechanism further includes shell, and the shell and planet carrier are circumferentially fixed, shell It is equipped with the tooth for connecting with differential mechanism external world part or hole.In some cases, especially differential mechanism is as rear differential mechanism The case where, the planet carrier of differential mechanism, which needs to input part with torque by shell, to be connect or interlocks, and at this moment shell just must be with row Carrier is circumferentially fixed.

Above-mentioned central cycloid differential mechanism, the Type B planetary gear are a kind of duplicate gear, two layers in duplicate gear Gear is engaged with A type planetary gear and output gear B respectively.Duplicate gear is the tooth for including two independent flank profils and helical angle A gear part or component for wheel, when Type B planetary gear selects duplicate gear, two respective gear wheels of Type B planetary gear It can be engaged respectively with A type planetary gear and output gear B, be conducive to preferably adjust transmission ratios, Type B planetary gear in this way Two gears be can be by the component of key or non-circular axis connection together, such as when A type planetary gear selection helical gear is same When output gear B when being spur gear again, the part that Type B planetary gear is engaged with A type planetary gear is helical gear, with output gear The part of B engagement is spur gear.

Cycloid differential mechanism of the invention can be realized by setting A type planetary gear and Type B planetary gear gear ratio The distribution setting of torque output；The distribution of torque output can also be realized by the gear ratio of A type wobble gear and output gear A Setting can also export distribution setting by the gear ratio between Type B planetary gear and output gear B come torque, this is this hair One important advance advantage of bright difference device is solved by the way that the gear ratio of output torque distribution is adjusted at setting above-mentioned two Various differential mechanisms adjust the range-restricted of torques distribution in the prior art, compared with prior art also reduce differential mechanism to adjust The difficulty of processing and processing cost of torque distribution and the moulding of design are saved, certain differential mechanisms compared with the prior art more improve Torque carrying capability under same size reduces the differential mechanism volume under same load ability in other words, reduces transmission mechanism Rotary inertia can effectively promote transmission efficiency.

The engine power that cycloid differential mechanism of the invention is mainly used for vehicle is exported by the backward wheel of gearbox, is made When for center differential, usually gearbox outputs torque to differential carrier, output gear A and output gear B difference Front and back differential mechanism is output torque to, structure of the invention is easier to realize the output torque of output gear A and output gear B It is not reciprocity, suitable for the center differential of vehicle, by the distribution to output torque make vehicle be more prone under normal conditions forerunner or The ride characteristic of rear-guard.

Detailed description of the invention

The central cycloid differential design schematic diagram (cross-sectional view) of Fig. 1 embodiment 1.

The central cycloid differential mechanism part explosive view of Fig. 2 embodiment 1.

The central cycloid differential mechanism perspective view of Fig. 3 embodiment 1.

The central cycloid differential design schematic diagram (cross-sectional view) of Fig. 4 embodiment 2.

The central cycloid differential mechanism part explosive view of Fig. 5 embodiment 2.

The central cycloid differential mechanism perspective view of Fig. 6 embodiment 2.

The central cycloid differential design schematic diagram (cross-sectional view) of Fig. 7 embodiment 3.

The central cycloid differential mechanism part explosive view of Fig. 8 embodiment 3.

The central cycloid differential mechanism perspective view of Fig. 9 embodiment 3.

In figure: 1, planet carrier；2, A type planetary gear one end have the gear part of non-circular shaft；3, A type planetary gears include Excentric sleeve part；4, Type B planetary gear (indicates a part) when Type B planetary gear is duplicate gear；5, A type wobble gears； 6, output gear A；7, output gear B；8, shell.

