WO2009033901A2

WO2009033901A2 - Device and method for reducing rattling noises in a toothed gear mechanism

Info

Publication number: WO2009033901A2
Application number: PCT/EP2008/060446
Authority: WO
Inventors: Luiz Carlos Proenca; Juliano Sanches; Claudemir Abreu
Original assignee: Zf Friedrichshafen Ag
Priority date: 2007-09-07
Filing date: 2008-08-08
Publication date: 2009-03-19
Also published as: WO2009033901A3; DE102007042762A1

Abstract

The invention relates to a device for reducing rattling noises in a toothed gear mechanism, comprising a toothed, annular spring element (3), which is resilient in the circumferential direction and is mounted on the side of the driven toothed gear (1) of a toothed gear pair facing away from the synchronization unit (2), the spring element having the same number of teeth and the same tooth geometry as the driven toothed gear (1) and being connected to the toothed gear (1) such that the teeth (6) thereof are disposed at an offset by a predetermined deviation angle with regard to the teeth (7) of the toothed gear (1) such that if the driven toothed gear (1) is engaged in the driving toothed gear (4) in the mounted state, the spring element (3) is pre-tensioned.

Description

Apparatus and method for reducing rattle noise in one

gear transmission

The present invention relates to a device for reducing race noise in a gear transmission according to the preamble of claim 1. The weather relates to a method for reducing race noise in a gear transmission,

Rattling and rattling noises are caused by vibrations of unloaded gears and circuit parts within their funktioπs- and production-related game and are usually caused by torsional vibrations of Getriebewelien.

When the amplitude of the torsional vibrations exceeds a threshold, the non-switched idler gears of the transmission from their trailing edge and oscillate back and forth within the backlash, the amplitude of the torsional vibrations of the moment of inertia of the idler gear and the idler wheel retarding acting drag torque depends; The shocks when hitting the loose parts at the game limits are the cause of the resulting noise, which can occur both in the Neutraisteiiung the transmission and while driving. The torsional vibrations of transmission gears are caused by the irregularity of the engine speed due to the periodic combustion process, the consumption and emission reduction measures increasing the nonuniformity of the engine speed curve.

The vibrations of the gears are transmitted directly or via bearings as KörperschalS on the shafts of the transmission, the majority being transmitted via the shaft bearings to the housing, where the vibrations often disadvantageously amplified due to resonance effects become. From the gearbox part of the vibrations is directly as Luttschal! radiated, with another part as KörperschaSI on the transmission suspensions to the body weitergeieitet.

To reduce the rattle noise is known from the prior art to use arranged in a clutch disc Torsionsdämpter, thereby creating the disadvantage that is limited due to the arrangement of Torsioπsdämpfers near the center of the clutch disc, the space, causing problems in όer insulation leads.

Another way to reduce the rattle noise is to use two-mass flywheels; These are usually used in luxury vehicles or in vehicles with very high noise levels. By using two-mass flywheels, the oscillation frequency is shifted to be in an unused area; Usually wins the vibration frequency below the teerlaufdrehzah ^{) of} the vehicle engine. Disadvantageously, the use of dual-mass flywheels results in a significant cost increase. In addition, when the engine is started, the resonance that occurs can result in damage to the two-mass flywheels. Another problem can arise in sporty driving; In this case, the masses can collide during a quick clutch actuation, resulting in a very high torque peak.

Furthermore, it is known from the prior art, to reduce the rattle noise to use absorbers to attenuate the resonance phenomena. In this case, the absorber has the same resonant frequency but an opposite phase. The design effort in the use of absorbers proves to be high due to the required vote. From the prior art it is also known to take measures to reduce the rattle noise, which are based on a modification of the gears.

From DE 4400874 A1, for example, a transmission with a drive shaft, an Ablriebswelle and arranged on Ween parts, mutually associated pairs of fixed and loose parts such as gears, synchronous rings, sliding sleeves, Kupplungsiamelien u. Like. Known in which a Rassein and rattling is prevented by the fact that in at least one of the mating pairings 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 is each gear a butt! facing away and the other pole turned away; Polenen Poland on a gear are the same poles on the other gear opposite.

