阅读说明：本技术 用于无级变速器的传动带的横向部段和包括该横向部段的传动带 (Transverse segment for a drive belt for a continuously variable transmission and drive belt comprising such a transverse segment ) 是由 F·M·A·范德斯勒伊斯 H·F·拉默斯 于 2018-05-22 设计创作，主要内容包括：本发明涉及一种用于传动带(50)的横向部段(1),所述传动带具有环堆组(8)并且具有沿环堆组的周向安装在所述环堆组(8)上的横向部段(1),所述横向部段包括基部(10)和两个柱部(11),所述柱部(11)相应地从基部(10)的侧部在高度方向上向上延伸,其中,基部(10)的在柱部(11)之间的上侧限定出支撑表面(13a、13b),并且所述柱部(11)分别包括在相应的相对的柱部(11)的方向上延伸的钩部(9)。所述支撑表面(13a、13b)包括基本轴向取向的中心区段(13b),以及在其至少一侧上包括远离中心区段(13b)向下取向的侧区段(13a)。由此,便于将横向部段(1)安装在环堆组(8)上以组装传动带(50)。(The invention relates to a transverse section (1) for a drive belt (50) having a ring stack (8) and having a transverse section (1) which is mounted on the ring stack (8) in the circumferential direction of the ring stack, comprising a base part (10) and two pillar parts (11), the pillar parts (11) extending in height direction from the side of the base part (10) in each case, wherein the upper side of the base part (10) between the pillar parts (11) defines a support surface (13a, 13b) and the pillar parts (11) each comprise a hook part (9) which extends in the direction of the respective opposite pillar part (11). The support surface (13a, 13b) comprises a substantially axially oriented central section (13b) and on at least one side thereof a side section (13a) oriented downwardly away from the central section (13 b). Thereby, mounting of the transverse segments (1) on the ring stack (8) for assembling the drive belt (50) is facilitated.)

1. Transverse segment (1) for a drive belt (50), which drive belt (50) has a ring stack (8) and has a transverse segment (1) mounted on the ring stack (8) in the circumferential direction of the ring stack (8), which transverse segment (1) comprises a base part (10) and two pillar parts (11), which pillar parts (11) extend in the height direction from the sides of the base part (10), wherein the upper side of the base part (10) between the pillar parts (11) defines a support surface (13a, 13b), at least one of the pillar parts (11) comprising a hook part (9) extending in the width direction in the direction of the respective opposite pillar part (11), characterized in that the support surface (13a, 13b) comprises a central section (13b) oriented substantially in the width direction and comprises a side section (13a) on at least one side of the support surface (13a, 13b), the side section (13a) is oriented at an acute angle to the central section (13b) and downward in the height direction away from the central section (13b), the side section (13a) being located below the hook (9) of the at least one post (11) in the height direction.

2. The transverse section (1) according to claim 1, characterized in that the hook (9) of the at least one pillar (11) extends in the direction of the respective opposite pillar (11) over the entire extension of the side section (13a) of the support surface (13a, 13b) in the direction of the respective opposite pillar (11).

3. The transverse section (1) according to claim 1 or 2, characterized in that the side sections (13a) of the support surfaces (13a, 13b) extend over a distance which is equal to or greater than the distance in height direction between the hook (9) of the at least one post (11) and the central section (13b) of the support surfaces (13a, 13b), and preferably equal to about 1.5 times the distance in height direction between the hook (9) of the at least one post (11) and the central section (13b) of the support surfaces (13a, 13 b).

4. The transverse section (1) according to claim 1, 2 or 3, characterised in that the central section (13b) of the support surface (13a, 13b) extends in the width direction substantially parallel to and over the entire width of the gap between the post (11), the respective hook (9) or the hook (9) of the post (11).

5. The transverse section (1) according to any one of the preceding claims, characterized in that a central section (13b) of the support surface (13a, 13b) is located centrally in the width direction between two posts (11), both posts (11) comprising hooks (9) extending in the width direction towards the respective opposite post (11), respectively, and the support surface (13a, 13b) is provided with said side sections (13a) below the respective hooks (9) on both sides of its central section (13 b).

