DE102017221603B4 - Lateral drive shaft of a drive train of a motor vehicle with an external constant velocity joint - Google Patents

Abstract

Lateral drive shaft (6) of a drive train which can be connected to a transmission output shaft (4) of a drive unit (1) via an internal constant velocity joint (5) and is connected to a steerable wheel (9) via an external constant velocity joint (7) and in which the external constant velocity joint (7) comprises an inner hub (17), - the inner hub (17) is arranged and mounted on the side drive shaft (6) in a rotationally fixed manner, and - the inner hub (17) laterally from two mutually spaced end faces (17a, 17b) is limited, characterized in that both end faces (17a, 17b) have at least one recess (16) of the same shape, which is a fully circumferential and annular groove (16a).

Description

• - die Innennabe auf der seitlichen Antriebswelle drehfest angeordnet und gelagert ist, und
• - die Innennabe seitlich von zwei zueinander beabstandeten Stirnflächen begrenzt ist.

The invention relates to a lateral drive shaft of a drive train which can be connected to a transmission output shaft of a drive unit via an internal constant velocity joint and is connected to a steerable wheel via an external constant velocity joint and in which the external constant velocity joint comprises an inner hub, wherein

• - The inner hub is arranged on the side drive shaft in a rotationally fixed manner, and
• - The inner hub is laterally delimited by two mutually spaced end faces.

A side drive shaft of the type described above, for example, describe the German patent application DE 27 02 940 A1 as well as the German published application DE 199 05 451 A1 . The German published application DE 38 04 922 A1 has the object of an arrangement in a power transmission, wherein the homokinetic joint described has depressions, thanks to which a second bearing and the end of a fastening body can be installed, ie placed, within the joint.

In the beginning, the development work in the context of vehicle acoustics focused exclusively on noise reduction. The focus was initially on the internal combustion engine as the dominant noise source of the motor vehicle and later also on the auxiliary units as noise sources, which make a significant contribution to the overall noise emission.

Attempts are increasingly being made not only to reduce the noise caused by the motor vehicle, but also to influence or use it in a targeted manner, which is also commonly referred to as noise design or sound design. This development work is motivated by the knowledge that the purchase decision of a potential customer when purchasing a vehicle is not insignificantly influenced by the noise of the internal combustion engine or the vehicle. For example, the driver of a sports car prefers a vehicle or an engine whose noise emphasizes the sporty character of the vehicle.

Airborne noise sources and structure-borne noise sources can basically be distinguished as noise sources on a motor vehicle.

The airborne sound sources include, for example, the intake noise, the exhaust outlet noise and the fan noise of the radiator, whereas the structure-borne noise sources include, in particular, the drive train connected to the body via the engine mount and the rolling and also mounted tires on the body.

The engine structure, which is stimulated by structure-borne vibrations and alternating forces, emits structure-borne noise as airborne noise via its engine surfaces and thus generates the actual engine noise.

The most important components with shock and force excitation are the crankcase, the cylinder block, the cylinder head, the crank mechanism, the piston and the valve train. These components are exposed to the mass and gas forces.

The crankshaft, together with the engine parts coupled to it, forms an oscillatory system. Here, the crankshaft is excited to torsional vibrations by the temporally changing rotational forces which are introduced into the crankshaft via the connecting rods articulated on the individual crankpins. The torsional vibrations of the crankshaft lead to both noise due to structure-borne noise and noise due to the introduction of structure-borne noise into the body and into the internal combustion engine.

Excitation of the crankshaft in the natural frequency range can result in high torsional vibrations, which can even lead to fatigue failure.

Due to the high dynamic loading of the crankshaft by the mass and gas forces, the designers endeavor to design the internal combustion engine as far as possible, i.e. to realize optimized mass balancing. All measures that compensate or reduce the effect of the mass forces on the outside are summarized under mass balancing. In this context, the cranking of the crankshaft, the number and arrangement of the cylinders and the firing order of the individual cylinders are selected in such a way that the most optimal possible mass balance is achieved.

