DE202014003168U1 - Constant velocity joint, drive shaft and drive train arrangement - Google Patents

Abstract

Constant-velocity rotary joint comprising: an outer joint part (3) with a longitudinal axis (A3) and with exactly six outer ball tracks (4), an inner joint part (5) with a longitudinal axis (A5) and with exactly six inner ball tracks (6), each with an outer ball track (4) and an inner ball track (6) form a track pair (4, 6) with each other, each a torque-transmitting ball (7) in each track pair (4, 6), with at least some of the balls (7) each having a diameter (D7 ) and together define a rolling circle diameter (PCD), a ball cage (8) which is arranged between the outer joint part (3) and the inner joint part (5) and has circumferentially distributed cage windows (9), each of which has at least one of the torque transmitting balls (7) record, characterized in that the ratio of the diameter (D7) of the balls (7) and the rolling circle diameter (PCD) of the balls (7) is at least 0.26 and at most 0.31 (0.26 ≤ D7 / PCD ≤ 0.31 ).

Description

The invention relates to a constant velocity universal joint for the drive train of a motor vehicle, a drive shaft with such a constant velocity universal joint and a drive train with such a drive shaft for a motor vehicle.

There are various drive concepts for motor vehicles known. In addition to drive arrangements with only one drivable axle (front axle or rear axle) or with two permanently drivable axles (front axle and rear axle), drive arrangements are also known in which a first drive axle (front axle or rear axle) is permanently drivable and a second drive axle (rear axle or front axle) is switched on when needed. Such drive arrangements with, if necessary, switchable drive axle are also referred to as "hang-on" or "on-demand" systems.

From the DE 199 19 454 A1 a vehicle drive device with an internal combustion engine, a gear change transmission and an electric machine is known. The internal combustion engine drives the rear wheels permanently via a cardan shaft. The electric machine is drivingly connected via a separating clutch and a drive shaft with the front wheels when needed.

From the DE 10 2008 037 886 A1 a drive arrangement for a multi-axle driven motor vehicle is known. The drive arrangement comprises a transfer case which transmits torque introduced by a drive unit to a first and a second drive train. The first drivetrain is continuously drive connected to the transfer case to permanently transmit torque to a first drive axle. If desired, the second driveline may be drivingly connected to the transfer case to transfer torque to the second drive axle.

In the demand-engageable drive train constant velocity joints are used, which are selected according to the respective technical requirements. These can be so-called constant-velocity fixed joints, in which the inner joint part and the outer joint part are angularly movable, but immovable, relative to one another. Likewise, synchronized sliding joints are used, in which the inner joint part and the outer joint part are not only angularly movable, but also longitudinally displaceable relative to one another.

The drive shafts of the as needed engageable drive train, that is side shafts and optionally longitudinal drive shaft may have fixed joints, sliding joints or both types of joints. In addition, the drive shafts may include longitudinal displacement units, which allow a length compensation; These are used in particular with drive shafts with only fixed joints or in waves where large displacement must be realized.

From the DE 20 2004 021 771 U1 is known a constant velocity joint in the form of a counter-track joint, as well as various applications for such a counter track joint in drive shafts.

From the EP 0 802 341 A2 is a constant velocity universal joint in the form of a fixed joint known. The constant velocity fixed joint has eight pairs of tracks, in each of which a torque transmitting ball is guided. For a particularly compact design, it is provided that the ratio of rolling circle radius and diameter of the balls is between 3.3 and 5.0.

From the US 6 299 543 B1 is a constant velocity universal joint in the form of a double-offset Verschegelgel joint (DO joint) known. The sliding joint has eight pairs of tracks, in each of which a torque transmitting ball is guided. For a particularly compact construction, it is provided that the ratio of rolling circle radius and diameter of the balls is between 2.9 and 4.5.

From the JP 2010 265 925 A is a constant velocity joint (DO joint) known with six pairs of tracks and torque transmitting balls. It is envisaged that the ratio of pitch radius and diameter of the balls is between 2.5 and 2.8.

From the EP 1 927 775 A1 is a double offset Verschegelgelenk with various ratios of characteristic dimensions known.

From the US Pat. No. 8,070,611 B2 is known a constant velocity joint in the form of a VL joint. The outer joint part has a first group of straight ball tracks and a second group of ball tracks crossing the longitudinal axis. Correspondingly, the inner joint part has a first group of straight ball tracks and a second group of ball tracks crossing the longitudinal axis. Various ratios of characteristic dimensions are exemplified.

