A FLYWHEEL ARRANGEMENT, A VEHICLE AND A METHOD OF MANUFACTURING A FLYWHEEL ARRANGEMENT

Abstract

A flywheel arrangement for an engine of a vehicle, includes: a flywheel configured to be connected to a crankshaft of the engine for common rotation around a center axis, a pendulum weight arranged between the center axis and a radially peripheral surface of the flywheel, the pendulum weight being movable with respect to the flywheel along a predetermined pendulum path, a ring member positioned radially outside of the pendulum weight, the ring member being connected for common rotation with the flywheel around the center axis, and at least one pair of cooperating bearing surfaces, each pair of cooperating bearing surfaces including an outer bearing surface provided on the ring member and an inner bearing surface provided on the pendulum weight, the at least one pair of cooperating bearing surfaces together defining the predetermined pendulum path.

Claims

1. A flywheel arrangement for an engine, comprising: a flywheel configured to be connected to a crankshaft of the engine for common rotation around a center axis, at least one pendulum weight arranged between the center axis and a radially peripheral surface of the flywheel, the at least one pendulum weight being movable with respect to the flywheel along a predetermined pendulum path, the flywheel arrangement further comprises a ring member positioned radially outside of the at least one pendulum weight, the ring member being connected for common rotation with the flywheel around the center axis, at least one pair of cooperating bearing surfaces, each pair of cooperating bearing surfaces comprising an outer bearing surface provided on the ring member and an inner bearing surface provided on the at least one pendulum weight, the at least one pair of cooperating bearing surfaces together defining the predetermined pendulum path of the at least one pendulum weight, wherein the flywheel is made of cast iron and the ring member is made of steel alloy.

2. The flywheel arrangement according to claim 1, further comprising at least one rolling element positioned between and configured to cooperate with the at least one pair of cooperating bearing surfaces to provide the predetermined pendulum path.

3. The flywheel arrangement according to claim 1, wherein, for each pendulum weight, the at least one pair of cooperating bearing surfaces comprises two angularly spaced pairs of cooperating bearing surfaces.

4. The flywheel arrangement according to claim 1, wherein the outer bearing surface is formed at least partly on a protrusion of the ring member, the protrusion extending radially inwards from an annular main portion of the ring member.

5. The flywheel arrangement according to claim 4, wherein the at least one pendulum weight comprises at least one pocket formed in connection with the inner bearing surface, the pocket being configured to receive at least a portion of the protrusion of the ring member when the pendulum weight moves along the predetermined pendulum path.

6. The flywheel arrangement according to claim 1, wherein the flywheel is made of grey cast iron, and/or wherein the ring member is made of a bearing steel alloy.

7. The flywheel arrangement according to claim 1, further comprising a plurality of separate key members by means of which the ring member is secured to the flywheel, each key member being fitted into a keyseat provided in the flywheel and attached to the ring member.

8. The flywheel arrangement according to claim 7, wherein the key members and the ring member are made of the same material.

9. The flywheel arrangement according to claim 7, wherein each key member is attached to a radially extending connection portion of the ring member.

10. The flywheel arrangement according to claim 9, wherein the at least one pendulum weight comprises at least two neighbouring pendulum weights, and wherein the radially extending connection portion is arranged between the two neighbouring pendulum weights.

11. The flywheel arrangement according to claim 7, wherein each key member is attached to the ring member by means of at least one fastening member, such as at least one pin.

12. The flywheel arrangement according to claim 1, wherein the ring member is press-fitted to the flywheel.

13. The flywheel arrangement according to claim 1, further comprising at least one stopping element positioned such that it defines an end point of the predetermined pendulum path, at which end point the at least one pendulum weight is configured to come into contact with the at least one stopping element, wherein the at least one stopping element is located radially inwardly with respect to the at least one pendulum weight.

14. The flywheel arrangement according to claim 1, further comprising a cover plate provided on a side face of the flywheel, which cover plate sealingly covers the pendulum weights.

