WO2015165511A1

WO2015165511A1 - A transverse segment for a pushbelt for a continuously variable transmission with a protruding tilting zone

Info

Publication number: WO2015165511A1
Application number: PCT/EP2014/058783
Authority: WO
Inventors: Lichao PAN
Original assignee: Robert Bosch Gmbh
Priority date: 2014-04-30
Filing date: 2014-04-30
Publication date: 2015-11-05
Also published as: CN106461020B; JP6542260B2; JP2017515070A; CN106461020A

Abstract

The invention concerns a transverse segment (32) for a drive belt (3) for a belt-and-pulley-type continuously variable transmission with a number of such transverse segments (32) and an endless carrier (31) that is located, at least in part, in an opening (33) of the transverse segments (32) such that the transverse segments (32) are movable along the circumference of the carrier (31). The transverse segment (32) is provided with a protrusion (50) on one side thereof, which protrusion (50) adjoins the opening (33) and that extends in parallel therewith, and, on its opposite side, with a recess (51), which recess (51) likewise adjoins the opening (33) and extends in parallel therewith.

Description

A TRANSVERSE SEGMENT FOR A PUSHBELT FOR A CONTINUOUSLY VARIABLE TRANSMISSION WITH A PROTRUDING TILTING ZONE

This disclosure relates to a transverse segment that is destined to be part of a pushbelt-type drive belt for a continuously variable transmission. A pushbelt for a continuously variable transmission is commonly known. Such a pushbelt comprises at least one, but usually two endless, i.e. ring-shaped carriers that are each composed of a number of concentrically mounted continuous bands, which carriers carry a number of transverse segments. The transverse segments are movably arranged along the entire circumference of the carriers and transmit forces that are related to the operation of the transmission wherein the pushbelt is provided .

In the following description of the transverse segment, the mentioned directions refer to the situation in which the transverse segment is part of the pushbelt. A longitudinal or thickness direction of the transverse segment corresponds to a circumferential direction of the pushbelt. A vertical or height direction of the transverse segment corresponds to a radial direction of the pushbelt. A horizontal or width direction of the transverse segment corresponds to a direction perpendicular to both the longitudinal direction and the vertical direction. The indication of any transverse segment as a leading transverse segment or a trailing transverse segment with respect to an adjacent transverse segment is related to a direction of movement, i.e. direction of rotation of the pushbelt as a whole during operation in the transmission.

The transverse segment is provided with at least one opening for at least partially receiving at least one endless carrier. For contacting the radial inside of the endless carrier, the transverse segment comprises a carrier contacting surface that represents the radial inside or lower boundary of the opening. For the purpose of contacting the conical sheaves of a pulley of the continuously variable transmission, the transverse segment is on both sides, as seen in the horizontal direction, provided with pulley sheave contacting surfaces that mutually diverge in radially outward direction at an angle that corresponds to the angle that is defined by and between the conical pulley sheaves.

As seen in the vertical direction, the thickness of the transverse segment reduces to allow the adjacent transverse elements to mutually rotate about the horizontal direction, whereby the pushbelt as a whole follows a curved trajectory such as is required between the conical pulley sheaves. Typically, an upper portion of the transverse segment is provided with an essentially constant thickness, whereas a thickness of a lower portion thereof decreases in downward direction. Such thickness decrease can be stepwise, but normally includes a convexly curved part of at least one of the main faces of the transverse segment that are oriented in the longitudinal, i.e. circumferential directions of the pushbelt.

The said convexly curved part of the respective main face, which respective main face is, hereinafter, named the front main face, is often referred in the art either as a rocking edge or as a tilting zone. This convexly curved part forms a transition between a top part of the front main face, which top part is oriented parallel to the respectively opposite, i.e. back main face of the transverse segment, and a bottom part thereof, which bottom part is slanted towards the back main face in radial inward direction. This particular design of the transverse segment is, for example, known from the Japanese patent publication JP 2000-065153 (A) .