From the DE 10 2004 062 843 A1 is known a sliding joint in the form of a VL joint with inner axial stops and integrated intermediate shaft. The outer joint part has outer ball tracks, which form over the circumference alternately equal first crossing angles. Correspondingly, the inner joint part has inner ball tracks that alternately have the same size over the circumference Forming crossing angles. Preferred size ratios of the joint are listed.

From the DE 196 48 537 C1 is a constant velocity universal joint shaft with two identical constant velocity universal joints, which are each designed in the form of sliding joints of the type VL joint.

Depending on the type of drive and load collective of the vehicle (front-wheel drive, rear-wheel drive, four-wheel drive, hang-on drive) define the joint size and main design features of typical constant velocity joints, such as ball diameter, number of balls, rolling circle radius of the balls, outer race diameter, Profilwellenverzahnungsdurchmesser, etc. These in part contradictory demands on durability and breaking strength lead to compromises in construction.

In particular, when used in demand-engageable drive trains have special requirements for constant velocity universal joints in terms of life and breaking strength. In particular, joints for hang-on drives are subject to a significantly different load characteristic compared to permanently driven drive trains.

Proceeding from this, the present invention seeks to propose a constant velocity joint, which is particularly well suited in terms of breaking strength and life for use in a demand-engageable drive train. The object is also to propose a drive shaft with such a constant velocity joint and a corresponding drive train.

A solution consists in a constant velocity universal joint comprising: an outer joint part having a longitudinal axis and exactly six outer ball tracks, an inner joint part having a longitudinal axis and having exactly six inner ball tracks, wherein each one outer ball track and one inner ball track form a track pair with each other, each a torque transmitting ball in each pair of tracks, wherein at least a part number of the balls each have a diameter (D7) and together define a pitch circle diameter (PCD), a ball cage which is disposed between the outer joint part and the inner joint part and circumferentially distributed cage windows, each having at least one of the torque transmitting balls The ratio of the diameter (D7) of the balls and the pitch circle diameter (PCD) of the balls is at least 0.26 and at most 0.31 (0.26 ≤ D7 / PCD ≤ 0.31).

An advantage of the proposed constant velocity joint is that it is particularly small build and inexpensive to produce, but still meets the requirements of the breaking strength and durability when used in the switchable powertrain. In comparison with known joints with six balls results from the inventive ratio of ball diameter (D7) and Kugelrollkreisradius (PCD) a particularly small design of the joint. The cross-sectional area of the cage bars can be increased, which improves the breaking strength of the joint. Overall, the constant velocity joint proposed hereby is particularly suitable for use in an optionally drivable secondary drive train of a motor vehicle, in particular for a secondary drive train driven by an electric motor.

In the present case, the following definitions apply to specific joint-specific details:
The rolling circle radius (PCR) of the balls defines the radius around the center of the joint on which the centers of the balls are located with the joint extended.

The pitch circle diameter (PCD) of the balls defines according to the diameter on which the centers of the balls lie with the joint extended. The pitch circle diameter (PCD) is twice the pitch circle radius (PCR) of the joint (PCD = 2 × PCR).

The pitch circle radius (R17) of the toothing is defined as a mean radius of the shaft toothing between the inner joint part and a shaft toothing to be connected thereto in a rotationally fixed manner.

Accordingly, the pitch circle diameter (D17) of the toothing is defined as the mean diameter of the shaft toothing of the inner joint part.

The diameter (D7) describes the diameter of a ball of the constant velocity joint.

The outer joint part has an outer diameter (D3).

The number (n) of the balls of the constant velocity joint is six according to the invention.

The ring cutting surface (F21) indicates the surface which is defined by a longitudinal section through an annular web of the ball cage, that is by the ball cage in the region of a cage window.

The web section surface (F11) indicates the surface which is formed by a cross section through an axial web lying in the circumferential direction between two cage windows.