Specific embodiment

Embodiment 1, as shown in Fig. 1 ~ Fig. 3, planet carrier has been selected and the planet carrier of shell one and has been had in the present embodiment The planet carrier part of external splines forms, and A type planetary gear is 3 identical involute spur gears, and Type B planetary gear is 3 phases Same duplicate gear, and duplicate gear is the involute spur gear of the same number of teeth of the same modulus of two-stage, A type planetary gear and B The type planetary gear number of teeth is all equal, and 3 A type planetary gears form 3 gears with 3 Type B planetary gear intermeshings respectively Pair, A type planetary gear have selected the planetary gear of the crank axle containing two-stage crank throw, and implementation method is in each planetary gear structure The excentric sleeve that phase phase difference 180 degree is loaded on the flat shaft of the gear part of part forms the two-stage crank throw of crank axle, partially Spindle sleeve and gear, which are fitted together, constitutes the planetary gear members with crank axle, and the present embodiment has selected the A of two 32 teeth The output gear A of type wobble gear and 34 teeth has separately constituted the cycloid internal gear pair that tooth difference is 2, and wherein output gear A is interior Gear, the two-stage crank throw that the excentric sleeve on each A type planetary gear is formed are respectively embedded into the difference of two A type wobble gears Axis hole；The present embodiment has selected in straight-tooth toothed ring gear as output gear B；Output gear A is also machined with for output torque External gear, the center of output gear B are equipped with the axis hole with spline, and planet carrier center is equipped with splined hole for connecting torque input zero Part, housing body part both ends form housing member by screw thread and fixed screw by limit part, zero in differential carrier body Part is limited in corresponding position by shell；In the present embodiment in addition to excentric sleeve selects tin bronze alloys to be made for material, other Part selects chrome-molybdenum steel to be process for material.

Embodiment 2, as shown in Fig. 4 ~ Fig. 6, planet carrier has selected planet carrier zero of the two panels with external splines in the present embodiment Part composition, A type planetary gear are 3 identical involute spur gears, and Type B planetary gear is 3 identical duplicate gears, and The two-stage of duplicate gear is the involute spur gear of the same number of teeth of same modulus, A type planetary gear and the Type B planetary gear number of teeth All equal, 3 A type planetary gears form 3 gear pairs, the choosing of A type planetary gear with 3 Type B planetary gear intermeshings respectively With the planetary gear of the crank axle containing two-stage crank throw, implementation method be each planetary gear members gear part it is flat The excentric sleeve that phase phase difference 180 degree is loaded on shape shaft forms the two-stage crank throw of crank axle, and excentric sleeve and gear are mounted in Together constitute the planetary gear members with crank axle, the present embodiment selected the A type wobble gear of two 32 teeth respectively and The output gear A of 34 teeth constitutes the cycloid internal gear pair that tooth difference is 2, and wherein output gear A is internal-gear, each A type row The two-stage crank throw that excentric sleeve on star gear is formed is respectively embedded into the not coaxial aperture of two A type wobble gears；The present embodiment choosing Toothed ring gear in straight-tooth has been used to engage as output gear B, output gear B and three Type B planetary gears；Output gear A is also processed There is the external gear for output torque, the center of output gear B is equipped with the axis hole with spline, and planet carrier passes through external splines and shell It is circumferentially fixed, it is machined with the gear teeth of torque input outside shell, housing body part both ends have limit part to pass through screw thread and solid Determine screw composition housing member, the part in differential carrier body is limited in corresponding position by shell；Eccentric shaft is removed in the present embodiment It is other than material is made that set, which selects tin bronze alloys, and other parts select chrome-molybdenum steel to be process for material.

Embodiment 3, as shown in Fig. 7 ~ Fig. 9, planet carrier has been selected and the planet carrier of shell one and a piece of in the present embodiment Planet carrier part composition with internal spline, A type planetary gear is 3 identical involute spur gears, and Type B planetary gear is also 3 identical involute spur gears, A type planetary gear and the Type B planetary gear number of teeth are all equal, 3 A type planetary gear difference With 3 Type B planetary gear intermeshing 3 gear pairs of composition, A type planetary gear has selected the crank axle containing two-stage crank throw Planetary gear, implementation method are that phase phase difference 180 degree is loaded on the flat shaft of the gear part of each planetary gear members Excentric sleeve form the two-stage crank throw of crank axle, excentric sleeve and gear are fitted together and constitute the planet with crank axle Gear part, the present embodiment have selected the A type wobble gear of two 32 teeth and the output gear A of 34 teeth to separately constitute tooth difference to be 2 cycloid internal gear pair, wherein output gear A is internal-gear, the two-stage that the excentric sleeve on each A type planetary gear is formed Crank throw is respectively embedded into the not coaxial aperture of two A type wobble gears；The present embodiment has selected in straight-tooth toothed ring gear as output gear B；Output gear A is also machined with the external gear for output torque, and the center of output gear B is equipped with the axis hole with spline, planet Frame center is equipped with splined hole for connecting torque input part, and housing body part both ends have limit part to pass through screw thread and fixation Screw forms housing member, and the part in differential carrier body is limited in corresponding position by shell；Excentric sleeve is removed in the present embodiment Selecting tin bronze alloys is other than material is made, and other parts select chrome-molybdenum steel to be process for material.

