JP4867039B2 - Belt pulley - Google Patents

Description

  The present invention is a belt pulley that is rotatable about a rotation shaft, and includes a belt placement surface, a first member, and a second member, one of the members being on the input side and The other is disposed on the output side, the first member and the second member are rotatable relative to each other, and a spring acts between the first member and the second member, The spring is deformed when the first and second members are relatively rotated.

  Belt pulleys have long been used for various drive purposes. An important use of belt pulleys is in power machines or motor vehicles for driving units, in particular auxiliary units that utilize belts, for example lighting machines, water pumps, air compressors. In this case, it must be taken into account that the power machine has a rotational non-uniformity due to regular discontinuous fuel combustion in the individual cylinders in an internal combustion engine and which can cause an increase in the belt drive load. . This rotational non-uniformity can increase tension fluctuations, thereby increasing belt wear and possibly increasing belt squeak noise.

  An input unit and an output unit that is rotatable relative to the input unit, and the input unit and the output unit are rotationally coupled to a compression coil spring that is compressible in the circumferential direction via a damping device. A known drive disk for a belt is known (see, for example, Patent Document 1). This drive disk includes a vibration absorbing damper having a mass damper in order to reduce vibration. However, the belt force (Riemenkraefte) has not yet been reduced to the desired degree by this configuration. Therefore, with this structure, belt wear can increase.

In order to attenuate the rotational vibration in the belt pulley, it has also been proposed to provide a freewheel device on the belt pulley (see, for example, Patent Document 2 in particular). With this configuration, the force is transmitted from the belt pulley only in one rotation direction, and the free wheel acts in the other rotation direction. The disadvantage of this known form is that the optimum reduction of the fluctuations in belt force due to freewheels has not yet been achieved.
German Patent No. 4225314 German Patent Application Publication No. 19511188

  An object of the present invention is to further improve the belt pulley so that the fluctuation of the belt force is suppressed to be low.

  This problem is solved by allowing the first member and the second member to rotate over a limited angular range relative to each other, with a free stroke in which the spring does not deform.

  A particularly good belt force reduction is achieved by combining the spring action with a free stroke that allows relative movement between the first member and the second member within a limited angular range. The When the first member and the second member move relative to each other in the first direction starting from the rest position, the spring acts and transmission of rotational vibration is reduced. On the other hand, when the first member and the second member move relative to each other in the opposite second direction starting from the rest position, the spring over a limited angular range is due to the free stroke. Is not deformed so that the transmission of force between the first member and the second member is extensively reduced.

  According to an advantageous embodiment of the invention, the spring is formed as a metal spring, in particular with at least one spring element extending in the circumferential direction over at least part of the circumference of the first member. According to the invention, a compact structural shape of the belt pulley is possible by means of a spring element which is formed, for example, in the shape of a C, an arc, a sickle and / or an annular arc and can form a bending torsion spring.

  According to the invention, the at least one spring element further comprises a first opposing bearing provided on the first member via the first connection section and a second member via the second connection section. Can be connected to a second counter-supporting portion provided in

  In this case, the free stroke is such that the first connection section of the spring body is the first so that the relative rotation of the first member and the second member can be performed without deformation of the spring in the angular range. This can be achieved particularly easily by being relatively movable with respect to the opposite bearing part. Furthermore, the configuration in which the free stroke is made in the region of the spring allows a particularly compact belt pulley structure.

  The first opposing bearing portion has an entrainment portion, and the entrainment portion starts with the first connection section in the first rotational direction starting from a stationary position when the first and second members are in relative motion. The free stroke between the first member and the second member can be realized easily and robustly by entraining and releasing the angular range in the opposite rotational direction.

  According to a particularly advantageous embodiment of the invention, the entrainment part and the first connection section are in particular formed in a bowl shape having bowl-shaped openings facing (fitting) to each other.

  Advantageously, there is provided at least one stopper acting between the first and second members that limits the maximum angular range of relative movement between the first and second members.

  According to the invention, the angular range is limited to values below 120 °, in particular below 80 °, preferably below 50 ° and / or the angular range is limited to values above 1 °, in particular above 2.5 °. It has proven to be advantageous.

  According to an advantageous embodiment of the invention, the second connection section is connected to this second counter-bearing part so that the spring always moves during the rotational movement of the second counter-supporting part.

