CN113898699A

CN113898699A - Dual mass flywheel

Info

Publication number: CN113898699A
Application number: CN202111147892.4A
Authority: CN
Inventors: 颜克志; 吴春华; 易铭翰; 梁小立; 甄臻
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2021-09-29
Filing date: 2021-09-29
Publication date: 2022-01-07
Anticipated expiration: 2041-09-29
Also published as: CN113898699B; DE102022123280A1

Abstract

There is provided a dual mass flywheel comprising: a spring (200); a primary mass (100) comprising a first housing (110) and a second housing (120), the first housing (110) for connection to a power source; a hub member (300) and a flange (400) integrally formed or connected to each other, the spring (200) being disposed between the primary mass (100) and the flange (400) to damp torsional vibrations, the hub member (300) serving as an output; and a diaphragm spring (500) that is provided in a compressed state between the flange (400) and the second housing (120) in an axial direction (AX). The radially inner end (122) of the second housing (120) is closer to the radially inner side of the dual mass flywheel than the radially inner end of the diaphragm spring (500), or the radially inner end (122) of the second housing (120) is flush with the radially inner end of the diaphragm spring (500) in the radial direction (RA).

Description

Dual mass flywheel

Technical Field

The present application relates to dual mass flywheels, and more particularly, to dual mass flywheels having improved water resistance.

Background

The applicant's utility model CN210371835U discloses a dual mass flywheel with a centrifugal pendulum unit. Referring to fig. 1A, the dual mass flywheel includes: a primary mass 1 for drive coupling with an output shaft of an engine; a secondary mass 3 and a hub core 4, the hub core 4 being for driving coupling to an input shaft of a gearbox; a flange 5 fixedly mounted to the secondary mass 3; at least two arc springs 6 disposed in a spring receiving space defined by the primary mass 1 and capable of pressing the flange 5; and two or three centrifugal force pendulum units 7, the centrifugal force pendulum units 7 being mounted to the flange 5 at intervals in the circumferential direction of the dual mass flywheel.

The primary mass 1 comprises a first housing 11 and a second housing 12, the first housing 11 and the second housing 12 being connected together at a radially outer portion of the dual mass flywheel and forming a spring receiving space which receives at least two arcuate springs 6.

The dual mass flywheel further comprises a diaphragm spring 8, the inner circumference of the diaphragm spring 8 being fixedly mounted between the secondary mass 3 and the flange 5, the outer circumference of the diaphragm spring 8 being pressed against the second housing 12. A friction pad made of plastic may be provided between the outer peripheral portion of the diaphragm spring 8 and the second housing 12. The diaphragm spring 8 (and friction pad) can not only achieve axial position limitation of the secondary mass 3 on one axial side (right side in fig. 1A), but also achieve a damping (vibration damping) function through friction.

Disclosure of Invention

It is an object of the present application to provide a dual mass flywheel having improved water resistance.

There is provided a dual mass flywheel comprising:

a spring;

a primary mass including a first housing and a second housing, the first housing and the second housing defining a spring receiving space that receives the spring;

a secondary mass, the spring disposed between the primary mass and the secondary mass to dampen torsional vibrations; and

a diaphragm spring disposed in a compressed state between the secondary mass and the second housing in an axial direction of the dual mass flywheel,

the radial inner end of the second shell is closer to the radial inner side of the dual-mass flywheel than the radial inner end of the diaphragm spring, or the radial inner end of the second shell and the radial inner end of the diaphragm spring are flush in the radial direction of the dual-mass flywheel.

In at least one embodiment, the flange includes a base circle portion and a flange wing portion protruding from the base circle portion toward a radially outer side, and the second housing and the base circle portion of the flange overlap in a radial direction of the dual mass flywheel.

In at least one embodiment, the radial length of the second housing is greater than 1/3 for the radius of the dual mass flywheel,

preferably, the radial length of the second housing is greater than 2/5 and less than 1/2 of the radius of the dual mass flywheel.

In at least one embodiment, the radial length of the diaphragm spring is less than 1/5 the radius of the dual mass flywheel,

preferably, the radial length of the diaphragm spring is less than 1/9 of the radius of the dual mass flywheel.

