CN102434592A - Symmetrical constant velocity universal joint and variants thereof - Google Patents

Abstract

Axial lines of two transmission shafts have an included angle bisection surface in space. The invention provides a symmetrical constant velocity universal joint which is a universal joint in which moving pairs are symmetrical by the included angle bisection surface of the axial lines of the transmission shafts. A transmission shaft of a basic variant of the symmetrical constant velocity universal joint is provided with N circumferentially-equant fork shafts which respectively form an included angle Alpha with the axial lines of the transmission shafts, wherein N is more than or equal to 2. Each fork shaft is provided with a spherical roller provided with a sliding bearing or rolling needle. Another transmission shaft sleeve is also provided with N circumferentially-equant roller ways which respectively form an included angle Alpha with the axial lines of the transmission shafts. The spherical roller rotates in the roller ways along with the two transmission shafts or change of the included angle. The fork shafts and the shaft sleeve can be centered by the spherical surface and a stop pin. The axial lines of the fork shafts and the axial lines of the roller ways are symmetrical along the included angle bisection surface. The symmetrical constant velocity universal joint has four variants, has the advantages of simple structure, simple manufacturing process and high bearing capability and can substitute the traditional cross-shaped constant velocity universal joint, the traditional ball cage constant velocity universal joint and the traditional three-junction approximate constant velocity universal joint.

Description

Symmetric type constant velocity universal joint and anomaly thereof

Constant velocity universal joint is the bindiny mechanism of two transmission shaft constant-speed transmission motions and power.Several frequently seen constant speed or almost constant speed's universal joint are arranged at present.1, rzeppa universal joint, it has, and bearing capacity is low, curve raceway manufacturability is poor, shortcoming such as centering only.2, the diesis constant velocity universal joint is not felt relieved usually, and during the transmission shaft variable angle, transmission shaft moves axially, if add the centering of sliding ball strand in the centre, is not again constant velocity universal joint completely, and also not uniform rotation of minor axis in the middle of the double word has dynamic load simultaneously.3, triadius type almost constant speed universal joint, it is not a constant velocity universal joint completely, and fork shaft has the circular runout of three times of transmission shaft speed-frequencies, and the variable angle scope is little.

The symmetric type constant velocity universal joint utilizes the bisector plane of two axial lines angle to be symmetry plane, and kinematic pair or pairing element are with this bisector plane symmetry, to obtain the characteristic of constant speed.Several kinds of following anomalies are arranged:

Basic model (A type) is formed (Fig. 1) by three basic parts.A N fork shaft that circumferentially is uniformly distributed with that becomes the α angle with axis arranged on the transmission shaft.Be installed with the sphere roller that has needle bearing or sliding bearing on the axle.Another root transmission shaft has N to be the raceway at α angle with axis angle.The sphere roller also endwisely slips on a fork shaft in rolling in the raceway with the rotation of transmission shaft and the variation of crossed axis angle.Because they have identical α angle, raceway axis and fork shaft axis are with the equidistant point symmetry.Prop up fork and raceway number and can be more than two, so just have a plurality of spherial rolling bodies to carry, nearly six to eight, because the sphere roller diameter is big, bearing capacity saves big several times than ball-cage constant velocity universal.

Basic model is converted into low paratype (Type B); Two transmission shafts have external splines; Be with two spline housings above, spline housing can be accomplished on axle and move axially, and minor axis two 180 ° of distributions and the vertical drive shaft line (Fig. 2) is arranged on the spline housing; Minor axis is through open type rocking arm of needle roller bearing support, and the left and right sides rocking arm on two transmission shafts is through needle bearing connection up and down.The axis of two needle bearings is through the intersection point of the axis of two transmission shafts.Two transmission shafts link through ball pivot simultaneously, and the centre of sphere is the intersection point of the axis of two transmission shafts.Two rocking arm angles equate that four edge lengths also equate.Sliding pair (spline) on two transmission shafts of Type B, the minor axis revolute pair on the spline housing are faced with two transmission axis angle five equilibriums respectively and are claimed.Revolute pair axis between two rocking arms intersects at the ball pivot center on equidistant point, just on the intersection point of two drive shaft axis.If the ball pivot of centre is designed to the ball pivot that slides, also can obtain non-centering constant velocity universal joint, transmission shaft also can move axially.Spline on two transmission shafts can replace to reduce friction with axial ball receway.

