JP4518373B2 - Fixed structure for bush-shaped rubber-metal bearings - Google Patents

Description

  The present invention relates to a bushing-type rubber-metal bearing fixing structure having a closed metal inner ring and having a rubber layer deposited on the peripheral surface of the inner ring.

  Further, the present invention relates to a fixing structure for a bush type rubber-metal bearing having a closed metal outer ring and having a rubber layer deposited in the outer ring.

  Rubber-metal bearings of the above type are used for multifaceted purposes. For example, a rubber-metal bearing used as a support bearing for a spring strut is known (see, for example, Patent Document 1). The function of the rubber-metal bearing is then limited to a buffering action.

  A forklift truck in which a front drive axle is elastically supported on a vehicle frame is also known (see, for example, Patent Document 2). In addition to the buffer function, the bearing structure also assumes the function of tilting and supporting the lifting platform fixed to the drive axle. Both bearings used for suspension of the drive axle are each composed of a plurality of rubber-elastic cushioning elements, which are distributed and arranged in the circumferential direction of the drive axle, and have a relative rotation. It is secured in a shape fitting manner so that it cannot move and cannot shift in the axial direction. The bearing movement during the rotation of the drive axle is performed exclusively on the rubber. In short, the bearing in this case is not a bearing having a closed metal inner ring, unlike the prior art disclosed based on the above-mentioned Patent Document 1.

  If a rubber-metal bearing of the type mentioned at the beginning of the specification must also take on the function of a joint bearing, other than a secure joint between the rubber layer and the inner or outer ring (this is generally obtained by vulcanization) In addition, it is indispensable that the inner ring or outer ring of the rubber-metal bearing is non-rotatably coupled to a constituent member (for example, an axle) that contacts the inner ring or the outer ring.

  In order to fix the inner ring or outer ring of a rubber-metal bearing of the type mentioned at the beginning of the description, a conventional shaft-hub joint is used which is configured in a shape-fitting type and / or a frictional connection type. Shape-fitting joints (fitting keys, dentitions, etc.) are generally rather unfavorable for alternating loads, and also increase the manufacturing cost. For this reason, a frictional connection shaft-hub joint is awarded under such use conditions.

In the case of friction connection type joints, a so-called press fit can be obtained by carefully harmonizing the production tolerances of the components involved in the friction connection. Generated. In order to achieve this objective, it is necessary to maintain a remarkably narrow manufacturing tolerance in order to ensure that the friction-coupled joint is completely unrotatable and that the pivoting movement takes place in the rubber layer. It is obvious.
German Republic Patent No. 3532681 (C2) specification German Patent Application Publication No. 1008881 (A1) Specification

  An object of the present invention is to improve a fixing structure of the type described at the beginning of the specification, and to obtain a frictional connection joint that is reliable for rubber-metal bearings at a small manufacturing cost.

  The constituent means of the present invention for solving the above-described problem is that the inner ring of the rubber-metal bearing is fixed to the outer periphery of the cylindrical body in a frictional connection manner in an assembled state, so that at least the axial extension length of the inner ring is In a part of the region, it is plastically deformed in the radial direction.

  The above-mentioned problem that forms the basis of the present invention is further provided in a combination with the above-described solution means in which the outer ring of the rubber-metal bearing is fixed to the inner periphery of the hollow cylindrical body in a frictional connection manner in the assembled state. In order to achieve this, it is solved by plastic deformation in the radial direction in the region of at least a portion of the axial extension length of the outer ring.

  Therefore, the idea of the present invention is to consciously plastically deform the inner ring or outer ring when assembling a rubber-metal bearing in order to obtain the maximum frictional connection under any circumstances. is there. Unlike the friction connection type joint which is used only in the elastic deformation region, which is conventionally used for the shaft-hub joint in the prior art, in the fixing structure of the present invention, the rubber-metal bearing is assembled. The inner ring or outer ring is first deformed to an extent that causes a plastic flow of the metal based on the overelastic limit. After the end of the plastic flow movement, the inner ring or outer ring is fixed under the maximum possible preload. In short, not only the elastic deformation region of metal is used but also a part of the plastic deformation region is additionally used.

  The fixing structure of the present invention is reliable and meets the manufacturing cost. Force transmission is possible in any spatial direction. The joint of the present invention is particularly suitable when the torque and rotational moment directions are changed alternately and when alternating stress is generated in all directions. In addition, the fixed form according to the invention of the rubber-metal bearing allows a relatively large tolerance between the components, which simplifies the production of the components.

  When the inner ring of the rubber-metal bearing is fixed to the outer periphery of the cylinder in a frictional connection manner, in an advantageous embodiment of the invention, the cylinder has a radius within the region of the axial extension length of the inner ring. A conical shape comprising two adjacent cylindrical elements which have axial dividing lines and are axially connectable, wherein at least one cylindrical element reduces the outer diameter towards said dividing line Further, the inner ring of the rubber-metal bearing can be plastically deformed in the radial direction in the region of at least a part of the axial extension length of the inner ring by joining the two cylindrical elements. It is proposed to configure. By this means, the force required for plastic deformation is generated very easily.