  In particular, the vibration technical characteristics of the belt pulley are that a hollow divided into partial spaces is provided, the partial spaces being connected to each other via at least one damping path, the hollow being at least partially. Filled with a damping fluid so that upon relative movement of the first member and the second member, at least one volume of the subspace changes such that the damping fluid moves through a damping path between the subspaces. It is improved by becoming. With this arrangement, a hydraulic damping of the relative movement between the first member and the second member is achieved. Furthermore, this damping effectively reduces noise as well as the force generated, for example, between the first connection section and the first counter bearing.

  Advantageously, at least one of the partial spaces is arranged radially between the first member and the second member.

  A particularly effective damping is that the first member and / or the second member has at least one extrudate projecting into the hollow, by means of which the first member and the second member This can be achieved if at least one volume of the subspace changes during relative movement.

  Improvement can also be achieved by changing the size of the cross section of the attenuation path in accordance with the relative positions of the first member and the second member. This can achieve a displacement-dependent damping along the possible relative movement between the first member and the second member, in which case the flow resistance is less if the damping path cross-section is small. Since the damping force increases, the damping force increases. When the cross-sectional area of the damping path is large, the damping force decreases.

  Furthermore, according to the invention, the spring can have at least two spring elements which are arranged functionally in parallel or in series.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  Each figure shows a belt pulley 1 that can rotate around a rotation axis D and has a first member 11 and a second member 12. The first member 11 on the input side is disposed radially inward and formed in a ring shape. Via this hub-shaped first member 11, the belt pulley can be fixed to a drive shaft, for example, a crankshaft of an engine of an automobile (not shown), or can be fixed to cover it.

  The second member 12 on the output side arranged on the outer side in the radial direction is rotatable relative to the first member 11. A spring 2 acts between the first and second members.

  The second member 12 has an enclosing annular portion 3 that forms a mounting surface 4 for a belt (not shown). In this case, the mounting surface 4 has a groove 5 extending around and a raised edge 6 for belt guidance.

  The spring 2 that is deformed when the first and second members 11 and 12 are relatively rotated is formed as a metal spring made of spring steel. In the illustrated embodiment, the spring has four spring elements 7, 7 ′, 7 ″, 7 ″ ″ arranged side by side in the axial direction of the rotation axis D. The spring elements 7, 7 ', 7 ", 7"' are identical to one another.

  Each spring element 7, 7 ′, 7 ″, 7 ′ ″ is connected via a first connection section 8 to a first opposing bearing 9 provided on the first member 11 and to a second connection. It is connected via a section 10 to a second opposing support portion 13 provided on the second member 12.

  The arrangement and embodiments of the spring elements 7, 7 ′, 7 ″, 7 ′ ″ and their connection with the first member 11 and the second member 12 are particularly exemplified in the description of the spring element 7. Explained. The other spring elements 7 ′, 7 ″, 7 ′ ″ are also formed identically as stamped parts and are fixed to the first and second members 11, 12 in the same manner as the spring elements 7. ing.

  The spring 2 is formed as a bending torsion spring and is characterized by a compact structural shape. Each of the spring elements 7, 7 ′, 7 ″ and 7 ″ ″ forming the spring 2 can be formed in a C shape, an arc shape, a sickle shape and / or a ring segment shape. In the illustrated embodiment, each spring element 7, 7 ', 7 ", 7"' extends around the first member 11 over an angular range exceeding 270 °. In this case, the spring elements 7, 7 ′, 7 ″, 7 ′ ″ are arranged radially outward with respect to the first member 11 and the second member 12, and around these members Extend. In this case, the first connection section 8 and the second connection section 10 are formed by bending at a right angle inward in the radial direction.

  In this case, the individual spring elements 7, 7 ′, 7 ″, 7 ″ ″ are arranged in parallel in terms of functional technology.