15. A vehicle comprising a flywheel arrangement according to claim 1.

16. A method of manufacturing a flywheel arrangement, the flywheel arrangement comprising: a flywheel configured to be connected to a crankshaft of the engine for common rotation around a center axis, at least one pendulum weight arranged between the center axis and a radially peripheral surface of the flywheel, the at least one pendulum weight being movable with respect to the flywheel along a predetermined pendulum path, a ring member positioned radially outside of the at least one pendulum weight, the ring member being connected for common rotation with the flywheel around the center axis, at least one pair of cooperating bearing surfaces, each pair of cooperating bearing surfaces comprising an outer bearing surface provided on the ring member and an inner bearing surface provided on the at least one pendulum weight, the at least one pair of cooperating bearing surfaces together defining the predetermined pendulum path of the at least one pendulum weight, the method comprising: providing the flywheel configured to receive the at least one pendulum weight and the ring member, press-fitting the ring member to the flywheel and subsequently machining the ring member to form the at least one outer bearing surface, and mounting the at least one pendulum weight between the center axis and the radially peripheral surface of the flywheel.

17. The method according to claim 16, further comprising: prior to press-fitting the ring member, fitting a plurality of key members into keyseats of the flywheel, and after press-fitting the ring member, attaching radially extending connection portions of the ring member to the plurality of key members.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples.

[0047] In the drawings:

[0048] FIG. 1 schematically shows a vehicle according to an embodiment of the invention,

[0049] FIG. 2 is a perspective view of a flywheel according to an embodiment of the invention,

[0050] FIG. 3 is an exploded view of the flywheel arrangement in FIG. 2,

[0051] FIG. 4 is a planar view showing a portion of the flywheel arrangement in FIG. 2,

[0052] FIG. 5 is a cross-section along the line V-V in FIG. 4, and

[0053] FIG. 6 is a flow chart schematically illustrating a method according to an embodiment of the invention.

[0054] The drawings show diagrammatic exemplifying embodiments of the present invention and are thus not necessarily drawn to scale. It shall be understood that the embodiments shown and described are exemplifying and that the invention is not limited to these embodiments. It shall also be noted that some details in the drawings may be exaggerated in order to better describe and illustrate the invention. Like reference characters refer to like elements throughout the description, unless expressed otherwise.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

[0055] FIG. 1 schematically shows a vehicle 3 according to an embodiment of the invention. The vehicle 3 includes a powertrain 4 with an engine 5 connected to a crankshaft (not shown), to which a flywheel arrangement 1 is connected for common rotation. A drive shaft 6 connects the engine 5 to driving wheels 7 of the vehicle 3 via a transmission 8 connected to the flywheel via a clutch (not shown).

[0056] A flywheel arrangement 1 according to an embodiment of the invention is shown in closer detail in FIG. 2. Reference is also made to FIG. 3, in which the flywheel arrangement 1 is shown in an exploded view, and to FIG. 4, showing a portion of the flywheel arrangement in closer detail. The flywheel arrangement 1 includes a flywheel 100 configured to be connected to the crankshaft of the powertrain 4 for common rotation about a center axis C. A centrifugal pendulum absorber 2 is provided, comprising a plurality of pendulum weights 200, in the shown embodiment five pendulum weights 200, which are circumferentially arranged between the center axis C and a radially peripheral surface 101 of the flywheel 100, facing a side face 103 of the flywheel 100. Radially outside of the pendulum weights 200, a ring member 300 is arranged, connected for common rotation with the flywheel 100 around the center axis C.

[0057] Each pendulum weight 200 comprises two angularly spaced concavely curved inner bearing surfaces 201 facing the ring member 300. The ring member 300 in turn, for each pendulum weight 200, comprises two concavely curved outer bearing surfaces 301, each outer bearing surface 301 facing one of the inner baring surfaces 201. Thus, an outer bearing surface 301 and an inner bearing surface 201 together form a pair of cooperating bearing surfaces 201, 301. Between each pair of cooperating bearing surfaces 201, 301, a rolling element 400 in the form of a roller is positioned, configured to be in rolling contact with the bearing surfaces 201, 301. The pendulum weight 200 is thereby movable with respect to the flywheel 100 along a predetermined pendulum path, herein a tautochrone curve, which predetermined pendulum path is defined by the two pairs of cooperating bearing surfaces 201, 301 and the rolling elements 400.

[0058] The pendulum weight 200 has a basic shape of an annulus sector as seen in a plane (or section) perpendicular to the central axis C. Thus, an outer peripheral surface 206 of the pendulum weight 200, facing the ring member 300, is a convex surface with a first radius of curvature, and an inner peripheral surface 207 of the pendulum weight 200 is a concave surface with a second radius of curvature, which is smaller than the first radius of curvature. The inner bearing surfaces 201 are provided on recesses 205 formed in the outer peripheral surface 206 of the pendulum weight 200.