In at least one embodiment, the radial length of the diaphragm spring is less than 2/5 of the radial length of the second housing,

preferably, the radial length of the diaphragm spring is less than 1/4 of the radial length of the second housing.

In at least one embodiment, the dual mass flywheel further comprises a first friction ring, which is arranged at least partially between the secondary mass and the diaphragm spring, in particular at least partially between the flange as at least part of the secondary mass and the diaphragm spring, in the axial direction, which is arranged between the first friction ring and the second housing; or,

in the axial direction, the first friction ring is arranged at least partially between the second housing and the diaphragm spring, which is arranged between the first friction ring and the secondary mass.

Further, the first friction ring includes:

an axial portion extending along the axial direction; and

a radial portion connected to the axial portion and extending in a radial direction of the dual mass flywheel;

the axial section has a first structure, wherein a second structure corresponding to the first structure is provided on a radial inner end of the second housing or on a flange, and the first structure is coupled to the second structure, so that the first friction ring is connected to the second housing or to the flange in a rotationally fixed manner.

Further, the radial portion bears axially against the secondary mass or the second housing under the action of the diaphragm spring; the axial portion radially abuts the second housing or the secondary mass.

Further, one or more protrusions protruding toward a radially outer side are provided at an outer circumferential portion of the axial portion, one or more recesses corresponding to the protrusions are provided at a radially inner end of the second housing, and the protrusions are correspondingly coupled with the recesses; or,

one or more recesses recessed radially inward are provided at an outer peripheral portion of the axial portion, and one or more protrusions corresponding to the recesses are provided at a radially inner end of the second housing, the protrusions being correspondingly coupled with the recesses.

Furthermore, an auxiliary mounting structure is further arranged on the first friction ring.

Further, the diaphragm spring is made of metal, and the first friction ring is made of plastic.

Further, the dual mass flywheel further comprises a support and a second friction ring, which are arranged between the first housing and the secondary mass, in particular between the first housing and a hub part being part of the secondary mass, thereby defining an axial gap between the first housing and the secondary mass or the hub part,

the second friction ring is stepped in cross section and includes an axial portion, a first radial portion extending from the axial portion toward a radially outer side, and a second radial portion extending from the axial portion toward a radially inner side, the second radial portion being pressed against the secondary mass or the hub member by the support member.

Here, the radially inner end of the second housing is located radially inward of the dual mass flywheel with respect to the diaphragm spring. Thus, when the dual mass flywheel is installed between, for example, an engine and a transmission, the corresponding parts of the transmission do not directly contact the diaphragm spring, and deformation of the diaphragm spring during assembly can be avoided or reduced.

Drawings

FIG. 1A is a cross-sectional view of a prior art dual mass flywheel.

Fig. 1B is a schematic view of the second housing 12 of the prior art dual mass flywheel being lengthened.

Fig. 2 is a front view of a dual mass flywheel according to one embodiment of the present application.

Fig. 3 is an oblique perspective view of the dual mass flywheel shown in fig. 2.

Fig. 4A is a cross-sectional view of the dual mass flywheel taken along line Y-Y in fig. 2.

Fig. 4B is a cross-sectional view of the dual mass flywheel taken along line X-X in fig. 2.

Fig. 5A is an enlarged schematic view of the upper half in fig. 4A, and fig. 5B is an enlarged schematic view of the lower half in fig. 4A.

Fig. 6A is a partially enlarged perspective view of the dual mass flywheel shown in fig. 2, and fig. 6B is a partially cross-sectional enlarged schematic view of the dual mass flywheel shown in fig. 2.

Description of the reference numerals

1 primary mass

3 secondary mass

4 hub core

5 Flange

6 arc spring

7 centrifugal force pendulum unit

8 diaphragm spring

11 first casing

12 second casing

12A second housing extension

100 primary mass

110 first shell

111 radial part of the first housing

112 axial portion of the first housing

120 second shell

121 radially outer end of the second housing

122 radially inner end of the second casing

122G groove

200 spring

300 hub parts

310 hub core

320 hub flange

330 through hole for mounting bolt

400 flange

410 rivet

500 diaphragm spring

600 first friction ring

610 radial portion of a first friction ring

620 axial portion of first friction ring

700 support

800 second friction ring

810 axial portion of second friction ring

820 first radial part of second friction ring

830 second radial portion of the second friction ring

Central axis of O

Axial direction of AX

RA radial

C circumferential direction

Detailed Description

Exemplary embodiments of the present application are described below with reference to the accompanying drawings. It should be understood that the detailed description is only intended to teach one skilled in the art how to practice the present application, and is not intended to be exhaustive or to limit the scope of the application.

