MXPA06008925A - Tooth profile of a spline shaft - Google Patents

Abstract

The invention relates to the groove profile for a form-fitting hub-shaft connection. Said groove profile has a substantially rectangular or trapezoid groove cross-section (3). At least one radially outward projecting rib (6) is provided on the groove root (5) or the groove head (4) of either the hub (1) or the shaft (2) and allows to establish a linear contact with the radially opposite groove surface across the front face (6') of the rib (6) that has a small width (b). The radial distance of said front face (6') relative to the longitudinal axis of the hub (1) or shaft (2) can be produced by cold-rolling with very narrow tolerances, thereby achieving a radial connection of hub (1) and shaft (2) which is virtually free from play.

Description

PROFILE OF DENTATION OF A STROKE ARROW DESCRIPTION OF THE INVENTION The present invention relates to a toothing profile according to the preamble of claim 1. • In order to achieve a positive connection between a hub and an arrow, adjusting or sliding tab connections are frequently used. When it comes to transferring large torques and a displacement between hub and arrow must be allowed, a multiple groove profile or respectively a fluted arrow is often used. The slots, in this, frequently have a rectangular or trapezoidal profile. Profiles are produced in this by machining with chip removal or by cold forming, for example, by impact rolling methods. In front of machining with chip removal, cold forming has the advantage of greater economy when large quantities of units must be produced. Just in the cold transformation during the production of such profiles, a series of parameters is of decisive importance for the precision of the profile. These are, in particular, the diameter, the tooth width, the partition, the groove shape, respectively the side of the tooth and its direction, the oval of the workpiece, etc. The adjustments of these individual parameters are finally accumulated reaching adjustment errors between cube and arrow that are important for an effective union between cube and arrow. These adjustments must be designed, therefore, with appropriate play to, in the first instance, allow the union. This necessary game, however, produces a reduction in the quality of the adjustment in pairs between the hub and the arrow, which has a negative effect depending on the parameters and the application of the joint. It often happens that the quality requirements of these parts in process can only be met conditionally in the subsequent cold transformation. This problem can arise in carriers of clutch plates for automatic transmissions of vehicles or, for example, in a pronounced way in the production of telescopic tubes of articulated arrows that are used, for example, in large unit quantities in the vehicular construction. For this purpose, an internal and external tube with a corresponding profile on the inner side, respectively external, respectively is used. Due to the large quantities of units, the cold transformation method is of great interest for economic production, but due to the high speeds of rotation of the telescopic tubes of articulated arrows during the operation there are great demands on the precision of the union of profile between the inner and outer tube. In the use of conventional profiles between the two tubes there is a buckling set that can cause unacceptable radial movements of the articulated arrow during the operation, which can cause the destruction of the articulated arrow in case of large loads and revolutions. The buckling play is caused by the radial play between the profile of the inner and outer tubes. The aim of the present invention was to find a toothing profile for the motor components, in particular for articulated arrows, shaped to slide between them, which minimizes radial play or eliminates it as much as possible. This objective is achieved inventively by means of a toothing profile with the features of claim 1. Other preferred inventive embodiments are derived from the features of the other claims 2 to 6. The inventive slot profile for a hub and arrow connection to positively connecting manner having essentially a rectangular or trapezoidal groove cross section has at the bottom of the slot or at the head of the groove of the hub or the arrow at least one rib projecting radially outwards. Thus, a line and area support is formed in the radial direction relative to the longitudinal axis of the hub respectively of the arrow. Such support can advantageously be performed with little or even free play. Preferably, each groove bottom or each groove crest of the hub or arrow has at least one rib. In this way, a defined connection of the profiles between the hub and the arrow is achieved throughout the periphery and a precise radial positioning of the arrow in the hub is achieved. Preferably, the rib is formed in parallel extension relative to the side of the groove, preferably along the entire length of the groove bottom respectively of the corresponding groove ridge. Just in the case of large tooth lengths, as they occur in the case of telescopic tubes, a connection of line and precise radial area between the grooves of the hub and the arrow, respectively of the inner and outer tubes, is thus achieved. external. Preferably, the rib has a trapezoidal cross section that decreases outwardly. Such a shape is easy to produce by cold transformation and has great shape stability. Preferably, a rib has a maximum width of 50%, preferably 25% of the width of the respective bottom respectively groove crest. The narrower the rib is formed, the less the support area of the rib head in the corresponding area of the bottom respectively of the opposite groove ridge. In this way it is possible to achieve exact geometrical conditions also on larger profile lengths. Preferably, the radius of the support area of the rib to the bottom respectively the crest of the opposite slot with respect to the longitudinal axis of the hub respectively of the arrow is formed free of play or with preload. The radial play between the hub and the arrow can then be practically completely canceled out. It has also been verified that it is even possible to introduce a preload, that is, the radius of the support area of the rib is greater than the radius of the support area of the bottom respectively of the groove ridge, if the ribs are formed in the profile of the rib. Cube. This is particularly appropriate in the case of thin-walled hollow profiles, where the hub or the arrow or both are shaped as hollow profiles. It is also possible to compensate in this way