6. Drive belt (50) with a ring stack (8) and a plurality of transverse segments (1) according to any one of claims 1 to 5, the transverse segments (1) being mounted on the ring stack (5) in the circumferential direction of the ring stack (5), while the ring stack (8) is located essentially in the middle of the base (10) of the respective transverse segment (1) in the width direction and is in contact with the central section (13b) of the support surface (13a, 13 b).

7. Drive belt (50) consisting of only one ring stack (8) and a plurality of transverse segments (1) according to any one of claims 1 to 5, which transverse segments (1) are mounted on the ring stack (8) in the circumferential direction of the ring stack (5).

Technical Field

The present disclosure relates to a transverse segment intended to be part of a drive belt for a continuously variable transmission having two pulleys and a drive belt. Such a drive belt is well known and is primarily applied to travel around two transmission pulleys between the pulleys, which pulleys each define a V-shaped groove of variable width in which a respective circumferential portion of the drive belt is retained.

Background

The known type of drive belt comprises a substantially consecutive row of transverse segments mounted on a plurality of endless belts or rings around their circumference, said endless belts or rings being stacked on each other in a radial direction. Each such transverse segment defines a central opening which is open towards the radially outer side of the drive belt and which accommodates and constrains a respective circumferential segment of such a ring stack, while allowing the transverse segment to move along its circumference. Drive belts of this particular type are known, for example, from British patent GB1286777 and European patent publication EP-1219860-A1.

In the above and in the following description, the axial, radial and circumferential directions are defined with respect to a drive belt placed in a circular attitude. The thickness dimension of the transverse section is defined in the circumferential direction of the push belt, the height dimension of the transverse section is defined in said radial direction, and the width dimension of the transverse section is defined in said axial direction. The thickness dimension of the ring stack is defined in said radial direction and the width dimension of the ring stack is defined in said axial direction.

The known transverse section comprises a base portion and two pillar portions extending from the base portion in a radially outward direction, i.e. in the height direction, on either side of the base portion. The central opening that receives the ring stack is defined between the base portion and the two post portions. Between the column parts, the opening is delimited by a substantially axially aligned, radially outwardly facing support surface of the base part, which support surface interacts with and supports the ring stack from the radially inner side thereof. At least one, but preferably both, of the pillar parts of the known drive belt are provided with a hook part which extends in the axial direction over the central opening and is thus also partly closed in the radially outward direction. Thus, the bottom, i.e. the radially inner surface of such a hook engages the ring stack from the radially outer side of the ring stack, whereby the ring stack is received in the central opening of the transverse section in a radially outward direction.

For assembling the drive belt, it is generally not possible to fold the ring stack in the axial direction to allow it to pass between the hooks of the transverse segments and to unfold in the central opening of the transverse segments. In particular, in practice, the ring stack may be damaged by such folding and unfolding thereof. Thus, i.e. in order to mount the transverse segments on the ring stack, the transverse segments are respectively slid in a rotational orientation onto the ring stack which is unfolded, i.e. has a substantially rectangular cross section, and then rotated into axial alignment with the ring stack. In order to allow such an installation, the overlap, i.e. overhang, of the hook of the transverse section and the ring stack in the axial direction must be small relative to the width of the ring stack. However, when such an overlap is small, in particular smaller than the axial play of the transverse segments relative to the ring stack in the assembled drive belt, it may happen that the transverse segments separate from the ring stack during operation of the drive belt, which would compromise its integrity and continue to operate.

It should be noted that in principle, this overlap may be increased by increasing the height of the central opening of the transverse section, defined as the smallest distance in the radial direction between the support surface and the bottom surface of the hook, in particular with respect to the thickness of the ring stack, thereby increasing the radial gap therebetween. In practice, however, such radial clearances must be small relative to the thickness of the ring stack to ensure the desired, i.e. optimum, performance of the drive belt. In practice, therefore, alternative methods are adopted for accommodating the ring stack in the central opening of the transverse section after it has been mounted on the latter. However, while many such alternative approaches have been proposed in the art for many years, they generally increase the cost and/or complexity of the drive belt or its assembly, and therefore are not amenable to high volume manufacturing.