In the present application, unless otherwise specified, the axial direction, the radial direction, and the circumferential direction refer to the axial direction AX, the radial direction RA, and the circumferential direction C of the dual mass flywheel, respectively, the axially inner side refers to a side closer to the center of the dual mass flywheel in the axial direction AX, and the axially outer side refers to a side farther from the center of the dual mass flywheel in the axial direction AX; the radially inner side means a side close to the center axis O of the dual mass flywheel in the radial direction RA, and the radially outer side means a side away from the center axis O of the dual mass flywheel in the radial direction RA.

As shown in fig. 1A, the radial length of the second housing 12 (also sometimes referred to as a cover plate) is small. When the dual mass flywheel (hereinafter, sometimes simply referred to as a flywheel) is assembled with the engine and the transmission, the input shaft of the transmission may extend into the hub core 4, and the hub core 4 and the flange 5 may be inclined by the input shaft of the transmission, which may cause the diaphragm spring 8 to deform.

In order to prevent the diaphragm spring from being deformed, as shown in fig. 1B, the applicant has conceived a solution of lengthening the second housing 12 shown in fig. 1A, i.e., increasing the radial length of the second housing 12 so as to extend further toward the radially inner side, to form an extension 12A shown in fig. 1B.

However, it is desirable that the dual mass flywheel also have a waterproof function, and simply lengthening the second housing 12 shown in fig. 1A would allow a large gap S to exist between the second housing 12 (including the extension 12A) and the diaphragm spring 8, which gap S is likely to store some water. Thus, water is liable to enter the inside of the flywheel from a gap that may occur between the diaphragm spring 8 and the second housing 12, resulting in a grease failure inside the flywheel.

The following embodiments of the dual mass flywheel of the present application are made in view of the above circumstances.

As shown in fig. 2 through 6B, one embodiment of the present application provides a dual mass flywheel, which may include a primary mass 100, a spring 200, a secondary mass (which may include a hub member 300, a flange 400), and a diaphragm spring 500.

The primary mass 100 may include a first case 110 and a second case 120, the first case 110 and the second case 120 defining a spring receiving space in which the spring 200 is received. Here, the first housing 110 may be used to be connected to a power source such as an engine.

Here, for example, the first housing 110 may include a radial portion 111 extending substantially along the radial direction RA and an axial portion 112 extending from the radial portion 111 toward the second housing 120. The radially outer end 121 of the second housing 120 may be welded, for example, to the axial portion 112.

Here, as an example, the first housing 110 may be connected to a crankshaft of an engine.

The spring 200 may be an arc spring or a linear spring. By way of example only, the spring 200 may be a compound spring such as a metal spring, a rubber spring, an air spring, or a rubber-metal spiral compound spring.

The hub member 300 and the flange 400 may be integrally formed or separately provided and coupled to each other. The spring 200 is disposed between the primary mass 100 and the secondary mass to attenuate torsional vibrations, and more particularly, the spring 200 may be disposed between the primary mass 100 and the flange 400 to attenuate torsional vibrations. Here, the hub member 300 may serve as an output for outputting the torque from the first housing 110. Alternatively, the hub member 300 may also serve as an input, with the first housing 110 serving as an output.

Here, as an example, the hub member 300 may include a hub core 310 and a hub flange 320, and the hub flange 320 and the flange 400 may be fixedly coupled to each other by a plurality of coupling members, for example, rivets 410.

The diaphragm spring 500 is disposed in a compressed state between the secondary mass (more specifically, may be the flange 400) and the second housing 120 in the axial direction AX of the dual mass flywheel.