In an alternative design of the transverse segment that is known from JP 58-081252 (A) , the said transition between the parallel top part of the front main face and the slanted bottom part of the transverse segment is provided by an essentially semi- cylindrical ridge that protrudes in longitudinal direction relative to the front main face. For accommodating the ridge, a groove is provided in the back main face of the transverse segment, such that in the pushbelt the protruding ridge of a respectively trailing transverse segment is located in the groove of a respectively leading transverse segment. A principal advantage of this latter transverse element design is that in the pushbelt adjacent transverse segments remain in contact over the relatively large surface area of the ridge also in the curved trajectory of the pushbelt. Furthermore, such a ridge and groove connection between the adjacent transverse segments positions these relative to one another in the vertical direction and favourably prevents a relative a rotation about the longitudinal direction there between.

During operation of the pushbelt, the endless carrier will slip, i.e. will move relative to the transverse segments, which movement is accompanied by an unwanted loss of power by friction (heat) . Such power loss can be minimised by minimising the vertical separation between the carrier contacting surface and the tilting zone, because a longitudinal or slip speed of the endless carrier relative to the transverse segments is known to be proportional to such separation. In the design of the transverse segment according to JP 2000-065153 (A) the tilting zone can in theory adjoin the carrier contacting surface to reduce the said slip speed to zero, although in practice several restrictions apply in this respect, most notably restrictions posed by the preferred manufacturing processes of blanking and stone tumbling the transverse. However, in the design of the transverse segment according to JP 58-081252 (A) the ridge can only be provided at some distance is necessarily positioned at some distance below the carrier contacting surface. That is to say that although the protruding convex curvature of the ridge can be in theory be designed to adjoin the carrier contacting surface, it will continue there from in radial inward direction over the width of the convex curvature defining it.

The present disclosure seeks to combine at least some of the advantage features of both such known designs. In particular, the present disclosure seeks to provide for a design of the transverse segment, more in particular of the transition between the parallel top part of the front main face of the transverse segment and the slanted bottom part thereof, that is both located favourably close to or even adjoins the carrier contacting surface and that favourably provides a contact area between adjacent transverse segments in the pushbelt instead of just a contact line.

According to the present disclosure, the carrier contacting surface of the transverse segment extends from in between the main faces thereof to beyond one such main face. Preferably, the carrier contacting surface is connected to the bottom part of said one main face via a convexly curved transition surface and to the respective other one main face of the transverse segment via a concavely curved transition surface. In the pushbelt, the thus protruding part of the carrier contacting surface of a respectively trailing transverse segment is accommodated in the recess formed between the said other one main face and the carrier contacting surface by the concavely curved transition surface of the leading transverse segment. Hereby, the said convexly curved transition surface of the trailing transverse segment constitutes the tilting zone thereof, which latter transition surface arrives in sliding contact with the concavely curved transition surface of the leading transverse segments to allow these adjacent transverse segment to mutually rotate about the horizontal direction.

In this latter, novel design of the transverse segment the tilting zone is not only be provided favourably close, even adjacent to the carrier contacting surface, but also the said transition surfaces define a relatively large surface area that is favourably available for the contact between the adjacent transverse segments in the pushbelt.

It is noted that hereinafter the transverse segment is described with the protrusion being formed on the front side thereof and with the recess being formed on the back side thereof, however, this can just as well be the other way around without alternating the present disclosure.

Preferably, according to the present disclosure both a first or front one and a second or back one of the transition surfaces are defined by an essentially constant radius of curvature, i.e. are shaped as a circular arc. More preferably, the centre of curvature of the front transition surface lies in the said plane defined by the top part of the front main face. More preferably, the centre of curvature of the back transition surface lies in a plane defined by at least a part of the back main face.

Preferably, the radius of curvature of the front transition surface amounts to essential half the thickness of the transverse segment. More preferably, the radius of curvature of the back transition surface also amounts to essential half the thickness of the transverse segment.