  The belt pulley 1 shown in each drawing has a so-called free stroke, and by this free stroke, the first member 11 and the second member 12 become spring elements 7, 7 ′, 7 ″, 7 ′. It is possible to rotate relative to each other in at least one direction over a limited angular range without deforming the spring 2 having ''. Here, the term free stroke represents the function of free movement between the first member 11 and the second member 12, in particular without essential deformation of the spring 2. In order to obtain this free stroke, the first connection section 8 is formed so as to be movable relative to the first opposing bearing portion 9, and the first member 11 and the second member 12 are relatively relative to each other. The rotation can be performed within the angular range without deformation of the spring 2. For this purpose, the first counter-supporting part 9 has an entraining part 14. The entrainment portion is formed such that the first connection section 8 entrains the spring element 7 in the first rotational direction starting from the stationary position during the relative movement of the first member 11 and the second member 12. ing. At the time of the movement in the second rotational direction set in reverse starting from the rest position, the entrainment part 14 does not take the first connection section 8 and moves freely with respect to the first connection section 8. .

  In the first member 11, the entraining portion 14 forms a protruding portion facing outward. On the opposite side, another protruding portion facing outward is formed. Both protrusions form extrudates 25 and 25 'which will be described later.

  The second member 12 is provided with inwardly protruding portions on both sides, and these protruding portions form stoppers 15a, 15b, 15c and 15d for the entraining portion 14, and thereby the first member The region of free movement between the member 11 and the second member 12 is limited. In this case, according to the invention, the angular range is limited to values less than 120 °, in particular less than 80 °, preferably less than 50 °. In the illustrated embodiment, this angular range is about 50 °. And in some applications, it is advantageous if the angular range exceeds 1 °, in particular 2.5 °.

  In the illustrated embodiment, the entraining portion 14 of the first opposing bearing portion 9 and the first connection section 8 are formed in a bowl shape, and the bowl-shaped openings are opposed to each other. The protruding portions of the first connection section 8 and the opposing bearing portion 9 (or the entrainment portion 14) can be engaged with each other.

  As shown, the second connecting section 10 of the spring element 7 has a second counter-bearing so that the spring element 7 is always moved during the rotational movement of the second counter-supporting part 13 or the second member 12. Connected to the unit 13. Unlike the case of the first connection section 8 and the first counter-supporting part 9, the configuration of the second connection section 10 and the second counter-supporting part 13 is such that they cannot move relative to each other. It has become. In this case, the second connection section 10 is formed as an enlarged leg, which forms the second counter-supporting part 13 of the correspondingly shaped second member 12. It is accommodated in the recess. This leg provides a uniform introduction of force from the spring element 7 to the second opposing bearing 13.

  For the absorption and transmission of the spring force, the first member 11 has a number of identical first power transmission elements 16 corresponding to the number of spring elements 7, 7 ′, 7 ″, 7 ′ ″, 16 ′, 16 ″, 16 ′ ″, in which one opposing bearing 9 is formed for each spring element 7, 7 ′, 7 ″, 7 ′ ″. ing. The first counter bearing 9 with the first power transmission elements 16, 16 ′, 16 ″, 16 ″ ″ is connected to the hub element 18 via coupling means 17 formed as a screw. In this case, in the illustrated embodiment, four coupling means 17 are arranged on the circumference. The hub element 18 is formed from a thin plate in the form of a ring and has three hub sections 19, 19 ', 19 "that are C-shaped in cross section and are substantially the same length and arranged at right angles to each other. Spring elements 7, 7 ', 7 ", 7"' are accommodated in the space formed by the hub sections 19, 19 ', 19 ". In this case, the hub section 19 is provided with a further hub section 19 ″ ″ facing inward at right angles.

  For the absorption and transmission of the spring force, the second member 12 has a number of identical second power transmission elements 20, corresponding to the number of spring elements 7, 7 ′, 7 ″, 7 ′ ″. 20 ′, 20 ″, 20 ′ ″, in which one second counter-bearing 13 for each spring element 7, 7 ′, 7 ″, 7 ′ ″. Is formed. In this case, the second power transmission element 20, 20 ′, 20 ″, 20 ′ ″ is connected to a ring 22 extending around via a coupling means 21 formed as a screw, Is provided with a ring-shaped part 3 forming a mounting surface 4 for the belt via a holding section 23 bent at a right angle towards the outside in the radial direction. The ring 22 and the retaining section 23 are fastened to each other via a coupling means 31 which in this case is formed as a screw. Each of the second power transmission elements 20, 20 ′, 20 ″, 20 ′ ″ has an open, generally C-shaped shape, and the first power transmission elements 16, 16 ′, 16 ″, Adjacent to 16 '' ', each extends over a circumferential portion of the first power transmission element.