The GT factor (GT) of the constant velocity joint is defined as the product of the square of the diameter (D7) of the balls multiplied by the pitch circle radius (PCR) of the balls multiplied by the number (n) of balls which is six, that is GT = D7 ² × PCR × 6. The GT factor for a six-ball joint can also be described by the GTC factor as GT = D7 ² × PCD × 3. The GT factor, also known as the Joint Capacity Factor (JCF) is a factor for the estimation of the life behavior of a joint. With the GT factor, the normal torque of a joint can be determined, which serves as the basis for the lifetime calculations of the joint. The ratio of the GT factor (GT) to the pitch diameter (D17) of the serration reflects the relation between the life and strength of the joint.

Preferably, at least one of the following size ratios applies to the constant velocity joint according to the invention, wherein said size ratios can be realized alone, alternatively or in addition to one another:
The ratio of the diameter (D7) of the balls and outer diameter (D3) of the outer joint part is at least 0.17 (0.17 ≦ D7 / D3).

The ratio of the diameter (D7) of the balls and outer diameter (D3) of the outer joint part is a maximum of 0.21 (D7 / D3 ≤ 0.21).

The ratio of the GT factor (GT) to the tooth diameter (D17) of the shaft toothing of the inner joint part is smaller than 1900 mm ² , preferably smaller than 1500 mm ² .

The ratio of the ring sectional area (F21) of the ball cage to the GT factor (GT) is greater than 0.75 / mm (F21 / GT> 0.75 / mm).

The ratio of the ring sectional area (F21) of the ball cage to the GT factor (GT) is smaller than 1.5 / mm (F21 / GT <1.5 / mm).

The ratio of the land area (F11) of the ball cage to the GT factor (GT) is greater than 0.75 / mm (F11 / GT> 0.75 / mm).

The ratio of the web sectional area (F) of the ball cage to the GT factor (GT) is less than 1.5 / mm (F11 / GT <1.5 / mm).

The ratio of the diameter (D7) of the balls and pitch circle diameter (D17) of the shaft teeth is at least 0.48 (0.48 ≦ D7 / D17), more preferably at least 0.55 (0.55 ≦ D7 / D17).

The ratio of diameter (D7) of the balls and pitch circle diameter (D17) of the shaft toothing is a maximum of 0.72 (D7 / D17 ≤ 0.72), in particular a maximum of 0.65 (D7 / D17 ≤ 0.65).

The mentioned proportions contribute individually or in combination to a particularly compact constant velocity joint, which is particularly suitable for use in the drive train of a demand-engageable drive axle. The conditions concerning the balls and the rolling circle radius advantageously lead to a small, lightweight and therefore inexpensive to produce joint. Overall, the constant velocity joint proposed hereby is therefore particularly well adapted to the requirements in the drive train of an optionally drivable secondary drive axle.

The embodiment of the invention, in particular, a strengthening of the ball cage is achieved, which is in some ways a weak point in terms of the life of a constant velocity joint. The ball cage is given a particularly high breaking strength by the fact that comparatively small balls are used in relation to the rolling circle radius. This results in an enlargement of the web cross sections of the ball cage, which leads to an overall improved breaking strength.

According to a preferred embodiment it is provided that at least some of the outer ball tracks cross the longitudinal axis in radial view and that at least some of the inner ball tracks cross the longitudinal axis in radial view, wherein the angle (α1) under which the outer ball tracks cross the longitudinal axis, and the angle ( α2), under which the inner ball tracks intersect the longitudinal axis are the same size and oppositely directed. Preferably, the angles (α1, α2) are each greater than 11 ° and / or less than 16 °. In this case, the track skew angles for applications in side shafts are particularly preferably 14 ° to 16 ° and for applications in longitudinal drive shafts in particular 11 ° to 14 °. With these values, the cage is particularly relieved, resulting in an increased breaking strength and life of the cage.

A solution of the above object further consists in a drive shaft for use in the drive train of a motor vehicle having at least one inventive constant velocity universal joint. The constant velocity universal joint may have one or more of the above configurations. The drive shaft accordingly offers the same advantages that have been mentioned in connection with the joint, to the description of which reference is made. The joint contributes to an efficient drive shaft, which is particularly light is well adapted to the specific technical requirements.

The drive shaft may be a longitudinal drive shaft connecting a power takeoff unit to an axle differential, or a side shaft drivingly connecting an axle differential to a vehicle wheel. In particular, the drive shaft may also be part of a drive train driven by an electric motor as the drive source.

