WO2009118160A2

WO2009118160A2 - Linear roller bearing and switch device with a linear roller bearing

Info

Publication number: WO2009118160A2
Application number: PCT/EP2009/002161
Authority: WO
Inventors: Arnold Trissler
Original assignee: Schaeffler Kg
Priority date: 2008-03-26
Filing date: 2009-03-25
Publication date: 2009-10-01
Also published as: WO2009118160A3; CN102066784A

Abstract

The invention relates to a linear roller bearing for a linearly movable mounting with non-round roller bodies which the roller body (1) based on a the basic form of a ball has two parallel flattenings(2) running perpendicular to the roller axis.

Description

Name of the invention

Linear roller bearing and switching device with linear roller bearing

description

Field of the invention

The invention relates to a linear roller bearing for a linearly movable bearing with non-circular rolling elements and a switching device with a linear roller bearing.

Background of the invention

Rolling bearings with non-circular rolling elements have already been proposed for special applications. From FR 1 031 490 A a linear roller bearing is known, the rolling elements have a cylindrical basic shape, wherein the central portion of the rolling bodies concave to adapt to the inner bearing ring and the two outer Wälzkörperabschnitte are adapted to adapt to the outer bearing ring conical. The preparation of such multi-section rolling elements is however complicated and expensive.

In DE 40 41 489 A1 a rolling element with non-circular Wälzkörpem has been proposed, which may have approximately the shape of a triangle or a triangular prism in cross-section. In this way, the bearing friction in the rolling bearing should be reduced. However, these rolling elements require a complex production.

Linear roller bearings are all known rolling bearings with limited or infinite linear stroke. The rolling elements of the linear bearing run either in endless stroke in longitudinal guides with U-bends or in spiral paths in series - or are guided or held in pockets of a cage of the linear bearing. [66] A linear bearing with unlimited stroke is known from DE 199 41 926 A1. The linear roller bearing comprises a guide carriage, which is supported by balls on a guide rail and movable along it. The forward and return of the balls takes place in recirculating ball, which are complicated. In addition, the space required for such a linear bearing is comparatively large. [67]

Linear bearings with limited stroke are used, for example, in switching elements that perform an axial movement. From DE 102 15 874 A 1, a device for the storage and auxiliary operation of a switching element is known, which has a limited in a bearing ring slidable piston. On the piston, a switching shaft is arranged, which is mounted relative to the bearing ring by a rolling bearing. By acting on the pressure chamber bounded by the piston with a pressure medium such as air or hydraulic fluid, a switching function can be realized by the displacement of the switching shaft. Typical applications of such linear bearings are circuits in commercial vehicles. [69]

From DE 102004 053205 A1 a fluid-operated switching device for a variable speed transmission is known. The piston is displaceably mounted in a cylinder by means of a linear roller bearing. To seal the pressure chamber arranged on the piston sealing ring is provided. This switching device has the disadvantage that it requires a comparatively large installation space. Another disadvantage is the fact that the sealing gap between piston and cylinder changes when the actuating element is acted upon by bending moments. [70]

DE 101 587 129 A1 shows a switching device with a shift rail and with a shift fork. At the ends of the shift rail, a piston which can be acted upon by pressure medium is fastened in each case. The pistons are also part of the sliding bearing of this switching device. DE 102 15 873 AI shows a combination of a linear roller bearing and a piston for a switching device of the type considered. The linear roller bearing is pivotally connected to the actuator by means of snap connection. [66]

The rolling elements of the linear roller bearing according to DE 102 15 873 A1 run on Wälzlaufbahnen a sleeve-shaped outer ring, which is closed at the end with a bottom. The outer ring is at the same time pressure chamber for the means of pressure-actuated piston and has for this purpose in the vicinity of the bottom flow openings. The raceway for the rolling elements, which in this case are balls, are at the same time the limit for the pressure chamber. The pistons are usually provided with seals that seal the pressure chamber from the environment. The seals move with the piston. The piston is fixed to the guide of the linear roller bearing.

