DE102007042762A1 - Apparatus and method for reducing rattle noise in a gear transmission - Google Patents

Abstract

It is proposed a device for reducing rattle noise in a gear transmission, which comprises a on the side facing away from the synchronization (2) side of the driven gear (1) of a pair of gears mounted toothed, annular and circumferentially resilient spring element (3) having the same number of teeth and tooth geometry such as the driven gear (1) and connected to the gear (1) such that its teeth (6) are angularly offset with respect to the teeth (7) of the gear (1) by a predetermined deviation such that the driven gear (1) is engaged with the driving gear (4) in the assembled state, the spring element (3) is biased.

Description

The The present invention relates to a device for reduction of rattle noise in a gear transmission according to the The preamble of claim 1. Furthermore, the Invention to a method for reducing rattle noise in a gear transmission.

Rattle- and rattling noises are caused by vibrations of unloaded Gears and circuit components within their functional and production-related game and are usually by Caused torsional vibrations of the transmission shafts.

If the amplitude of the torsional vibrations exceeds a threshold, lift the non-shifted idler gears of the transmission from their traction edge and swing within the backlash back and forth, where the amplitude of the torsional vibrations of the moment of inertia of the loose wheel and the delaying acting on the idler gear Drag torque depends; the shocks at Impact of the loose parts on the game boundaries are the cause of the resulting noise, which in both the neutral position of the transmission as well as while driving can occur. The torsional vibrations of the gear shafts are due to the nonuniformity the engine speed due to the periodic combustion process causing the measures to reduce consumption and emissions increase the non-uniformity of the course of the engine speed.

The Vibrations of the gears are directly or over Bearing transmitted as structure-borne noise to the shafts of the transmission, the largest part about the shaft bearings is transmitted to the housing, where the vibrations are often adversely enhanced due to resonance effects. from Gearbox becomes part of the vibrations directly as Airborne sound emitted, with another part as structure-borne noise over the transmission suspensions forwarded to the body becomes.

to Reduction of rattle noise is known in the art known, arranged in a clutch disc torsion damper to use, thereby creating the disadvantage that due the arrangement of the torsion damper in the vicinity the center of the clutch disc of the space limited which leads to problems with the insulation.

A Another possibility to reduce the rattle noise, is that two-mass flywheels are used; These are usually used in luxury vehicles or vehicles used with very high noise. By the Using two-mass flywheels becomes the vibration frequency relocated to lie in an unused area; usually the oscillation frequency is below the idle speed of the Vehicle engine. Disadvantageously, the use results of two-mass flywheels in a significant cost increase. In addition, when starting the engine, the resonance occurring Damage to the two-mass flywheels to lead. Another problem can be with sporty driving arise; Here, the masses in a fast Clutch operation collide, creating a very high torque peak arises.

Of Another is known from the prior art, for reduction the rattling noise absorber to weaken the To use resonance phenomena. Here, the absorber has the same Resonant frequency but an opposite phase. The constructive Effort in the use of absorbers proves due to the required vote as high.

Out the prior art is also known measures to reduce to seize the rattle noise, which on a modification the gears are based.

From the DE 4400874 A1 For example, is a transmission with a drive shaft, an output shaft and arranged on the shafts, mutually associated pairs of fixed and loose parts such as gears, synchronizer rings, sliding sleeves, clutch plates u. Like. Known, in which rattling and rattling is prevented in that at least one of the mating pairs of fixed and loose parts, the parts are repelled from each other by magnetic force. In particular, it is provided in a gear pairing that each of the associated wheels are repelled from each other by magnetic force, wherein the magnetic or magnetized material is provided in a disc which rests firmly on the front side of each of the gears and the discs a constant over the circumference having aligned axial polarization. Here, each gear facing a pole and the other pole facing away from; the poles on a gear are the same poles on the other gear opposite.