  A rolling bearing 32 is provided between the ring 22 of the second member 12 and the first member 11, and the first member 11 and the second member 12 are rotated with each other via this bearing. Can do. Alternatively, a sliding bearing can be provided.

  However, in order to prevent static or dynamic imbalance, the inner two spring elements 7 'and 7' 'and the first power transmission elements 16', 16 '' and second power belonging thereto The transmission elements 20 ′, 20 ″ comprise the two outer spring elements 7, 7 ′ ″ and the first power transmission elements 16, 16 ′ ″ and the second power transmission elements 20, 20 belonging to them. It is arranged with a shift of about 180 ° around the rotation axis D with respect to '' '.

  The illustrated belt pulley has a hollow divided into subspaces 24, 24 ′, 24 ″, 24 ′ ″, 24 ″ ″, this hollow being at least partly a damping fluid (not shown). Filled with. In this case, the first member 11 has extrudates 25 and 25 ′ protruding into the hollow, and this extrudate is the partial space 24, during relative movement of the first member 11 and the second member 12. Change the volume of 24 '. The partial spaces 24, 24 ′ are connected to each other via a damping path, which is essentially formed by a gap between the extruded body 25 and the second power transmission element 20. When the entrainment portion 14 moves toward the stopper 15c during the relative movement of the first and second members, the volume of the partial space 24 is reduced, and at the same time, the volume of the partial space 24 'is increased. As a result, the damping fluid moves from the partial space 24 to the partial space 24 ′ through the attenuation path. At this time, since the cross-sectional area of the attenuation path is extremely smaller than the cross-sectional area of the partial spaces 24, 24 ′, the fluid flow has a resistance that attenuates the motion between the first member 11 and the second member 12. Give birth. Advantageously, the magnitude of the cross-sectional area of the attenuation path in that case varies according to the relative position of the first and second members. According to the present invention, when the first member 11 and the second member 12 are positioned relative to the terminal region of the limited angular range, the cross-sectional area is smaller than when it is in the central region, thereby damping The cross section of the attenuation path is configured so that becomes larger.

  In parallel with the rotational attenuation, the entrainment unit 14 reduces the volume of the partial space 24 ″ and expands the volume of the partial space 24 ″ ″. Since the fluid flows around the entrainment 14 and the connection section 8 through a gap determined by both members 8, 14, this greatly contributes to rotational damping.

  The damping mechanism is also effective during relative movement in the opposite direction from the first member 11 and the second member 12. In particular, the squeezing of the fluid from the hollow 24 ″ ″ ″ achieves a damped sliding in the intermeshing direction from the entrainment 14 into the first connection section 8.

  In order to improve the damping function, a ring-shaped disk 26 is provided between the individual spring elements 7 and 7 'and between 7 "and 7"', respectively. The hollow is sealed outwardly via sealings 27, 28. The sealing 27 is formed as a radial shaft seal ring, the seal lip of which abuts on the side of the ring 22 facing outwards. The sealing 28 is fixed to the second member 12, and the first member 11 contacts the seal lip.

  The first member 11, in particular its hub section 19 ″, is provided with a rotational vibration absorbing damper on the outside. The absorber has a ring-shaped rotating mass 29 fixed to the hub section 19 ″ via a rubber spring 30.

It is a perspective view of the belt pulley concerning the present invention by the partial sectional view on the right side. It is a perspective view of the belt pulley shown in FIG. 1 by the partial sectional view on the left side. It is sectional drawing of the belt pulley shown to FIG. 1 and 2 along the AA surface. FIG. 3 is a cross-sectional view of the belt pulley shown in FIGS. 1 and 2 along the plane BB. FIG. 3 is a cross-sectional view of the belt pulley shown in FIGS. 1 and 2 along the CC plane. FIG. 3 is a plan view of a spring arrangement of the belt pulley shown in FIGS. 1 and 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Belt pulley 2 Spring 3 Annular part 4 Belt mounting surface 5 Groove 6 Peripheral part 7, 7 ', 7'',7''' Spring element 8 1st connection division 9 1st counter bearing part 10 1st 2 connection sections 11 1st member 12 2nd member 13 2nd opposing support part 14 Entrainment part 15a, 15b, 15c, 15d Stopper 16, 16 ', 16'',16''' 1st power transmission Element 17 Coupling means 18 Hub element 19, 19 ′, 19 ″, 19 ′ ″ Hub section 20, 20 ′, 20 ″, 20 ′ ″ Second power transmission element 21 Coupling means 22 Ring 23 Holding section 24 , 24 ′, 24 ″, 24 ″, 24 ″ ″ Partial space 25, 25 ′ Extruded body 26 Disk 27 Sealing 28 Sealing 29 Rotating mass body 30 Rubber spring 31 Coupling means 32 Rolling bearing D Rotating shaft

