Pulley for guiding a belt for carrying a traveling body and / or a counterweight of an elevator system

Abstract

The invention relates to a pulley (118) for guiding a belt (106) for carrying a traveling body (102) and / or a counterweight (104) of an elevator system (100). The pulley (118) comprises a plurality of circumferential grooves (202) spaced axially apart from one another, which are used to accommodate a plurality of ribs (204) of the belt (106), wherein each groove (202) has two mutually opposing groove sides (300) for force transmission by frictional engagement with one of the ribs (204), and a circumferential groove (302) is provided between the two groove sides (300). The width (B) of the groove (302) is at least 25% of the axial distance (A) of the groove 202 and at least 80% of the height (H) of the groove (202).

Description

Technical Field

[0001] The present invention relates to a pulley for guiding a belt for carrying a traveling body and / or a counterweight of an elevator system, a device for carrying a traveling body and / or a counterweight of an elevator system provided with such a pulley, and an elevator system having such a device. Background Art

[0002] In elevators with a traction sheave drive, the traveling body and counterweight are connected to each other via a support mechanism, such as ropes, belts, or belts. Force is typically transmitted between the support mechanism and the traction sheave via friction. Because the support mechanism typically not only holds the weight of the traveling body and / or counterweight but also, driven by the traction sheave, allows for displacement of the traveling body and / or counterweight, it is also referred to as a holding and traction mechanism (STM).

[0003] For example, a V-ribbed belt with multiple parallel, V-shaped longitudinal ribs can be used as a belt. This V-ribbed belt is deflected or driven via one or more pulleys with corresponding grooves. If such a belt is fed into the pulley at an angle, undesirable noises may occur at low angles of pull. At higher angles of pull, the belt may come out of the grooves.

[0004] The behavior of a belt under inclined pulling, such as its tendency to generate noise or to creep, is primarily influenced by the geometry of the groove flanks and the surface pressure between the belt and pulley. Tests have shown that increasing the surface pressure, for example due to an increase in the load to be conveyed, can reduce the tendency to generate noise or creep, while reducing the surface pressure, for example due to an increase in the pulley diameter, can lead to the opposite effect. Summary of the Invention

[0005] There is a major need to make pulleys of elevator systems more robust against loads caused by oblique traction. In particular, it would be desirable to provide a pulley with which the contact pressure of the belt can be increased without reducing the pulley diameter and / or increasing the tensile load on the belt. Furthermore, there is a need for a device for carrying a traveling body and / or counterweight of an elevator system, provided with such a pulley, and an elevator system provided with such a device.

[0006] This need is achieved by a pulley, a device and an elevator system according to the independent claims. Advantageous embodiments are defined in the dependent claims and in the following description.

[0007] A first aspect of the present invention relates to a pulley for guiding a belt carrying a traveling body and / or counterweight of an elevator system. The pulley has a plurality of circumferential, axially spaced grooves for accommodating belt ribs. Each groove has two opposing groove sides for force transmission via frictional engagement with one of the ribs. Each groove has a circumferential groove between the two groove sides. The groove has a width of at least 25% of the axial extent of the groove and at least 80% of its height. Preferably, the groove sides each form a wedge-shaped profile. In particular, the groove sides extend in a straight line.

[0008] With grooves of this size, it is possible to prevent the belt from generating excessive noise during oblique pull. This also counteracts the tendency of the belt to pull out of the groove during oblique pull. For example, this allows the belt to start climbing at a relatively large oblique pull angle compared to conventional pulleys. Furthermore, the pulley can be advantageously incorporated into existing elevator systems without significant modifications, such as replacing the belt.

[0009] The pulley can be a traction pulley or a deflecting roller. The traction pulley is generally driven by a drive engine and actively rotated by the drive engine. Thus, by utilizing the traction of the circumferential surface of the traction pulley, the belt extending along this circumferential surface can be actively driven, that is, displaced. In contrast, the deflecting roller is not connected to the drive engine. Instead, it passively rotates when the belt extending along the circumferential surface of the deflecting roller moves in its longitudinal direction.