Here, the radially inner end 122 of the second housing 120 (or, in other words, the inner circumferential surface of the second housing 120) may be closer to the radially inner side of the dual mass flywheel than the radially inner end of the diaphragm spring 500; of course, the radially inner end 122 of the second housing 120 may be flush with the radially inner end of the diaphragm spring 500 in the radial direction RA. Thus, when the dual mass flywheel is installed between, for example, an engine and a transmission, the corresponding parts of the transmission do not directly contact the diaphragm spring 500, and deformation of the diaphragm spring 500 during assembly can be avoided or reduced.

The diaphragm spring 500 is located entirely at the radial inner end 122 of the second housing 120, and both the radial outer end of the diaphragm spring 500 and the radial inner end 122 of the second housing 120 are located radially inward of the dual mass flywheel, which means that a gap or space between the diaphragm spring 500 and the second housing 120 is small and water is not easily accumulated, so that the waterproof performance of the dual mass flywheel can be improved. Here, the flange 400 may include a base circle portion and flange wing portions protruding from the base circle portion toward a radially outer side, and the flange 400 may be rotated by pressing the flange wing portions by the spring 200. Alternatively, the base circle portions of the second housing 120 and the flange 400 overlap in the radial direction RA of the dual mass flywheel. That is, the second shell 120 and the base circle portion have portions at the same radial height, or, viewed in the axial direction AX, there is a shielding or overlap between the second shell 120 and the base circle portion.

Alternatively, referring to fig. 4B, the radial length W1 of the second housing 120 is greater than 1/3 of the radius R of the dual mass flywheel. Preferably, the radial length W1 of the second housing 120 is greater than 2/5 of the radius R of the dual mass flywheel.

Here, the radial length W1 of the second housing 120 refers to a length located in half of the axial cross section of the second housing 120.

Here, a larger length or elongated second housing 120 is proposed, and the radial length W1 of the second housing 120 is increased, meaning that the waterproof height of the dual mass flywheel is increased. The dual-mass flywheel is not easy to enter water, and the waterproof performance is improved.

Here, the radial length W1 of the second housing 120 is preferably less than 1/2 of the radius R of the dual mass flywheel. The radial length W1 of the second housing 120 is smaller than the radius R1/2 of the dual mass flywheel, so that the second housing 120 is not unnecessarily lengthened, and a sufficient space can be provided for the radially inner structures such as the rivet 410, the mounting bolt through hole 330, and the hub 310, which will be described later.

Alternatively, referring to fig. 4B and 5B, the radial length W2 of the diaphragm spring 500 is less than 1/5, and more preferably less than 1/9, of the radius R of the dual mass flywheel.

Optionally, radial length W2 of diaphragm spring 500 is less than 2/5 of radial length W1 of second housing 120, and preferably, radial length W2 of diaphragm spring 500 is less than 1/4 of radial length W1 of second housing 120.

Alternatively, referring to fig. 5A and 5B, the dual mass flywheel further includes a first friction ring 600 (may also be referred to as a diaphragm spring friction ring), the first friction ring 600 is at least partially disposed between the secondary mass (particularly the flange 400) and the diaphragm spring 500 in the axial direction AX, the diaphragm spring 500 is disposed between the first friction ring 600 and the second case 120, and a length of protrusion of the diaphragm spring 500 from the first friction ring 600 may be less than 1/2 of a radial length W2 of the diaphragm spring 500. Optionally, in the axial direction AX, the first friction ring 600 may also be at least partially disposed between the second housing and the diaphragm spring 500, the diaphragm spring 500 being disposed between the first friction ring 600 and the secondary mass.

Here, the diaphragm spring 500 having a small radial length is defined from different angles, which makes a gap between the diaphragm spring 500 and the second housing 120, which may constitute a water storage space, small, so that water is not likely to remain in the gap between the diaphragm spring 500 and the second housing 120 even when wading, and the waterproof performance of the dual mass flywheel can be improved.

Alternatively, referring to fig. 6B, the first friction ring 600 may include: an axial portion 620 extending along the axial direction AX; and a radial portion 610 extending from one axial end of the axial portion 620 in the radial direction RA of the dual mass flywheel.