Claims (12)

A belt pulley that is rotatable about a rotation axis (D), comprising a belt mounting surface (4), a first member and a second member (11, 12), One of the members is disposed on the input side and the other is disposed on the output side, and the first member and the second member (11, 12) are relatively rotatable with respect to each other. A spring (2) acts between the second members (11, 12), and the spring is deformed during the relative rotational movement of the first member and the second member (11, 12). A belt pulley,
The first member and the second member (11, 12) can be connected to each other without deformation of the spring (2) over an angular range that is limited to values less than 120 ° and / or limited to values greater than 1 °. There is a free stroke that allows relative rotation,
The spring (2) is formed as a metal spring, is formed in a C-shape as a punched part and extends at least part of the circumference of the first member (11) in the circumferential direction ( 7, 7 ′, 7 ″, 7 ′ ″) and constituting a torsion spring.   A first counter, wherein the at least one spring element (7, 7 ′, 7 ″, 7 ′ ″) is provided on the first member (11) via a first connection section (8) Connected to the bearing part (9) and connected to a second counter-bearing part (13) provided on the second member (12) via a second connection section (10) Item 2. The belt pulley according to Item 1.   In order to obtain said free stroke, the first connection section (8) of the spring body (7, 7 ′, 7 ″, 7 ′ ″) is relative to the first counter bearing (9). In this case, the relative rotation of the first member and the second member (11, 12) within the angular range is performed without deformation of the spring (2). The belt pulley according to claim 2.   The first opposing bearing part (9) has an entraining part (14), which entrains from a rest position when the first member and the second member (11, 12) move relative to each other. The belt pulley according to claim 2 or 3, wherein the first connection section (8) is entrained in the first rotation direction and the first connection section is released over the angular range in the reverse rotation direction.   5. A belt pulley according to claim 4, wherein the entrainment part (14) and the first connection section (8) are formed in a bowl shape, in particular with a bowl-shaped opening facing each other. .   At least one stopper (15a, 15b, 15c, 15d) acting between the first and second members (11, 12) is provided, the stopper being the first member and the second member. 6. A belt pulley according to claim 1, wherein the maximum angular range of relative movement between the members (11, 12) is limited.   The belt pulley according to claim 1, wherein the angular range is limited to values less than 80 ° and / or limited to values greater than 2.5 °.   The second connection section (10) is connected to the second opposing bearing part (13), so that the spring (2) always moves during the rotational movement of the second opposing bearing part (13). The belt pulley according to any one of claims 1 to 7, wherein the belt pulley is configured as described above.   A hollow divided into partial spaces (24, 24 ′, 24 ″, 24 ′ ″, 24 ″ ″) is provided, and the partial spaces (24, 24 ′, 24 ″, 24 ″) are provided. ′, 24 ″ ″) are connected to each other via at least one damping path, the hollow being at least partially filled with damping fluid, relative to the first member and the second member (11, 12). In motion, the subspace (24, 24 ', 24) moves so that the damping fluid moves through a damping path between the subspaces (24, 24', 24 ", 24 '", 24 ""). The belt pulley according to any one of claims 1 to 8, wherein at least one volume of '', 24 '' ', 24' '' ') is changed.   At least one of the subspaces (24, 24 ′, 24 ″, 24 ′ ″, 24 ″ ″) is radially disposed between the first member and the second member (11, 12). The belt pulley according to claim 9, wherein the belt pulley is provided.   The first member (11) and / or the second member (12) has at least one extrudate (25, 25 ') protruding into the hollow, the extrudate being the first Changing at least one volume of the subspace (24, 24 ', 24 ", 24'", 24 "") during relative movement of said member and said second member (11, 12). The belt pulley according to 9 or 10.   The belt pulley according to any one of claims 9 to 11, wherein a size of a cross section of the damping path changes according to a relative position of the first member and the second member (11, 12).

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