[0010] A circumferential groove can be understood as a recess in the outer side of a pulley that extends in the circumferential direction of the pulley. The grooves can be arranged side by side with a specific axial spacing. For example, the axial distance can be measured from the groove center to the groove center of two adjacent grooves. Axial in this context means in the direction of the pulley's axis of rotation. A circumferential groove can have a constant cross-section or a constant profile along the outer circumference of the pulley.

[0011] Geometrically, the groove side can be understood as the outer side of a truncated cone, whose cone axis is identical to the rotation axis of the pulley. Depending on whether the generatrix of the truncated cone is straight or curved, the groove side can be flat or arched, for example concave or convex.

[0012] The two groove sides can be opposite to each other. For example, the two groove sides can be oriented perpendicularly or obliquely relative to each other to form a wedge shape. In particular, the two groove sides can be designed to be mirror-symmetrical about a plane extending perpendicular to the rotation axis of the pulley.

[0013] Each groove can have a groove height that is at least as great as the sum of the groove depth and the projection height of the groove side. This means that the height is defined as the height resulting from the projection of the groove side onto an axis orthogonal to the axis of rotation. In this context, the groove height is defined as the radial extent of the groove from the groove bottom to the outermost edge of the groove. The groove bottom is defined as the groove bottom of the respective groove.

[0014] In other words, each groove may be radially divided into an outer first section and an inner second section adjacent to the first section, wherein the first section comprises the groove sides and the second section comprises the surrounding groove.

[0015] The groove can form a section of the groove which is configured as an undercut region compared to the groove section defined by the groove side. In other words, when viewed in cross section, the groove can be seen as consisting of two sections, i.e., a radially outer section and a radially inner section.

[0016] The radially outer section is laterally delimited by the groove flanks. This radially outer section tapers from the radially outer portion toward the radially inner portion, i.e., the groove flanks extend obliquely in cross section relative to the pulley's axis of rotation. Consequently, the ribs of the belt engaging in the pulley's grooves can exert a pressing force on the groove flanks in a direction perpendicular to the pulley's axis of rotation.

[0017] The radially inner section is laterally delimited by the walls of the groove. These walls are oriented so that the inner section formed by the groove acts as an undercut compared to the overall cross-section of the groove. For example, the walls of the groove can be arranged in the radial direction, that is, in particular, in a plane perpendicular to the axis of rotation of the pulley. Thus, in the radially inner section, the ribs of the belt engaging the groove of the pulley do not contact the surface of the groove, or, if necessary, contact with a reduced pressure, which is significantly less than the pressure exerted on the sides of the groove.

[0018] Viewed in cross section, an edge can separate the radially outer section defined by the groove side and the radially inner section in the region of the groove at the transition between these two sections. The edge can be convex or sharp. Alternatively, the edge can also be slightly rounded, wherein the radius of curvature in the region of the edge should be significantly smaller than the radius of curvature of the groove side, which is designed to be curved in cross section, for example.

[0019] The belt can be, for example, a V-ribbed belt or a composite V-ribbed belt. The belt can have multiple parallel ribs extending longitudinally of the belt. Each rib can be formed with an outer contour that matches the inner contour of the groove. For example, the ribs can have a wedge-shaped or trapezoidal cross-section. The rib heads can be rounded or flattened, for example.

[0020] The width of the groove can be understood as the axial extension of the groove, that is, the extension of the groove in the direction of the rotation axis of the pulley. The depth of the groove can be understood as the radial extension of the groove, that is, the extension of the groove in a direction perpendicular to the rotation axis of the pulley.

[0021] The groove may have a rectangular cross-section, for example. The corners of the cross-section may be rounded according to manufacturing requirements. The groove may also have other cross-section shapes depending on the intended use. The cross-section of the groove may be, for example, arcuate or bow-shaped.

[0022] For example, the bottom of the groove can be designed to be flat, that is, it can extend substantially straight in a cross section, for example, parallel to the axis of rotation of the pulley. The bottom of the groove can also be shaped differently depending on the intended use. For example, the bottom of the groove can extend in an arc or bow shape in a cross section.