Preferably, the carrier contacting surface is oriented slightly downwards in the vertical direction as seen in a direction from the back main face to the front main face. More preferably, an angle between the carrier contacting surface and a line perpendicular to the back main face of the transverse segment essentially corresponds to a largest angle of rotation possible between two adjacent transverse segments in the pushbelt and/or to the angle of rotation between two adjacent transverse segments that is associated with a smallest running radius of the pushbelt in the transmission.

The above-described, novel transverse segment will now be explained further with reference to the drawing, in which equal reference signs indicate equal or similar parts and in which:

figure 1 is a schematic side view of a continuously variable transmission having a pushbelt;

figure 2 is a front view of a known transverse segment for a pushbelt for a continuously variable transmission;

figure 3 is a side view of the known transverse segment of figure

2; figure 4 is a front view of a novel transverse segment in accordance with the present disclosure;

figure 5 is a side view of the novel transverse segment of figure 4;

figure 6 is an isometric projection of the novel transverse segment of figures 4 and 5;

figure 7 schematically represents an array of a number of

consecutive novel transverse segments in accordance with the present disclosure; and

figure 8 represents a side view of two further embodiments of the novel transverse segment.

Figure 1 schematically shows a continuously variable transmission, such as for utilization in a motor vehicle. The continuously variable transmission comprises two pulleys 1 and 2 arranged on respective pulley shafts 6, 7. A drive belt 3 is provided in a closed loop around the pulleys 1, 2 and serves for transmitting torque between the pulley shafts 6, 7. The pulleys 1, 2 are each provided with two pulley sheaves 4 and 5, with the drive belt 3 being positioned and clamped between said two pulley sheaves 4, 5 of each pulley 1, 2. Thus, a force may be transmitted between the pulleys 1, 2 by the drive belt 3 with the aid of friction there between .

In the illustrated configuration of the transmission, the upper pulley 1 will rotate more quickly than the lower pulley 2. By changing the distance between the two conical sheaves 4, 5 of the pulleys 1, 2, the so-called running radius R of the drive belt 3 on each pulley 1, 2 can be changed in a mutually coordinated manner and, as a result, a (transmission) ratio between the rotational speeds of the two pulleys 1, 2 can be varied.

The drive belt 3 of figure 1 includes a flexible endless carrier 31 and an essentially contiguous row of transverse segments 32 that are mounted on and arranged along the circumference of the endless carrier 31. The transverse segments 32 are provided moveable with respect to the endless carriers 31, at least in the circumferential direction thereof, such that a torque can be transmitted between the transmission pulleys 1, 2 by the transverse segments 32 pressing against one another and pushing each other forward along the endless carrier 31 in a direction of rotation of the pushbelt 3 and of the pulleys 1, 2. This particular type of drive belt 3 is well-known and is commonly denoted as a pushbelt 3. The transverse segments 32 and the endless carriers 31 of the pushbelt 3 are typically made of metal, usually a steel alloy. The transverse segments 32 take-up a clamping force exerted between the sheaves 4, 5 of each pulley 1, 2 via contact faces 37 thereof (see figures 2 and 3) , one such contact face 37 being provided at each axial side of each transverse segment 32, which contact faces 37 are mutually diverging in radial outward direction at an V-angle Φ that essentially matches a sheave angle Φ defined between the sheaves 4, 5 of each pulley 1, 2.

In Figure 2, the pushbelt 3 is shown in a cross section thereof facing in the circumferential direction thereof, i.e. facing in a direction perpendicular to the axial or width direction W and the radial or height direction H of the belt 3, which pushbelt circumferential direction corresponds to a longitudinal or thickness direction T of the transverse segment 32.

Figure 2 reveals the presences of two endless carriers 31 that are shown in cross-section in this figure 2 and that carry and guide the transverse segments 32 of the pushbelt 3, whereof one transverse segment 32 is shown in front elevation. In this exemplary embodiment of the pushbelt 3 the endless carriers 31 are shown to be composed of five individual continuous bands 43 each, which bands 43 are mutually concentrically nested to form the endless carrier 31. In practice, however, the endless carriers 31 often comprise more than five endless bands 43, e.g. nine or twelve or possible even more.

