EP1646812A1

EP1646812A1 - Oil-guiding shaft

Info

Publication number: EP1646812A1
Application number: EP04740364A
Authority: EP
Inventors: Gabor Diosi; Josef Haupt; Martin Brehmer
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2003-07-23
Filing date: 2004-06-28
Publication date: 2006-04-19
Also published as: WO2005019699A1; US20060191746A1; DE10333432A1; CN1820156A; KR20060037378A; JP2006528316A

Abstract

The invention relates to an oil-guiding shaft (1; 8) comprising a shaft interior (35), which is coaxial or axially parallel to the shaft longitudinal axis (34), and comprising a means, which is placed inside the shaft interior (35) and which serves to divide the shaft interior into at least two oil-guiding channels that are separate from one another. In order to be able to realize a number of oil-guiding channels in a comparatively thin shaft (1; 8), the invention provides that the channels (3; 4; 5; 9; 10; 11; 12) are, on the inner wall (2) of the shaft (1), provided in the form of channels (3; 4; 5; 9; 10; 11; 12) that are open over the longitudinal extension thereof, are separated from one another by a tube (6, 13) that is inserted into the shaft interior (35), and are sealed from one another.

Description

Oil-bearing shaft

The invention relates to an oil-carrying shaft according to the preamble of independent claims 1 and 7.

Shafts are known in many areas of technology, through whose axial bore a liquid or gaseous medium can be passed. Such shafts are also used in particular in transmissions where it is important to conduct a hydraulic oil under pressure from a control pressure source to a transmission component to be actuated with this control pressure medium, as space-saving as possible. Transmission components of this type are generally piston-cylinder arrangements with which clutches or brakes of the transmission can be actuated, or with which the distance between conical disks of a continuously variable belt transmission can be adjusted to change the transmission ratio.

If such a transmission shaft has a diameter that is sufficiently large with respect to the torque to be transmitted, two or more axial bores arranged in parallel next to one another can also be provided in the shaft according to the prior art. The control pressure medium can be fed into and removed from the axial bores at the ends of the axial bores and / or via radial bores in the shaft, which are fluidically connected to the axial bores. Particularly with regard to the comparatively thin shafts, which are not infrequently used in transmission engineering, there is often a desire to provide them with more than just an axially aligned bore for receiving control pressure medium and / or lubricant, the control pressure medium in the different lines generally having different control pressures.

Since a plurality of axially parallel bores cannot be formed in such thin shafts without the risk of material weakening, according to the prior art a hollow cylindrical tube is inserted into a preferably coaxial bore of the shaft, which tube forms a first pressure medium line with its axial cavity , By varying the outside diameter of such a tube relative to the axial bore wall surrounding the tube, a further pressure medium line is also created, which is connected in terms of printing technology to the actuators mentioned at the beginning, with generally radially oriented feed or discharge bores.

Against this background, a primary shaft of a continuously variable belt transmission with an axial bore is known, for example, from DE 199 21 750 AI, into which a tube which is rotationally sealed against this axial bore and which itself has two longitudinal bores is inserted.

In addition, a secondary shaft of a continuously variable belt transmission is known from DE 196 03 598 AI, in which a tube inserted into an axial bore of this shaft is fixed with one end in the transmission housing in a rotationally fixed manner, while the other tube end is in one slide bearing arranged in the axial bore is mounted. In this construction too, the hollow cylindrical interior of the tube serves as the first control pressure line, while a cylindrical annular space formed between the outside diameter of the tube and the inside diameter of the axial bore forms a second control pressure line.

Finally, US Pat. No. 6,015,359 A discloses a secondary shaft of a continuously variable belt transmission with an axial bore, in which a special plug is firmly inserted. This stopper divides the secondary shaft axial bore into two chambers, the stopper itself being supplied centrally with a control pressure medium via a tube likewise inserted into the axial bore. This control pressure medium, which is under high pressure, can be conducted via three radial plug bores and a radially outer annular gap into associated radial secondary shaft bores. In addition, three small axial bores are formed in the stopper, which connect the two aforementioned chambers with one another in terms of flow technology.