Can Type B be changed into another kind of lower pair universal joint (C type).Spline housing on the cancellation axle, two rocking arms are divided into four rocking arms (Fig. 3).Adorn a vertical shaft on the transmission shaft, vertical shaft is connected with bearing with two rocking arms.Left and right sides rocking arm connects with ball pivot.Connect with ball pivot between two transmission shafts.Because four rocking arm brachiums equate that three ball pivots are on the angle bisector plane, the vertical shaft axis (revolute pair) on two transmission shafts is also with angle bisector plane symmetry.Ball pivot between the rocking arm of left and right sides transmission shaft can install needle bearing additional.

The D type is the variation of basic model.If raceway axis and raceway transmission shaft angle be near the angle of fork shaft and this transmission shaft, or do not wait, raceway and fork shaft number are three.This type covers and satisfies the raceway axis and the raceway drive shaft axis is not parallel, all universal joints of one of three conditions of fork shaft axis and fork shaft drive shaft axis out of plumb and curve raceway (Fig. 4).Because its is more near complete basic model of constant speed, than existing trident almost constant speed universal joint more near constant speed, the characteristics that the radial vibration of fork shaft transmission shaft is little, the crossed axis angle excursion is big.The curve raceway is the envelope surface of sphere.Axis can be circular arc or other curve with and synthesis thread.

A, B, C type all are complete constant velocity universal joints.The D type is almost constant speed's universal joint, but than triadius type almost constant speed universal joint constant speed more.

Claims (4)

1. the characteristic of symmetric type constant velocity universal joint is that mechanism kinematic pairs or pairing element are faced title with two transmission axis angle five equilibriums; The raceway axis of basic model is straight line and faces with five equilibrium with corresponding fork shaft axis respectively and claim; The centre of sphere of sphere roller is on the five equilibrium face; The fork shaft number equals the raceway number and can be the integer more than or equal to two, and fork shaft and raceway pass through sphere roller transmitting movement respectively with the circumferential five equilibrium of own drive shaft axis between them.

2. the transmission shaft of two of the symmetric type constant velocity universal joint kinds of lower pair modification can be realized moving at the uniform velocity fully and transmission of power 0 to 70 ° of scope; Sliding pair on two transmission shafts of Type B; Revolute pair on the spline housing is faced with two transmission axis angle five equilibriums respectively and is claimed; Revolute pair common axis line between two rocking arms intersects at the ball pivot center on equidistant point, just on the intersection point of two drive shaft axis; Spline on two transmission shafts can replace to reduce friction with axial ball receway; Revolute pair on two transmission shafts of C type is faced with two transmission axis angle five equilibriums respectively and is claimed that the ball pivot center of the spherical pair centre of sphere between two rocking arms and two transmission shafts is on equidistant point up and down, and the three spherical pair centre ofs sphere point-blank.

3. if raceway axis and raceway transmission shaft angle are near the angle of fork shaft and this transmission shaft; Or do not wait; Raceway number, fork shaft number all are three; Be the variation D type of basic model, this type cover satisfy the raceway axis with the raceway drive shaft axis is not parallel, three conditions of fork shaft axis and fork shaft drive shaft axis out of plumb and curve raceway all universal joints because basic model of its more approaching complete constant speed; Than existing trident almost constant speed universal joint more near constant speed, the characteristics that the radial vibration of fork shaft transmission shaft is little, the crossed axis angle excursion is big.The center line of curve raceway can be circular arc, also can be other curve or other curve synthesis thread.

4. whether the ball-joint of the low paratype (B, C type) of symmetric type constant velocity universal joint can be through increasing the mode that the pair that endwisely slips is designed to feel relieved and does not feel relieved; Basic model A type also can be through putting the mode that the axial displacement that whether limits the fork shaft transmission shaft is designed to feel relieved and does not feel relieved with variation D type at track, the fork shaft transmission shaft can resolve into two parts and be connected with snap ring through spline.

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