[0023] In principle, the grooves prevent the belt ribs from contacting the groove bottom. In other words, when the ribs engage the grooves, the grooves and ribs each define a cavity. This ensures that frictional forces are transmitted via a defined surface, namely, the groove sides. The grooves can also be used to collect wear and dirt or to compensate for belt thickness fluctuations.

[0024] By widening the groove, the height of the groove side projection can be reduced without otherwise changing the groove profile, thereby reducing the belt contact surface. By reducing the contact surface, the belt contact force is increased while the load remains constant, which, as described above, has a positive impact on the belt's diagonal traction behavior.

[0025] A second aspect of the present invention relates to a device for supporting a traveling body and / or counterweight of an elevator system. The device comprises at least one belt and at least one pulley according to an embodiment of the first aspect of the present invention, wherein the belt has a plurality of ribs extending longitudinally of the belt. The pulley is at least partially wrapped around the belt. The ribs are each received by a groove of the pulley.

[0026] A third aspect of the invention relates to an elevator system comprising a travelling body, a counterweight and an apparatus according to an embodiment of the second aspect of the invention, wherein the travelling body or the counterweight is carried by at least one belt of the apparatus.

[0027] The enabling features and advantages of embodiments of the present invention may be considered primarily, but not limitingly, to be based on the concepts and insights described below.

[0028] The following dimensions are to be understood as nominal dimensions. Actual dimensions may deviate upward and / or downward from the corresponding nominal dimensions by predetermined tolerances. For longitudinal dimensions described below, tolerances may be, for example, within a hundredth of a millimeter, i.e., less than 0.1 mm. For angular dimensions described below, tolerances may be, for example, within a tenth of a degree, i.e., less than 1 degree.

[0029] According to one embodiment, the groove has a width between 1 mm and 3 mm. Suitable values ​​for the groove width are, for example, 1.8 mm, 2 mm, or 2.2 mm. However, other values ​​are also possible. The groove width can be selected, for example, based on the pulley diameter. For example, the larger the pulley diameter, the larger the groove width can be selected. This can compensate for the decrease in surface pressure caused by the increase in pulley diameter.

[0030] According to one embodiment, the axial spacing of the grooves is between 4 mm and 6 mm. A suitable value for the axial spacing of the grooves is, for example, 5 mm. Other values ​​are also possible depending on the belt used. The corresponding axial distance between the outermost groove and the front edge of the pulley deviates from the axial distance between adjacent grooves, for example, is greater than this axial distance. For example, the axial distance between the groove center of the outermost groove and the front edge of the pulley can be at least 6 mm, in particular at least 7 mm.

[0031] According to one embodiment, the height of the groove is between 2 mm and 3 mm. As mentioned above, the height of the groove can be measured based on the bottom meter of the groove.

[0032] According to one embodiment, the depth of the groove is greater than 0.5 mm. For example, the depth of the groove can be at least 1 mm. However, the depth of the groove can also be less than 1 mm.

[0033] According to one embodiment, the pulley has a diameter of at least 120 mm. Suitable values ​​for the (straightening) pulley diameter are, for example, 125 mm and 150 mm. Other values ​​are also possible, depending on the intended use. The pulley diameter can also be significantly smaller than 120 mm.

[0034] According to one embodiment, the groove has a rectangular cross-section. The walls that laterally delimit the groove can be substantially straight in cross-section and oriented parallel to one another and preferably parallel to a plane running orthogonally to the pulley's axis of rotation. The bottom that radially delimits the groove can also be substantially straight in cross-section and extend parallel to the pulley's axis of rotation. A radius can be provided at the transition between the wall and the bottom. The radius typically has significantly smaller dimensions than the wall and the bottom.

[0035] According to one embodiment, the two groove sides are oriented at an angle of at least 90 degrees to one another. This angle may also be referred to as an opening angle or a wedge angle. For example, with an opening angle or a wedge angle of 90 degrees, each of the groove sides may enclose an angle of 45 degrees with the axis of rotation. For example, the opening angle or the wedge angle may be in the range of 90 to 150 degrees. Alternatively, an opening angle or a wedge angle of less than 90 degrees is also feasible.

