Gear actuator with a switch for coupling shift shafts

Abstract

A switch for selectively coupling different shift shafts (100, 200) of a gear actuator comprises a first shift shaft (100) with a first gearwheel (110) which is fastened fixedly on the first shift shaft (100) for conjoint rotation; a second shift shaft (200) with a second gearwheel (210) which is fastened fixedly on the second shift shaft (200) for conjoint rotation; a rotary actuator (300) with a drive gearwheel (310) on a drive shaft (320) for providing a torque. The drive gearwheel (310) is axially displaceably mounted on the drive shaft (320) in order to selectively couple the rotary actuator (300) to the first gearwheel (110) or to the second gearwheel (320).

Description

[0001] DESCRIPTION

[0002] GEARBOX ACTUATOR WITH SWITCH FOR COUPLING SHIFT SHAFTS

[0003] The present invention relates to a changeover switch for coupling switching shafts and in particular to a switching mechanism for coupling a rotary motion source, such as can be provided by an electric motor, to a plurality of switching shafts.

[0004] Electromobility is becoming increasingly important, not only for passenger cars but also for commercial vehicles. This also applies to transmission actuators, which are increasingly powered by electric motors. For trucks in particular, it is necessary to design different transmission actuators depending on the load to be transported, providing more or fewer gears to convert the required drive torque accordingly.

[0005] Currently, the associated problems, such as flexible and reliable switching with a single actuator, are still inadequately addressed. Therefore, there is a need for options for selectively switching a torque actuator with different switching shafts.

[0006] At least some of the above-mentioned problems are solved by a switch according to claim 1. The dependent claims relate to further advantageous embodiments of the switch as defined in claim 1.

[0007] The present invention relates to a switch for selectively coupling different shift shafts of a transmission actuator. The switch comprises:

[0008] - a first selector shaft with a first gear;

[0009] - a second selector shaft with a second gear;

[0010] - a rotary actuator having a drive gear on a drive shaft to provide torque, wherein the drive gear is axially slidably mounted on the drive shaft to selectively couple the rotary actuator to the first gear or to the second gear.

[0011] The axial direction can be defined so that it extends in the direction of the axis of rotation of the rotary movement (e.g. the rotary actuator).

[0012] Optionally, the first gear is rotationally mounted on the first selector shaft to transmit torque to the first selector shaft. Alternatively, the first gear can be mounted on the first selector shaft via a converter (e.g., via a thread or a worm drive) to convert a rotational movement of the first gear into a first axial movement of the first selector shaft.

[0013] The same can apply to the second gear, i.e., the second gear is optionally mounted on the second selector shaft in a rotationally fixed manner to transmit torque to the second selector shaft. Alternatively, the second gear can also be mounted on the second selector shaft via a converter (e.g., via a thread or a worm drive) to convert a rotational movement of the second gear into a second axial movement of the second selector shaft.

[0014] Optionally, more than two axial positions can be assumed by the drive gear, so that more than two switching shafts can be controlled with the actuator.

[0015] Optionally, the switch includes a bracket that holds the first shift shaft and the second shift shaft parallel and spaced from each other to use different shift shafts for shifting gears by means of the transmission actuator.

[0016] Optionally, the switch includes a shift lever that couples to the drive gear to move the drive gear axially when the shift lever is actuated.

[0017] Optionally, the switch includes a linear actuator coupled to the shift lever and configured to provide a force that axially displaces the drive gear between the first gear and the second gear. Optionally, the drive gear is coupled directly or indirectly to the first gear or the second gear. This allows, for example, a torque to be changed and transmitted with the same or opposite sign.

[0018] Optionally, the drive shaft comprises an axially extending groove and the drive gear comprises a projection within a cylindrical opening, wherein the projection engages in the axially extending groove and is displaceable along the axially extending groove.

[0019] It is understood that the groove is only one example of a rotationally fixed coupling. According to further embodiments, the drive shaft is rotationally fixedly coupled to the drive gear by another coupling, but axially displaceable relative to each other.

[0020] Embodiments also relate to a gear actuator with a changeover switch as previously described.

[0021] Embodiments also relate to a commercial vehicle, in particular a truck, with a transmission actuator as described above.