DE 102 15873 A1 describes an arrangement with which the disadvantages of rigid connections are to be avoided. In such a connection between the piston and the actuator, the piston tends to tilt in its leadership when the components of the assembly are not adjusted very precisely to each other. It is therefore proposed to produce an articulated connection between pistons and linear bearings, with which over the joint form and position deviations can be compensated. In the case under consideration according to DE 102 15873 Al the piston is connected to the guide designed as a ball cage. The person skilled in the art when looking at the good solution, the high production costs, which must be expected in the production of such a switching device. Based on the increased effort, for example, with the various relatively complicated designed items. [66]

Summary of the invention

The invention is based on the object with which the disadvantages described above are avoided. To solve this problem is provided according to the invention in a linear roller bearing of the type mentioned that the rolling elements based on the basic shape of a ball having two parallel flats which are pierced perpendicularly from the rolling axis.

The inventively provided rolling elements have the advantage that they are relatively simple and therefore inexpensive to produce. The rolling elements are based on the basic shape of a ball and have on opposite sides parallel, flat flat surfaces. When installed, the rolling axis extends from a flattened side to the opposite flattened side, accordingly, the rolling axis is also the axis of symmetry for the rolling elements. These rolling elements have a smaller space requirement compared to conventional spherical rolling elements. The linear roller bearing according to the invention therefore has an increased compared to rolling bearings with spherical rolling elements and can be used advantageously in such bearings in which predominantly or almost exclusively an axial, translational movement, for example, a lifting movement takes place, whereas a radial movement is not or is present only to a minor extent.

According to one embodiment of the invention, it may be provided that the linear roller bearing has a pocket having cage, in each of which two rolling bearings are arranged side by side. In each case two rolling elements are adjacent to each other so that their flattened sides adjacent to each other. The individual pairs of rolling elements are separated from each other by webs of the cage.

The rolling elements of the linear roller bearing according to the invention can be accommodated in or in the cage, which is limited axially movable in a sleeve or a housing.

According to an alternative embodiment of the linear roller bearing according to the invention, it may have several, in particular four or more rows of rolling elements. Such a linear roller bearing has a relative to its construction space requirement particularly high load rating. Conversely, such a linear roller bearing can be built comparatively small because of its high load rating.

The bearing according to the invention can be used in shift locks for securing adjustment positions of an axially displaceable actuating element. Schaltarretierung have a locking pin, at the end of a locking element, preferably a locking ball is arranged, wherein the locking pin is slidably mounted in a housing and by means of the linear roller bearing. Such a shift lock can be made relatively small.

Alternatively, the bearing according to the invention may be provided for a switching element of a transmission, wherein the switching element is mounted by means of the linear roller bearing. The switching element may preferably be a rocker arm, a shift shaft, a shift rod or a shift fork. The storage according to the invention can also be used when the switching element has a non-round, preferably rectangular cross-section. In this case, the rolling elements of the linear roller bearing can be accommodated in a preferably rectangular cage adapted to the non-round cross section.

In the linear bearing according to the invention, it may be provided that the rolling bearing has a housing in which guide tracks are formed for the rolling elements. The rolling elements in the guideways in the interior of the housing, for example, a rod or shaft, which is displaceable relative to another component. The rolling elements touch this other component with their opposite side, which protrudes at least slightly out of the housing.

In the case of the linear bearing according to the invention, the guide tracks can consist of two straight sections running parallel to the direction of actuation and of these arcuate sections connecting them. In a relative movement of the two mutually displaceable components, which corresponds, for example, a switching operation, the rolling elements of a guideway move in each case in a a round trip. One part of the balls moves forward, another part moves backwards or perpendicularly, with respect to the direction of movement.

It is particularly preferred that the linear bearing according to the invention is provided for a switching element which is mounted by means of the linear roller bearing. The switching element may be, for example, a rocker arm, a shift shaft, a shift rod or a shift fork.

The switching element may be attached to a piston rod, shift rail or shift rod, which has a piston which is displaceably mounted in a cylinder to form a pressure chamber which can be acted upon by a pressure medium by means of the rolling bearing. Linear bearings of this kind are used, for example, in commercial vehicle gearboxes or in automated manual transmissions or power-assisted manual transmissions. [67]

According to one embodiment of the invention, it may be provided that the piston and the cage of the linear roller bearing are integrated in the pressure-medium-actuated switching device according to the invention to form a single component. In contrast, two assemblies are required in conventional switching devices, on the one hand to ensure storage and on the other hand, the creation of a pressure chamber. Usually, bearing and piston are arranged in parallel or one behind the other, wherein two separate modules are used. Accordingly, the overall length of the bearing length, piston thickness and Kobenhub results. By the piston and the linear roller bearing or its cage are formed as a single integral component, the length of the switching device is reduced considerably.