[0036] According to one embodiment, the two groove sides are each designed to be flat. In other words, when viewed in cross-section, the groove sides can extend in a straight line. Such flat groove sides are relatively easy to implement during pulley manufacturing. Grooves with flat sides are sometimes also referred to as V-shaped.

[0037] According to one embodiment, the two groove sides are respectively designed to be arched. In other words, these groove sides can extend in a curved manner, for example in an arc, semicircular or bow shape when viewed in cross section. These groove sides can be arched inwardly or outwardly.

[0038] According to one embodiment, the tangent to the groove side has an angle of at least 35 degrees relative to the pulley's axis of rotation. This angle can also be referred to as the run-up angle. This refers to the shallowest angle of the tangent at which the belt engages and begins to rise in the groove. While the groove profile remains otherwise unchanged, the run-up angle can be increased, for example, by widening the groove, that is, by undercutting the curved groove side.

[0039] According to one embodiment, the ribs of the belt and / or the grooves of the pulleys are designed so that the ribs contact at least one pulley primarily or essentially on the groove sides of the groove. The belt and pulley can be adapted to each other, in particular, with respect to their cross-sectional geometry, so that the ribs of the belt rest on the groove sides of the groove, while the surface of the pulley in the region of the groove does not contact the groove, or, if necessary, contacts the groove with a surface that is smaller than the area of ​​the groove sides and / or with a contact force that is smaller than the contact force in the region of the groove sides. This prevents uncontrolled force transmission via the groove bottom.

[0040] It should be noted that some possible features and advantages of the present invention are described herein with reference to different embodiments of a pulley on the one hand and an apparatus or elevator system equipped with the pulley on the other hand. Those skilled in the art will recognize that the features described can be combined, matched, or replaced in a suitable manner to achieve other embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The embodiments of the present invention are described below with reference to the accompanying drawings, wherein neither the drawings nor the description should be considered as limiting the present invention.

[0042] Figure 1 An elevator system according to one embodiment of the present invention is shown.

[0043] Figure 2 Show Figure 1 Pulley 1 in.

[0044] Figure 3 Show Figure 2 Cross-sectional view of a section of a pulley.

[0045] Figure 4 Show the Figure 2 A diagram showing the surface pressure for different pulley diameters.

[0046] Figure 5 Shown is a diagram illustrating possible geometries of curved trench sides according to one embodiment of the present invention.

[0047] The figures are schematic and not drawn to scale. The same reference numerals in different figures denote identical or identically functioning features. DETAILED DESCRIPTION

[0048] Figure 1 A highly simplified view of an elevator system 100 is shown. The elevator system 100 includes a traveling body 102 and a counterweight 104, which are supported by a belt 106. For example, the belt 106 is fixed at both ends to the shaft ceiling of the elevator system 100. The belt 106 is guided between its ends through a counterweight roller 108, a traction sheave 110, a first traveling body roller 114, and a second traveling body roller 116. The counterweight 104 is suspended from the counterweight roller 108, and the traction sheave 110 is coupled to a motor 112. The two traveling body rollers 114 and 116 are fixed to the traveling body 102. The counterweight roller 108, the traction sheave 110, the first traveling body roller 114, and the second traveling body roller 116 are each designed as a pulley 118 with a specific groove profile, as described in more detail below. By rotating the traction sheave 110 , the belt 106 moves in the direction of its longitudinal axis, thereby changing the height of the traveling body 102 or the counterweight 104 . The driving force is applied by friction between the traction sheave 110 and the belt 106 .

[0049] The pulley 118 together with the belt 106 forms an arrangement 120 for carrying the vehicle 102 and the counterweight 104. The arrangement 120 may also include more than one belt 106.

[0050] Alternatively, the lifting device 100 may also be configured without the counterweight 104 .

[0051] Figure 2 Show Figure 11 shows a perspective view of a pulley 118 in FIG. The pulley 118 is rotatable about an axis of rotation 200 and has a plurality of circumferential grooves 202 on its outer side that are spaced axially apart from one another. Furthermore, a section of the belt 106 is shown that has a plurality of ribs 204 extending in the longitudinal direction of the belt 106. In the region of the pulley 118 around which the belt 106 is wound, each rib 204 engages in one of the grooves 202. The profiles of the grooves 202 and ribs 204 can complement one another. For example, the grooves 202 and ribs 204 can each form a wedge-shaped profile.