As the above explanations make clear, the implementation of several oil-carrying lines in thin shafts has so far only been accomplished incompletely because their construction is complex and the manufacturing effort is therefore relatively large. It is therefore the task of presenting a shaft with several axial oil-carrying lines or channels, which is technically simple in its construction and can be produced inexpensively.

This object is achieved according to the invention by two technical solutions which result from the features of the two independent claims 1 and 7. advantageous Refinements and developments to these two basic solutions can be found in the respective subclaims. According to the first solution, the oil-carrying shaft has a shaft interior which is coaxial or axially parallel to the shaft longitudinal axis, and a means arranged in this shaft interior for dividing the shaft interior into at least two oil-conducting channels which are separate from one another. For this purpose, it is provided that the channels are designed as channels which are initially open along their longitudinal extent (similar to axial grooves) on the inner wall of the shaft and are separated from one another and sealed off from one another by a tube inserted into the shaft interior.

In an embodiment of this invention, the open channels of the shaft are formed by bores which overlap in terms of their cross-sectional geometry. These open channels can be introduced or formed in the shaft, for example, by means of a drilling tool or by kneading.

Regardless of the manufacturing process, it is also preferably provided that the initially still open channels are designed in the form of a circular arc in cross section. Furthermore, it can make sense that the open channels are arranged in the shaft in such a way that their longitudinal axes lie on an imaginary plane. In another variant of the invention, on the other hand, it can be provided that at least two of the initially still open channels are added to form another open channel. are ordered that their three longitudinal axes are not on an imaginary plane.

According to the second solution to the technical problem on which the invention is based, the oil-carrying shaft is also provided with a hollow cylindrical shaft interior which is coaxial or axially parallel to the shaft longitudinal axis, a means for dividing the shaft interior being arranged in at least two channels separated from one another in the shaft interior. In contrast to the first-mentioned technical solution, it is provided that a profiled tube is arranged in this hollow cylindrical shaft interior, the circumferential surfaces of which deviate from a circular geometry form the desired channels or lines with the respectively opposite regions of the shaft inner wall.

Regardless of whether the shaft is designed according to the first or the second technical solution, these shafts can have a number of advantageous configurations.

For example, it can be provided that at least one radial lubricant bore is formed in the shaft, which leads from a lubricant source to the tube arranged in the shaft interior.

In addition, it is advantageous if the pipe has at least at one of its ends a connection area with which it is supported on the wall of the shaft interior and / or is mounted there and seals the oil-carrying channels against one another. With regard to the geometry of the tube inserted into the shaft interior, it can be provided that it has a cylindrical, three-legged, star-shaped or rectangular cross-sectional geometry with an at least partially circular outer circumference. About this at least partially circular outer circumference, the tube is supported pressure-tight on the wall of the shaft interior to form the channels. The tube inserted into the interior of the shaft can be designed as a hollow or as a solid profile. A tube designed as a hollow profile, however, has the advantage that its interior inside the shaft interior can be used as one of the channels for the oil.

Finally, it is considered to be advantageous in the case of such a shaft if it has bores leading radially to the ducts, through which holes oil can be fed or drained into the ducts.

To clarify the invention, a description is attached to the description, in which exemplary embodiments of the two shafts according to the invention are shown. In this show:

1 shows a longitudinal section through a gear shaft with axial oil-guiding channels formed in the central area, FIG. 2 shows a cross section through the shaft according to FIG. 1 in the central area, but without an inserted tube, FIG. 3 shows a cross section through the shaft as in FIG. 2, but with the tube inserted, 4 shows a cross section through another shaft with an inserted tube, FIG. 5 shows a longitudinal section through another transmission shaft with axial oil-guiding channels formed in the central area, FIG. 6 shows a cross section through the shaft according to FIG. 5 in the central area with inserted rectangular tube, FIG. 7 shows a cross section through the shaft according to FIG. 5 with inserted star-shaped or three-legged tube and FIG. 8 shows a cross section through the shaft according to FIG. 5 with inserted star-shaped or three-legged solid profile.