The torsional vibrations of the crankshaft lead to fluctuations in the speed of the internal combustion engine and are also transmitted to the camshaft via the control drive or camshaft drive, the camshaft itself also constituting an oscillatory system and can excite further systems, in particular the valve train, to vibrate.

It is also possible to introduce vibrations into other ancillary units via traction drives driven by the crankshaft. In addition, the vibrations of the crankshaft are introduced into the drive train, via which one Forwarding into the transmission and the drive shafts down to the tires of a vehicle can take place.

To reduce speed fluctuations, the mass of the oscillatory system is increased by arranging a flywheel on the crankshaft. Due to the larger mass, the system has an increased inertia. The rotation of the crankshaft becomes more uniform.

If the flywheel, which is usually attached to the crankshaft on one side and connected to the transmission via the clutch on the other side, is designed as a dual-mass flywheel, the flywheel also takes on the function of a vibration damper, which detects the torsional vibrations between the clutch and drive reduces.

To dampen the torsional vibrations of the crankshaft or in the drive train, torsional vibration dampers, i.e. Torsional vibration damper can be provided. As a result of a relative movement of the mass of the vibration damper to the crankshaft, part of the torsional vibration energy is reduced by friction work.

The development work regarding the noise reduction of the engine has led to the fact that the noise component of the engine, i.e. the actual engine noise steadily decreased. Modern motor vehicles are usually equipped with very smooth-running internal combustion engines, the operating noise of which is barely perceptible in the vehicle interior, or may even be drowned out by other noises such as the noise of the rolling wheels, ventilation or the like.

Of particular importance for the acoustic driving comfort is - in addition to the structure-borne noise introduction via the engine mounting - the structure-borne noise introduction via the side drive shafts into the mounting and suspension of the tires or wheels and from there into the body. The vibrations entered via the side drive shafts can be perceived by the driver of the motor vehicle in individual cases on the steering wheel and in the seat. This affects comfort in a particularly disadvantageous manner.

The vibration behavior or noise behavior when idling an internal combustion engine with an automatic transmission is particularly problematic in this context.

The German patent specification DE 33 18 449 C2 deals with the above problem; as well as the present invention. 1 shows a section of the drive train of a motor vehicle, namely the storage 13 , 14 and suspension 15 a steerable wheel 9 on the body 2nd together with the associated side drive shaft 6 .

A drive unit is shown 1 a front wheel drive motor vehicle using rubber buffers 3rd as an engine mount on the chassis 2nd is stored. On each side of the drive unit 1 is a gearbox output shaft 4th arranged transversely, which has an internal constant velocity joint 5 with a side drive shaft 6 connected is. The side drive shaft 6 is in turn via an external constant velocity joint 7 with a journal 8th connected, which is a steerable wheel 9 picks up and drives.

The journal 8th turns in a steering knuckle 10th which has an upper and a lower ball joint 11 , 12th at the outer end of two wishbones 13 , 14 is pivotally mounted. At their inner ends are the two wishbones 13 , 14 articulated on the chassis 2nd attached. Between the upper wishbones 13 and the chassis 2nd is a suspension and suspension device 15 arranged.

The internal constant velocity joint 5 is used regularly as a tripod sliding joint 5 formed, which comprises a tripode and a tulip. The axial displaceability of the tripod joint 5 prevents axial vibrations (see double arrow f) from entering the side drive shaft 6 or filters out the vibrations in the axial direction.

Radial vibrations of the transmission output shaft 4th are, however, via the internal constant velocity joint 5 unimpeded, ie unfiltered into the side drive shaft 6 initiated. These radial vibrations (see arrows F ) are from the rigid side drive shaft 6 from the internal constant velocity joint 5 to the outer constant velocity joint on the wheel side 7 dynamically transmitted and arrive via the journal 8th , the steering knuckle 10th and the wishbones 13 , 14 in the chassis 2nd . Some of these vibrations are transmitted to the steering wheel and the driver's seat and are perceived by the driver. This affects comfort in a particularly disadvantageous manner.