The transverse segments 32 of the pushbelt 3, whereof a side elevation is shown in Figure 3, has two main faces 38 and 39 that are oriented in mutually opposite circumferential directions of the pushbelt 3. In the following, a front main face of the main faces

38, 39 is indicated in general by the reference sign 38, whereas a back main face thereof is indicated in general by the reference sign

39. In the pushbelt 3, at least a part of the front main face 38 of the transverse segment 32 abuts against at least a part of the back main surface 39 of a respectively leading transverse segment 32, whereas at least a part of the back main face 39 of the transverse segment 32 abuts against at least a part of the front main face 38 of a respectively trailing transverse segment 32, such that a pushing force can be exerted between these adjacent transverse segments 32.

In order to accommodate the endless carriers 31, the transverse segment 32 is provided with two cut-outs 33, one on either lateral side of a central, middle portion 35 thereof. As a result, a lower portion 34 of the transverse segment 32 is located below the endless carriers 31, the middle portion 35 of the transverse segment 32 is located in between the endless carriers 31 and an upper portion 36 of the transverse segment 32 is located above the endless carriers 31. The surface parts of the lower portion 34 of the transverse segment 32 at the location of the cut-outs 33 that face upwards, generally towards the upper portion 36 of the transverse segment 32, and that arrive in contact with the radial inside of the endless carrier 31, are called the carrier contacting surfaces 42 of the transverse segment 32. These carrier contacting surfaces 42 thus extend between the front and back main faces 38, 39 of the transverse segment 32.

Furthermore, the transverse segment 32 is shown to be provided with a projection 40 that protrudes from its front main face 38 thereof and with a corresponding hole 41 that is provided in its rear main face 39. In the pushbelt 3, the projection 40 of the trailing transverse segment 32 is at least partially located in the hole 41 of the leading transverse segment 32, such that mutual displacement of these adjacent transverse segments 32 in a plane perpendicular to the circumferential direction of the pushbelt 3 is prevented or, at least, limited.

At least in the exemplary embodiment of the transverse segment 32 in figures 2 and 3, the back main face 39 thereof is essentially flat, whereas its front main face 38 is provided with a so-called tilting zone 18 that forms, in the height direction H, the transition between a top part of the front main face 38, extending essentially in parallel with its back main face 39, and a bottom part thereof that is slanted towards the back main face 39. The tilting zone 18 allows the adjacent transverse segments 32 to mutually rotate at entering or exiting the pulleys 4, 5, even when these are mutually abutting and the said pushing force is exerted there between. Although, figures 2 and 3 indicate the tilting zone 18 only schematically by way of a single line, in practice the tilting zone 18 is mostly provided in the shape of a convexly curved surface.

The present disclosure provides for an alternative, novel design of the transverse segment 32, in particular of the tilting zone 18 thereof, which alternative design aims to provide a favourable mutual contact of the adjacent transverse segments 32 in the pushbelt 3, at least in terms of an improved wear resistance and/or efficiency thereof. An embodiment of such novel transverse segment 32 is illustrated in the figures 4, 5 and 6, whereof figure 4 provides a front elevation, whereof figure 5 provides a cross- section along the line A-A in figure 4 and whereof figure 6 provides an (isometric) 3D view.