DE 4426325 A1 discloses an anti-rattle device for a pair of intermeshing teeth in a transmission, between which there is a clearance in which an elastomeric material on one of the gears is in contact with teeth of the other gear, the elastomeric Material is arranged radially on the one gear, that the outer diameter is greater than the Fußkreisdurchmesser of the gear provided therewith. In the known device, the one gear has on one end face a recess into which the egg-elastic material is arranged as a ring or disc.

From DE 19616503 C2 a transmission gear is known, with the rattle or rattle noises when meshing in another gear avoid should be. For this purpose, the Gelriebezahπrad on at least one of its end faces on a magnetic toothed disc whose diameter corresponds to that of the gear and their Zahnanzah! from the Zahnanzah! of the gear deviates.

Within the scope of DE 19913563 C1 is an anti-rattle tooth lock washer ^¬ be written, which is intended in particular for a motor vehicle transmission, having an outer diameter corresponding to an associated gear, and with a deviating from the gear Zahnanzah !. According to DE 19913563 C1, the known anti-rattle toothed disc 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 disc ,

Furthermore, it has been proposed to ring springs between a synchronization and the associated gear as well as between the components of a synchronization to arrange, whereby a frictional force is generated to reduce vibration of the components.

From 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 Vorgelegeweile, which in turn is connected via a Abtriebszahnradpaar 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.

It is provided that between the first and the second gear of the additional shaft, a biased spring element is provided to the drive gear pair and the driven gear pair a spring to transfer torque for the suppression of gear noise, wherein the spring torque is greater than the moment of inertia of the drive or the output gear pair, this construction requires a high manufacturing and assembly costs; Furthermore, the weight and the required installation space are disadvantageously increased by the additional shaft, which does not serve the torque transfer.

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

Furthermore, from US 4,660,432 a device for the automatic elimination of backlash in gear drives known. It includes a first and a second gear, which are respectively disposed on each side of the drive gear of the gear ratio between the input and output shafts and 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 υnό the second gear are resiliently connected and non-rotatably connected to the drive shaft, wherein the corresponding spring means are biased such that when the gears mesh with the meshing with the drive gear, they are pressed radially viewed in the opposite direction. This construction disadvantageously requires a large one Number of additional components, which significantly increases the manufacturing and assembly costs.

The present invention has for its object to provide a device for reducing rattle noise in a gear transmission, which is inexpensive to produce and assemble and avoids the disadvantages of the known from the prior art devices. Another object of the invention is to provide a method for reducing rattle noise in a gear transmission.

This object is achieved for a device for reducing rattle noise in a gear transmission by the features of claim 1; A method for reducing rattle noise in a gear transmission is the subject of claim 9. Other Ausgesfaltungen and advantages according to the invention will be apparent from entsprechendenen corresponding Uπteransprücheπ.

Accordingly, it is proposed, by means of a side facing away from the synchronization side 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 , the amount is equal to or greater than the amount of force caused by the angular acceleration resulting from the inertia of the IVI engine speed and the moment of inertia J of the drive gear.

According to the invention, the ring-shaped spring element has an outer toothing with the same number of teeth and tooth geometry as the driven gear is mounted such that its teeth are beveled with respect to the teeth of the gear by a predetermined deviation! are arranged offset. When the driven gear with the driving gear {Drive gear) is engaged in the mounted state, the spring element is biased, wherein the biasing force of the calculated counterforce F _D corresponds.

The spring element can erfiπduπgsgemäß be connected to the driven gear by means of laser beam welding or current welding. It is also possible to connect the two parts by pressing or by positive engagement with each other. In this case, for the preparation of the connection radially considered the inner Tei! processed the Federeiementes, so that the teeth of the Federeiementes are not directly connected to the gear or with the teeth of the gear.

In an advantageous development of the invention it is proposed to generate in addition to the counterforce generated by the spring element, a counterforce which is generated by friction between the spring element and the driven gear. Here, in the context of a first embodiment, it is provided that the spring element has a Telier spring geometry, so that after assembly the teeth of the spring element are pressed against the teeth of the gear due to the normal force generated by the TeSterfedergeometrie.

As an 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 assembly of the plan executed Federeiementes a normal force is generated, which prints the teeth of the spring element against the teeth of the gear.