Here, an inner circumferential portion of the diaphragm spring 500 may abut to the radial portion 610, and an outer circumferential portion of the diaphragm spring 500 may abut to the second housing 120. Alternatively, the inner peripheral portion of the diaphragm spring 500 may abut to the second housing 120, and the outer peripheral portion of the diaphragm spring 500 may abut to the radial portion 610.

Preferably, the axial portion 620 of the first friction ring 600 abuts the radially inner end 122 of the second housing 120 in the radial direction RA, so that at the circumferential contact surface of the axial portion 620 opposite the radially inner end 122, substantially no gap is present, whereby water is prevented from entering the interior of the dual mass flywheel from the gap between the axial portion 620 and the radially inner end 122. While the radial portion 610 of the first friction ring 600 abuts against the flange 400 under the axial force of the diaphragm spring 500, so that at the circumferential contact surface of the radial portion 610 opposite to the flange 400, there is substantially no gap, thereby making it possible to prevent water from entering the interior of the dual mass flywheel from the gap between the radial portion 610 and the flange 400. With this arrangement, it is possible to prevent both entry of water into the interior of the dual mass flywheel from the gap at the contact surface between the first friction ring 600 and the flange 400 (extending radially to the interior of the dual mass flywheel) and entry of water into the interior of the dual mass flywheel from the gap at the contact surface between the first friction ring 600 and the second housing 120 (extending axially to the interior of the dual mass flywheel) at the first friction ring 600, so that the gap between the flange 400 and the second housing 120 can be well sealed with the first friction ring 600 and the diaphragm spring 500, and entry of water into the interior of the dual mass flywheel from between the flange 400 and the second housing 120 can be prevented.

Alternatively, referring to fig. 2, 6A and 6B, the radially inner end 122 of the second housing 120 may be formed with a plurality of (e.g., three) grooves 122G, the axial portion 620 includes a plurality of (e.g., three) protrusions 620P protruding from an outer circumferential surface of the axial portion 620 toward the radially outer side, and the number and circumferential positions of the protrusions 620P correspond to those of the grooves 122G. Here, the protrusion 620P may be exemplified as the first structure, and the groove 122G may be exemplified as the second structure. The second structure may also be formed on the flange 400. The first structure is coupled to the second structure, so that the first friction ring 600 is connected to the second housing 120 or the flange in a rotationally fixed manner. When the dual mass flywheel is assembled, the protrusion 620P is received in the groove 122G, thereby preventing the first friction ring 600 from rotating with respect to the second housing 120, so that the diaphragm spring 500 does not rotate with respect to the second housing 120 or the first friction ring 600, and water does not easily enter the interior of the dual mass flywheel from a gap between the diaphragm spring 500 and the second housing 120 or the first friction ring 600. Here, the diaphragm spring 500 may be made of metal, and the first friction ring 600 may be made of plastic. The first friction ring 600 made of plastic is in direct contact with the diaphragm spring 500 made of metal, compared to the flange 400 made of metal, for example, being in direct contact with the diaphragm spring 500 made of metal.

When the first friction ring 600 is installed, as shown in fig. 6A-6B, the diaphragm spring 500 is first assembled with the first friction ring 600; then, each protrusion 620P is aligned with the corresponding groove 122G, and then each protrusion 620P is inserted into the groove 122G. During this insertion, the axial portion 620 of the first friction ring 600 is correspondingly inserted into the inside of the second housing 120. In addition, an auxiliary mounting (or tooling) structure may be provided at an end of the axial portion 620 opposite to the radial portion 610 to hold the first friction ring 600 during installation and transportation.

Although in this embodiment, the projection 620P is provided at the outer peripheral portion of the axial portion 620 of the first friction ring 600, the groove 122G is provided at the radially inner end 122 of the second housing 120; however, the groove may be a through hole. Alternatively, the outer circumference of the axial portion 620 may be provided as a groove, and the radial inner end 122 may be provided with a protrusion, the groove being coupled with the protrusion; alternatively, a protrusion and a groove are provided at an outer circumferential portion of the axial portion 620 of the first friction ring 600, and a groove and a protrusion are correspondingly and couplable provided at the radial inner end 122 of the second housing 120, the protrusion of the axial portion 620 is coupled with the groove of the radial inner end 122, and the groove of the axial portion 620 is coupled with the protrusion of the radial inner end 122.