A solution of the above object is further in a drive train arrangement for a motor vehicle having a permanently drivable primary drive train and an optional switchable secondary drive train, wherein the secondary drive train has a drive shaft according to the invention with a constant velocity joint according to the invention.

It can be provided according to a first possibility that the primary and the secondary drive train are both driven by a common drive source, such as an internal combustion engine. According to a second possibility, it is conceivable that the drive train, which can be driven primarily, is driven by a first drive source, in particular by an internal combustion engine, while the optionally drivable secondary drive train is driven by a second drive source, in particular an electric motor. Such drive concepts are also referred to as hybrid drive.

In both cases, the drive train arrangement is adapted to the technical requirements in an advantageous manner. Thus, the drive train according to the invention for the secondary drive train has a shorter life, but an equally high or even higher breaking strength, as one of the drive shafts of the primary drive train. Due to the higher breaking strength, the joint can withstand the high torque to be transmitted over the entire required service life, which are to be transferred from the electric drive to the vehicle wheels.

Preferred embodiments will be explained below with reference to the drawing figures. Hereby shows:

• a) im Längsschnitt;
• b) weitere Details des Gelenks im Längsschnitt;
• c) schematisch einen Teil der Kugelbahnen in Abwicklung;
• d) den Kugelkäfig als Detail in einem Querschnitt durch die Stege des Kugelkäfigs;

1 an inventive constant velocity universal joint in a first embodiment

• a) in longitudinal section;
• b) further details of the joint in longitudinal section;
• c) schematically a part of the ball tracks in settlement;
• d) the ball cage as a detail in a cross section through the webs of the ball cage;

• a) in dreidimensionaler Darstellung;
• b) im Längsschnitt;
• c) das Gelenkinnenteil als Detail in Axialansicht;
• d) das Gelenkinnenteil als Detail in Radialansicht;

2 a constant velocity universal joint according to the invention in a second embodiment;

• a) in three-dimensional representation;
• b) in longitudinal section;
• c) the inner joint part as a detail in axial view;
• d) the inner joint part as a detail in radial view;

• a) im Längsschnitt;
• b) in Axialansicht;

3 a constant velocity universal joint according to the invention in a third embodiment;

• a) in longitudinal section;
• b) in axial view;

4 an inventive drive shaft with a constant velocity universal joint according to the invention 2 in longitudinal section.

The 1a to 1e , which will be described together below, show a constant velocity universal joint according to the invention 2 in a first embodiment. The constant velocity universal joint 2 comprises an annular outer joint part 3 with outer ball tracks 4 , a hub-shaped inner joint part 5 with inner ball tracks 6 , torque transmitting balls 7 , in pairs of tracks each consisting of an outer and an inner ball track 4 . 6 are guided, as well as a ball cage 8th with circumferentially distributed windows 9 in which the bullets 7 are included. The constant velocity joint is designed in the form of a sliding joint, which in addition to angular movements between the inner joint part 5 and outer joint part 3 also allows axial relative movements.

From the outer ball tracks 4 each have first ball tracks 4 _{1 seen} over the circumference a first crossing angle α1 and second ball tracks 4 ₂ have an equal opposite crossing angle α2 to the longitudinal axis A3 of the outer joint part 3 on. From the inner ball tracks 6 each have first ball tracks 6 _{1 seen} over the circumference a first crossing angle β1 and second ball tracks 6 ₂ have an equal opposite crossing angle β2 to the longitudinal axis A5 of the inner joint part 5 on. When the joint is stretched 2 fall the longitudinal axes A3, A5 of the outer joint part 3 and the inner joint part 5 together.

Intersecting outer and inner ball tracks 4 ₁ , 6 ₁ ; 4 ₂ , 6 ₂ are distributed over the circumference associated with each other in pairs, wherein each of the crossing angles α1, β1; α2, β2 relative to the longitudinal axis A3, A5 of the elongated joint in the individual pairs are equal in size and opposite plotted. This is the control function of the ball tracks 4 . 6 for each of balls received by pairs of tracks 7 ensured, each with its center at the intersection of the center lines of the railway pairs. The ball tracks 4 . 6 each run helically around the respective longitudinal axis A3, A5, or viewed in settlement straight. Due to the V-shaped structure of the outer or inner ball tracks considered in settlement 4 ₁ , 6 ₁ ; 4 ₂ , 6 ₂ , these types of joints are also referred to as VL joints (sliding joint Löbro). In the VL joint according to the invention, the angles α1, β1; α2, β2 each greater than 11 ° and / or less than 16 °.

