Arrangement for Shifting at Least Two Freewheels

The present invention concerns an arrangement for operating at least two idle wheels, independent of an associated shaft of a transmission, according to the type defined in the preamble of Claim 1.

The pamphlet DE 10 2004 001 961 B4 discloses, for example, a power shift transmission having a countershaft gear design. In the known power shift transmission, shiftable idle wheels are assembled at the respective counter shafts in order to be able to connect the counter shafts with the transmission input shafts. To operate a so-called winding path, in which the two transmission parts are coupled together, the known power shift transmission, has a control element which
allows two idle wheels of a counter shaft to be coupled for joint rotation without connecting the idle wheels with the counter shaft. The known control element is activated by means of an exterior control device, which is located on the outside in radial position of the idle wheels to be shifted. This increases considerably the radial installation space required for the known control element.

Therefore, the present invention is based on the objective to propose an arrangement of the type mentioned above, which is designed in a compact manner and requires the least installation space.

According to the invention, this objective is achieved through the characteristics of Claim 1. Further advantageous embodiments are shown in the sub-claims and drawings.

Accordingly, the invention proposes an arrangement for coupling at least two idle wheels, independent of an associated transmission shaft, having at least one shift device, which comprises an actuator and a control unit, in which the control unit including the actuator can be moved in axial direction. According to the invention, at least part of the actuator can be assembled in the shaft. In this way, an internally operated assembly is provided which allows for a switch able connection of two idle wheels. This means that the control unit of the invention- based arrangement of forming a direct connection between two adjacent idle wheels of a shaft is activated internally, i.e., from inside the shaft. As a result, a transmission equipped with the proposed arrangement can be produced in a compact and cost-efficient manner and with a large number of gears and can therefore be used preferably for front-transverse drive system of a vehicle.

The arrangement proposed by the invention can involve a friction-locked and/or form-fit control unit. Preferably, the form-fit control unit consists bf a jaw clutch and synchronization is used for the friction locked control unit. It is also possible to use a combination of the control units mentioned above or a combination of any other control units.

Preferably, the actuator of the arrangement can be designed as an electrically powered spindle drive, or the like. However, it is also possible j to use different drive systems, for example, pneumatic, mechanical, hydraulic drive systems. When using a spindle drive, it is advantageous to implement a pre-assembled modular construction in which the module can be easily inserted in the shaft designed, for example, as a hollow shaft. Depending on the intended use, the spindle drive can be connected with the shaft or with a housing part of the transmission.

In the context of a possible design variant f the invention, it can be arranged that the spindle drive comprises an electric motor, or the like, which powers the spindle coaxially to the shaft, which is coupled with a spindle nut to allow for axial movement. Thus, the spindle nut can produce an axial displacement of the control unit in order to connect the two idle wheels when engaged, independent of the shaft. It is also possible to form other operative connections between actuator and control unit.

Preferably, in the invention-based arrangement, the form-fit control unit can comprise, for example, a sliding sleeve that is coupled with the actuator. Said sliding sleeve is arranged on the shaft together with a shift dog, or the like, which is swivel-mounted on the shaft. It is located between the shiftable idle wheels and can be j moved in axial direction. The shift dog is permanently connected with one of the idle wheels by means of a synchronized gear tooth system. It is also possible to use different form-fit; shift dog connections in which the two control elements are arranged independently from one another. One control element is permanently connected with one of the idle wheels while the other control element is coupled with the actuator.

To provide the connection between the sliding sleeve and the actuator, it can be arranged that the sliding sleeve is coupled with the spindle nut of the drive by means of driving bolts, or the like, to allow for axial movement. Each driving bolt is guided through a radial hole of the shaft. Preferably, the bore hole can be designed as an elongated hole to allow the driving bolts to move in axial direction with the sliding sleeve.