The DE 33 18 449 C2 proposes measures to solve the problems outlined above, which are intended to prevent the radial vibrations of the journal 8th to reach. This means that the transmission path and the transmission of the radial vibrations are influenced.

The aim should be to include the assembly with the side drive shaft 6 as well as the one with the drive shaft 6 connected parts, such as the tripod of the interior Constant velocity joint 5 to give a certain mass distribution, thereby dynamically decoupling the two constant velocity joints 5 , 7 should be achieved.

Against the background of what has been said above, it is the object of the present invention to provide a lateral drive shaft of a drive train according to the preamble of claim 1, with which the radial vibrations introduced into the wheel suspension or wheel bearing and the body or the forces causing these vibrations are at least reduced, possibly eliminated.

• - die Innennabe auf der seitlichen Antriebswelle drehfest angeordnet und gelagert ist, und
• - die Innennabe seitlich von zwei zueinander beabstandeten Stirnflächen begrenzt ist,

und die dadurch gekennzeichnet ist, dass

• - beide Stirnseiten mindestens eine formgleiche Ausnehmung aufweisen, die eine vollumfänglich verlaufende und ringförmig ausgebildete Nut ist.

This object is achieved by a side drive shaft of a drive train which can be connected to a transmission output shaft of a drive unit via an internal constant velocity joint and is connected to a steerable wheel via an external constant velocity joint and in which the external constant velocity joint comprises an inner hub, wherein

• - The inner hub is arranged on the side drive shaft in a rotationally fixed manner, and
• the inner hub is laterally delimited by two spaced end faces,

and which is characterized in that

• - Both end faces have at least one recess of the same shape, which is a fully circumferential and ring-shaped groove.

The inner hub of the outer constant velocity joint, which is arranged on the wheel side on the side drive shaft and is mounted on it in a rotationally fixed manner, has, according to the invention, a recess or a plurality of recesses on each of the two end faces.

By making a recess, i.e. material removal into the regularly flat end face, the bending stiffness of the inner hub is specifically reduced. I.e. the inner hub becomes more flexible due to material removal, i.e. more elastic and gives more clearly under load when radial forces from the gearbox, i.e. via the gearbox output shaft and the side drive shaft into the inner hub of the external constant velocity joint. The less rigid or less rigid inner hub according to the invention transmits the radial forces that are responsible for the radial vibrations less dynamically.

The lower the bending stiffness of the side drive shaft or the inner hub, the lower the transmitted radial forces that are introduced into the wheel via the external constant velocity joint and into the body via suspension and, in individual cases, to the steering wheel and the driver's seat .

The object on which the invention is based is thus achieved, namely a lateral drive shaft is provided with which the radial vibrations introduced into the wheel suspension or wheel bearing and the body or the forces causing these vibrations are at least reduced, if necessary eliminated.

According to the invention, both end faces have at least one recess of the same shape. The same shape in the above context means that the recesses are the same in shape, i.e. in shape, but also the dimensions are identical.

This supports the efforts to form or provide an inner hub that is as symmetrical as possible. This contributes to the symmetry of the inner hub. This results in particular advantages under load, namely a more uniform distribution of the load over the entire inner hub and a more uniform deformation of the hub.

According to the invention, the at least one recess of the same shape is annular, the at least one annular recess being a circumferential groove.

I.e. the at least one recess completely surrounds the inner hub, i.e. over 360 °. I.e. the recess extends over the entire circumference of the inner hub, specifically around the longitudinal axis of the inner hub.

Among other things, this offers advantages in the manufacture of the inner hub, in particular when introducing the recess or the groove; for example on a lathe.

A full circumferential annular groove also has the advantage that it does not introduce any imbalance into the inner hub. A groove is rotationally symmetrical with respect to the longitudinal axis of the inner hub or the axis of rotation of the drive shaft.