The invention will be explained in more detail below with reference to the accompanying drawings. Show it; Fig. 1: A perspective view of a gear, a synchronizing isierungsbauteils and a toothed, annular and circumferentially resilient spring element;

Fig. 2: A perspective view of a gear, a synchronizing isierungsbauteils and a toothed ^¬ th, annular and spring-elastic in Umfangsπchtung spring element in the mounted state;

Fig. 3: A schematic view of the driven

A gear comprising a toothed, annular and circumferentially resilient Federeiement and the Anlriebszahnrades which engage with each other;

4 shows a schematic view of a part of the toothed, annular and circumferentially resilient spring element for illustrating the parameters used for calculating the counterforce;

5 shows a schematic view of a part of a weathered embodiment of the toothed, annular and circumferentially resilient spring element;

Fig. 6: A schematic view of the driven

A gear comprising a toothed, annular and circumferentially resilient spring element and the drive gear, which engage with each other, wherein the position of the spring element at different values for the spring deflection is drawn;

7 shows a schematic view of a part of the driven gear and the toothed, annular and spring-elastic spring element mounted thereon for the purpose of verifying the forces acting during operation of the gearbox to avoid rattling noises according to an advantageous development of the invention;

Fig. 8; A schematic view of another embodiment of the driven gear and the toothed, annular and Umfaπgsrichtung resilient Federeeementes before όer assembly (left part of the figure) and in the assembled state; and

Fig. 9; A schematic view of another embodiment of the driven gear and the toothed, annular and Umfaπgsrichtung 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 w 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 one of the geometry and the Herstellungsmateria! dependent mass moment of inertia J have.

If the drive gearwheel is not rotating due to the irregularity of the motor speed! is accelerated, is due to the active connection with the ange- The driven gear accelerates it. However, if after this acceleration, the drive gear, for example due to a Zyünderdekompresεion of the engine is decelerated, a shock between a tooth of the driven gear and a tooth of the drive gear, since the driven gear is not slowed down so much due to the inertia, whereby the rattling arises.

Therefore, it is proposed to _apply to the driven gear of a gear _pair, a counterforce F _ßi 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 όe <n teeth of the drive gear always in operative connection, resulting in avoiding the shocks and thus the rattle noise.

It applies; F _ßi = T _ci / r, with Tci = counter torque in Nm and r = radius of the exercise of the counterforce force on the gear in m.

For the counter-moment also applies; Tci = J ^ x w, where J ^ is the mass moment of inertia when rotating about the z-axis, i. the axis of rotation of the gear is. It also applies:

./. Outside

Diameter of the gear in m {basic diameter, since the Massenvertei- Su ng on the outer diameter of a gear is not continuous) and d = inner diameter of the gear in m. T - 1

Accordingly: m ^ vp = - (D - a -) ^■ 7S5U, with V = volume of the an¬

driven gear, t = board of the gear, p = density, in the case of steel 7850 kg / m ³

The force F ₀ can be determined as follows by the maximum angle of the transmission shafts, the outer diameter and the inner diameter of the gearwheel, and the density of the gearwheel material.

From the above equations we obtain for the counterforce F _c :

/ - ^' _,

, whereby it can be calculated.

According to the invention and with reference to FIGS. 1, 2 and 3, the counterforce F ₀ , generated by the fact that on the side facing away from the synchronization 2 of the driven gear 1, a toothed, annular and circumferentially resilient device Federelernent 3 is attached.

The annular spring element 3 has a toothed toothing with the same teeth and tooth geometry as the toothed wheel 1 and is connected to the toothed wheel 1 such that its teeth are offset with respect to the teeth of the toothed wheel 1 by a predetermined deviation. When the driven gear 1 with the driving gear {drive gear wheel) 4 in the mounted state is engaged, as shown in Fig. 3, the spring element 3 is biased, wherein the biasing force of the calculated counterforce F ₀ , corresponds. In one revolution of the gear 360 ° each tooth of the spring element 3 is charged once. The spring deflection in Umfaπgsrichtung is known at the required preload force as a function of the biasing force, the modulus of elasticity of the spring material and dimensional parameters of the Federelemeπtes determinable, so that the spring element can be mounted accordingly.

The bending stress τ- _a is given by the following formula:

_τ: _r - F, with L = length of contact of a tooth of the spring element h - lr to the corresponding gear wheel of the drive gear, b = thickness of the Fe dereiementes and h = width of the teeth of the spring element. The parameters L, b and h are illustrated in FIG.