In the illustrated embodiment of the transverse segment 32 according to the present disclosure, the carrier contacting surfaces 42 thereof extend from in between the back main face 39 and the front main face 38 to beyond the front main face 38 of the transverse segment 32. Hereby, a protrusion 50 is formed between on the front side of the transverse segment 32 (i.e. the side associated with the front main face 38) and a recess 51 is formed on the back side 39 thereof (i.e. the side associated with the back main face 39) . In the pushbelt 3, such projection 50 of a trailing transverse segment 32 is accommodated in the recess 51 of a leading transverse segment 32 (see also figure 7), such that these transverse segments 32 can rotate relative to one another about the axial direction of the pushbelt 3. It is noted that the fulcrum point of such relative rotation is determined by the shape of the projection 50 and recess 51. It is further noted that although the transverse segment 32 is described with the protrusion 50 being formed on the front side 38 thereof and with the recess 51 being formed on the back side 39 thereof, this can also be the other way around without alternating the teaching of the present disclosure.

In the illustrated embodiment of the transverse segment 32 the carrier contacting surfaces 42 thereof are connected to the bottom part of the front main face 38 via convexly curved front transition surfaces 52. Furthermore, the carrier contacting surfaces 42 of the transverse segment 32 are connected to the back main face 39 via concavely curved front transition surfaces 53. Since the top part of the front main face 38 and the back main face 39 are oriented in the height direction and since the carrier contacting surfaces 42 are oriented, at least approximately, in the thickness direction, the front transition surfaces 52 and the back transition surface 53 provided there between include an angle of approximately 90 degrees, thus forming protrusions 50 and recesses 51 that effectively define a quarter cylinder segment.

In this novel design of the transverse segments 32, the said relative rotation thereof is accompanied by the convexly curved front transition surface 52 of the projections 50 sliding along and in contact with the concavely curved back transition surface 53 of the recesses 51. To allow the said transition surfaces 52, 53 to mutually slide smoothly, these are both shaped according to a circle segment. Also for this purpose, the centre of curvature of the front transition surface 52, which centre also serves as the fulcrum point for the relative rotation between the adjacent transverse segments 32 in the pushbelt 3, coincides with the front main face 38 of a respective transverse segment 32, whereas such centre of curvature of the back transition surface 53 coincides with the back main face 38 thereof. Furthermore, for the same purpose the centres of curvature of the front transition surface 52 and of back the transition surface 53 preferably lies in the plane defined by the carrier contacting surfaces 42. Finally for the same purpose, the radius of curvature of the front transition surface 52 and of the back transition surface 53 amounts to essentially half the thickness of the transverse segment 32. Or, in other words, essentially one half of the carrier contacting surfaces 42 is located in between the back main face 39 and the front main face 38, whereas the other half of the carrier contacting surfaces 42 protrudes beyond the front main face 38 of the transverse segment 32.

With the above-described design thereof, the front and back transition surfaces 52, 53 define a relatively large surface area that is favourably available for the contact between the adjacent transverse segments 32 in the pushbelt 3. As a result, a contact pressure exerted between the adjacent transverse segments 32 during operation of the pushbelt is favourably relatively low. Additional- ly, the fulcrum point of the required relative rotation of such adjacent transverse segments 32 lies close to or even coincides with the carrier contacting surfaces 42, whereby the movement of the endless carrier 31 relative of the transverse segments 32 during operation of the pushbelt 3 -and hence the unwanted power loss associated therewith- is minimal only.

It is noted that in the novel design of the transverse segment 32 a rounded transition edge between the front main face 38 and the carrier contacting surfaces 42, which is normally formed in manufacturing or which results from wear during operation, has no impact on the location of the said fulcrum point whatsoever. In contrast thereto, in the conventional transverse segment 32, such rounded transition edge requires a vertical separation to be applied between the carrier contacting surface 42 and the tilting zone 18 to the detriment of the overall torque transmission efficiency of the transmission.

It is further noted that, when adjacent ones of the novel transverse segments 32 are mutually rotated, an effective thickness of these novel transverse segments 32 in the circumference direction of the pushbelt favourably remains constant. In contrast thereto, when adjacent ones of the conventional transverse segment 32 are increasingly rotated relative to one another, a line of contact there between displaces in radially inward direction along the tilting zone 18, whereby the effective thickness of these conventional transverse segments 32 decreases, thereby disadvanta- geously increasing a play or clearance in the row of transverse segments 32 of the pushbelt 3.

