DE4119819A1

DE4119819A1 - Linear guide with zero angular plane - has balls retained in grooves in inner part which has offset from slots in outer part

Info

Publication number: DE4119819A1
Application number: DE4119819A
Authority: DE
Inventors: Wolfgang Dipl Ing Steinberger
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 1991-06-15
Filing date: 1991-06-15
Publication date: 1992-12-17

Abstract

The guide which permits relative longitudinal movement between two parts (1, 2) is designed to prevent relative rotation between the two parts. The inner part (1) has longitudinal grooves (4, 5) which receive the balls (7). The outer part has slots (12) which receive the balls (7) which are retained by an elastically deformable sleeve (8). In order to eliminate any angular play between the inner (1) and outer (2) parts the slots (12) in the outer part are slightly offset relative to the grooves (4) in the inner part or the grooves are offset relative to the slots. USE/ADVANTAGE - Linear guide with zero angular play.

Description

The invention relates to the longitudinal guidance of two components relative to each other, the axial relative to each other adjustable but rotatable with each other, with an inner part designed as a shaft, in the Outer surface circumferentially distributed, parallel to the longitudinal axis extending grooves are arranged with a die Shaft enclosing outer part, which the grooves of the Wave opposite, to the wave and outward itself has opening openings, wherein in the grooves of Wave and the opposite breakthroughs of the Outer part balls are supported and the balls from the Projections protrude radially outwards and from one shared, radially elastic ring are.

From DE 32 06 437 C2 a joint is known that in addition the angling of the inner part and outer part against a longitudinal displacement. However, this is with play in the circumferential direction between the two components afflicted because the balls are in contact depending on the direction of rotation changes and no defined position of the balls in the Grooves or the breakthroughs is given.

Longitudinal guides for selector shafts for gear change transmissions with several in a cage and in grooves from Ball and outer part guided balls are from DE 40 20 160 A1 known.

The invention has for its object a longitudinal guide to create a relative adjustment between a Shaft and an outer part allowed, but in the both directions of rotation a play-free take between these two components.

This object is achieved in that at least one of the grooves or at least one of the Breakthroughs with a circumferential offset to the neighboring ones Grooves or breakthroughs is arranged by the The circumferential offset of the others differs from one another.

Due to the circumferential offset or the different Pitch spacing results in a play-free connection, so that use of the longitudinal guide, for example with shift shafts, such as those found in manual transmissions can be used. In the event that a Torque transmission between the shaft and the outer part is only required in one direction of rotation, it is off sufficient if one of the grooves or one of the through breaks to the others.

In an embodiment of the invention, however, it is possible The longitudinal guide should be designed so that the same torque is load ratios in both possible rotation or Swivel directions result in what is provided that two There are groups of grooves or openings, the grooves of which each have the same circumference offset, but the two different groups below have different pitches.

Perfect rolling conditions of the balls without sliding arise when the length of the breakthroughs, that of elastic ring and the grooves of the desired Displacement are adjusted. For use cases which the displacement or smoothness between the shaft and the outer part is not in the foreground, it may also be enough if the breakthroughs that the bullets record, are shorter than the desired adjustment length of the two components to each other and the displacement path only in the length of the grooves of the shaft is taken into account.

The running grooves are preferably circular in cross section shaped. Due to the different dimensioning the distribution distances automatically arises clocks between the balls and the grooves a that the adjacent grooves associated balls opposite flanks of the grooves to the system com to achieve game suppression. The one with it associated further advantage relates to the possibility provide for coarser tolerances during production, which is due to the elastic behavior of the ring in the mon balanced state.

There are two alternative designs for the breakthroughs possible. According to a first embodiment is pre see that the breakthroughs, seen in cross section, Have side faces that are parallel to that of the center point of the balls containing between them Radial plane run.

However, it is also possible that the breakthroughs, in the cross seen cut a side surface that is parallel to the the center of the associated radial containing the sphere plane runs and a side surface that acts as a circular arc is designed to have.

The advantage of this training is that the pressure angle that results in a favorable introduction of force Torque transmission allowed.

The elastic ring is preferably fixed to the outer part connected. He can, for example, by friction on the Be held outer surface of the outer part.

It is also possible to add several balls per groove see who are kept in a cage.

Preferred embodiments of the invention are in the Drawing shown schematically.

It shows

Fig. 1 shows a cross section through a first Execute ungsform,

Fig. 2 is a longitudinal section of FIG. 1,

Fig. 3 shows a cross section through a second Execute ungsform,

Fig. 4 shows a longitudinal section through an embodiment with several balls per groove and

Fig. 5 shows a cross section through the outer part of the embodiment of FIG. 4 with offset Druchbrüchen.

In the longitudinal guide according to FIGS. 1 to 3, the shaft 1 is received axially displaceably with play in the bore 3 of an outer member 2. The shaft 1 has in its outer surface parallel to the longitudinal axis or axis of rotation X extending grooves 4 , 5 . The grooves form groups. The path center planes B 1 of the grooves 4 forming the first group are offset from one another by 180 °. This also applies to the center plane B 2 of the two grooves 5 belonging to the second group.