an ovality of the cross section that occurs precisely in the case of hollow profiles, due to inhomogeneities of the material. Preferably in each case at least two ribs, arranged parallel to one another, are formed in a groove bottom respectively the groove ridge. Depending on the dimensions of the profiles and the cube and arrow dimensions, as well as the forces to be transmitted and the speed of rotation, it may be advantageous to provide more than one rib. The pockets that are formed next to the respective ribs between the radially opposed areas of the bottoms or the profile ridges have also proved to be a great advantage for the distribution of lubricant in the interstices of the profiles. The objective is also achieved by means of a telescopic tube for articulated arrows with an internal tube and an external tube in which the inner tube or the outer tube have a groove profile according to one of claims 1 to 6. Preferably, the inner tube and the External tubes are formed here as hollow bodies with approximately profile thickness. uniform. Such articulated arrows are particularly suitable for use in motor vehicles for the transmission of the motor force to the axles, respectively 'rear wheels. Furthermore, a method for the production of a groove profile according to one of claims 1 to 6 is proposed inventively by the cold rolling method in which one or several profiled rollers or cylinders - in accordance with the profile mandrel necessary for production of the profile and that is inside the hollow component with a profile shaped according to the nerve - the surface of the hub or the arrow is hooked. In this way, the rib can advantageously be produced in one step together with the formation of the grooves. Preferably, the profile rollers or profile cylinders are placed in periodic impact contact. Particularly precise profiles can be produced by this impact rolling method. Next - an exemplary embodiment of the present invention is explained in more detail by means of the drawings. These samples: Fig. 1 the cross section by a telescopic tube with the inventive slot profile; 2 shows the cross-section through a partial view of a groove according to FIG. 1 inventively configured; Fig. 3 the cross section of a partial view of an alternative embodiment of a telescopic tube; Fig. 4 the cross section of a partial view of another alternative embodiment of a telescopic tube; 5 shows the cross section through a partial view according to FIG. 2 with an alternative configuration of the inventive slot. In figure 1 the cross section is represented by the external tube 1 and the inner tube 2 formed as a hollow profile of a telescopic tube, such as is used, for example, in the construction of vehicles. Both the outer tube 1 and the internal tube 2 have in this a profile arranged uniformly along the periphery with grooves 3 having a trapezoidal cross-section. In FIG. 2, a section of a single slot profile of the telescopic tube according to FIG. 1 is shown in more detail. The outer tube 1 has a trapezoidal slot 3 with a groove ridge 4 facing the inner part. The groove ridge 4 has a cylindrical area relative to the longitudinal axis of the telescopic tube. The inner tube has a groove 3 formed correspondingly with a groove bottom 5 oriented towards the outer part. The groove bottom 5 also has a cylindrical area analogously to the groove ridge 4. At the bottom 5 of the groove is now formed a rib 6 projecting outwards. The front face 6 'of the rib 6 is supported in the present example in the center of the groove ridge 4 of the outer tube, advantageously without play. Thanks to the reduced support width b in comparison with the width B of the slot of the groove ridge 4, a point-to-area connection is practically created, respectively - in consideration of the longitudinal extension of the grooves 3 - a line-to-area connection . In addition, the reduced width b of the rib 6 allows an accurate production with respect for minimum tolerances even with the cold transformation method, which first allows a game-free design of the formation of pairs. The sides 7 of the grooves 3 of the outer tube 1 and of the internal tube 2 facing each other advantageously have a small play with each other in order to compensate for inaccuracies of the side angle and the partition of the grooves at the same time. produce the groove profile and allow the formation of pairs, between external tube 1 and internal tube 2. The clearance can be, for example, 0.05 mm in the case of an average tube diameter of 100 mm and a wall thickness of 2 mm. Values can thus be achieved with the cold transformation method. Now, without advantageously each slot bottom 5 of each groove 3 has a similar rib 6, the radial clearance of the connection between the outer tube 1 and the inner tube 2 can advantageously be annulled in this way completely. In this way the buckling play is also reliably canceled, damaging such telescopic tubes. Figures 3 and 4 show other examples of embodiment of the inventive groove profile comprising the rib 6 in profiles 1 'respectively 2' of thick-walled tube. It is clear that a combination of two profiles 1 'and 2' of thick-walled tube is also conceivable, just as it is possible to use a solid profile as internal tube 2. Another alternative embodiment of the inventive groove profile is shown in Figure 5, where there are two ribs 6 with a location parallel to one another in the groove bottom 5. It has been verified, apart, that the bags 8 formed between the ribs 6 and the groove bottom 5, respectively the groove ridge 4, are perfectly suitable for the accommodation and distribution of lubricants and have better lubrication characteristics compared to the conventional groove profiles without ribs 6. It is without obvious difficulty for the skilled person that the ribs 6 can be formed, for example, on the inner face of the outer tube 1 on the groove ridge 4 and which are therefore oriented inwards. The ribs 6 can also be arranged in each case on the groove ridge 4 of the inner tube 2 respectively the groove bottom of the outer tube 1. Because the ribs 6 can be produced in precise dimensions, a preload can be set instead of the nullification of the play between the front face 6 'of the rib 6 and the crest 4 of the opposite slot, the front face 6' having a radius greater relative to the longitudinal axis of the outer tube 1, respectively of the inner tube 2 than the radius of the groove ridge 4. This is very particularly suitable for use in internal, respectively thin-walled inner tubes 1, whereby in this case also possible ovalities, ie deviations from the exact circular shape, can be compensated for in this way.