For example, the spindle nut can be connected to; the driving bolts by means of a radial groove provided on the outside of the spindle nut, and the driving bolts assembled at the sliding sleeve can engage in said spindle nut. Preferably, two opposite driving bolts can be assembled at the sliding sleeve. However, it is also possible to distribute additional driving bolts, for example, around the circumference of the sliding sleeve.

By means of the invention-based arrangement, a connection can be formed between the two idle wheels in that the sliding sleeve can be axially moved from a neutral position to a first switching position in such a way that the synchronized gear tooth system of the shift dog is coupled with the internal tooth system of the one idle wheel, as well as with the internal tooth system of the next idle wheel. Consequently, in this first switching position the two idle wheels are connected in a rotationally fixed manner and can be moved with a speed that is independent of the shaft. Moreover, in order to form a rotationally fixed connection between the idle wheel and the associated shaft, it is also possible to move in axial direction the sliding sleeve from neutral position to a further switching position in such a way that the external tooth system of the sliding sleeve is coupled with the internal tooth system of the idle wheel to be switched. In this way, the invention-based arrangement also allows one the idle wheels to be connected to the associated shaft.

Preferably, for independently receiving the shift dog, the external surface of the sliding sleeve can comprise a radial reception area, or the like, which supports rotationally, for example, the ring-shaped shift dog, independent of the sliding sleeve. To put the shift dog in an axially secure position, each side of the shift dog can be provided with an axial bearing, .or the like.

Independent of the respective design variant, it can be arranged that for the support of the gear wheels, or idle wheels, to be shifted, preferably angular ball bearings, or the like, are used. Since under load the idle wheels have a relative rotation to the shaft, a bearing is required which can support an axial load and even a tilting moment under a relative speed. However, it is also possible to use different bearings which can fulfill the conditions mentioned above.

The proposed arrangement can be used for any transmission. However, preferably, the arrangement can be used in connection with a double clutch transmission in countershaft gear design to shift several load-shiftable gears and at least one winding path. In particular, it can be used to connect idle wheels with the respective counter shaft, or even idle wheels with each other, independent of the counter shaft, in order to provide a winding path, i.e., to couple with a control unit that can be activated internally the two transmission parts of the double clutch transmission. It is, for example, also possible to connect by means of the arrangement proposed by the present invention several idle wheels simultaneously with the associated counter shaft.

Subsequently, the invention is explained in more detail by means of the drawings. It is shown:

Figure 1 A sectional view of a schematic diagram of an exemplary double clutch transmission with an invention-based arrangement; And

Figure 2 A sectional view of a schematic diagram of a possible design variant of the invention- based arrangement.

Figure 1 shows a sectional view of an exemplary multi-speed double clutch transmission to be used as a possible application area for an invention-based arrangement for shifting at least one idle wheel at an associated transmission shaft. The double clutch transmission comprises two clutches the input sides of which are connected with a drive shaft. In addition, a torsion vibration damper is connected to the drive shaft. The output sides of the clutches are connected with one of two transmission input shafts w_ K1, w_K2, respectively, which are coaxially arranged to each other. The first transmission input shaft w_ K1 has been designed as a solid shaft and the second transmission input shaft w_K2 as a hollow shaft. Furthermore, two counter shafts w_v1, w_v2 have been provided with have been arranged in axially parallel manner to one another. Each counter shaft w_v1, w_v2 is provided with several idle wheels, which engage to fixed wheels on the transmission input shafts w_ K1, K_v2.

To be able to operate the idle wheels of the respective transmission input shaft w_v1, w_v2, at least one invention-based arrangement for operating the two idle wheels 1, 2 has been provided, independent of the respective transmission input shaft w_v1, w_v2. Consequently, by means of the invention-based arrangement, the two transmission input shafts w_ K1 and w_K2 can be coupled through an internally activated control unit that so that the transmission input shafts w_ K1 and w_K2 are interconnected and the double clutch transmission is provided with at least one winding path.