[0059] The pendulum weights may be formed in one piece, but they may also be formed as two pieces which are assembled to form the pendulum weight. For example, the pendulum weight may comprise a radially outward portion and a separate radially inward portion which are assemblable to form the pendulum weight, wherein the inner bearing surfaces and the pockets are provided on the outward portion. This facilitates mounting of the pendulum weights in the flywheel arrangement.

[0060] The ring member 300 comprises an annular main portion 303 and a plurality of protrusions 302 extending radially inwards from the annular main portion (303). The outer bearing surface 301 is formed at least partly on such a protrusion 302. The pendulum weight 200 comprises two pockets 202 formed in the outer peripheral surface 206 in connection with each of the inner bearing surfaces 201, wherein each pocket 202 is configured to receive a portion of one of the protrusions 302 during use of the flywheel arrangement 1, when the pendulum weight 200 moves along the predetermined pendulum path.

[0061] The ring member 300 further comprises a plurality of radially extending connection portions 304, extending radially inwards from the annular main portion 303. Each radially extending connection portion 304 is arranged between two neighbouring pendulum weights 200.

[0062] A plurality of key members 700 are further provided, by means of which the ring member 300 is secured to the flywheel 100. Each key member 700 is, as shown in a sectional view in FIG. 5, fitted into a radially extending keyseat 102 provided in the flywheel 100 and each key member 700 is further attached to the radially extending connection portion 304 of the ring member 300 using fastening members in the form of e.g. nails, pins or screws via a hole 800 extending through the ring member 300 and at least partly into the key member 700. The key members 700 and the ring member 300 may thus be formed as separate pieces, but they may also be formed in one piece. The key members 700 and the ring member 300 may be made of the same material.

[0063] The flywheel arrangement 1 further comprises a plurality of stopping elements 500, each stopping element 500 being located radially inwardly with respect to the at least one pendulum weight 200. Each stopping element 500 abuts a radially inner portion of the connection portion 304 and is attached to a seat 104 of the flywheel 100. It is positioned such that it defines end points of the predetermined pendulum paths of two neighbouring pendulum weights 200, at which end points the pendulum weights 200 are configured to come into contact with the stopping element 500. The stopping elements are fastened using screws 501.

[0064] The flywheel arrangement 1 further comprises a cover plate 600 mounted to the ring member 300 and to the side face 103 of the flywheel by means of screws 601, 602, which cover plate sealingly covers the pendulum weights 200 such that a plurality of closed compartments B are formed, each pendulum weight 200 being located in one of the closed compartments B. Extending between each two neighbouring closed compartments, a channel 306 for fluid is provided in-between the cover plate 600 and the connection portion 304 of the ring member 300, fluidly connecting the two compartments B. Thus, lubricant may flow between the closed compartments during use of the flywheel arrangement 1. It is to be noted that the cover plate 600 has been removed in FIGS. 2 and 4.

[0065] The ring member 300 further comprises a ring gear 305, which may be a separate part or which may be formed integrally with the ring member 300.

[0066] FIG. 6 schematically shows a method of manufacturing a flywheel arrangement 1 according to an embodiment of the invention. Optional steps are marked with dashed lines.

[0067] In a first step S1, a flywheel 100 configured to receive the pendulum weights 200 and the ring member 300 is provided.

[0068] In an optional second step S2, a plurality of separate key members 700 are fitted into the keyseats 102 of the flywheel 100.

[0069] In a subsequent third step S3, the ring member 300 is press-fitted to the flywheel. In a fourth step S4, carried out after the third step S3, the ring member 300 is machined to form the outer bearing surfaces 301.

[0070] In the case where separate key members 700 were fitted in step S2, a fifth step S5 is carried out, in which radially extending connection portions 304 of the ring member 300 are attached to the plurality of key members 700, which have previously been fitted into the keyseats 102 of the flywheel 100.

[0071] In a sixth step S6, the pendulum weights 200 and, if applicable, the rolling elements 400, are mounted between the center axis C and the radially peripheral surface 101 of the flywheel 100. If assemblable pendulum weights are used, this step comprises assembling the pendulum weights in place.

[0072] The method may further comprise steps of attaching stopping members 500 and a cover plate 600 (not shown).

[0073] It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.