From the DE 4426325 A1 there is an anti-rattle device for a pair of intermeshing teeth in a transmission, between which there is a play in which an elastomeric material on one of the gears is in contact with teeth of the other gear, wherein the elastomeric material so radially on the a gear is arranged, that the outer diameter larger than the Fußkreisdurchmesser the verse versehe NEN gear is. In the known device, the one gear has on one end face a recess into which the elastomeric material is arranged as a ring or disc.

From the DE 19616503 C2 is a transmission gear known to be avoided with the rattle or rattling when meshing in another gear to be the. For this purpose, the gear wheel on at least one of its end faces on a magnetic toothed disc whose diameter corresponds to that of the gear and whose tooth number deviates from the number of teeth of the gear.

As part of the DE 19913563 C1 is described an anti-rattle toothed disc, which is particularly intended for a motor vehicle transmission, with an outer diameter corresponding to that of an associated gear, and with a different tooth number from the tooth. According to the DE 19913563 C1 the known anti-rattle toothed disk has a hard-magnetic material which is arranged annularly, the hard-magnetic material being assigned a container component having a soft-magnetic material, in which the hard-magnetic material is arranged and which is embedded in a core material of the anti-rattle toothed disk.

Of Another has been suggested between a synchronization and the associated gear and between the components of a synchronization To arrange corrugated springs, whereby a frictional force is generated, to reduce vibration of the components.

From the US 4,811,615 A a mechanism for eliminating gear noise in a transmission with a countershaft is known, wherein the drive shaft is connected via a drive gear pair with the countershaft, which in turn is connected via an output gear pair with the output shaft. It includes an additional shaft having first and second gears, one gear meshing with the drive gear pair and the other gear meshing with the output gear pair.

in this connection is provided that between the first and the second gear the additional shaft is provided with a prestressed spring element, To the drive gear pair and the output gear pair a spring moment to transmit the gear noise, wherein the spring moment is greater than the moment of inertia the drive or the output gear pair. This construction requires a high manufacturing and assembly costs; Furthermore be through the extra wave, not the moment transfer serves, the weight and the required space in disadvantageous Way increased.

The DE 10328482 A1 describes a gear transmission comprising a anti-rattle device, which comprises a first, about a first axis rotatable gear, a second, about a rotatable at a predetermined distance from the first axis and meshing with the first gear, a rotatably connected to the first gear Reibumfangsfläche and with the second gear rotatably connected Reibumfangsfläche, wherein the Reibumfangsflächen and the transferability of a friction torque are in mutual contact. To ensure the contact, the one Reibumfangsfläche is biased in the axial direction; Preferably, this Reibumfangsfläche is formed on the outer circumference of a plate spring washer.

Furthermore, from the US 4,660,432 a device for automatically eliminating the backlash in gear drives known. It comprises a first and a second gear, which are respectively arranged on each side of the drive gear of the gear ratio between the drive and the output shaft and have the same number of teeth and the same diameter as the drive gear, so that they mesh with the meshing with the drive gear also comb. The first and second gears are resiliently mounted and non-rotatably connected to the drive shaft, wherein the respective spring means are biased such that when the gears mesh with the meshing with the drive gear, these are radially pressed in each case in the opposite direction. This construction disadvantageously requires a large number of additional components, which considerably increases the manufacturing and assembly costs.

Of the present invention is based on the object, a device to reduce rattle noise in a gear drive specify which is inexpensive to produce and assemble and the disadvantages of the known from the prior art devices avoids. Another object of the invention is a method to reduce rattle noise in a gear drive specify.

These Task is for a device for reducing rattle noise in a gear transmission by the features of claim 1 solved; a method for reducing rattle noise in a gear transmission is the subject of claim 9. Other inventive embodiments and advantages will be apparent from the corresponding subclaims.

Accordingly, it is proposed by means of a on the side facing away from the synchronization of the driven gear of a gear pair of a gear transmission toothed, annular and circumferentially resilient spring element, which is in operative connection with the teeth of the drive gear, to generate a counter force F _ci whose amount is equal to or greater than the amount of Force caused by the angular acceleration resulting from the engine speed nonuniformity and the moment of inertia J of the drive gear.