The invention-based arrangement for operating two idle wheels 1, 2 independent from the associated counter shaft w_v1 of the transmission comprises a shift device which has an internal actuator and a control unit, whereas the control unit can be axially moved with the actuator. The invention-based arrangement can also be provided at the other counter shaft w_2 for operating additional idle wheels. The arrangement shown in Figure 1 is therefore only used as an example.

According to the invention, the internally activated shift device of the invention-based
i . - , " arrangement is able to couple with one another two idle wheels 1, 2associated with the mutual counter shaft w_v1 in order to provide a winding path.

According to Figure 2, the control unit comprises a sliding sleeve 3 which is coupled with the actuator and a shift dog 4. The sliding sleeve 3 is located on the counter shaft w_v1 and can be moved in axial direction. It can also be moved in axial direction by the actuator. For this purpose, radically extending driving bolts 5, 5' are mounted at the sliding sleeve 3. These driving bolts 5, 5' engage with the actuator. The embodiment according to Figure 2 provides two driving bolts 5, 5' which are located opposite from each other. However, it is also possible to distribute additional driving bolts around the circumference of the sliding sleeve.

In the design variant shown, the actuator is activated internally and has an electrically operated spindle drive 6 which extends radically to the inside. The spindle drive 6 is a module located in the counter shaft w_v1 that is designed as a hollow shaft and is connected to the counter shaft in a rotationally fixed manner. The spindle drive 6 comprises an electric motor 7 which powers a spindle 8 that is coupled for axial movement with a spindle nut 9. On the outside, the spindle nut 9 has a radial groove 10 and the driving bolts 5, 5' attached to the sliding sleeve 3 are engaging with this groove. Through respective elongated holes 19, 19' of the counter shaft w_ v1, each driving bolt 5, 5' is directed radically to the inside. By means of respective circular movements of the spindle 8, the sliding sleeve 3 can be axially moved in both directions.

On the outside surface of the sliding sleeve 3, a radial reception area 11 has been provided for receiving in rotatable manner the approximately ring-shaped shift dog 4. As a result, the shift dog 4 can be rotated, independent of the sliding sleeve 3. Since the actuator with the coupled sliding sleeve 3 rotates together with the associated counter shaft w_ v1, the shift dog, which can rotate independently from the counter shaft, is secured in axial direction by means of axial bearings 12,12'.

On its exterior, the shift dog 4 has a radial synchronized gear tooth system 15 which permanently engages to an internal tooth system 16 of the second idle wheel 3. If the sliding sleeve 3 is moved by the actuator from the neutral position of the arrangement shown in Figure 2 to the left (in reference to the drawing plane), the synchronized gear tooth system 15 of the shift dog 4 can engage with the internal tooth system 14 of the first idle wheel 1, as well as with the internal tooth system 16 of the second idle wheel 2. In this first switching position, both idle wheels 1,2 are coupled to one another, independent of the counter shaft w –v1, in order to provide a winding path at the transmission.

The sliding sleeve 3 comprises an external tooth system 13 which can be coupled with a corresponding internal tooth system 14 of the first idle wheel 1. For this purpose, the sliding sleeve 3 has to be moved by the actuator from the neutral position of the arrangement shown in Figure 2 (in reference to the drawing plane) to the right. In this second switching position, the external tooth system 13 of the sliding sleeve 3 engages with the internal tooth system 14 of the first idle wheel 1. In this way, the first idle wheel 1 is operated by being connected with the counter shaft w_ v1 in a rotationally fixed manner.

Independent of the design variant, at least one of; the idle wheels 1, 2 can be rotatably mounted with angular ball bearings 17, 18 on the counter shaft w_ v1. Furthermore, an electrical, or a pneumatic, mechanical, hydraulic or similar drive system can be used as a drive mechanism for the control unit.