Although in this exemplary embodiment the first friction ring 600 is connected in a rotationally fixed manner to the second housing 120, the first friction ring 600 may alternatively be connected in a rotationally fixed manner to the flange 400, in which case, for example, the first friction ring 600 can be inserted via its axial portion 620 into a corresponding structure on the flange 400, preferably in which case the axial portion 620 is of a circumferentially discontinuous structure, i.e. has a plurality of fingers, and correspondingly a plurality of recesses (in particular through holes) are provided on the flange 400, into which the fingers are inserted in order to connect the first friction ring 600 in a rotationally fixed manner to the flange 400; while the radial portion 610 of the first friction ring 600 abuts against the first housing 120.

Alternatively, referring to fig. 5A and 5B, the dual mass flywheel may further include a support 700 and a second friction ring 800 (may also be referred to as a support friction ring), the support 700 and the second friction ring 800 being disposed between the first housing 110 and the hub member 300 so as to define an axial gap between the first housing 110 and the hub member 300. The cross section (axial section) of second friction ring 800 may be stepped and include an axial portion 810, a first radial portion 820 extending from axial portion 810 toward the radial outside, and a second radial portion 830 extending from axial portion 810 toward the radial inside, second radial portion 830 being pressed against hub component 300 by support member 700.

The support member 700 and the second friction ring 800 may prevent water from entering the interior of the dual mass flywheel, particularly the position of the spring 200, from the gap between the hub member 300 and the first housing 110; in particular, for restricting the water, which enters the space between the hub member 300 and the first housing 110 from the mounting bolt through-hole 330, from entering the interior of the dual mass flywheel.

Here, the supporter 700 may have a structure bent toward the second friction ring 800 and in surface contact with the second radial portion 830. Here, the outer circumferential surface of the axial portion 810 may substantially contact the inner circumferential surface of the flange 400, and the inner circumferential surface of the axial portion 810 may substantially contact the outer circumferential portion of the support 700, which facilitates radial positioning of the second friction ring 800. Alternatively, since the support member 700 and the second radial portion 830 and the hub member 300 are pressed against each other in the axial direction such that there is no gap between the contact portions of the three, the outer circumferential surface of the axial portion 810 may not contact the inner circumferential surface of the flange 400, and the inner circumferential surface of the axial portion 810 may not contact the outer circumferential portion of the support member 700.

The curved structure and the large contact area of the support member 700 and the second friction ring 800 improve the waterproof performance of the dual mass flywheel.

Referring to, for example, fig. 5A, a plurality of mounting bolt through-holes 330 may be formed on a hub flange 320 of the hub member 300, and bolts may pass through the mounting bolt through-holes 330 to fix the support member 700 together with the first housing 110 to, for example, a crankshaft of an engine.

The second friction ring 800 is located radially outward of the mounting bolt through hole 330.

As described above, the present application provides a dual mass flywheel using an elongated second housing 120 and a small diaphragm spring 500, on one hand, the elongated second housing 120 increases the waterproof height of the dual mass flywheel; on the other hand, the diaphragm spring 500 is not easy to deform, the acting radius of the diaphragm spring 500 is reduced, and a diaphragm spring capable of providing larger axial force can be designed.

In the dual-mass flywheel, a water storage space is almost not available near the diaphragm spring 500, water is not easy to enter the inside of the flywheel from the diaphragm spring 500, grease in the flywheel can be prevented from losing efficacy due to water inflow, the waterproof performance of the flywheel can be obviously improved, and the performance and the durability of the dual-mass flywheel can be improved.

It should be understood that the above embodiments are merely exemplary, and are not intended to limit the present application. Various modifications and alterations of the above-described embodiments may be made by those skilled in the art in light of the teachings of this application without departing from the scope thereof.