Claims (10)

1. central cycloid differential mechanism, it is characterized in that: A type planetary gear by planet carrier, at least two one end with crank axle, extremely Few two Type B planetary gears, at least one A type wobble gear, output gear A, output gear B composition；Each A type planetary gear Rotation axle center be fixed on the planet carrier, each A type planetary gear rotation axial line and planet carrier rotation axis parallel, often A A type planetary gear is at least engaged with a Type B planetary gear, the same level-one crank throw of crank axle on each A type planetary gear Axle journal axial line opposed gear rotation axis parallel and apart from identical, the crank axle phase on all A type planetary gears is identical, The axle journal of crank throw at the same level on each A type planetary gear is each passed through each axis hole on the same A type wobble gear, output gear It takes turns A rotation shaft and planet carrier rotation shaft is coaxial, output gear A engages composition with each A type wobble gear respectively simultaneously Internal gear pair, all A type wobble gear numbers of teeth are equal；Each Type B planetary gear rotation axle center is fixed on the planet carrier, often A Type B planetary gear rotation axial line and planet carrier rotation axis parallel, each Type B planetary gear at least with an A type Planetary gear engagement, output gear B rotation shaft and planet carrier rotation shaft are coaxial, output gear B and meanwhile respectively with each B The engagement of type planetary gear；Each A type planetary gear and Type B planetary gear meshed gears are than identical, planet carrier, output gear A The tooth connecting with differential mechanism external world part or hole are respectively provided with output gear B.

2. center cycloid differential mechanism according to claim 1, it is characterized in that: above-mentioned planet carrier is by the tooth or hole by outer Power rotation drives each A type planetary gear and each Type B planetary gear as the rotation of planet carrier is revolved, each A type row Crank axle on star gear drives all A type wobble gears to rotate with planet carrier, and all A type wobble gears drive output gear A Rotation, each Type B planetary gear drive output gear B rotation, and output gear A and output gear B pass through tooth or hole output respectively Rotation；As output gear A and identical output gear B revolving speed, all parts are stationary with respect to planet carrier in differential mechanism；When defeated When gear A and the output loading imbalance of output gear B cause revolving speed difference out, output gear A and output gear B occur relatively Rotation, both contrary relative rotation occurred with planet carrier respectively for output gear A and output gear B, and all A types is caused to swing Revolution relative to planet carrier rotation axis occurs with planet carrier respectively for gear, each A type wobble gear relative to planet carrier from The revolution of shaft axis drives each A type planetary gear rotation by crank axle, is limited to A type planetary gear and Type B planetary gear Engagement and planetary gear B and output gear B engage, output gear A and output gear B can only be with a fixed revolving speeds Contrary relative rotation occurs relative to planet carrier than relationship.

3. center cycloid differential mechanism according to claim 1, it is characterized in that: above-mentioned A type wobble gear and output gear A group At gear pair be cycloid tooth wheel set.

4. center cycloid differential mechanism according to claim 1, it is characterized in that: above-mentioned A type planetary gear and Type B planetary gear It is helical gear or worm screw.

5. center cycloid differential mechanism according to claim 1, it is characterized in that: including at least three A type planetary gear and at least 3 Type B planetary gears.

6. center cycloid differential mechanism according to claim 1, it is characterized in that: the differential mechanism includes revolution phase phase difference Two A type wobble gears of 180 degree.

7. center cycloid differential mechanism according to claim 1, limits it is characterized in that: the planet carrier is equipped at least one Structure, position limiting structure radially limit output gear A and output gear B, and position limiting structure is to output gear A and output gear B axle To limit, position limiting structure axially limits A type planetary gear and Type B planetary gear.

8. center cycloid differential mechanism according to claim 1, it is characterized in that: the differential mechanism further includes shell, the shell It is equipped with position limiting structure at least one, position limiting structure radially limits planet carrier, output gear A and output gear B, position limiting structure To output gear A and output gear B axle to limit.

9. center cycloid differential mechanism according to claim 1, it is characterized in that: the differential mechanism further includes shell, the shell Circumferentially fixed with planet carrier, shell is equipped with tooth or hole for connecting with differential mechanism external world part.

10. center cycloid differential mechanism according to claim 1, it is characterized in that: the Type B planetary gear is a kind of duplex-gear It takes turns, two layers of gear in duplicate gear is engaged with A type planetary gear and output gear B respectively.