  When the outer ring is fixed to the inner periphery of the hollow cylindrical body in a frictional connection manner, the hollow cylindrical body is divided in one radial direction within the region of the axially extending length of the outer ring in an equivalent manner. Consists of two adjacent hollow cylindrical elements that have a line and are axially buttable, and at least one hollow cylindrical element is configured in a conical shape such that the inner diameter increases toward the dividing line In addition, the outer ring of the rubber-metal bearing can be plastically deformed in the radial direction in the region of at least a part of the axial extension length of the outer ring by abutting the hollow cylindrical elements. It is advantageous to do so.

  In a particularly advantageous configuration of the invention, the cylinder is configured as an axle arranged on the front side of a forklift vehicle, the axle being supported on the vehicle frame by two rubber-metal bearings, A tiltable lifting platform is fixed to the axle and is rotatable about the axle center axis together with the axle.

  When configured in this way, the axle vibration damping suspension system additionally takes on the function of the tilting support of the lifting platform. The pivoting movement in this case takes place in the rubber layer of the rubber-metal bearing. Instead of bearings that are already known from the prior art and costly in terms of manufacturing technology and with form-fitting fixing, rubber-metal bearings of relatively simple construction are now used. . In this case, the fixing structure according to the invention with plastic deformation of the inner ring ensures that the inner ring maintains a frictional connection with the axle under any circumstances.

  It is advantageous if a wheel motor and an axle middle piece are provided as cylindrical elements of the axle, respectively. The rubber-metal bearing is then arranged in each case in the region of the dividing line of the constituent elements. In short, it is not necessary to produce the dividing line specially.

  It turned out that the axle was cast. In this case, mechanical (cutting) processing of the axle section provided as a bearing seat for the rubber-metal bearing can be omitted. The tolerance that can be achieved during casting is sufficient for the fixing structure of the invention.

  The above advantages are also obtained when the axle part used is forged.

  The production of the inner ring or outer ring is also simplified. For example, it is possible to use a ring which is formed by rolling (rounding) and welded, or a ring made of a semi-finished tube, in which case there is no need for cutting.

  Of course, instead of the exact circular geometry of the inner and / or outer ring and / or cylinder and / or hollow cylinder, a circle-dependent geometry, for example a polygonal geometry, is used. Are also within the scope of the present invention. In this case, the principle of the fixing structure of the present invention is used.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  The illustrated fixing structure of the present invention is used for fixing a bush-shaped rubber-metal bearing to the front axle of a forklift truck. The axle, which can be configured as a drive axle, must be rotatable about the central axis M, for example, by 10 ° in both rotational directions, in order to incline the lifting platform mounted on the axle. I must.

  The rubber-metal bearing has a metal inner ring 1, a metal outer ring 2 and a rubber layer 3 interposed between the two metal rings, which rubber layer is advantageously added. It is joined to both metal rings by a sulfur treatment.

  The axle is configured as a cylindrical body and is composed of a plurality of tubular cylindrical elements in the present embodiment. In FIG. 1, two of the plurality of cylindrical elements that end face each other in the region of the rubber-metal bearing. Cylindrical elements 4 and 5 are shown, so that there is a dividing line T at the butt. The right-hand cylindrical element 5 can be formed as a casing component of the wheel motor as viewed in the drawing, whereas the left-hand cylindrical element as viewed in the drawing forms, for example, an axle intermediate piece of an axle.

  Both the cylindrical elements 4 and 5 are configured to reduce the outer diameter to a conical shape toward the dividing line T. The cylindrical element 5 on the right hand as viewed in FIG. 1 has an axial stopper 5a (assembly stopper) formed integrally therewith. Both conical sections are asymmetrical with respect to the dividing line T in this embodiment. The conical section of the cylindrical element 4 has a conical angle α, which can be different from the conical angle β of the conical section of the cylindrical element 5. The cone length can be chosen in relation to the expected production tolerance.

  The inner ring 1 of the rubber-metal bearing has a nominal diameter d equal to the nominal diameter D of the axle before assembly. When the cylindrical elements 4 and 5 are constructed as pure cylinders, this is practically the tolerance that a so-called press fit must guarantee the frictional connection between the inner ring 1 and the axle in terms of production technology. It is none other than that you have to keep strictly.

  In the fixing structure according to the invention, instead, the rubber-metal bearing is first arranged for assembly and is arranged axially between the two cylindrical elements 4 and 5, which are divided into two conical shapes. This is possible by having a diameter smaller than the nominal diameters D, d of the axle and inner ring 1 on each end face side. The cylindrical elements 4 and 5 are then combined and then moved in a direction (in the direction of arrow F) in which the end faces abut each other until they abut each other.