Against the background of the above, the invention proceeds from improving the known drive belt, which is equipped with transverse segments, the post sections of which are each provided with a hook. In particular, the present disclosure is directed to increasing the amount of overlap between such hooks and the ring stack without compromising the generally high performance and low cost of existing drive belts.

Disclosure of Invention

According to the present disclosure, the support surface comprises on at least one axial side thereof a side section which is not only oriented in the axial direction but also in a radially inward direction, i.e. angularly oriented with respect to a substantially axially oriented central section of the support surface. By providing such side sections at an angle, the angle at which the ring stack is inserted into the central opening of the novel transverse section is increased compared to the insertion angle allowed by known transverse section designs. Furthermore, this increased insertion angle allows a wider ring stack to be assembled, thereby advantageously increasing the overlap.

On the basis of geometric considerations, the lateral sections of the support surface preferably extend over a distance equal to or greater than the height of the central opening, in particular up to 2 times this height, preferably about 1.5 times. Furthermore, the side section preferably extends along a substantially straight line at least in a large part thereof. It is also preferred that convexly curved transition sections are provided between the side sections and the central section of the support surface to avoid sharp edges forming therebetween and to avoid disadvantageously high contact stresses between the ring stack and the transverse sections during operation of the drive belt.

In the latter respect, it should be noted that the support surface is also generally convexly curved. By such a convex shape of the support surface, for example as described in us patent No. 4,080,841, a preferred, i.e. centered, alignment of the ring stack with respect to the support surface of the transverse section is intended. However, according to the invention, the radius of curvature of the support surface is much larger than the radius of curvature of the transition section, so that it can be clearly distinguished therefrom. More particularly, the radius of curvature of the support surface is at least 1 order of magnitude, and preferably about 2 orders of magnitude, greater than the radius of curvature of the transition sections between the side and central sections of the support surface.

More particularly, according to the present disclosure, the extension surface is preferably substantially coincident with or positioned radially inward of an imaginary, i.e. virtual, straight line drawn through:

-a first point defined by a transition between a side section of the support surface and a central section thereof; and

a second point on the outer contour of the hook portion of the post portion on an axial side of the support surface opposite to the first point, the second point defining an axial extension of the inlet of the central opening towards the post portion.

The latter geometry of the transverse section allows it to be advantageously mounted on the ring stack without having to bend the latter, while achieving a relatively small value of the radial clearance and a relatively large value of the overlap.

It is noted that in the context of the present disclosure, i.e. for mounting the transverse segments to the ring stack, it is sufficient to provide a single extension surface at one axial side of the support surface. However, it may be preferred to provide extension surfaces on both axial sides of the support surface, so that the overall design and mass distribution of the transverse section may be symmetrical with respect to the radial direction (mirror surface), as is customary in the field of transverse section design.

Drawings

The above-described novel transverse section design according to the present disclosure will now be further explained with reference to the accompanying drawings, in which:

figure 1 is a simplified schematic side view of a transmission with two pulleys and a drive belt comprising a ring stack and a row of transverse segments mounted on the ring stack along its circumference;

figure 2 schematically shows the known drive belt in a cross-sectional view facing in its circumferential direction, and also comprises a separate side view of only its transverse section;

figure 3 schematically shows a drive belt assembly step in which the transverse segments are mounted on the ring stack after being folded;

figure 4 schematically shows a drive belt assembly step in which the transverse segments are mounted on the ring stack in their natural, i.e. free-form or undeformed state;

fig. 5 schematically shows, in a front view thereof, a novel transverse section according to the present disclosure;

FIG. 6 is an enlarged view of a detail of the novel transverse section of FIG. 5, and

fig. 7 shows further design details of the novel transverse section of fig. 5.

Detailed Description

Fig. 1 schematically shows a central part of a continuously variable transmission 100 for a drive train of, for example, a passenger motor vehicle. The transmission 100 is well known and includes at least a first variable pulley 101 and a second variable pulley 102. In the drive train, a first pulley 101 is coupled to and driven by a prime mover, such as an electric motor or an internal combustion engine, and a second pulley 102 is coupled to and drives the drive wheels of the motor vehicle, typically via a plurality of transmissions.