[0052] The straightening diameter or reference diameter D of the pulley 118 d For example, between 52 and 150 mm, in particular between 80 and 100 mm, and preferably 87 mm.

[0053] Figure 3 Show Figure 2 sectional view of a section of a pulley 118. The outline of the groove 202 can be seen. In addition, a section of the belt 106 is shown, which engages with one of its ribs 204 in one of the grooves 202.

[0054] Each groove 202 has two mutually opposite groove sides 300. These groove sides 300 are used for friction-locking force transmission between the pulley 118 and the belt 106, wherein the ribs 204 respectively contact these groove sides 300 with their rib sides.

[0055] In this example, the groove sides 300 are straight and enclose a wedge angle or opening angle W of 90 degrees plus / minus 0.2 degrees. Alternatively, as Figure 5 As shown in FIG, the groove sides 300 can be designed, for example, in an arc-shaped, circular or semicircular form and / or be oriented at an opening angle W different from 90 degrees to one another.

[0056] A groove 302 extends between the two groove sides 300 of the groove 202, the groove forming the groove bottom of the groove 202 and undercutting the groove sides 300. The groove 302 may completely surround the pulley 118.

[0057] The groove profile is selected such that the width B of the groove 302 is at least 25% of the axial distance A of the groove 202 and at least 80% of the height H of the groove 202. Figure 3 As shown in , the width B can be 2 mm, the distance A is 5 mm plus / minus 0.03 mm, and the height H is 2.12 mm. However, as mentioned above, many other combinations of A, B, and H are also possible.

[0058] By means of this engagement of the groove 302, at a given height H, the projected height H of the groove side 300 and thus also the bearing surface of the rib 204 can be reduced to an extent that is relevant to the oblique traction performance of the belt 106 compared to a design with a narrower groove (indicated by the dotted line).

[0059] The distance A between the groove center of the outermost groove 202 and the front edge 304 of the belt pulley 118 is given here as an example of 7.5 mm.

[0060] The depth T of the groove 302 may be greater than 0.5 mm. Figure 3 In the example, the depth T is approximately 1 mm.

[0061] As in Figure 3 As shown by way of example in FIG, the groove 302 can have a rectangular cross section. Here, the corners of the groove 302 can be rounded.

[0062] exist Figure 3 It can also be seen in FIG that the ribs 204 and the grooves 302 together respectively enclose a cavity 306 , ie the ribs 204 do not contact the corresponding bottoms of the grooves 302 when the belt 106 is loaded. Therefore, force transmission is achieved only via the groove sides 300 .

[0063] Figure 4 , the effect of the width B on the surface pressure p between the groove side 300 and the ribs 204 is illustrated graphically. The scale of the width B includes values ​​between 0 and 3 mm. A first curve 401, a second curve 402 and a third curve 403 are shown, the first curve 401 representing a straightening diameter D of 87 mm. d The second curve 402 represents the surface pressure p on the pulley 118 with a straightening diameter D of 125 mm. d The third curve 403 represents the surface pressure p on the pulley 118 with a straightening diameter D of 150 mm. d The surface pressure p on the pulley 118.

[0064] It can be seen that in order to d = 87 mm, a width of 1 mm is required to achieve a surface pressure p of about 5 MPa. d =125mm requires a width B of 1.8mm and D d =150mm, a width B of 2.2mm is required.

[0065] Figure 5A diagram illustrating a possible geometry of a curved groove flank 300 is shown. Furthermore, a curve is plotted that indicates the rise angle K at each point on the groove flank 300, i.e., the angle formed by the tangent to the point and the axis of rotation 200 (here, the abscissa). The width B is plotted on the abscissa, starting from the center axis of the groove 202. The center axis corresponds to the left-hand ordinate, which intersects the abscissa at B=0 and on which the height H is plotted. The rise angle K or the opening angle W is plotted on the right-hand ordinate.

