DE102006057450A1 - Shaft bearing for eccentric drive in a radial piston engine incorporates channels between outer periphery and shaft aperture - Google Patents

Abstract

A radial roller bearing (1) has an outer ring (2) whose mantle has an inner roller (3) race surface and an inwards-folded ring-shaped rim (5, 6) around a central aperture (7a, b) for an axle or shaft. The rim incorporates one or more channels (8) linking the rim outer periphery with the central aperture (7a).

Description

The The invention relates to an outer ring according to the preamble of claim 1, a radial rolling bearing with the outer ring and an eccentric drive with the radial rolling bearing.

outer rings for radial rolling bearings are common sleeve-shaped structures, the end are formed with a radially inwardly projecting board. The outer rings serve on the one hand for receiving the rolling elements arranged therein and optionally Wälzkörperkäfige and also provide a radially inward facing tread to Rolling the rolling elements for Available.

A well-known application of radial rolling bearings is the storage of shafts for eccentric drives in radial piston machines. Such eccentric drive is for example in the document DE 692 10 752 T2 disclosed. In the described eccentric drive, the rotational movement of a shaft is converted into an oscillating linear motion of one or more radial pistons with the aid of which a diaphragm is moved in order to pump fluid or the like. The shaft has for the movement implementation on a free shaft end patch, cylindrical extension, which is arranged in the longitudinal direction eccentric to the shaft. A radial roller bearing, which is arranged on the cylindrical extension, transmits the eccentric stroke of the cylindrical extension produced by the rotational movement of the shaft to one or more pistons, which bears radially aligned on the outer surface of the radial roller bearing.

Also the publication DE 198 39 430 A1 , Which is considered as closest prior art, discloses such an eccentric drive for a radial piston pump, wherein in contrast to the device in the aforementioned document on the rotary shaft an eccentric rotatably mounted, which causes the Exzenterhub.

Of the Invention is based on the object, an outer ring, a radial roller bearing and to propose an eccentric drive that provides increased operational safety enable.

These Task is through an outer ring with the features of claim 1, a radial rolling bearing with the features of Claim 11 and an eccentric drive with the features of the claim 13 solved. Advantageous or preferred embodiments will be apparent the subordinate claims, the following description and / or the attached figures.

Of the outer ring according to the invention is trained for a radial rolling bearing and comprises a jacket region and at least one outer ring, in particular the jacket area of the outer ring, in the axial direction unilaterally terminating annular, radially inboard board.

Of the Mantle area or section is realized in a cylindrical shape and has the cylinder inner surface a tread for the Rolling elements of the radial roller bearing on. The cylinder inner surface can optionally have several treads in particular by Zwischenborde, Endborde or appropriate Grooves are separated or closed at the ends. The Cylinder outer surface is preferably as a tread for a transmission link formed, wherein it is preferably provided that the tread on the entire axial width of the outer ring - in particular smooth and / or uninterrupted - extends.

The on the outer ring in the axial direction end arranged and / or integrally formed Board is annular in frontal view of the outer ring and has in a cross section parallel to the axial longitudinal extent of outer ring on both sides a rectangular cut surface, preferably perpendicular or in particular arranged slightly inclined to the shell region is. The shelf extends radially inwards and encloses an opening, to carry out or introduction an axle or shaft to be supported with or without eccentric section is trained. Radially outward includes the board with the cylinder outer surface preferred flush from.

at remote embodiments it can also be provided that the board protrudes beyond the cylinder outer surface, so that a radially outwardly projecting Web portion is formed, for example, as edge-side stop can be used.

According to the invention, it is provided that the free on-board front side, ie the axial end face of the outer ring, at least one channel or a relief-like channel embracing the canal Embodiment, wherein the channel extending from the radial outside of the outer ring to the bore throughout extends. In this case, the channel is preferably designed as an open channel and in particular has a width and / or a depth which between 0.2 and 1.5 times the material thickness of the outer ring is or are.

In the invention, it was considered that due to the design of eccentric drives, the design of the drive shaft of the eccentric drive is bent. The resulting during operation radial forces and other force components also result in axial forces that lead to an axial offset of the radial roller bearing. For a start-up or installation of the radial rolling bearing, for example, on a Housing, a housing shoulder or the like takes place in unfavorable cases, a full-surface sealing of the radial rolling bearing over the end face, so that an oil supply or circulation is prevented or at least greatly deteriorated. This deterioration leads in the worst case to a lack of lubrication and thus to a lifetime reduction of the radial rolling bearing.