According to the invention, the annular spring element has an external toothing with the same number of teeth and tooth geometry as the driven gear and is mounted such that its teeth are angularly offset with respect to the teeth of the gear by a predetermined deviation. When the driven gear is engaged with the driving gear (driving gear) in the assembled state, the spring element is biased, the biasing force corresponding to the calculated counterforce F _ci .

The Spring element according to the invention with the driven Gear by means of laser beam welding or current welding get connected. It is also possible the two parts To connect by pressing or by positive engagement with each other. This is considered for the preparation of the connection radially of inner part of the spring element processed so that the teeth of the spring element not with the gear or with the teeth of the gear are directly connected.

in the Within the scope of an advantageous development of the invention, it is proposed in addition to the counterforce generated by means of the spring element to generate a counterforce caused by friction between the spring element and the driven gear is generated. Here is in the frame a first embodiment, that the spring element has a diaphragm spring geometry, so that after assembly the Teeth of the spring element against the teeth of the gear due to the normal force generated by the diaphragm spring geometry be pressed.

alternative to the diaphragm spring geometry of the spring element can be provided that the spring element facing side of the driven gear is concave, so that after the assembly of the plan executed Spring element is generated a normal force, which the teeth of the spring element presses against the teeth of the gear.

The Invention will be described below with reference to the accompanying drawings exemplified in more detail. Show it:

1 : A perspective view of a gear, a synchronizing component and a toothed, annular and circumferentially resilient spring element;

2 : A perspective view of a gear, a synchronizing component and a toothed, annular and circumferentially resilient spring element in the mounted state;

3 Fig. 10 is a schematic view of the driven gear including a toothed annular and circumferentially resilient spring member and the drive gear engaged with each other;

4 : A schematic view of a part of the toothed, annular and circumferentially resilient spring element to illustrate the parameters used for the calculation of the reaction force;

5 : A schematic view of a part of another embodiment of the toothed, annular and circumferentially resilient spring element;

6 : A schematic view of the driven gear, comprising a toothed, annular and circumferentially resilient spring element and the drive gear, which are engaged with each other, wherein the position of the spring element is plotted at different values for the spring deflection;

7 : A schematic view of a portion of the driven gear and mounted thereon toothed, annular and circumferentially resilient spring element to illustrate the forces acting in the operation of the transmission forces to prevent rattle noise according to an advantageous embodiment of the invention;

8th : A schematic view of another embodiment of the driven gear and the toothed, annular and circumferentially resilient spring element before assembly (left part of the figure) and in the assembled state; and

9 : A schematic view of another embodiment of the driven gear and the toothed, annular and circumferentially resilient spring element before assembly (left part of the figure) and in the assembled state.

According to the invention, it is assumed that the angular acceleration ẇ of the transmission shafts varies due to the non-uniformity of the engine speed, whereby rattling noises arise due to the backlash and that the rotating masses have a depending on the geometry and the manufacturing material mass moment of inertia J.

If the drive gear due to the nonuniformity of Engine speed is accelerated, due to the operative connection mit the accelerated gear this accelerated; but when after this acceleration, the drive gear, z. B. due to a Cylinder decompression of the engine is decelerated, takes place Shock between a driven gear tooth and a tooth of the drive gear, since the driven gear due The inertia is not slowed down so much, causing the Rattles arise.

Therefore, it is proposed to apply to the driven gear of a gear pair, a counterforce F _ci on the driving gear whose amount is equal to or greater than the amount of force caused by the angular acceleration and the moment of inertia J of the driving gear. As a result, the teeth of the driven gear with the teeth of the drive gear always remain in operative connection, resulting in avoiding the shocks and thus the rattle noise.