[0066] The climbing angle K can be summarized as a measure of the inclination at which the belt 106 climbs out of the groove 202 under lateral forces. The larger the climbing angle K, that is, the steeper the groove flank 300 rises, the smaller the inclination of the belt 106 required for climbing. For example, a climbing angle K of approximately 40 degrees can be achieved with a groove or undercut having a width B = 2 mm. However, a climbing angle K of only approximately 30 degrees can be achieved with a groove or undercut having a width B = 1 mm.

[0067] Finally, it should be noted that terms such as "having," "comprising," etc. do not exclude any other elements or steps, and terms such as "a" or "an" do not exclude a plurality. Furthermore, it should be noted that features or steps described with reference to one of the above embodiments may also be used in combination with other features or steps of other above-described embodiments. Reference numerals in the claims should not be construed as limiting.

Claims

1. A pulley (118) for guiding a belt (106) for carrying a traveling body (102) and / or a counterweight (104) of an elevator installation (100), wherein: The pulley (118) has a plurality of circumferential grooves (202) axially spaced from each other for accommodating ribs (204) of the belt (106), each of the grooves (202) including two groove sides (300) opposite to each other for transmitting force by frictionally locking with one of the ribs (204), and a circumferential groove (302) between the two groove sides (300), each of the grooves being divided radially into an outer first section and an inner second section adjacent to the outer first section, wherein the outer second section A section includes groove sides, the inner second section includes a circumferential groove, characterized in that the width (B) of the groove (302) is at least 25% of the axial spacing (A) of the groove (202) and at least 80% of the height (H) of the groove (202), and in the inner second section, the ribs of the belt that are engaged in the groove of the pulley do not rest on the surface of the groove or only rest on the surface of the groove with a reduced pressing force that is significantly smaller than the pressing force caused on the groove sides, wherein the groove sides (300) each form a wedge-shaped profile and the groove sides (300) extend in a straight line.

2. The pulley (118) according to claim 1, wherein The width (B) of the groove (302) is between 1 mm and 3 mm.

3. The pulley (118) according to any one of the preceding claims, wherein The axial spacing (A) of the grooves (202) is between 4 mm and 6 mm.

4. The pulley (118) according to any one of the preceding claims, wherein The height (H) of the groove (202) is between 2 mm and 3 mm.

5. The pulley (118) according to any one of the preceding claims, wherein The depth (T) of the groove (302) is greater than 0.5 mm.

6. The pulley (118) according to any one of the preceding claims, wherein The diameter (D) of the pulley (118) d ) is between 52 mm and 150 mm, in particular between 80 mm and 100 mm and preferably 87 mm.

7. The pulley (118) according to any one of the preceding claims, wherein The groove (302) has a rectangular cross section, wherein the corners of the groove are preferably rounded.

8. The pulley (118) according to any one of the preceding claims, wherein The two groove sides (300) are oriented at an angle (W) of at least 90 degrees to each other.

9. The pulley (118) according to any one of the preceding claims, wherein The two groove sides (300) are respectively designed to be flat.

10. The pulley (118) according to any one of the preceding claims, wherein The two groove sides (300) are respectively designed to be arched.

11. The pulley (118) according to claim 10, wherein The tangent angle (K) of the groove side (300) relative to the rotation axis (200) of the pulley (118) is at least 35 degrees.

12. A device (120) for carrying a traveling body (102) and / or a counterweight (104) of an elevator installation (100), wherein: The device (120) comprises: at least one belt (106) having a plurality of ribs (204) extending longitudinally of the belt (106); and At least one pulley (118) according to any of the preceding claims, wherein the at least one belt (106) is at least partially wound around at least one pulley (118), and the ribs (204) are respectively received by grooves (202) of the pulley (118).

13. The device (120) according to claim 12, wherein The rib (204) and / or the groove (202) are designed such that the rib (204) contacts at least one pulley (118) only at the groove side edges (300) of the groove (202).

14. An elevator device (100), comprising: Traveling body (102); counterweight (104); and The device (120) according to claim 12 or 13, wherein the traveling body (102) and / or the counterweight (104) are carried by at least one belt (106) of the device.

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