The transmission pulleys 101, 102 each generally include; a first conical pulley disc fixed to the pulley shaft 103, 104 of the respective pulley 101, 102; and a second conical pulley disc which is axially displaceable relative to the respective pulley shaft 103, 104 and is only fixed to the respective pulley shaft 103, 104 in a rotationally fixed manner. The drive belt 50 of the transmission 100 is wound around the pulleys 101, 102 while being accommodated between the pulley sheaves thereof. As shown in fig. 1, the trajectory of the drive belt 50 in the transmission 100 includes two straight portions ST and two curved portions CT in which the drive belt 50 is wound around a respective one of the two transmission pulleys 101, 102. The drive belt 50 consists of a ring stack 8 and a plurality of transverse segments 1, which transverse segments 1 are mounted on the ring stack 8 in an at least approximately successive arrangement along the circumference of the ring stack 8. For the sake of simplicity, only some of these transverse sections 1 are shown in fig. 1. In the drive belt 50, the transverse segments 1 are movable along the circumferential direction of a ring stack 8, which ring stack 8 is typically composed of a plurality of flexible endless metal bands or rings stacked on top of each other, i.e. nested within each other. During operation of the transmission 100, the transverse section 1 of the drive belt 50 at the first pulley 101 is driven in its rotational direction by friction. These driven transverse segments 1 push the preceding transverse segment 1 in the circumferential direction of the ring stack 8 of the drive belt 50 (the ring stack 8 itself may be rotating) and finally rotationally drive the second pulley 102 again by friction. In order to generate such friction (force) between the transverse section 1 and the transmission pulleys 101, 102, said pulley discs of each pulley 101, 102 are pressed against each other, whereby they exert a clamping force on the transverse section 1 in its axial direction. For this purpose, an electronically controlled and hydraulically acting movement device (not shown) acting on the movable pulley disc of each pulley 101, 102 is provided in the transmission 100. In addition to exerting a clamping force on the drive belt 50, these kinematic means also control the respective radial positions R1 and R2 of the drive belt 50 at the pulleys 101, 102, and thus the speed ratio provided by the transmission 100 between its pulley shafts 103, 104.

In fig. 2, a known drive belt 50 is schematically shown. On the left side of fig. 2, the drive belt 50 is shown in a sectional view and on the right side of fig. 2 only comprises a side view of its transverse section 1. As can be seen from fig. 2, the transverse section 1 of the drive belt 50 is shaped like the letter "V", i.e. substantially V-shaped. In other words, the side faces 12 of the transverse section 1 which are in contact (friction) with the transmission pulleys 101, 102 are oriented at an angle to each other which closely matches the angle existing between the conical pulley discs of the transmission pulleys 101, 102. These pulley contact surfaces 12 are corrugated or have a rough surface structure by means of a macroscopic contour, so that only the higher-lying peaks of the corrugated contour or of the surface roughness come into contact with the transmission pulleys 101, 102. This particular feature of the transverse section design allows the friction between the drive belt 50 and the transmission pulleys 101, 102 to be optimized by having the cooling oil applied in the known transmission 100 be contained in the lower part of the corrugated profile or surface roughness.

Each transverse segment 1 defines a base part 10 and two column parts 11, wherein the base part 10 extends substantially in the axial direction of the drive belt 50 and the column parts 11 extend from a respective axial side of the base part 10 substantially in the radial direction of the drive belt 50. In its thickness direction, each transverse segment 1 extends between its front 3 and rear 2 surfaces, both the front 3 and rear 2 surfaces being oriented at least substantially in the circumferential direction of the drive belt 50. An opening 5 is defined centrally between the post portion 11 and the base portion 10 of each transverse section 1, in which opening 5 a circumferential section of the ring stack 8 is accommodated. The radially outward portion 13 of the peripheral surface of the base, hereinafter referred to as the support surface 13, forms the radially inner boundary of the central opening 5, supporting the ring stack 8 from the radially inner side. The support surface 13 is generally convexly curved to promote preferred centered alignment of the ring stack 8 during operation, i.e., rotation, of the drive belt 50 in the transmission 100.