According to the invention, the spring deflection or deflection SF ₀ (afeo the deflection of a tooth of the spring element 3 in Umfaπgsrichtung) in dependence of the counterforce F _{c ;: determined} as follows and corresponds to the bias of the spring element 3 when the driven gear 1 and the drive gear 4 are engaged.

S _n , = - - -, where E = elastic modulus of the spring material; for a

E ^■ h ^■ h ^'

made of steel spring element is E 206000 N / mm ^.

Furthermore, the maximum permitted spring deflection S _{max is given} by the following formula; ^■ b - for β - L

V zz with τ _bmax = maximum allowed bending stress of the

E -h - lr 4 - Z /

Spring material.

The maximum permitted spring deflection applies to the pretensioning of the spring element 3 and the further forces acting on the spring element 3; in the case of torque 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,

The object of FIG. 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 gear 1 to be connected to the spring element 3, resulting in a smaller counterforce which can be generated while the thickness of the spring element remains the same results.

In Fig. 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 are engaged with each other, wherein the position of the spring element 3 at different values for the spring deflection SR _:! is drawn. Here, the position of the spring element in the prestressed state by the interaction with a tooth 5 of the gear 4 is designated A; Arrow B illustrates the direction of the counterforce F _C: C denotes the position of the spring element 3 without AusSenkung (ie, before mounting the gear pair} and D, the position of the Federele- rnenfes 3 at maximum deflection S _fnax .

In the context of a particularly advantageous embodiment of the invention, which is the subject of FIGS. 7, 8 and 9, it is proposed, in addition to generated by the spring element 3 counterforce generate a counterforce 2U, which is generated by friction between Zen teeth 6 of the spring element and the teeth 7 of the driven gear 1. This principle is shown in Fig. 7, wherein the reaction force generated by the Federeäement 3 with Fei and due to a normal force F _N , which presses the teeth 6 of the Federele- menfes 3 against the teeth 7 of the driven gear 4, generated frictional force with Fat * is designated.

By this concept, the total counter force is increased, which allows the use of the spring element at higher loaded gears, without exceeding the maximum allowable bending stress of the spring material. In addition, the load of the spring element can be reduced, resulting in the same in a longer life.

To generate the frictional force has, according to a first embodiment of the invention, the subject of Fig. 8, the spring element 3 on a Teilerfedergeornetrie. As a result, the teeth 6 of the spring element 3 are pressed against the teeth 7 of the gear 1 due to the normal force generated by the Teferfedergeometrie after the connection of the Fe derelementes 3 with the gear 1, whereby the force required for the realization of the frictional force Normaϊ force F _{N is} generated.

A further possibility for generating the normal force Fu is the subject matter of FIG. 9. In this case, the side of the driven gear 1 facing the spring element 3 is concave, so that, after the assembly of the spring element 3 which is flat on the side facing the gear wheel 1, due to the elasticity properties of the spring element 3, a normal force F _{N is} generated, which presses the teeth 6 of the spring element 3 against the teeth 7 of the gear 1. Furthermore, according to an advantageous embodiment of the invention, the teeth 7 of the gear 1 zuge- turned surface of the teeth 6 of Federeiemeπtes 3 be processed accordingly to increase Reiben friction coefficient.

Of course, any constructive training, especially any spatial arrangement of the device for reducing rattle noise in a transmission per se and as far as technically feasible, falls within the scope of the present claims, without affecting the function of the device, as indicated in Ansprüchenen claims even if these training courses are not explicitly shown in the figures or in the description.

Sezugszeichen

1 driven gear

2 synchronizing components!

3 spring reins

4 driving gear, drive gear

5 tooth of the drive gear

6 tooth of the FederereSernenies

7 tooth of the driven gear

A position of the spring element in the prestressed state

B direction of drag

C Position of the spring element without countersinking

D Position of the spring element at maximum deflection

Claims

claims

1. A device for reducing rattle noise in a gear transmission, characterized in that it comprises a on the synchronization (2) facing away from the driven gear (1) of a pair of gears 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 is connected to the gear (1) that its teeth (6) with respect to the teeth (7) of the gear (1) are arranged angularly offset by a predetermined deviation, so when the driven gear (1) is engaged with the driving gear (4) in the mounted state, the spring element (3) is biased.