In figure 7 a number of consecutive novel transverse segments 32 in accordance with the present disclosure are depicted to illustrate the mutual orientation thereof as it occurs in the pushbelt 3. To the left and right side of figure 7 three transverse segments 32 are depicted in a rotated orientation relative to the transverse segment 32 that respectively precedes (figure 7 left side) or succeeds (figure 7 right side) . In the middle of figure 7 four mutually aligned transverse segments 32 are depicted, i.e. whereof the top part of the front main face 38 and of back main face 39 are oriented in parallel.

From figure 7 it appears that the relatively rotated transverse segments 32 are in mutual contact via (at least) the front and back transition surfaces 52, 53 of the projections 50 and recesses 51 thereof. Furthermore, it appears from figure 7 that, as a result of the relative rotation between adjacent transverse segments 32, the orientation of the carrier contacting surfaces 42 relative to the local circumferential direction of the pushbelt 3 changes. Therefore, the carrier contacting surfaces 42 extend at least slightly in downward direction as seen in the direction from the recess 51 to the projection 50 and relative to the virtual line VL that is oriented perpendicular to the back main face 39 and the said top part of the front main face 38. In this respect it is advantageous that the edges of the carrier contacting surfaces 42 do not protrude between adjacent transverse segments 32, not even in the most strongly curved part of the trajectory of the pushbelt 3 in the transmission, in which trajectory part an angle l of relative rotation between the adjacent transverse segments 32 is largest. Thus, preferably, the carrier contacting surfaces 42 are oriented at an angle 2 relative to the said virtual line VL that corresponds to the said angle al of the largest relative rotation between the transverse segments 32. Furthermore in the preferred embodiment of the transverse segments 32 of figure 7, the centre of curvature CoC of the front transition surface 52 of a respective transverse segment 32 coincides with a point of intersection between the top part of the front main face 38 and a tangent line VL of the carrier contacting surfaces 42 oriented perpendicular to the top part of the front main face 38.

Two further embodiments of the novel transverse segment 32 in accordance with the present disclosure are illustrated in the figure 8 in a cross-section thereof. In the embodiment on the left side of figure 8, the centre of curvature CoC of the front transition surface 52, although still coinciding with the front main face 38 of the transverse segment 32, lies above (the plane defined by the) carrier contacting surface 42. Alternatively, in the embodiment on the right side of figure 8, the centre of curvature CoC of the front transition surface 52 lies below carrier contacting surface 42. By selecting one of these latter two embodiments of the novel transverse segment 32 the direction of the slip of the endless carrier 31 relative to the transverse segments 32 is controlled, whereas by the vertical separation between a respective centre of curvature CoC of the front transition surface 52 and the carrier contacting surface 42 controls the slip speed.

The present disclosure, in addition to the entirety of the preceding description and all details of the accompanying figures, also concerns and includes all the features of the appended set of claims. Bracketed references in the claims do not limit the scope thereof, but are merely provided as non-binding examples of the respective features. The claimed features can be applied separately in a given product or a given process, as the case may be, but it is also possible to apply any combination of two or more of such features therein.

The invention (s) represented by the present disclosure is (are) not limited to the embodiments and/or the examples that are explicitly mentioned herein, but also encompasses amendments, modifications and practical applications thereof, in particular those that lie within reach of the person skilled in the relevant art .

Claims

1. Transverse segment (32) for a drive belt (3) with a number of such transverse segments (32) and an endless carrier (31) that is located, at least in part, in an opening (33) of the transverse segments (32) such that the transverse segments (32) are movable along the circumference of the carrier (31), characterized in that, on one side of the transverse segment (32) a protrusion (50) is provided, which protrusion (50) adjoins the opening (33) and extends in parallel therewith, and in that on the opposite of the transverse segment (32) a recess (51) is provided, which recess (51) likewise adjoins the opening (33) and extends in parallel therewith.