  Based on the geometrical relationship between the inner ring 1 and the axle, the inner ring 1 is plastically deformed, ie expanded, in the radial direction. In this case, the inner ring 1 is supported by an axial stopper 5a of the cylindrical element 5, thereby obtaining a specific axial position of the rubber-metal bearing. The plastic deformation operation in the radial direction is finished when the end surfaces of the cylindrical elements 4 and 5 are in contact with each other.

  FIG. 2 shows a rubber-metal bearing with the axle omitted, and an inner ring 1u that is not yet plastically deformed before assembly (shown schematically by a dashed line) and plastically deformed after assembly. The difference from the inner ring 1 is clearly shown. Depending on the generation tolerance and the shape of the conical section, the inner ring 1 is expanded more or less strongly starting from both ends. In this case, two plastic deformation regions A and B are generated. A non-deformable region C is located between the two plastic deformation regions A and B when viewed in the axial direction.

  The frictional connection between the inner ring 1 and the axle is made in the plastic deformation regions A and B and the transition region accompanied by the elastic deformation of the inner ring 1 (arrow K in FIG. 1). By means of the fixing system according to the invention, a frictional connection joint with the greatest possible adhesion is obtained. Of course, the plastic deformability of the metal is only partially exploited, and in this case, a sufficient safe distance is maintained against the fracture limit of the metal.

  The fixing structure according to the invention in a similar manner not shown in the drawing also applies to the outer ring 2 of a rubber-metal bearing which is fixed in the hollow cylinder 6.

  A further advantage of the fixing structure of the present invention is that it does not require expensive press tools. This is particularly important when the rubber-metal bearing has to be replaced for reasons of wear. By disassembling the cylindrical element 5 (the casing component of the wheel motor), it is possible to easily remove the worn rubber-metal bearing while the axle (cylindrical element 4) remains assembled. A new rubber-metal bearing is fixed by recombining the two cylindrical elements 4,5.

It is a schematic sectional drawing of the fixing structure of this invention.

It is sectional drawing of the rubber-metal bearing in a plastic deformation state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Inner ring made of metal, 1u Inner ring in an unplastically deformed state, 2 Outer ring made of metal, 3 Rubber layer, 4,5 Cylindrical element, 5a Axial stopper, 6 Hollow cylindrical body, M Center axis, T Dividing line , Α, β Conical section cone angle, D Nominal diameter of axle, d Nominal diameter of inner ring, F Arrow indicating butt direction, A, B Plastic deformation area, C No deformation area, K arrow

Claims (5)

A bushing-shaped rubber-metal bearing fixing structure, wherein the rubber-metal bearing has a closed metal inner ring, and a rubber layer is attached to the outer peripheral surface of the inner ring. In the form of
In order that the inner ring (1) of the rubber-metal bearing is fixed to the outer periphery of the cylindrical body in a frictional connection manner in the assembled state, the radius is at least in a region (A, B) of the inner ring axial extension length. Plastically deformed in the direction ,
The cylindrical body has one radial dividing line (T) in the region of the axial extension length of the inner ring (1) and two adjacent cylindrical elements (4, 4) that can be butted in the axial direction. 5), and at least one cylindrical element (4 or 5) is formed in a conical shape whose diameter decreases toward the dividing line (T). The inner ring (1) can be plastically deformed in the radial direction in the region (A, B) of at least a part of the axially extending length of the inner ring by the butting of both the cylindrical elements (4, 5). Characteristic fixing structure for bush-shaped rubber-metal bearings. A fixing structure for a bush-shaped rubber-metal bearing, wherein the rubber-metal bearing has a closed metal outer ring, and a rubber layer is attached to the inner peripheral surface of the outer ring. In the format that has been
In order for the outer ring (2) of the rubber-metal bearing to be fixed to the inner periphery of the hollow cylindrical body (6) in a frictional connection manner in the assembled state, a region of at least a part of the axial extension length of the outer ring It is plastically deformed radially in,
The hollow cylinder (6) has one radial dividing line in the region of the axial extension length of the outer ring (2), and from two adjacent hollow cylinder elements that can be butted in the axial direction. And at least one hollow cylindrical element is formed in a conical shape whose inner diameter increases toward the dividing line, and the outer ring (2) of the rubber-metal bearing is formed by the two hollows. A bushing-shaped rubber-metal bearing fixing structure characterized in that it can be plastically deformed in the radial direction in the region of at least a part of the axially extending length of the outer ring by abutment of a cylindrical element . The cylindrical body is configured as an axle disposed on the front side of the forklift truck, the axle is pivotally supported on the vehicle frame by two rubber-metal bearings, and the tiltable lifting platform includes the axle. fixing structure is fixed, and is rotatable about the axle central axis (M) is with the axle, according to claim 1 or 2 wherein the. The fixing structure according to claim 3 , wherein each of the cylindrical elements (4, 5) of the axle is provided with one wheel motor and an axle middle piece. The fixed structure according to claim 3 or 4 , wherein the axle is cast.

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