The following applies: F _ci = T _ci / r, where Tci = counter torque in Nm and r = radius of the counter force applied to the gear in m.

mit m = Masse des Zahnrades in kg, D = Außendurchmesser des Zahnrades in m (Grunddurchmesser, da die Massenverteilung am Außendurchmesser eines Zahnrades nicht kontinuierlich ist) und d = Innendurchmesser des Zahnrades in m.For the counter torque also applies: Tci = J _zz × ẇ, where J _{zz is} the mass moment of inertia when rotating about the z-axis, ie the axis of rotation of the gear. It also applies:

with m = mass of the gear in kg, D = outer diameter of the gear in m (basic diameter, since the mass distribution on the outer diameter of a gear is not continuous) and d = inner diameter of the gear in m.

mit V = Volumen des angetriebenen Zahnrades, I = Breite des Zahnrades, ρ = Dichte, für den Fall von Stahl 7850 kg/m³ Accordingly:

with V = volume of the driven gear, I = width of the gear, ρ = density, in the case of steel 7850 kg / m ³

The force F _ci can be determined by the maximum angular acceleration of the gear shafts, the outer diameter and the inner diameter of the gear and the density of the gear material as follows.

wodurch diese berechnet werden kann.From the above equations we obtain for the counterforce F _ci :

whereby this can be calculated.

According to the invention and referring to 1 . 2 and 3 the counterforce F _ci is generated by that at the synchronization 2 opposite side of the driven gear 1 a toothed, annular and circumferentially resilient spring element 3 is attached.

The annular spring element 3 has an external toothing with the same number of teeth and tooth geometry, as the gear 1 and becomes so with the gear 1 connected, that its teeth with respect to the teeth of the gear 1 are arranged angularly offset by a predetermined deviation. When the driven gear 1 with the driving gear (drive gear) 4 engaged in the assembled state, as in 3 shown is the spring element 3 biased, wherein the biasing force of the calculated counterforce F _ci corresponds. With one revolution of the gear by 360 °, each tooth of the spring element 3 once charged.

The Spring deflection in the circumferential direction is required in known Preload force as a function of the preload force, the modulus of elasticity the spring material and dimensional parameter of the spring element determinable, so that the spring element can be mounted accordingly can.

mit L = Kontaktlänge eines Zahnes des Federelementes zum korrespondierenden Zahnrad des Antriebszahnrades, b = Dicke des Federelementes und h = Breite der Zähne des Federelementes. Die Parameter L, b und h sind in 4 veranschaulicht.The bending stress τ _b is given by the following formula:

with L = contact length of a tooth of the spring element to the corresponding gear of the drive gear, b = thickness of the spring element and h = width of the teeth of the spring element. The parameters L, b and h are in 4 illustrated.

mit E = Elastizitätsmodul des Federmaterials; für ein aus Stahl hergestelltes Federelement beträgt E 206000 N/mm².According to the invention, the spring deflection or deflection S _Fci (ie the deflection of a Tooth of the spring element 3 in the circumferential direction) as a function of the counterforce F _{ci determined} as follows and corresponds to the bias of the spring element 3 when the driven gear 1 and the drive gear 4 engage.

with E = modulus of elasticity of the spring material; for a spring element made of steel, E is 206000 N / mm ² .

mit τ_bmax = maximal erlaubte Biegespannung des Federmaterials.Furthermore, the maximum permitted spring deflection S _{max is given} by the following formula:

with τ _bmax = maximum permitted bending stress of the spring material.

The maximum permitted spring deflection applies to the preload of the spring element 3 and the others on the spring element 3 acting forces; in the case of moment transmission by the gear pair, the forces due to the transmitted moments are higher than the spring force, resulting in a larger spring deflection, which according to the invention does not exceed S _max .

Subject of the 5 is an embodiment of the annular toothed spring element 3 , In this embodiment, the length of the teeth is less than the length of the teeth of the spring element 3 To be connected gear 1 What results in a constant thickness of the spring element in a lower counterforce can be generated.

In 6 is a schematic view of the driven gear 1 comprising a toothed, annular and circumferentially resilient spring element 3 and the drive gear 4 , which engage with each other, wherein the position of the spring element 3 is _plotted at different values for the spring _deflection S _Fci . Here, the position of the spring element in the prestressed state by the interaction with a tooth 5 of the gear 4 denoted by A; Arrow B illustrates the direction of the counterforce F _ci . C denotes the position of the spring element 3 without deflection (ie before mounting the gear pair) and D the position of the spring element 3 at maximum deflection S _max .