However, the path center planes B 1 of the grooves 4 to each other (B 2 ) of the grooves 5 are arranged with one another at different pitch intervals. Thus, starting from the groove 4 located above in the drawing figure 1 to the groove 5 following the clockwise rotation, there is a pitch C which is smaller than the pitch to the groove 5 following the counterclockwise rotation. The same then applies in the further sequence, so that between two neighboring disclosed first and second grooves 4 , 5 times a larger pitch D and a smaller pitch C is given. In the grooves 4 , 5 balls 7 aufgenom men who are guided in openings 6 of the outer part 2 in the circumferential direction on side surfaces 11 , 12 openings 6 . The openings 6 are also open to the outside. They are acted upon radially inward by a resilient ring 9 seated firmly on the outer surface 8 of the outer part 2 . Since the breakthroughs 6 are arranged at the same pitch, due to the different pitches of the first and second grooves 4 , 5 , there is a contact ratio to one another, which guarantees freedom from play in the two directions of rotation A, B of the shaft 1 and the outer part 2 accomplishes. Thus, for example, with respect to the first grooves 4, there are contact conditions in which the balls 7 each lie against the contact points 13 on the flank of the grooves 4 lying at the front in the direction of rotation A 1. Further support is provided via the contact point 14 on the side face 11 the opening 6 of the outer part 2 and via the contact point 15 on the inner surface 10 of the elastic ring 9th In the case of the second grooves 5 , the ball 7 rests with respect to the groove on the flank opposite to the first groove 4 , namely the front in the direction of rotation A, with the contact point 13 . The breakthrough is supported at contact point 14 on the opposite side surface 12 . Due to the elastic prestressing via the elastic ring 9 , the balls are inevitably adjusted to the running groove 4 or 5 and to the corresponding side surface 11 , 12 of the associated opening 6 . Depending on the Spielver ratios and the individual tolerance ratios of a single groove, the ball 7 is more or less high to the edge of the web that results between the groove and the outer surface of the shaft.

The contact points 13 , 14 , 15 are selected so that perfect rolling conditions occur in the grooves 4 , 5 adapted to the displacement length and in the correspondingly long openings 6 . This ensures smooth operation. Depending on the switching or rotational direction A or A 1 of the shaft 1 opposite the outer part 2 , half of the balls 7 each take part in the torque transmission in the illustrated embodiment.

In the embodiment of Fig. 1, the sides extending surfaces 11, 12 of the apertures 6 to the radial plane parallel RE, which runs 12 guided balls 7 through the center points between the side surfaces 11. In the embodiment according Fig. 3, the side surfaces are formed under different. Thus, the side surface 12 is designed accordingly to the side surface 12 in the embodiment according to FIG. 1, namely as a parallel to the radial plane RE, while the other side surface 11 runs in a circular arc. This results in more favorable conditions with respect to the transmission of torque, so that higher moments can be transmitted in one direction than in the other direction of rotation.

In the embodiment of FIGS. 4 and 5 it can be seen that two balls 7 are arranged side by side in each breakthrough 6, which are held by a cage 16 . Furthermore, 5 of Fig. Seen that the openings 6 of the outer member 2 with different distances division C, D are arranged. The grooves 4 , 5 are evenly distributed (with the same spacing to each other) in the shaft 1 . The arrangement of the openings 6 with different pitch C, D follows the teaching as described in connection with FIGS. 1 to 3 for the grooves 4 , 5 . In all embodiments, the grooves 4 , 5 are designed in cross section as a circular arc.

Claims

1.Longitudinal guidance of two components opposite one another, which are axially relatively adjustable relative to one another, but can be rotated relative to one another, with an inner part designed as a shaft, in the outer surface of which circumferentially distributed running grooves extending parallel to the longitudinal axis are arranged, with an outer part surrounding the shaft, the opposite the grooves of the shaft, to the shaft and outwardly opening openings, wherein balls are supported in the grooves of the shaft and the respective opposite openings of the outer part and the balls protrude radially outwards from the openings and from a common, radially elastic ring are acted on, characterized in that at least one of the grooves ( 4 , 5 ) or at least one of the openings ( 6 ) is arranged with a circumferential offset (C, D) to the adjacent grooves ( 5 , 4 ) or openings ( 6 ), that of the circumferential offset the other n deviates from each other.

2. Longitudinal guide according to claim 1, characterized in that two groups of grooves ( 4 , 5 ) or through openings ( 6 ) are present, the grooves of which each have the same circumferential offset but the two different groups have different spacings (C, D) from one another .

3. Longitudinal guide according to claim 1, characterized in that the length of the openings ( 6 ) and that of the elastic ring ( 9 ) is adapted to the displacement length.

4. Longitudinal guide according to claim 1, characterized in that the grooves ( 4 , 5 ) are circular in cross-section.

5. Longitudinal guide according to claim 1, characterized in that the openings ( 6 ), viewed in cross section, have side surfaces ( 11 , 12 ) which are parallel to the radial plane (RE) containing the center (M) of the balls ( 7 ) guided between them (RE) ) run.

6. Longitudinal guide according to claim 1, characterized in that the openings ( 6 ), seen in cross section, a side surface ( 12 ) which runs parallel to the radial plane (RE) containing the center point (M) of the associated ball ( 7 ) and a Side surface ( 11 ), which is designed as a circular arc.

7. Longitudinal guide according to claim 1, characterized in that the elastic ring ( 9 ) is fixedly connected to the outer part ( 2 ).

8. Longitudinal guide according to claim 1, characterized in that there are several balls ( 7 ) for each groove ( 4 , 5 ), which are held in a cage ( 16 ).