By the inventive design of outer ring a radial rolling bearing with at least one open, frontally into the outer ring introduced channel ensures that even with full-surface investment of the outer ring to a plane contact surface an oil circulation can be done by the at least one channel. In this way is a lack of lubrication prevented and thus the reliability the outer ring, of the radial rolling bearing and finally improved the eccentric drive.

Generally can the outer ring machined or non-cutting, in particular reshaping implemented as a needle sleeve be. Preferably, the outer ring integrally formed.

at a preferred embodiment of the outer ring is the at least one channel introduced by forming in the board. In particular, in a realization of the outer ring as a needle sleeve can the necessary for generating the at least one channel forming process economical be integrated into the production process.

optional Is it possible, that the at least one board has a plurality of channels, in particular separated or isolated run. But also an education a channel structure comprising several interconnected channels, represents a possible Alternative of the invention. By the use of several channels For example, it is possible to prevent position-dependent effects, preference being given to this three or four channels are introduced into the board. In general, however, the cross section, the Number and / or shape of the channels depending on the required operating behavior of the outer ring or of the radial rolling bearing be varied.

In a possible Alternative execution run the channel or channels rectilinearly radially from the outside inside. In a modification, the channel or channels can also spiral or shovel-like, the latter similar to a blade geometry an impeller be educated. These and other modifications may in particular be formed and / or arranged so that in operation during a rotation of the outer ring the oil active in the outer ring conveyed or active from the outer ring conveyed out will, leaving an oil circulation through the outer ring and thus supported by the radial rolling bearing.

at A preferred development are the described, oil-producing channels with regard to the conveying direction realized alternately and / or mixed. This training allows a direction independent Installation of the outer ring or the use of the outer ring for applications with alternating directions of rotation.

at a particularly preferred embodiment two of the shelves are provided, which close the outer ring on both sides, wherein on each of the two shelves at least one channel or a channel structure is provided. This embodiment will particularly advantageous in applications where either the radial rolling bearing on both sides on a contact surface or where the radial rolling bearing mutually applied to a contact surface and the oil circulation must be ensured. In particular, the one board is as hardboard and the other board as a flange educated.

The Channel structures of the two shelves are in a first embodiment formed mirror-symmetrical to each other and / or oil-producing Channel structures oriented in the same direction. Alternatively, the oil-producing Channel structures also be designed in opposite directions, so that during the rotation of the outer ring a suction side and an ejection side for the oil.

at a constructive implementation of the outer ring is fully hardened and in this way particularly to the field of application of the eccentric drive customized. Especially for this application area, the outer ring is also thick-walled, whereby e.g. an outer ring thick-walled, if it has a material thickness of 1.5 mm, 2 mm or more.

One Another object of the invention is a radial rolling bearing, which the outer ring includes, as just described. The radial rolling bearing has preferred as rolling elements Roll on and is designed in particular as a support roller bearings. Preferably are the rolling elements in particular captive guided in a Wälzköperkäfig. Especially is the radial rolling bearing designed without inner ring, allowing it directly on a shaft, axle or eccentric section is suspendable.

at An advantageous development is the opening or openings for receiving the shaft or axis offset to the central or rotational axis of the radial rolling bearing arranged or formed oval.

Another object of the invention is an eccentric drive for a positive displacement machine, in particular for a diaphragm pump, such as a 5-piston radial diaphragm pump for LPG.

Of the Eccentric drive has a shaft by means of a motor or the like is in rotation and the one eccentric having formed portion which integrally connected to the shaft is or is attached to or on the shaft. The eccentric section leads a rotation of the shaft to a Exzenterhub in the radial direction. On the eccentric section is the radial rolling bearing described above placed and lies with the cylinder outer surface of the outer ring on a transmission member on, so that the Exzenterhub is converted into a linear stroke or is feasible. In particular, the transfer member as a plunger or Piston formed.

Prefers is the eccentric section and / or the radial roller bearing arranged at a free end of the shaft, in particular such that the radial rolling bearing is stored flying.

at an advantageous embodiment of the eccentric drive are more eccentric Offset of the eccentric section to the shaft, the diameter of the Shaft in the contact area to the radial roller bearing and the opening diameter of the radial rolling bearing the side facing the shaft so matched to each other that a particular rotating crescent-shaped space between investment area the shaft and opening area of the radial rolling bearing is formed. This dimensioning of the eccentric drive has the Advantage that at least on the shaft side of the radial roller bearing an oil flow allows is and a pumping action can be achieved.