In the context of a particularly advantageous embodiment of the invention, the subject of 7 . 8th and 9 is, is proposed, in addition to the means of the spring element 3 counterforce generated by friction between the teeth 6 of the spring element and the teeth 7 of the driven gear 1 is produced. This principle is in 7 represented by the spring element 3 generated counterforce with Fci and due to a normal force F _N , which the teeth 6 of the spring element 3 against the teeth 7 of the driven gear 4 expresses frictional force generated by Fat _ci .

By this conception increases the total counterforce, which the use of the spring element at higher loaded Gears allows without the maximum allowable Bending stress of the spring material to exceed. moreover the load of the spring element can be reduced, resulting in a higher lifetime of the same results.

For generating the frictional force, according to a first embodiment of the invention, the subject of the 8th is the spring element 3 a diaphragm spring geometry on. As a result, after the connection of the spring element 3 with the gear 1 the teeth 6 of the spring element 3 against the teeth 7 of the gear 1 pressed due to the normal force generated by the plate spring geometry, whereby the force required for the realization of the frictional force normal force F _{N is} generated.

Another possibility for generating the normal force F _N is the subject of 9 , Here is the spring element 3 facing side of the driven gear 1 concave, so that after mounting on the gear 1 facing side plan running spring element 3 due to the elasticity properties of the spring element 3 a normal force F _{N is} generated which the teeth 6 of the spring element 3 against the teeth 7 of the gear 1 suppressed. Furthermore, according to an advantageous embodiment of the invention, the teeth 7 of the gear 1 supplied surface of the teeth 6 of the spring element 3 be processed accordingly to increase the friction coefficient.

Of course Every constructive training, especially every one, also falls spatial arrangement of the device for the reduction of Rattle noise in a transmission in itself and as far as technical useful, within the scope of the present claims, without the function of the device as stated in the claims is indicated to influence, even if these training is not explicit are shown in the figures or in the description.

1

powered gear

2

synchronization component

3

spring element

4

driving Gear, drive gear

5

tooth of the drive gear

6

tooth of the spring element

7

tooth of the driven gear

A

location of the spring element in the prestressed state

B

direction the drag

C

location of the spring element without deflection

D

location the spring element at maximum deflection

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 4400874 A1 [0009]
• - DE 4426325 A1 [0010]
• - DE 19616503 C2 [0011]
• - DE 19913563 C1 [0012, 0012]
• - US 4811615 A [0014]
• - DE 10328482 A1 [0016]
• US 4660432 [0017]

Claims (15)