Radial vibrations can occur in particular in motor vehicles with automatic transmissions that are stationary and in which the transmission is in the shift position " D "Is located. Then the side drive shafts, which are provided on both sides of the transmission and connect the transmission to the wheels, exert forces on the drive unit which generate a moment about the roll axis and have a vertical or radial force component.

Further advantageous embodiments of the side drive shaft are described below in connection with the subclaims.

Embodiments of the side drive shaft are advantageous in which the two mutually spaced end faces are aligned transversely to the side drive shaft.

In the context of the present invention, an end face is aligned transversely to the drive shaft if the end face forms an acute angle α 90 90 ° with the longitudinal axis of the drive shaft.

Since the inner hub of the outer constant velocity joint is arranged on the side drive shaft in a rotationally fixed manner and rotates with the rotating drive shaft, the longitudinal axis of the inner hub runs regularly coaxially with the longitudinal axis of the drive shaft. An end face oriented transversely to the drive shaft consequently also forms an acute angle α 90 90 ° with the longitudinal axis of the inner hub.

Embodiments of the side drive shaft are advantageous in which the two mutually spaced end faces are aligned perpendicular to the side drive shaft. An end face oriented perpendicular to the drive shaft forms a right angle α = 90 ° with the longitudinal axis of the side drive shaft or the inner hub.

Embodiments of the lateral drive shaft are advantageous in which the fully circumferential annular groove is rounded in the groove base, i.e. has no sharp edges and transitions.

Embodiments of the lateral drive shaft are advantageous in which the external constant velocity joint comprises a plurality of balls arranged in a cage. The balls serve as rolling elements for the mobility of the bearing, but also for power transmission.

In this context, embodiments of the lateral drive shaft are advantageous, in which the outer constant velocity joint is a Rzeppa joint which comprises an inner hub and an outer hub, the balls being arranged between the inner hub and the outer hub.

When using balls in the joint, embodiments of the lateral drive shaft can be advantageous in which the balls each have at least one further recess. This makes the balls more flexible or elastic.

When using balls in the joint, embodiments of the lateral drive shaft in which the balls each have at least one continuous channel are also advantageous.

Embodiments of the lateral drive shaft in which the balls each have at least one bore are advantageous. A bore has particular manufacturing advantages, i.e. the introduction of the recess or the channel.

Embodiments of the lateral drive shaft are advantageous in which the internal constant velocity joint is a tripod sliding joint.

This embodiment offers advantages with regard to the introduction of axial vibrations into the drive shaft. The axial displaceability of the tripod joint namely prevents the introduction of axial vibrations into the side drive shaft or filters out these vibrations in the axial direction; at least as long as the joint is not blocked and axially displaceable.

• 1 schematisch die Lagerung und Aufhängung eines lenkbaren Rades an der Karosserie mitsamt der seitlichen Antriebswelle sowie der Antriebseinheit gemäß der DE 33 18 449 C2 , und
• 2 schematisch eine erste Ausführungsform der seitlichen Antriebswelle eines Antriebsstranges mitsamt dem außenliegenden Gleichlaufgelenk sowie dem Achszapfen.

The invention is explained below using an exemplary embodiment and according to FIGS 1 and 2nd described in more detail. It shows:

• 1 schematically the storage and suspension of a steerable wheel on the body together with the side drive shaft and the drive unit according to the DE 33 18 449 C2 , and
• 2nd schematically shows a first embodiment of the side drive shaft of a drive train together with the external constant velocity joint and the journal.

1 has already been discussed in connection with the prior art, which is why reference is made here to the corresponding statements.

2nd shows schematically a first embodiment of the side drive shaft 6 a drive train together with the external constant velocity joint 7 as well as the journal 8th .

It is only meant to supplement 1 are executed, for which reason reference is otherwise made to 1 and the associated description. The same reference numerals have been used for the same components.

The side drive shaft 6 is in the installation position via an internal constant velocity joint 5 with a transmission output shaft 4th connected to a drive unit and can by means of a transmission output shaft 4th be rotated.