The outer joint part 3 has an inner cylindrical guide surface 12 for guiding the ball cage 8th , The ball cage 8th viewed in longitudinal section has a roof-shaped cage outer surface 10 so that it angular movements relative to the inner cylindrical guide surface 12 of the outer joint part 3 can perform, as well as a cylindrical cage inner surface 14 with which he is on an outer guide surface 13 of the inner joint part 5 is guided. As in particular in 1d it can be seen, the cage windows 9 in the circumferential direction of extending in the axial direction webs 11 limited. These axial webs 11 connect two ring bridges 21 of the ball cage 8th ,

The roof-shaped guide surface 13 of the inner joint part 5 is composed of a central spherical surface section and on both sides tangentially adjoining conical surface sections. With the guide surface 13 is the inner joint part 5 opposite the inner surface 14 of the ball cage 8th guided. Furthermore, on the inner joint part 5 a central opening 15 provided with an internal spline into which a shaft journal 16 with an opposite outer shaft toothing 17 is plugged in for torque transmission. For axial securing of the inner joint part 5 on the shaft journal 16 is a circlip 18 provided in an inner annular groove of the inner joint part 5 and an outer annular groove of the journal 17 intervenes.

The shaft journal 17 is part of a drive shaft which serves to transmit torque in the drive train of a motor vehicle. The drive shaft may be designed as a longitudinal drive shaft, which is used for power transmission between a drive unit and an axle differential, or as a side shaft, which serves for transmitting power from an axle differential to a vehicle wheel. In any case, the drive shaft is preferably used in an optionally switchable drive train of the motor vehicle having a permanently driven example of an internal combustion engine primary drive axle and a, for example, by an electric motor on demand switchable second drive axle.

The joint space between the outer joint part 3 and inner joint part 5 is on the shaft side by means of a sealing arrangement 18 sealed. The seal arrangement 18 includes a connection cap 19 , with the outer joint part 3 connected and opposite this by means of a ring seal 20 is sealed, a sealing bellows 22 and two tension bands 23 . 24 for fixing the sealing bellows 22 , The sealing bellows 22 has a larger first fret 25 , by means of the first tension band 23 on an outer seat of the connection cap 19 is fixed, a smaller second fret 26 , by means of the second tension band 24 on the shaft journal 16 is fixed, and a between the two coils extending bellows section, with which the sealing bellows 22 axial movements of the outer joint part 3 relative to the inner joint part 5 can compensate. The bellows section comprises several folds, which is why the sealing bellows can also be referred to as a bellows.

The outer joint part 3 has on the side opposite the sealing bellows following the ball tracks 4 a molded sleeve portion 28 for connecting the outer joint part 3 with a connection component (not shown), for example a hollow shaft. Connecting the outer joint part 3 with the connection component can be done for example by means of friction welding. In the direction of the connection component is the joint space by means of a floor 29 completed, which at the same time a stop surface for the inner joint part 5 can form.

In 1c a development of the sliding joint in the ball tracks is shown schematically. Here are the outer joint part shown by solid lines 3 and the inner joint part indicated by dashed lines 5 superimposed. In the outer joint part 3 are the first outer ball tracks 4 ₁ , which include the first crossing angle α1 with the longitudinal axis A3, and the second outer ball tracks 4 ₂ , which form with the longitudinal axis A3 the same opposite directional crossing angle α2. The inner joint part 5 is analogous to first inner ball tracks 6 ₁ and second inner ball tracks 6 ₂ , which also form the same size but oppositely directed crossing angle β1, β2 with the longitudinal axis A5. The from the ball cage 8th balls held in a common plane M. 7 are here as first balls 7 ₁ and second balls 7 ₂ differentiated. Due to the intersecting ball tracks 4 . 6 every track pair gets on the balls 7 exerted an axial force during torque transmission. The first bullets 7 ₁ exerted axial force is directed in each case opposite to that on the second balls 7 ₂ applied axial force. The mentioned axial forces has the ball cage 8th counteract the bullets 7 in the common plane M should hold. The axial forces themselves reverse each other in reversing the torque direction in the opposite axial direction. This is where the balls lie 7 each at a lateral edge of the respective cage window 9 at.