Device for reducing rattle noise in a toothed gearing, characterized in that it is connected to the synchronization ( 2 ) facing away from the driven gear ( 1 ) a gear pair mounted toothed, annular and circumferentially resilient spring element ( 3 ), which has the same number of teeth and tooth geometry as the driven gear ( 1 ) and so with the gear ( 1 ) that its teeth ( 6 ) concerning the teeth ( 7 ) of the gear ( 1 ) are arranged angularly offset by a predetermined deviation, so that when the driven gear ( 1 ) with the driving gear ( 4 ) is engaged in the mounted state, the spring element ( 3 ) is biased. Means for reducing rattle noise in a gear transmission, according to claim 1, characterized in that the biasing force corresponds to a counterforce F _ci whose amount is equal to or greater than the amount of force due to the angular acceleration and the moment of inertia J of the driving gear ( 4 ) is caused. Device for reducing rattle noise in a gear transmission, according to claim 1 or 2, characterized in that the biasing force F _ci by the maximum angular acceleration of the transmission shafts, the outer diameter and the inner diameter of the gear ( 4 ) and the density of the gear material can be determined. Device for reducing rattle noise in a gear transmission, according to claim 1, 2 or 3, characterized in that at a known biasing force, the spring _deflection S _Fci in the circumferential direction _Rich as a function of the biasing force, the modulus of elasticity of the spring material and dimension-related parameters of the spring element can be determined. Device for reducing rattle noise in a gear transmission, according to one of the preceding claims, characterized in that the spring element ( 3 ) with the driven gear ( 1 ) is connected by means of laser beam welding, current welding, compression or by positive locking Device for reducing rattle noise in a gear transmission, according to one of the preceding claims, characterized in that the spring element ( 3 ) in such a way with the driven gear ( 1 ), that the teeth ( 6 ) of the spring element ( 3 ) against the teeth ( 7 ) of the driven gear ( 1 ). Device for reducing rattle noise in a gear transmission, according to claim 6, characterized in that the spring element ( 3 ) has a plate spring geometry, wherein after the connection of the spring element ( 3 ) with the driven gear ( 1 ) the teeth ( 6 ) of the spring element ( 3 ) against the teeth ( 7 ) of the gear ( 1 ) are pressed due to the normal force F _N generated by the diaphragm spring geometry. Device for reducing rattle noise in a gear transmission, according to claim 6, characterized in that the spring element ( 3 ) facing side of the driven gear ( 1 ) is concave, so that after assembly of the on the gear ( 1 ) facing side plan executed spring element ( 3 ) due to the elasticity properties of the spring element ( 3 ) a normal force F _{N is} generated which the teeth ( 6 ) of the spring element ( 3 ) against the teeth ( 7 ) of the gear ( 1 ) presses. A method for reducing rattle noise in a gear transmission, characterized in that on the driven gear of a gear pair, a counterforce F _{ci is} applied to the driving gear whose amount is equal to or greater than the amount of force due to the angular acceleration and the moment of inertia J of the driving gear is caused, whereby the teeth of the driven gear with the teeth of the drive gear always remain in operative connection, resulting in avoiding the shocks and thus the rattle noise. Method for reducing rattle noise in a gear transmission, according to claim 9, characterized in that the counterforce F _ci by a at the synchronization ( 2 ) facing away from the driven gear ( 1 ) a gear pair mounted toothed, annular and circumferentially resilient spring element ( 3 ) is generated, which has the same number of teeth and tooth geometry as the driven gear ( 1 ) and so with the gear ( 1 ) that its teeth ( 6 ) concerning the teeth ( 7 ) of the gear ( 1 ) are arranged angularly offset by a predetermined deviation, so that when the driven gear ( 1 ) with the driving gear ( 4 ) is engaged in the mounted state, the spring element ( 3 ) is biased, wherein the biasing force of the opposing force F _ci corresponds. A method for reducing rattle noise in a gear transmission, according to claim 10, characterized in that the biasing force F _ci by the maximum angular acceleration of the transmission shafts, the outer diameter and the inner diameter of the driving gear ( 4 ) and the density of the gear material of the gear ( 4 ) is determinable. A method for reducing rattle noise in a gear transmission, according to claim 10 or 11, characterized in that at a known biasing force, the spring _deflection S _Fci in the circumferential direction as a function of the biasing force, the modulus of elasticity of the spring material and dimensional parameters of the spring element ( 3 ) is determined. A method for reducing rattle noise in a gear transmission, according to claim 10, 11 or 12, characterized in that in addition to that by the spring element ( 3 ) counterforce F _ci , another counterforce Fat _ci due to friction between the teeth ( 6 ) of the spring element ( 3 ) and the teeth ( 7 ) of the driven gear ( 1 ) is produced. Method for reducing rattle noise in a gear transmission, according to claim 13, characterized in that the force required for the realization of the frictional force normal force F _N by a cup spring geometry of the spring element ( 3 ) is produced. Method for reducing rattle noise in a gear transmission, according to claim 13, characterized in that the force required for the realization of the frictional force normal force F _N is generated by the fact that the spring element ( 3 ) facing side of the driven gear ( 1 ) is concave, so that after assembly of the on the gear ( 1 ) facing side plan executed spring element ( 3 ) the teeth ( 6 ) of the spring element ( 3 ) against the teeth ( 7 ) of the gear ( 1 ).