According to a further embodiment of the invention, it may be provided that the piston is arranged between two linear roller bearings. In this variant, a particularly good and reliable guidance of the piston results, in particular the sealing gap remains virtually unchanged, even if bending moments act on the piston rod through the adjusting element. In the context of the invention it can also be provided that the pressure chamber has raceways for the Wälzköφer. The tracks determine the degrees of freedom of movement of the rolling elements. It can also be provided that the pressure chamber is designed as a preferably thin-walled sheet-metal sleeve, on which the rolling bodies are supported. On the inside of the sheet metal sleeve raceways for the rolling elements can be arranged.

According to a first variant of the pressure medium-actuated switching device according to the invention, the rolling elements can be limited axially movable. The sliding movement of the rolling bodies received in the cage is limited on both sides by the pressure chamber or the metal sleeve.

According to a second, alternative embodiment, however, it can also be provided that the pressure-medium-actuated switching device is designed for an endless stroke and has at least one group of rolling bodies which can be moved in one revolution. Such a switching device is also suitable for larger positioning movements.

An even higher load rating of the linear roller bearing of the pressure-actuated switching device according to the invention can be achieved if the cage has pockets in each of which two rolling bodies are arranged next to one another.

The fluid-operated switching device according to the invention is suitable for all industrial applications in which adjusting movements, displacements or strokes must be generated, in particular the switching device can be used in transmissions for motor vehicles by the switching element is designed as a rocker arm, shift shaft, shift rod or shift fork of the transmission. 70] Brief description of the drawings

Further advantages and details of the invention are described below with reference to embodiments with reference to the figures. The figures are schematic representations and show:

1 shows a rolling element of a linear roller bearing according to the invention in a perspective view;

Figure 2 is a sectional view of a shift lock with a linear roller bearing according to the invention;

Figure 3 is a section along the line MI-III in Fig. 2;

FIG. 4 shows a further exemplary embodiment of a linear roller bearing according to the invention in a sectional view; and

5 shows a section along the line V-V in Figure 4.

FIG. 6 shows a linear rolling bearing for a pressure-medium-actuated switching device in a perspective view [70-2]

7 shows a sectional view of a pressure-medium-actuated adjusting device according to the invention, [70-4]

8 shows a further embodiment of a pressure-medium-actuated adjusting device according to the invention in section, [70-5]

9 shows a further embodiment of a pressure-actuated adjusting device according to the invention in section, [70-5]

10 shows an embodiment of a rolling bearing with infinite linear stroke in a perspective overall view. Detailed description of the drawings

Fig. 1 shows a non-circular rolling element 1, which can be used in a linear roller bearing. The rolling element 1 is based on the basic shape of a ball and has two parallel flats 2, which are opposite to each other and are pierced perpendicularly by the rolling axis 3.

Fig. 2 shows a shift lock 4 in a sectional view. The shift lock 4 comprises a housing 5, in which a locking pin 6 is axially displaceable. The locking pin 6 is mounted by means of a ünearwälzlagers 7 in the housing 5. The linear roller bearing 7, which is shown in Fig. 3 cut along the line IH-IIl, consists of two rows of rolling elements 1 with flats. 2