In a row of transverse segments 1 of the drive belt 50, at least a part of the front body surface 3 of a transverse segment 1 abuts at least a part of the rear body surface 2 of the respective preceding transverse segment 1 in the row, while at least a part of the rear body surface 2 of a transverse segment 1 abuts at least a part of the front body surface 3 of the respective subsequent transverse segment 1. Adjoining transverse segments 1 can be inclined relative to each other while being held in mutual contact at their surface portions 4 by axially extending and radially curved surface portions 4 of their front surfaces 3, which surface portions 4 are referred to hereinafter as inclined edges 4. Below the tilting edge 4, i.e. radially inwards, the transverse sections are tapered, as seen in the side view of fig. 2, to allow such mutual tilting without interfering below the tilting edge with the respective bases 10 of the adjoining transverse sections 1. Note that although in fig. 2 the bevel edge 4 is located in the base 10 of the transverse section 1, it is also known to locate it at least partially in the pillar portion 11, i.e. in two axially separated but radially aligned sections (not shown).

The pillar portions 11 of the transverse section 1 are each provided with a projection 6, which projection 6 projects from the respective front surface 3 substantially in the circumferential direction. In the drive belt 50, the projections 6 are inserted into recesses 7 provided in the opposite, i.e. rear surface 2 of adjacent transverse segments 1, to limit relative movement between the adjacent transverse segments 1 at least in the radial direction but usually also in the axial direction.

The post parts 11 of the transverse section 1 are also provided with hook parts 9, respectively, which hook parts 9 overhang the opening 5 in the axial direction. The hook 9, in particular its bottom surface, i.e. its radially inward surface 14, also partially closes the central opening 5 in a radially outward direction. In the drive belt 50, the hooks 9 of the transverse segments 1 overlap the ring stack 8 in the axial direction and thus prevent or at least hinder a possible separation of the transverse segments 1 from the ring stack 8 in the radially inward direction.

As schematically shown in figure 3, in order to assemble a drive belt 50 according to the above-described known design, the ring stack 8 must be bent considerably, i.e. folded in almost two layers, in the axial direction to pass through the entrance of the central opening 5 defined between them by the hooks 9 of the transverse segments 1. In practice, however, such a considerable elastic deformation of the ring stack 8 is often not possible due to the high stiffness and low yield strain of the ring material. In this respect, fig. 4 schematically illustrates a more practical method of drive belt assembly, wherein the ring stack 8 does not need to be deformed, at least not significantly. In fig. 4, the dashed rectangular outline schematically shows the position of the undeformed ring stack 8 relative to the transverse segments 1 during assembly of the drive belt, i.e. when mounting the transverse segments 1 on the ring stack 8. It is noted that in practice the individual rings and thus the entire undeformed ring stack 8 are typically slightly curved, i.e. convex, in the width direction, so that the effective thickness of the ring stack 8 in its said undeformed state is slightly greater than its physical thickness.

A limitation of the particular method of drive belt assembly shown in fig. 4 is that the hooks 9 of the transverse segments 1 can only overlap the ring stack 8 very little in the axial direction. In other words, the width W8 of the ring stack 8 can only be slightly larger than the width EW5 of the gap between its hooks 9, which gap provides access to the central opening 5 of the transverse segment 1. In particular, in the assembled state of the drive belt 50, the maximum possible overlap between the ring stack 8 and the hooks 9 (i.e. W8 minus EW5) may be geometrically related to the radial clearance RC between the ring stack 8 and the hooks 9. However, on this type of drive belt 50, such a radial clearance RC needs to be limited, in particular less than 30% of the (effective) thickness of the ring stack 8, preferably in the range between 15% and 25%. This makes the maximum possible overlap disadvantageously small. Thus, with this drive belt design and its method of assembly, there is a risk of the cross member 1 separating from the ring stack 8 during operation of the drive belt 50. This separation can occur in particular when, in the rows of the transverse sections of the drive belt 50, gaps are formed on either side of the transverse sections 1, for example due to wear of the belt 50 during the service life of the transmission and high instantaneous belt loads. If the overlap can be increased in some way, the risk of separation can be reduced.