2. Drive belt (3) with an endless carrier (31) and a number of transverse segments (32) according to claim 1, characterized in that the protrusion (50) of a respectively trailing transverse segment (32) of a pair of adjacent transverse segments (32) in the drive belt (3) is located in the recess (51) of a respectively leading transverse segment (32) of such pair.

3. Transverse segment (32) for a drive belt (3) with a number of such transverse segments (32) and an endless carrier (31) that is located, at least in part, in an opening (33) of the transverse segments (32) such that the transverse segments (32) are movable along the circumference of the carrier (31) while arriving in contact therewith through a carrier contacting surface (42) of a respective transverse segment (32) of the drive belt (3), at least a top part (36) of the transverse segment (32) that is located outside of the endless carrier (31) extends in thickness direction between a first main face (38) and a second main face (39) of the transverse segment (32) that are oriented in mutually opposite circumference directions of the endless carrier (31), characterized in that, in the circumference direction the carrier contacting surface (42) extends from in between the main faces (38, 39) of the transverse segment (32) to beyond a first (38) one thereof.

4. The transverse segment (32) according to claim 3, characterized in that the carrier contacting surface (42) is connected to the first main face (38) via a convexly curved first transition surface (52) and wherein the carrier contacting surface (42) is connected to the second main face (39) via a concavely curved second transition surface (53)

5. The transverse segment (32) according to claim 4, characterized in that the first transition surface (52) and the second transition surface (53) are arc-shaped.

6. The transverse segment (32) according to claim 5, characterized in that the first transition surface (52) and the second transition surface (53) are shaped according to circular arc.

7. The transverse segment (32) according to claim 6, characterized in that a radius of curvature of the first transition surface (52) and a radius of curvature of the second transition surface (53) are equal .

8. The transverse segment (32) according to claim 7, characterized in that the radius of curvature of the first transition surface (52) and the radius of curvature of the second transition surface (53) amount to approximately half a thickness dimension of the transverse segment (32 ) .

9. The transverse segment (32) according to claim 5, characterized in that a centre of curvature (CoC) of the first transition surface (52) essentially coincides with a plane defined by the first main face (52) of the transverse segment (32) .

10. The transverse segment (32) according to claim 5 or 9, characterized in that a centre of curvature of the second transition surface (53) essentially coincides with a plane defined by the second main face (52) of the transverse segment (32) .

11. The transverse segment (32) according to claim 5, 9 or 10, characterized in that a centre of curvature (CoC) of the first transition surface (52) and/or a centre of curvature of the second transition surface (53) essentially coincides with the carrier contacting surface (42) .

12. The transverse segment (32) according to any one of the claims 3-11, characterized in that, as seen in a direction from to the second main face (39) to the first main face (38), the carrier contacting surface (42) is inclined away from the top part (36) of the transverse segment (32), whereby it is oriented at an angle relative to a line oriented perpendicular to the second main face (39) of the transverse segment (32) .

13. The transverse segment (32) according to claim 12, characterized in that, the angle between the carrier contacting surface (42) and a line perpendicular to the second main face (39) of the transverse segment (32) essentially corresponds to a largest angle of rotation possible between two adjacent transverse segments (32) in the drive belt (3) .

14. Drive belt (3) with an endless carrier (31) and a number of transverse segments (32) according to any one of the claims 3-13, characterized in that the carrier contacting surfaces (42) of the adjacent transverse segments (32) in the drive belt (3) form an essentially continuous surface.

15. Continuously variable transmission comprising two pulleys (1, 2) and a drive belt (3) with an endless carrier (31) and a number of transverse segments (32) according to claim 12, characterised in that, the angle between the carrier contacting surface (42) and a line perpendicular to the second main face (39) of the transverse segment (32) essentially corresponds to the angle of rotation between two adjacent transverse segments (32) that is associated with a smallest running radius that is imposed by the transmission pulleys (1, 2) onto the drive belt (3) .