As shown in Fig. 3, the linear roller bearing 7 comprises a cage 8, the see-see 31, in each of which two juxtaposed rolling elements 1 are arranged. The rolling elements 1 are arranged so that the locking pin 6 can move axially against the force of a compression spring 9, which is supported on the one hand on the locking pin 6 and on the other hand at the bottom of the housing 5. From the position shown in Figure 2, the locking pin 6 can move axially until it abuts the bottom of the housing 5 or until the compression spring 9 is fully compressed. The locking pin 6 has a detent ball 10 designed as a locking element, which is roller-mounted. The shift lock 4 may be mounted in or on the housing of a manual transmission of a motor vehicle and acts on a movable part such as an input selector shaft, a shift rod or a shift rail. The shift lock 4 makes it easier to find and position a selected shift position. In addition, it allows the locking or fixing the found switching position. The driver is given the positive feeling that the gear is switched as desired by him, for example, when he briefly feels an increase in the operating force on the shift lever when engaging a gear. Because of the linear roller bearing 7, the rolling element 1 having flats 2, the shift lock 4, despite its small space requirement on a comparatively high load rating. 4 and 5 show a further embodiment of a linear roller bearing 11 in a sectional view. The linear roller bearing 11 comprises a housing 12, which is substantially cylindrical. In the housing 12, a rolling element 1 exhibiting cage 13 is received axially displaceable. In accordance with the preceding embodiment, four pairs of each two juxtaposed rolling elements 1 are arranged in such a row each in a pocket 21 that their flats 2 are opposite to each other. The linear roller bearing 11 shown in Hg. 4 and Fig. 5 has a total of seventeen double rows of rolling elements 1, whereby a comparatively high load capacity is ensured in a small space. The linear roller bearing 11 is designed for a limited stroke movement. Starting from the state shown in Fig. 4, the cage 13 with the rolling elements 1 can be moved axially until it abuts a collar 14 on the side of the housing 12. The linear roller bearing 11 can be used preferably in those applications in which an axial bearing is required ^' and in which a radial bearing is not required or only to a very small extent. Examples of such applications are bearings of shift elements of a transmission such as a rocker arm, a shift shaft, a shift rod or a shift fork. In the case of round switching shafts, the linear roller bearing 11 shown in FIGS. 4 and 5 can be used. In the case of non-circular switching elements, for example with punched switching rails with a square or rectangular cross-section, a suitably modified cage can be used, which is adapted to the outer contour of the switching element. The linear roller bearing 11 may be part of a pressure chamber having a piston and a switching element, in particular a power-operated circuit.

6 shows a linear roller bearing 41 in a perspective view. The linear roller bearing 41 comprises a cage 15, in which rolling elements 1 are received in an axially movable manner. The guide tracks 16 of the cage 15 are arranged so that the linear roller bearing 41 can perform an axial movement in the direction indicated by the arrow 17. The cage 15 of the linear roller bearing 41 is integrated with a piston 18 into a single component. The essentially cylindrical The shaped piston 18 is sealed by a piston seal 19 against a cylinder.

7 shows a pressure-medium-actuated adjusting device in a sectional view. The switching device 100 essentially consists of a piston rod 110 designed as a shift rod, at one end of which the piston 18 is sealed by means of the piston seal 19 with respect to a cylinder-shaped housing 12 which is designed as a thin-walled cup-shaped sheet-metal sleeve. Housing 12 and piston 18 define a pressure chamber 131 having a port 114 for supplying a pressure medium. As a pressure medium, for example, hydraulic fluid or air can be used.

The piston 18 is combined with the linear roller bearing 41 also shown in FIG. 6 to form a component. The rolling elements 1 of the linear roller bearing 4 are supported on the one hand on the inside of the housing formed as a sheet metal sleeve 12 and on the other hand on the piston rod 110 from. Due to the combined unit of piston 18 and linear bearings 41, the required axial space is particularly low. Since the piston seal 19 and the linear roller bearing 41 only have a small distance from one another, bending moments acting on the piston rod 110 have virtually no effect on the sealing gap of the piston seal 19.

On the piston rod 110 designed as a shift rod, a shift fork 151, shown only schematically, is attached as the shift element, which is part of a shift transmission of a motor vehicle engine. At the right in Fig. 7 the end of the piston rod 110 is a conventional linear roller bearing 116 or a linear roller bearing according to the invention.

The switching device 100 shown in Fig. 7 is actuated by the pressure chamber 131 is filled via the port 114 with the pressure medium. As a result, the piston 18 moves in the view of Fig. 7 to the right, so that the shift rod 151 is displaced via the piston rod 110, whereby a switching operation is triggered in a transmission. Fig. 8 shows a further embodiment of a fluid-operated switching device. The switching device 117 is a variant of the switching device 100 shown in Fig. 7, therefore, the same reference numerals are used for matching components. In accordance with the switching device of FIG. 7, the adjusting device 117 has a housing 12, in which a piston rod 110 is slidably mounted, which has a piston 18. On the piston rod 110, the shift fork 151 is attached to the housing 12 opposite end of the piston rod 110 is the linear roller bearing 116. Other than in the previous embodiment, the piston 18 is located between two linear bearings 119, 120 with non-circular rolling elements. 1 The linear bearings 119, 120, more specifically their cages 81, are connected to the piston 18 into a single component. As a result, an even higher-quality storage is achieved, which prevents tilting movements and ensures an absolutely reliable sealing of the pressure chamber 131 by the piston seal 19.