Further Features, advantages and effects of the invention will become apparent the following description of preferred embodiments and / or the attached Characters. Showing:

1a , b, c a first embodiment of a radial roller bearing according to the invention in various representations;

2 a modification of the first embodiment in plan view of the end face of the radial roller bearing;

3 a diaphragm pump with eccentric drive as an embodiment of the invention;

4a , b a section of the 3 to illustrate a particularly advantageous design of the eccentric drive.

Same or corresponding reference numerals are the same in the figures or corresponding parts.

The 1a shows a radial rolling bearing 1 in a schematic sectional view, wherein the radial rolling bearing 1 an outer ring 2 , a plurality of rolling elements 3 and a rolling element cage 4 Includes, the rolling elements 3 leads. The rolling elements roll radially on the outside 3 on the radially inner cylindrical surface of the outer ring 2 from.

The outer ring 2 is designed as a formed, completely hardened, thick-walled needle sleeve and has a hardboard 5 and a flange board 6 on, which are formed as radially inwardly curved, annular ribs and each having an opening 7a or b, through which the shaft or axle to be supported is guided.

As best of the 1b respectively. 1c that yields the radial rolling element bearing 1 show in a frontal plan view or side view, are on the free end faces of hard 5 or flange 6 a plurality of open channels 8th Forming formed, the star-like or regularly arranged by the radial outer side of the outer ring 2 to the opening 7a or b run. The through the channels 8th formed channel structure is formed so that in a flat contact the front side of flare 6 or hardboard 5 a flowable connection remains, allowing oil from the outside into the openings 7a or b can flow or circulate.

The 2 shows a modification of the radial rolling bearing 1 in the 1a , b and c in frontal plan view, wherein in the 2 the channels 8th are curved like a shovel. Due to the curvature of the channels is at a rotation of the outer ring 2 Oil active to the opening 7a respectively. 7b guided. The opposite end face of the outer ring 2 is optionally equipped with channels oriented in the same direction, in order to install the radial roller bearing independently of the direction 1 allow or equipped with oppositely oriented channels to a suction and a discharge side at the outer ring 2 to build. It is also possible that only one end face with channels 8th like in the 1b or 2 is equipped, or that on one side a mixture of equal and opposite directions, curved channels are introduced.

The 3 shows a radial piston diaphragm pump 9 in a schematic cross-sectional view, wherein the radial piston diaphragm pump 9 in the central area an eccentric drive 10 having. The eccentric drive 10 includes a motor driven shaft 11 at the free end of a tapered portion is provided as a shaft end on which an eccentrically shaped sleeve 12 is arranged rotationally fixed. To use with the sleeve 12 an eccentric stroke too generate, assigns the sleeve 12 an off-center passage opening, which receives the free shaft end. Alternatively, the free shaft end can be eccentric to the shaft 11 be applied in one piece.

On the sleeve 12 is - in this example without the interposition of an inner ring - the radial rolling bearing 1 placed. On the outside of the radial rolling bearing 1 are the five pistons 13 for the respective membrane 14 on, so that by turning the shaft 11 over the eccentric sleeve 12 Exzenterhub generated the piston 13 offset in radially directed, oscillating linear movements. These linear movements of the pistons 13 then lead in a known manner to a pumping movement of the membrane 14 , The eccentric stroke in this example is 1.2 mm (eccentricity of 0.6 mm) with an enveloping circle of the bearing of 8 mm, an outer diameter of 15 mm and an outer ring thickness of 1.8 mm.

For lubrication of the eccentric drive 10 the associated area is partially filled with oil. About a concentric to the wave 11 arranged and sluggish entrained plastic ring 15 , which has a rough thread, the oil is pumped, so that an oil circulation is promoted. Starting from the plastic ring 15 the oil gets over a support bearing 16 in the direction of the radial rolling bearing 1 transported.

Due to the small cross section of the shaft 11 and the high occurring radial forces on the free shaft end of about 350 N is the shaft 11 bent during operation. The shaft deflection causes the radial rolling bearing 1 With axial forces is applied, so that the radial rolling bearing 1 migrates in the axial direction. In the worst case, the radial roller bearing moves 1 so look it on the case or the shaft shoulder of the shaft 11 flatly sealingly abuts. To exclude a threatening restriction of the oil circulation even in these unfavorable cases, points the radial rolling bearing 1 like in the 1a , b, c or 2 shown, channels 8th on, even with flat contact of the radial rolling bearing 1 on housing or shaft shoulder allow oil circulation.