Reference numerals
1 first idle wheel
2 second idle wheel 3,3', 3" sliding sleeve 4,4' shift dog
5, 5' driving bolt
6 spindle drive
7 electric motor
8 spindle
9 spindle nut
10 nut
11 reception area
12,12' axial bearing
13 external tooth system of the sliding sleeve
14 internal tooth system of the first idle wheel
15 synchronized gear tooth system of the shift dog
16 internal tooth system of the second idle wheel
17 angular ball bearing
18 angular ball bearing
19,19' elongated hole
W _K1 first transmission input shaft
w_ K2 second transmission input shaft
w _v1 first counter shaft
w _v2 second counter shaft

Claims

1. An arrangement for coupling at least two idle wheels (1,2), independent of an associated shaft of a transmission, having at least one shift device, which comprises an actuator and a control unit, whereas the control unit with the actuator can be moved in axial direction, characterized in that at least part of the actuator is located in the shaft.

2. An arrangement according to Claim 1, characterized in that at least a friction-locked and/or form-fit control unit has been provided.

3. An arrangement according to Claim 1 or 2, characterized in that the actuator is designed as an electrically powered spindle drive (6).

4. An arrangement according to Claim 3, characterized in that the spindle drive (6) is located in the shaft designed as a hollow shaft.,

5. An arrangement according to Claim 3 or 4, characterized in that the spindle drive (6) is connected with the shaft or with a housing part of the transmission.

6. An arrangement according to any one of claims 3 to 5, characterized in that spindle drive (6) comprises an electric motor (7) which powers the spindle coaxially to the shaft, which is coupled with a spindle nut to allow for axial movement of the shaft.

7. An arrangement according to any one of the preceding claims, characterized in that it has been arranged that a form-fit control unit consists of a sliding sleeve (3) which is coupled with an actuator, that said sliding sleeve (3) has been arranged on the shaft together with a shift dog (4), which is swivel-mounted on the shaft, and that the sliding sleeve (3) is located between the shiftable idle wheels (1, 2) and can be moved in axial direction, whereas the shift dog (4) is permanently coupled with one of the idle wheels (2) by means of a synchronized gear tooth system.

8. An arrangement according to Claim 7, characterized in that the sliding sleeve (3) is coupled by means of driving bolts (5, 5') with a spindle nut of the spindle drive to allow for axial movement, whereas each driving bolt is guided through a radically extending elongated hole (19,19') of the shaft.

9. An arrangement according to Claim 7, characterized in that the outside surface of the spindle nut (9) comprises a groove (10), and that driving bolts (5, 5') attached to the sliding sleeve (3) engage with said groove.|

10. An arrangement according to any one of claims 6 to 8, characterized in that, in order to connect the two idle Wheels with one another, the sliding sleeve (3) can be axially moved from a neutral position to a first switching position in such a way that a synchronized gear tooth system (15) of the shift dog (4)| is coupled with the internal tooth system (14) of the first idle wheel (1), as well as with the internal tooth system (16) of the second idle wheel (2).

11. An arrangement according to any one of claims 6 to 9, characterized in that, in order to form a rotationally fixed connection between the first idle wheel (1) and the associated shaft, the sliding sleeve (3) can be axially moved from neutral position to a further switching position in such a way that the external tooth system (13) of the sliding sleeve (3) is coupled with the internal tooth system (14) of the idle wheel (1) to be switched.

12. An arrangement according to any one of claims 6 to 10, characterized in that the external surface of the sliding sleeve 3 comprises a radial reception area (11) for receiving in rotatable manner the approximately ring-shaped shift dog (4).

13. An arrangement according to any one of claims 6 to 11, characterized in that the shift dog(4)is secured in axial direction by means of axial bearings (12,12').

14. An arrangement according to any one of the preceding claims, characterized in that the idle wheels (1, 2) to be operated are rotatably mounted on the shaft with angular ball bearings (17,18).

15. An arrangement according to any one of the preceding claims, characterized in that the arrangement is used in a double clutch transmission for operating at least one winding path.