The following details the geometric features of the constant velocity universal joint according to the invention 2 received. The above definitions apply to individual sizes of the joint. It is envisaged that the ratio of diameter D7 of the balls 7 and pitch circle radius PCD of the balls 7 is at least 0.26 and / or at most 0.31 (0.26 ≤ D7 / PCD ≤ 0.31), preferably at most 0.30. In this embodiment, the balls 7 in relation to the pitch circle diameter PCD relatively small. So has the ball cage 8th relatively large sectional areas of the ring lands 21 (viewed in longitudinal section through the cage) and in the circumferential direction between two windows 9 lying axial webs 11 (viewed in cross-section through the cage). This results in a total of relatively large web surfaces, which in turn leads to a high breaking strength of the ball cage 8th and thus of the joint 2 leads.

Also, each lying in the circumferential direction between two ball tracks web portions of the outer joint part 3 are improved by the inventive design. This can be used for radial space reduction, so that with a constant tooth size of the inner joint part 5 , which defines a measure of the strength of a propeller shaft, a much more compact joint can be designed. In particular, the constructive use of relatively small balls in sliding joints of the type VL with inclined ball tracks (helix) allows an overall increased displacement range.

Continue to apply to the constant velocity joint 2 preferably one or more of the following proportions: The ratio of diameter D7 of the balls 7 and outer diameter D3 of the outer joint part 3 is at least 0.17 (0.17 ≤ D7 / D3). The ratio of diameter D7 of the balls 7 and outer diameter D3 of the outer joint part 3 is a maximum of 0.21 (D7 / D3 ≤ 0.21). The ratio of the GT factor (GT) to the gearing diameter D17 of the shaft gearing 17 of the inner joint part 5 is less than 1900 mm ² , preferably less than 1500 mm ² . The ratio of the ring interface F21 of the ball cage 8th GT factor (GT) is greater than 0.75 / mm (F21 / GT> 0.75 / mm). The ratio of the ring interface F21 of the ball cage 8th to GT factor (GT) is less than 1.5 / mm (F21 / GT <1.5 / mm). The ratio of the web section F11 of the ball cage 8th GT factor (GT) is greater than 0.75 / mm (F11 / GT> 0.75 / mm). The ratio of the web section F11 of the ball cage 8th GT factor (GT) is less than 1.5 / mm (F11 / GT <1.5 / mm). The ratio of diameter D7 of the balls 7 and pitch circle diameter D17 of the shaft toothing 17 is at least 0.48 (0.48 ≤ D7 / D17), in particular at least 0.55 (0.55 ≤ D7 / D17). The ratio of ball diameter D7 and pitch circle diameter D17 of the shaft toothing 17 is a maximum of 0.72 (D7 / D17 ≤ 0.72), in particular a maximum of 0.65 (D7 / D17 ≤ 0.65). The mentioned proportions contribute individually or together to a small, lightweight and therefore inexpensive to produce joint.

The 2a to 2d , which will be described together below, show a constant velocity universal joint according to the invention 2 in a second embodiment. The present constant velocity joint 2 corresponds largely to the in 1 shown joint, so that in terms of the similarities to the above description reference is made. The same or corresponding details are provided with the same reference numerals as in the 1a to 1d , The following is essentially based on the differences in the joint 2 towards the joint 1 received.

A first difference is that the present sliding joint 2 according to the 2a to 2d has a slightly shorter axial displacement than the joint to 1 , This is due to the shorter outer ball tracks 4 of the outer joint part 3 , or the shorter inner ball tracks 6 of the inner joint part 5 recognizable. Accordingly, the outer joint part 3 , the inner joint part 5 as well as the cage 8th , and therefore the entire joint 2 , a shorter axial length. Another special feature of the present joint 2 is that the outer joint part 3 bell-shaped with a bottom 29 and a shaft journal formed thereon 30 is designed. The shaft journal 30 has a serration at the end 31 , which can be plugged into a corresponding counter-toothing of a connection component for torque transmission. Incidentally, the joint corresponds 2 according to the 2a to 2d the joint according to the 1a to 1d , whose description is referred to avoid repetition. In particular, also apply to the present Verschegelegelenk 2 the above-mentioned size ratios according to the invention.