1 shows a cross section through a transmission shaft 1, in the central area of which an axially extending cavity is formed, which is referred to below as the shaft interior 35. This shaft interior 35 comprises three channels 3 which are still open in the preassembly state; 4; 5, which are formed in the structure chosen for the figures 1 to 3 like three superimposed and overlapping circular bores. After a tube 6 has been inserted into this shaft interior 35, it separates the three channels 3; 4/5 so pressure-tight that they can be used, for example, as independent control pressure lines. As illustrated in FIG. 1, the tube 6 is inserted with its one end 20 in a blind bore of the shaft 1 in a rotationally fixed manner, while the other end 19 of the tube 6 is mounted in the central bore of the shaft 1. In addition, the cross-sectional view through the shaft 1 in FIG. 1 shows that radial pressure medium supply bores 37 or pressure medium discharge bores 38 and / or lubricant bores 7 are also formed in the shaft 1, each with one of the channels 3; _4/5 fluidically communicate.

Fig. 2 now shows a cross section of the shaft 1 in its central region. As can be seen from this illustration, in the embodiment of the invention selected here, the channels 3; 4; 5 still open, so that they form the elongated shaft interior 35 with a common inner wall 2. The channels 3; 4/5 arranged in relation to one another in the shaft 1 such that their longitudinal axes together with the shaft longitudinal axis 34 lie on an imaginary plane 36 running through the shaft 1. As the cross-sectional illustration in FIG. 3 shows, the tube 6 inserted into this shaft interior separates the channels 3; 4; 5 from each other.

4 now shows a cross section through another shaft 8, the shaft interior of which is formed by four overlapping circular arc-shaped channels 9 that are still open in the shaft material; 10; 11 is formed. By inserting the tube 13, the three radially outer channels 9; 10/11 separated axially and radially from the tube 13 in a pressure-tight manner, a fourth channel 12 being formed by the tube 13 if it is designed as a hollow profile as shown here.

As illustrated in FIG. 4, a multiplicity (here four) of channels 9; 10; 11; 12 can be formed, the number of which depends only on the wave diameter and the necessary cross-section of the channels.

In this variant of the invention, too, at least one pressure medium supply or pressure medium discharge bores 37; 38 as well as the lubricant bore 7, a tube having to be inserted into this lubricant bore 7 if necessary in order to avoid undesired leakage flows from the central channel to the two adjacent channels.

The shaft interior 35 of the shaft 1; 8 can advantageously be produced by overlapping bores, by kneading a pipe blank in this regard or by a suitable casting mold.

The other solution of the technical problem on which the invention is based, which is mentioned in the brief description of the invention, is explained below with reference to FIGS. 5 to 8. 5, the shaft 14, which is largely comparable to the shaft 1, is provided with a cylindrical shaft interior 39 which is aligned coaxially with the longitudinal axis 34 of the shaft 14. A tube 16 is inserted into this shaft interior 39, which with its two axial ends 17; 18 is rotatably and pressure-tightly connected to the inner wall 15 of the shaft 14. As the cross-sectional representation according to FIG. 6 illustrates, the tube 16 in this case has an essentially rectangular cross-sectional geometry in its central region, although two of the four sides of this rectangle are geometrically attached to the inner wall 15 of the shaft interior 39. have suitable surfaces. As a result, these are pressure-tight against said inner wall 15.

The other two sides of the rectangular profile, on the other hand, preferably have an axial cross-section reduction in the sense of two axially aligned longitudinal grooves, so that in this area between the inner wall 15 of the shaft and the outer wall of the tube, two channels 21; 22 are formed with an approximately lenticular cross-sectional geometry. A third channel 23 is present inside the rectangular tube 16.

As is also made clear in FIG. 6, it can also be provided in this construction that the shaft 14 has at least one radial bore 33 which is used as a pressure medium supply or pressure medium discharge bore or as a lubricant supply bore or as a lubricant discharge bore. A look at FIG. 7 shows that while maintaining the coaxial shaft interior 39, a tube 27 which is approximately star-shaped or triangular in cross-section can also be inserted therein, through which the shaft interior 39 when selecting a hollow profile (as in this exemplary embodiment) in a total of four channels 24; 25; 27; 28 can be divided.