Claims (3)

1. Slot profile for a connection, cube and arrow in positive connection having an essentially rectangular or trapezoidal groove cross section, characterized in that the groove bottom or the groove ridge or the hub or the arrow have at least one rib that it projects radially outwards. Slot profile according to claim 1, characterized in that each groove bottom or each groove ridge of the hub. or the arrow has at least one nerve. Groove profile according to claim 1 or 2, characterized in that the rib is formed so that it extends parallel to the side of the groove, preferably along the entire length of the groove bottom respectively of the corresponding groove ridge. . Slot profile according to one of claims 1 to 3, characterized in that the rib has a trapezoidal cross-section that decreases outwards and a maximum width of 50%, preferably 25% of the width of the bottom respectively of the ridge. of corresponding slot. Slot profile according to one of the claims 1 to 4, characterized in that the radius of the support area of the rib towards the bottom or the opposite groove ridge with respect to the longitudinal axis of the hub respectively of the arrow is configured in the free game or with preload. Slot profile according to one of Claims 1 to 5, characterized in that at least two ribs arranged parallel to one another are formed in each case in a groove bottom or respectively groove ridge. 7. Telescopic tube for articulated arrows with an internal tube and an external tube, the inner tube or outer tube having a slot profile according to one of claims 1 to 6. 8. Telescopic tube according to claim 7, characterized in that the inner tube and the outer tube are shaped as hollow bodies with approximately uniform profile thickness. 9. Method for the production of a groove profile according to one of claims 1 to 6 by the cold rolling method, characterized in that one or more profile rollers or profile cylinders, in accordance with the profile mandrel necessary for the formation of the profile that is inside the hollow part with a profile configured corresponding to the rib, is put to hook the surface of the hub or the arrow. Method according to claim 9, characterized in that the profile rollers or the profile cylinders are periodically hitched in an impact manner.