According to the present disclosure, the width W8 of the ring stack 8 may be increased relative to the gap width EW5 of the opening 5 between the hooks 9, as schematically shown in fig. 5 in the exemplary embodiment of the novel transverse section 1, so that the overlap, i.e. the (combined) overhang of the hooks 9 over the ring stack 8, is also increased. In the novel transverse section 1, the support surface 13 does not extend substantially in the axial direction over the entire width of the opening 5 between the pillar portions 11, but comprises a side section 13a on either axial side of its central section 13b, which side section 13a is oriented away from said central section 13b of the support surface 13 in a radially inward direction. In particular, the side sections 13a are oriented at an acute angle with respect to the central section 13 b. A preferred, practically applicable range of such an angle is 10 to 30 degrees, more particularly 15 to 25 degrees.

By this design feature of the novel transverse section 1, when it is mounted on the ring stack 8, one axial side of the ring stack 8 extends radially inside the support surface 13, in particular one of the side sections 13a more or less parallel to the support surface 13. Thus, a much wider ring stack 8 can be inserted into the central opening 5 of the novel transverse section 1 than the known transverse section 1 of fig. 4 having a central opening 5 of the same gap width EW 5. Thereby, said overlap of the hooks 9 of the transverse segments 1 with the ring stack 8 is advantageously increased with respect to said radial gap RC therebetween. Alternatively, the radial gap RC may be advantageously reduced, or a combination of both.

In particular, the lateral sections 13a are located completely below the hooks 9 of the respective post 11, i.e. the lateral sections 13a remain within the axial extension of the respective hooks 9, and the central section 13b begins within the axial extension of the respective hooks 9. As shown in more detail in fig. 6 in an enlarged view of the lateral section of fig. 5, preferably a convexly curved transition section 13c of the support surface 13 is provided between said side section 13a and the central section 13b thereof. By means of such a transition section 13c, the occurrence of sharp edges and disadvantageously high contact stresses between the ring stack 8 and the transverse section 1 during operation of the drive belt 50 is avoided. Also in fig. 6, it is shown that the central section 13b of the support surface 13 is also generally convexly curved, however, the central section 13b is convexly curved with a relatively larger radius of curvature R300 of 300mm, for example, than the radius of curvature R10 of, for example, 10mm of the transition section 13 c.

Finally, two preferred geometrical aspects of the novel transverse section 1 are shown in fig. 7. First, the respective side section 13a of the support surface 13 is located radially inside a first virtual straight line L1 drawn by:

a first point P1 between such respective side section 13a and central section 13b of the support surface 13, and

a second point P2, the second point P2 being on the outer contour of the hook 9 of the post 11 on the opposite axial side of the support surface 13 from the first point P1, the second point P2 defining the axial extension of the entrance of the central opening 5 towards the post 11.

Thereby, during assembly of the drive belt 50, an unfavourable contact between the ring stack 8 and the respective side section 13a of the support surface 13 can be largely avoided.

Secondly, the respective top surfaces, i.e. the radially outer surfaces 15, of the hook portions 9 of the post portions 11 are located radially inside (or at most substantially coincide in a radially outward direction) a second imaginary straight line L2, which second imaginary straight line L2 is drawn through a side section 13a on the opposite side of the support surface 13 with respect to this respective post portion 11. Thereby, during assembly of the drive belt 50, an unfavourable contact between the ring stack 8 and the respective top surface 15 of the hook 9 can be largely avoided.

In addition to all of the details of the foregoing description and accompanying drawings, the present disclosure also relates to and includes all of the features of the claims. Reference signs in the claims do not limit their scope but are provided merely as a non-limiting example of corresponding features. Depending on the circumstances, the claimed features may be applied individually in a given product or in a given process, but any combination of two or more such features may also be applied therein.

The present disclosure, as represented by the present disclosure, is not limited to the embodiments and/or examples explicitly mentioned herein, but also includes modifications, adaptations and practical applications thereof, particularly those that may occur to one skilled in the art.