Finally, FIG. 8 shows that by inserting a three-leg solid profile 32 into the shaft interior 39 of the tube 14, which can be produced very cost-effectively, with a comparatively low manufacturing cost, a comparatively thin shaft 14 with a total of three oil-carrying channels 29; 30; 31 can be produced. reference numeral

1 shaft 2 wall of the shaft interior of shaft 1 3 channel 4 channel 5 channel 6 tube 7 pressure medium supply and pressure medium drainage holes; Lubricant holes 8 shaft 9 channel 10 channel 11 channel

12 channel

13 tube

14 wave

15 wall of the shaft interior of the shaft 14 16 pipe

17 Connection area

18 Connection area

19 Connection area

20 connection area 21 channel

22 channel

23 channel

24 channel

25 channel 26 channel

27 tube channel

channel

star profile

Pressure medium supply or pressure medium drainage holes;

Schier central bores

wave longitudinal axis

Wave interior

longitudinal axial plane

feed hole

Ableitungsbohrun

Wave interior

Claims

Patent claims

1. Oil-guiding shaft (1; 8), with a shaft interior (35) coaxial or axially parallel to the shaft longitudinal axis (34) and with a means arranged in the shaft interior (35) for dividing the shaft interior into at least two separate oil-guiding channels, thereby characterized in that the channels (3; 4; 5; 9; 10; 11; 12) than over their

Longitudinally open channels (3; 4; 5; 9; 10; 11; 12) are formed on the inner wall (2) of the shaft (1; 8) and separated from each other by a tube (6, 13) pushed into the shaft interior (35) and sealed against each other.

2. Shaft according to claim 1, characterized in that the open channels (3; 4; 5; 9; 10; 11; 12) formed in the shaft (1; 8) are formed by bores which overlap in terms of their cross section.

3. Shaft according to claim 1 or claim 2, characterized in that the open channels (3; 4; 5; 9; 10; 11; 12) are formed by means of a drilling tool or by kneading the shaft (1; 8).

4. Shaft according to one of the preceding claims, characterized in that the open channels (3; 4; 5; 9; 10; 11; 12) have an arcuate or groove-shaped cross-sectional geometry.

5. Shaft according to one of the preceding claims, characterized in that the open channels (3; 4; 5; 9; 10; 11; 12) are arranged in the shaft (1; 8) such that their longitudinal axes are on one plane ( 36).

6. Shaft according to one of claims 1 to 4, characterized in that at least two of the open channels (10; 11) are arranged to form a further open channel (9) in such a way that their longitudinal axes are not on one plane.

7. Oil-guiding shaft (14), with a hollow cylindrical shaft interior (39) coaxial or axially parallel to the shaft longitudinal axis (34) and with one in the

Means arranged inside the shaft for dividing the shaft interior into at least two oil-conducting channels separated from one another, characterized in that a profiled tube (16; 27; 32) is arranged in the hollow cylindrical shaft interior (39), the circumferential surfaces of which differ from the circular geometry with the respective opposite areas of the inner shaft wall (15) form the channels (21 to 26; 28; 29 to 31). 8. Shaft according to at least one of the preceding claims, characterized in that the shaft (1,

8th; 14) at least one radial lubricant bore (7; 33) is formed, which leads from a lubricant source or a lubricant consumer to the pipe (6; 13; 16; 27; 32).

9. Shaft according to at least one of the preceding claims, characterized in that the tube (6; 13; 16; 27; 32) has at least at one of its ends a connection area (18; 19; 20; 21) with which the tube (6; 13; 16; 27; 32) is supported and / or supported on the wall (2; 15) of the shaft interior and the channels (3 to 5; 9 to 12; 21 to 26; 28; 29 to 31) against each other seals.

10. Shaft according to at least one of the preceding claims, characterized in that the tube (6; 13; 16; 27; 32) has a cylindrical, star-shaped, three-legged or rectangular cross-sectional geometry with an at least partially circular outer circumference.

11. Shaft according to at least one of the preceding claims, characterized in that the tube (6; 13; 16; 27; 32) is designed as a hollow or solid profile.

12. Shaft according to claim 11, characterized in that the interior of the tube (6; 13; 16; 27) formed as a hollow profile forms one of the channels (4; 12; 23; 28).

13. Shaft according to at least one of the preceding claims, characterized in that the shaft (1; 8; 14) radially to the channels (3 to 5; 9 to 2; 21 to 26; 28; 29 to 31) leading bores (37; 38), through which pressure medium can be fed into the channels (3 to 5; 9 to 12; 21 to 26; 28; 29 to 31) or can be derived from them.