The 4a , b show the eccentric drive 10 in the 3 in a modified embodiment in wave-side plan view and in cross-sectional view. In this modification, the Exzenterhub by an eccentrically attached shaft end 17 achieved which inner ring free in the radial roller bearing 1 is stored. The outer diameter of the shaft 11 , the eccentricity e of wave 11 and shaft end 17 as well as the free diameter of the opening 7b of the radial rolling bearing 1 are dimensioned so that in wave-side plan view always a sickle-shaped, overlap-free space 18 between opening 7b and wave 11 remains. This free space 18 rotates together with the shaft 11 and secures even with a system of radial rolling bearing 1 to the wave shoulder of the wave 11 that a minimum flow area for the oil between shaft 11 and radial rolling bearings 1 remains.

1

radial bearings

2

outer ring

3

rolling elements

4

Rolling Element

5

hard board

6

flange rim

7a, b

openings

8th

channel

9

Radial piston diaphragm pump

10

eccentric

11

wave

12

shell

13

piston

14

membrane

15

Plastic ring

16

support bearings

17

shaft end

18

free space

Claims (14)

Outer ring ( 2 ) for a radial rolling bearing ( 1 ) having a jacket region which comprises a radially inwardly directed tread which is suitable for rolling rolling elements ( 3 ), and with one, the outer ring ( 2 ) terminating in the axial direction, radially inwardly directed, annular board ( 5 . 6 ), whereby the board ( 5 . 6 ) has an axially outwardly facing on-board face and an opening ( 7a , b) enclosing, for carrying out an axle or shaft ( 11 ), characterized in that the on-board front side at least one channel ( 8th ), which extends from the radial outer side of the outer ring ( 2 ) to the opening ( 7a , b) extends. Outer ring ( 2 ) according to claim 1, characterized in that the at least one channel ( 8th ) in the at least one board ( 5 . 6 ) is introduced by means of forming. Outer ring ( 2 ) according to one of claims 1 or 2, characterized in that the board ( 5 . 6 ) several of the channels ( 8th ) having. Outer ring ( 2 ) according to one of the preceding claims, characterized in that the channels ( 8th ) are formed scoop-like. Outer ring ( 2 ) according to claim 4, characterized in that the blade-like channels ( 8th ) in With respect to the blade direction different and / or arranged alternately. Outer ring ( 2 ) according to one of the preceding claims, characterized by two of the shelves ( 5 . 6 ), the outer ring ( 2 ) on both sides. Outer ring ( 2 ) according to one of the preceding claims, characterized in that the outer ring ( 2 ) is completely hardened. Outer ring ( 2 ) according to one of the preceding claims, characterized in that at least the jacket region is formed thick-walled. Outer ring ( 2 ) according to one of the preceding claims, characterized in that the outer ring ( 2 ) is made without cutting. Outer ring ( 2 ) according to one of the preceding claims, characterized in that the board or shelves ( 5 . 6 ) are formed as a hardboard and / or Bördelbord. Radial rolling bearing ( 1 ) for the radial support of an axle or shaft ( 11 ), characterized by an outer ring ( 2 ) according to any one of the preceding claims. Radial rolling bearing ( 1 ) according to claim 11, characterized in that the openings ( 7a , b) for receiving the shaft ( 11 ) or axis offset to the central axis of the radial rolling bearing ( 1 ) and / or outer ring ( 2 ) and / or are oval. Eccentric drive ( 10 ) for a displacement machine, in particular for a diaphragm pump ( 9 ), with a wave ( 11 ) which is set in rotation by means of a motor and which has an eccentrically formed section ( 17 ) and / or is rotatably connected thereto, with a radial rolling bearing ( 1 ), which on the eccentrically formed section ( 17 ) is fitted and rests with the radial outer surface of a transmission member, so that the rotational movement of the shaft ( 11 ) is converted into an oscillating linear movement of the transmission member, characterized in that the radial rolling bearing ( 1 ) according to one of the preceding claims 11 or 12 is formed. Eccentric drive ( 10 ) according to claim 13, characterized in that the eccentric section ( 17 ) and / or the radial rolling bearing ( 1 ) at a free end of the shaft ( 11 ) is arranged or are.