The 3a and 3b , which will be described together below, show a constant velocity universal joint according to the invention 2 in a further embodiment. The present constant velocity joint 2 corresponds largely to the in the 1 and 2 shown joints, so that reference is made to the above description in terms of similarities. The same or corresponding details are provided with the same reference numerals as in the 1a to 1d respectively 2a to 2d , The following will mainly refer to the differences in the present joint 3 compared with the joints described above.

A special feature of the sliding joint 2 according to the 3a and 3b is that this is designed as a so-called disc joint, that is, that the outer joint part 3 is disc-shaped. For driving connection with a flange, such as a transmission, the outer joint part has 3 a plurality of circumferentially distributed through holes 32 , through which screws (not shown) can be pushed through for connection to the connecting flange. It can be seen that the through holes 32 in the circumferential direction in each case between two adjacent outer ball tracks 4 are arranged, resulting in a compact size of the outer joint part 3 contributes. The present sliding joint 2 according to the 3a and 3b has, as the joint according to 2 , a relatively short axial displacement. This in turn is due to the short outer ball tracks 4 of the outer joint part 3 , or inner ball tracks 6 of the inner joint part 5 recognizable. Incidentally, the joint corresponds 2 according to the 3a and 3b the joints according to the 1 and 2 , whose description is referred to avoid repetition. In particular, also apply to the present Verschegelegelenk 2 according to 3 the above-mentioned size ratios according to the invention.

The constant velocity universal joints described above are each type VL sliding joints. However, it is understood that the inventive design also applies to any other ball synchronous joints, in particular sliding joints of the type DO (double offset), but also fixed joints, for example of the type AC (Angular Contact), UF (Undercut Free) or counter-track joints, and these should include.

The 4 shows a drive shaft according to the invention 33 with two substantially identical constant velocity universal joints 2 . 2 ' and a wave shaft connecting them together 34 , The two end joints are each in the form of a constant velocity joint according to the invention 2 . 2 ' according to the 2a to 2d designed. In this respect, reference is made to avoid repetition to the above description of the joints. The same details are provided with the same reference numerals as in the 1 to 3 , wherein the reference numerals of one of the two joints are provided with indices. The drive shaft 33 , which may also be referred to as a propeller shaft, is used in particular as a side shaft to transmit torque from a transaxle to a vehicle wheel.

The inner joint parts 5 . 5 ' are each rotationally fixed with the end-side splines 17 . 17 ' of the wave shaft 34 connected and fixed axially by means of axial securing rings. The outer joint parts 3 . 3 ' each are each bell-shaped and have a molded shaft journal 30 . 30 ' for connection to an axle differential or a wheel hub of the motor vehicle.

An advantage of the drive shaft according to the invention 33 is that these due to the relatively small constant velocity universal joints 2 . 2 ' has a particularly low weight and can be produced inexpensively. At the same time the drive shaft fulfills 33 the requirements for breaking strength and service life when used in an optionally connectable drive train. Because by the time-reduced use of the drive shaft 33 in an optional switchable powertrain the life requirements are lower. In contrast, especially in electric motor-driven secondary drive axles, particularly high demands on the breaking strength of the constant velocity joints. Here provides the drive shaft according to the invention 33 with the constant velocity universal joints according to the invention 2 . 2 ' a particularly effective solution to help reduce weight and fuel consumption.

LIST OF REFERENCE NUMBERS

2

CVJ

3

Outer race

4

outer ball track

5

Inner race

6

inner ball track

7

Bullet

8th

ball cage

9

cage window

10

outer surface

11

web

12

palm

13

outer surface

14

palm

15

opening

16

shaft journal

17

shaft splines

18

sealing arrangement

19

connection cap

20

ring seal

21

ring section

22

sealing bellows

23

strap

24

strap

25

first fret

26

second fret

28

sleeve extension

29

ground

30

shaft journal

31

shaft splines

32

Through holes

33

drive shaft

34

spindle shaft

A

longitudinal axis

D

diameter

F

area

GT

GT-factor

PCD

Pitch diameter

PCR

Pitch circle radius

R

radius

α

angle

β

angle

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19919454 A1 [0003]
• DE 102008037886 A1 [0004]
• DE 202004021771 U1 [0007]
• EP 0802341 A2 [0008]
• US 6299543 B1 [0009]
• JP 2010265925A [0010]
• EP 1927775 A1 [0011]
• US 8070611 B2 [0012]
• DE 102004062843 A1 [0013]
• DE 19648537 C1 [0014]