2. Device for reducing rattle noise in a gear transmission, according to claim 1, characterized geke n nzei ch net, that the biasing force corresponds to a counter force F _D whose amount is equal to or greater than the amount of force due to the Winkeibeschleunigung and the Moment of inertia J of the driving gear (4) is caused.

3. The device for reducing rattle noise in a gear transmission according to claim 1 or 2, characterized geken nzeich n et that the biasing force F _Ci triebewelien by the maximum angular acceleration of the Ge, the outer diameter and the inner diameter of the gear wheel (4) and the density of the Zahπradmaterials is determinable.

4. A device for reducing rattle noise in a gear transmission, according to claim 1, 2 or 3, characterized ge ke nzeic hn et that with a known biasing force, the spring deflection

in Urnfangsrich tion as a function of the biasing force, the modulus of elasticity of the spring materiais and dimensional parameters of the spring element can be determined.

5. A device for reducing rattle noise in a gear transmission, according to one of the preceding claims, characterized ze ze et I et that the FedereSement (3) with the driven gear (1) by means of laser beam welding, current welding, compression or by positive engagement is connected

6. A device for reducing rattle noise in a gear transmission, according to one of the preceding claims, characterized Porsche Style n ze I n et that the spring element (3) is so connected to the driven gear (1) that the teeth (6) of the spring element (3) are pressed against the teeth (7) of the driven gear (1).

7, means for reducing rattle noise in a gear transmission, according to claim 6, characterized geke nzei ch net, that the spring element (3) has a Belleville spring geometry, wherein after the connection of the FedereSementes (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 generated by the Teϊlerfedergeometrie normal force F _N.

8, means for reducing rattle noise in a gear transmission, according to claim 6, characterized ge ke nze net ch, that the spring element (3) facing side of the driven gear (1) is concave, so that after assembly of the 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.

9. A method for reducing rattle noise in a gear transmission, characterized in that on the driven gear of a gear pair, a counter force F _{C: is} exerted on the driving gear whose amount is equal to or greater than the amount of force due to Wiπkeibeschieuπiguπg and the mass 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.

10. A method for reducing rattle noise in a gear transmission, according to claim 9, characterized ge ke n nzei ch net, that the counterforce F _ci by a on the synchronization (2) facing away from the driven gear (1) of a pair of gears mounted toothed, annular and circumferentially resilient spring element (3) is generated, which has the same Zähneanzah! and tooth geometry such as the driven gear (1) and connected to the gear (1) that its teeth (6) with respect to the teeth (7) of the gear {1} are angularly offset by a predetermined deviation, so that when the driven gear {1} is engaged with the driving gear (4) in the assembled state, the spring element (3) is biased, wherein the biasing force of the counterforce F ₀ ; equivalent.

11. A method for reducing rattle noise in a gear transmission, according to claim 10, characterized Porsche Style n net that the biasing force F _Gi 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.

12. A method for reducing rattle noise in a toothed gear, according to claim 10 or 11, characterized ge ke nzeic hn et that with a known biasing force, the spring deflection

in the circumferential direction as a function of the biasing force, the modulus of elasticity of the spring material and dimensional parameters of the FedereSementes (3) is determined.

13. A method for reducing rattle noise in a gear transmission, according to claim 10, 11 or 12, characterized ge ke nzeich n et, that in addition to the by the spring element (3) generated counterforce F ₀ , another counterforce Fat _C: by friction between the teeth {6} of the spring element (3) and the teeth (7) of the driven gear (1) is generated.

14. A method for reducing rattle noise in a gear transmission, according to claim 13, characterized geke n nzei ch net, that required for the realization of the frictional force normal force FN by a TelSerfedergeometrie the spring element (3) is generated.

15. A method for reducing rattle noise in a gear transmission, according to claim 13, characterized ge ke n nze i ch net that required for the realization of the frictional force normal force F _N is generated by the fact that the spring element (3) facing the side of the industry ^¬ Benen gear (1) is concave, so that after the assembly of the on the gear (1) facing side plan running spring element (3), the teeth (6) of the spring element (3) against the teeth (7) of the gear ( 1).