Via an external constant velocity joint 7 is the drive shaft 6 connected to a steerable wheel, the wheel of an axle pin 8th is recorded.

The external constant velocity joint 7 is a Rzeppa joint in the present case 7a which is an inner hub 17th and an outer hub 18th includes as well as a variety of balls 19th in a cage, not shown, between the inner hub 17th and the outer hub 18th being held. In the present case the outer hub 18th from a bell 20th formed in one piece with the journal 8th is formed.

The inner hub 17th is on the wheel side on the side drive shaft 6 arranged and rotatably on the drive shaft 6 stored so that the inner hub 17th with a rotating drive shaft 6 rotates or rotates with. The longitudinal axis 17c the inner hub 17th runs coaxial to the longitudinal axis 6a the drive shaft 6 . The inner hub is against axial displacement 17th using the Seeger ring 21 on the drive shaft 6 secured.

The inner hub is on the side 17th of two mutually spaced end faces 17a , 17b limited, the present perpendicular to the drive shaft 6 are aligned and with the longitudinal axis 6a the side drive shaft 6 or the inner hub 17th form a right angle α = 90 °.

Both faces 17a , 17b have a recess 16 in the form of a full circumferential annular groove 16a on, the bottom of the groove being rounded or rounded. Ie the groove 16a extends over the entire circumference of the inner hub 17th , ie over 360 °, specifically around the longitudinal axis 17c the inner hub 17th around.

This execution of the recess 16 offers manufacturing advantages, with the introduction of an unbalance into the hub 17th is avoided.

The grooves are present 16a of identical shape, ie of the same shape or form, and of identical dimensions.

Reference list

1

Drive unit

2nd

Body, chassis

3rd

Engine mounts, rubber buffers

4th

Transmission output shaft

5

internal constant velocity joint, tripod sliding joint

6

side drive shaft

6a

Longitudinal axis of the side drive shaft

7

external constant velocity joint

7a

Rzeppa joint

8th

Axle journal

9

Wheel, steerable wheel

10th

Steering knuckle

11

upper ball joint

12th

lower ball joint

13

upper wishbone

14

lower wishbone

15

Suspension device, suspension device

16

Recess

16a

Groove

17th

Inner hub

17a

first face of the inner hub

17b

second face of the inner hub

17c

Longitudinal axis of the inner hub

18th

Outer hub

19th

Bullet

20th

Bell jar

21

Seeger ring

Claims (6)

Lateral drive shaft (6) of a drive train which can be connected to a transmission output shaft (4) of a drive unit (1) via an internal constant velocity joint (5) and is connected to a steerable wheel (9) via an external constant velocity joint (7) and in which the external constant velocity joint (7) comprises an inner hub (17), wherein - the inner hub (17) is arranged and mounted on the side drive shaft (6) in a rotationally fixed manner, and - the inner hub (17) laterally from two mutually spaced end faces (17a, 17b) is limited, characterized in that - both end faces (17a, 17b) have at least one recess (16) of the same shape, which is a fully circumferential and ring-shaped groove (16a). Lateral drive shaft (6) after Claim 1 , characterized in that the two mutually spaced end faces (17a, 17b) are aligned transversely to the lateral drive shaft (6). Lateral drive shaft (6) after Claim 1 or 2nd , characterized in that the two mutually spaced end faces (17a, 17b) are aligned perpendicular to the lateral drive shaft (6). Lateral drive shaft (6) according to one of the preceding claims, characterized in that the annular groove (16a), which runs completely around the circumference, is rounded in the groove base. Lateral drive shaft (6) according to one of the preceding claims, characterized in that the external constant velocity joint (7) comprises a plurality of balls (19) arranged in a cage. Lateral drive shaft (6) after Claim 5 , characterized in that the external constant velocity joint (7) is a Rzeppa joint (7a) which comprises the inner hub (17) and an outer hub (18), the balls (19) between the inner hub (17) and the outer hub (18) are arranged.

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