Claims (10)

Constant rotation joint comprising: an outer joint part ( 3 ) with a longitudinal axis (A3) and with exactly six outer ball tracks ( 4 ), an inner joint part ( 5 ) with a longitudinal axis (A5) and with exactly six inner ball track (A5) 6 ), wherein in each case an outer ball track ( 4 ) and an inner ball track ( 6 ) a pair of tracks ( 4 . 6 ), in each case a torque-transmitting ball ( 7 ) in each pair of tracks ( 4 . 6 ), wherein at least a part number of the balls ( 7 ) each have a diameter (D7) and together define a pitch circle diameter (PCD), a ball cage ( 8th ), which between the outer joint part ( 3 ) and the inner joint part ( 5 ) and circumferentially distributed cage windows ( 9 ) each having at least one of the torque transmitting balls ( 7 ), characterized in that the ratio of diameter (D7) of the balls ( 7 ) and pitch circle diameter (PCD) of the balls ( 7 ) is at least 0.26 and at most 0.31 (0.26 ≤ D7 / PCD ≤ 0.31). A constant velocity universal joint according to claim 1, characterized in that the ratio of the diameter (D7) of the balls ( 7 ) and outer diameter (D3) of the outer joint part ( 3 ) is at least 0.17 and / or at most 0.21 (0.17 ≤ D7 / D3 ≤ 0.21). A constant velocity universal joint according to claim 1, characterized in that a GT factor (GT) is defined diameter (D7) of the balls ( 7 ) squared times the pitch radius (PCR) of the balls ( 7 ) multiplied by the number of balls ( 7 ), which is six (GT = D7 ² × PCR × 6), where the ratio of the GT factor to the tooth diameter (D17) of the spline ( 17 ) of the inner joint part ( 5 ) is smaller than 1900 mm ² , preferably smaller than 1500 mm ² . A constant velocity universal joint according to any one of claims 1 to 3, characterized in that a section through a ring land ( 21 ) of the ball cage ( 8th ) a ring interface (F21) of the ball cage ( 8th ), wherein the ratio of the ring cut surface (F21) of the ball cage ( 8th ) to the GT factor (GT) is at least one of greater than 0.75 / mm (F21 / GT> 0.75 / mm) and less than 1.5 / mm (F21 / GT <1.5 / mm). A constant velocity universal joint according to any one of claims 1 to 4, characterized in that a section through an axial web ( 11 ) of the ball cage ( 8th ) a web section surface (F11) of the ball cage ( 8th ), wherein the ratio of the web section surface (F11) of the ball cage ( 8th ) to the GT factor (GT) is at least one of greater than 0.75 / mm (F11 / GT> 0.75 / mm) and less than 1.5 / mm (F11 / GT <1.5 / mm). A constant velocity universal joint according to any one of claims 1 to 5, characterized in that the ratio of the diameter (D7) of the balls ( 7 ) and toothing diameter (D17) of the shaft toothing ( 17 ) of the inner joint part ( 5 ) is at least 0.48 and at most 0.72 (0.48 ≤ D7 / D17 ≤ 0.72), in particular at least 0.55 and at most 0.65 (0.55 ≤ D7 / D17 ≤ 0.65). A constant velocity universal joint according to one of the preceding claims, characterized in that at least some of the outer ball track ( 4 ) the longitudinal axis (A3) of the outer joint part ( 3 ) in radial view and that at least some of the inner ball track ( 6 ) the longitudinal axis (A5) of the inner joint part ( 5 ) in radial view, the angles (α1) below which the outer ball tracks ( 4 ) intersect the longitudinal axis (A3) and the angles (α2) at which the inner ball tracks ( 6 ) cross the longitudinal axis (A5), are of the same size and directed in opposite directions. A constant velocity universal joint according to claim 7, characterized in that the angles (α1, α2) amount to between 11 ° and 16 °. Drive shaft for use in the drive train of a motor vehicle, characterized by a constant velocity universal joint ( 2 ) according to one of claims 1 to 8. Drive train arrangement of a motor vehicle comprising a permanently drivable primary drive train and an optionally switchable secondary drive train, characterized in that the secondary drive train is a drive shaft ( 33 ) according to claim 9.

Images