Fig. 9 shows a third embodiment of the invention. The switching device 121 shown in FIG. 9 comprises a piston rod 110, to which a switching element in the form of a shift fork 122 is attached, connections for a pressure medium are not shown in FIG. In the region of the piston rod 110, the shift fork 122 has a cylindrical housing 123, in which a piston 18, which has a piston seal 19, is guided axially movable. On both sides next to the piston 18 linear roller bearings 124, 125 are arranged, whose cages 81 are connected to the piston 18 to form a single component. The piston 18 and the housing 123 delimit two pressure chambers 131. Accordingly, the linear roller bearings 124, 125 are arranged in the pressure chambers 131. The cages 81 have a plurality of rows of rolling elements 1 on the circumference, which are axially movable in guideways 91. The linear roller bearings 124, 125 act as bearing points for the piston 18 and ensure exact axial guidance and a secure seal. [70]

Fig. 10 shows an embodiment of a linear roller bearing 42 with infinite linear stroke. The linear roller bearing 42 comprises a hollow cylinder designed as Housing 51, in which guide tracks 61 are formed for rolling elements 1. The guideways 61 consist of two straight sections 20 extending parallel to the direction of movement and arcuate sections 71 connecting them. As shown in FIG. 10, the rolling elements 1 are guided both on the inside and on the outside of the guideway 61. Upon movement of the rolling bearing 42, the rolling elements 1 are placed in a closed circuit. The flats 2 of the rolling elements 1 lie on the side of the guide tracks 61, the non-flattened sides of adjacent rolling elements 1 face each other and can touch each other. The guideways 6 and the corresponding raceways 71 in the housing 51 of the roller bearing 42 are formed so that the rolling elements 1 protrude inwardly and outwardly beyond the contour of the housing 51. [67]

reference numeral

Claims

claims

1. Linear rolling bearing for a linearly movable bearing with non-circular rolling elements, characterized in that the rolling element based on the basic form of a ball (1) has two parallel flats (2) which are pierced perpendicularly from the rolling axis.

2. Linear rolling bearing according to claim 1, characterized in that the linear roller bearing (7, 11) has a pocket (21, 31) having cage (8, 13), in each of which two rolling elements (1) are arranged side by side.

3. Linear rolling bearing according to claim 1, characterized in that the

Rolling elements (1) in a cage (8, 13, 15, 81) are received, which is limited axially movable in a housing (12, 123).

4. Linear rolling bearing according to claim 1, characterized in that the rolling elements (1) in guide tracks (61) are arranged circumferentially movable.

5. Linear rolling bearing according to claim 4, characterized in that the respective guide track (61) at least from a guide track (61) with two parallel to the direction of actuation straight sections

(20) and these connecting arcuate portions (71) consist.

6. shift lock (4) for securing adjustment positions of an axially displaceable switching element, with a at its end a Arretierele- element, preferably a locking ball, having locking pin (6), wherein the locking pin (6) in a housing (5) displaceable and by means of the linear roller bearing (7) according to claim 1 is mounted.

7. Switching device of a vehicle transmission with at least one linearly movable switching element, in which the switching element is mounted by means of at least one linear roller bearing (41, 119, 120) according to claim 1.

8. pressure medium-actuated switching device, with at least one switching element which is attached to a piston rod (110), wherein the switching device comprises a piston (18) for forming a pressure medium acted upon by a pressure chamber (131) by means of a linear rolling bearing (41 , 119, 120, 124, 125) according to claim 1 in a housing

(12, 123) is slidably mounted.

9. Switching device according to claim 8, characterized in that the linear roller bearing (41, 119, 120, 124, 125) has a guide tracks (16, 61, 91) having cage (15, 81), wherein in the guideways

(16, 61, 91) in each case at least one rolling body (1) is arranged and that the piston (18) and the cage (15, 81) are rigidly interconnected.

10. Switching device according to claim 8, characterized in that the linear rolling bearing (41, 119, 120, 124, 125) has a guide tracks (16, 61,

91) having cages (15, 81), wherein in the guide tracks (16, 61, 91) in each case at least one rolling element (1) is arranged and that the piston (18) and the cage (15, 81) in a single component are integrated.

11. Switching device according to claim 8, characterized in that the pressure chamber (131) has raceways for the rolling bodies (1).