Claims

1. A dual mass flywheel, comprising:

a spring (200);

a primary mass (100) comprising a first housing (110) and a second housing (120), the first housing (110) and the second housing (120) defining a spring receiving space in which the spring (200) is received;

a secondary mass, the spring (200) being disposed between the primary mass (100) and the secondary mass to damp torsional vibrations; and

a diaphragm spring (500), the diaphragm spring (500) being disposed in a compressed state between the secondary mass and the second housing (120) in an axial direction (AX) of the dual mass flywheel,

it is characterized in that the preparation method is characterized in that,

the radial inner end (122) of the second housing (120) is closer to the radial inner side of the dual mass flywheel than the radial inner end of the diaphragm spring (500), or the radial inner end (122) of the second housing (120) is flush with the radial inner end of the diaphragm spring (500) in the radial direction (RA) of the dual mass flywheel.

2. A twin mass flywheel as defined in claim 1 in which the radial length (W1) of the second casing (120) is greater than 1/3 of the radius (R) of the twin mass flywheel,

preferably, the radial length (W1) of the second housing (120) is greater than 2/5 of the radius (R) of the dual mass flywheel and less than 1/2 of the radius (R) of the dual mass flywheel.

3. A twin mass flywheel as defined in claim 1 in which the radial length (W2) of the diaphragm spring (500) is less than 1/5 of the radius (R) of the twin mass flywheel,

preferably, the radial length (W2) of the diaphragm spring (500) is less than 1/9 of the radius (R) of the dual mass flywheel.

4. A twin mass flywheel according to any of claims 1 to 3, characterised in that it further comprises a first friction ring (600), in the axial direction (AX), the first friction ring (600) being at least partially arranged between the secondary mass and the diaphragm spring (500), in particular between a flange (400) being at least part of the secondary mass and the diaphragm spring (500), the diaphragm spring (500) being arranged between the first friction ring (600) and the second housing (120); or,

in the axial direction (AX), the first friction ring (600) is arranged at least partially between the second housing and the diaphragm spring (500), the diaphragm spring (500) being arranged between the first friction ring (600) and the secondary mass.

5. A twin mass flywheel as defined in claim 4 in which the first friction ring (600) comprises:

an axial portion (620) extending along the axial direction (AX); and

a radial portion (610) connected to the axial portion and extending in a radial direction (RA) of the dual mass flywheel;

the axial portion has a first configuration and,

wherein a radially inner end (122) of the second housing (120) or a flange (400) is provided with a second structure corresponding to the first structure, the first structure being coupled to the second structure such that the first friction ring (600) is connected in a rotationally fixed manner to the second housing (120) or the flange.

6. A twin mass flywheel as defined in claim 5 in which the radial portion bears axially against the secondary mass or the second housing under the action of the diaphragm spring;

the axial portion radially abuts the second housing or the secondary mass.

7. A twin mass flywheel as defined in any of claims 4 to 6 in which one or more projections are provided at the outer peripheral portion of the axial portion, projecting radially outwards, and one or more recesses are provided at the radially inner end (122) of the second housing (120), corresponding to the projections, with which recesses the projections are correspondingly coupled; or,

one or more recesses recessed radially inward are provided at an outer peripheral portion of the axial portion, and one or more protrusions corresponding to the recesses are provided at a radially inner end (122) of the second housing (120), the protrusions being correspondingly coupled with the recesses.

8. A twin mass flywheel as defined in any of claims 4 to 7 in which the first friction ring is further provided with an auxiliary mounting formation thereon.

9. A twin mass flywheel as defined in any of claims 4 to 8 in which the diaphragm spring (500) is made of metal and the first friction ring (600) is made of plastic.

10. A dual mass flywheel according to any of claims 1 to 9, further comprising a support (700) and a second friction ring (800), the support (700) and the second friction ring (800) being arranged between the first housing (110) and the secondary mass, in particular between the first housing (110) and a hub component (300) being part of the secondary mass, thereby defining an axial gap between the first housing (110) and the secondary mass or the hub component (300),

the second friction ring (800) is stepped in cross-section and comprises an axial portion (810), a first radial portion (820) extending from the axial portion (810) towards a radially outer side and a second radial portion (830) extending from the axial portion (810) towards a radially inner side, the second radial portion (830) being pressed by the support (700) against the secondary mass or the hub component (300).