[0022] Embodiments also relate to a method for selectively coupling different shift shafts in a transmission actuator, wherein the method comprises displacing a drive gear on a drive shaft of a rotary actuator in order to selectively couple the rotary actuator to the first gear or to the second gear.

[0023] Embodiments solve the problems mentioned above in that the torque actuator (e.g., an electric motor) is designed with an axially displaceable drive gear, which is axially displaceable, for example, on a motor shaft of the electric motor via a groove. In this way, the drive gear is selectively coupled to various output gears on different shift shafts. For example, either a first shift shaft or a second shift shaft can be used for shifting in order to shift different gears with the transmission shifter via the respectively selected shift shaft. For this purpose, one or more shift drums with gates can be provided on the selected shift shaft, into which shift forks engage to effect shifting.It is also possible that before the drive gear of the exemplary electric motor is coupled to the shift shafts, a gear ratio is applied in order to be able to transmit different speeds or torques to the individual shift shafts.

[0024] The embodiments of the present invention will be better understood from the following detailed description and the accompanying drawings of the various embodiments, which, however, should not be construed to limit the disclosure to the specific embodiments, but are for explanation and understanding only.

[0025] Fig. 1 shows schematically a changeover switch according to an embodiment of the present invention.

[0026] Fig. 2 shows a detailed view of a switch with optional details according to further embodiments.

[0027] Fig. 1 schematically shows a changeover switch according to an embodiment of the present invention. The changeover switch comprises a first switching shaft 100 and a second switching shaft 200, and a rotary actuator 300. The first switching shaft 100 comprises a first gear 110 that actuates the first switching shaft 100. The second switching shaft 200 comprises a second gear 210 that actuates the second switching shaft 200. The rotary actuator 300 comprises a drive shaft 320 with a drive gear 310 that is rotationally fixedly connected to the drive shaft 320. The rotary actuator 300 is, for example, an electric motor.

[0028] In addition, the drive gear 310 is designed to be axially displaceable in an axial direction A in order to selectively couple either with the first gear 110 on the first shift shaft 100 or with the second gear 210 on the second shift shaft 200. The rotary actuator 300 can, for example, provide a drive torque DO, which can then, selectively, be provided via the first gear 110 as a first output torque D1 of the first shift shaft 100 or via the second gear 210 as a second output torque D2 of the second shift shaft 200. The output torques D1, D2 can be equal to the drive torque D0 or can be specifically adapted (e.g., have a different sign or a different magnitude). This can be achieved, for example, by appropriately selecting the number and size of the gears.

[0029] To achieve this, the first gear 110 can be rotationally coupled to the first selector shaft 100. According to further embodiments, the first gear 110 can also be coupled to the first selector shaft 100 via a converter (e.g., a screw drive or worm drive) to translate the rotational movement into an axial movement. The second selector shaft 200 can also optionally be coupled to the second gear 210 either rotationally or via a converter.

[0030] The shifting movements caused by the first shift shaft 100 and / or the second shift shaft 200 are therefore either rotary movements or axial movements. The rotary movements can then be converted into axial movements via shift drums, for example, on shift forks.

[0031] Fig. 2 shows optional details of the changeover switch according to further embodiments of the present invention, wherein the rotary actuator 300 is an electric motor. The electric motor 300 has a motor shaft 320 as the drive shaft, on which the drive gear 310 is mounted for axial displacement. Furthermore, the embodiment of Fig. 2 shows the first switching shaft 100 with the first gear 110 and the second gear 210, which couples to the second switching shaft 200, which is obscured by the rotary actuator 300 in Fig. 2.

[0032] In the embodiment shown, the drive gear 310 is not coupled directly to the first gear 110, but via another gear 120, so that the torque transmitted by the rotary actuator 300 has the same sign as the torque transmitted to the first shift shaft 100 - however, the magnitude of the torque can change.

[0033] According to the illustrated embodiment, the first shift shaft 100 includes a worm drive, so that the rotational movement of the electric motor 300 is converted into an axial displacement of the first shift shaft 100. This axial displacement can directly actuate one or more shift forks.

[0034] According to further embodiments, the first gear 110 is in turn rotationally fixedly coupled to the first shift shaft 100, on which one or more shift drums are located, which translate the rotational movements of the first shift shaft 100 into axial movements (e.g., via corresponding gates). Shift forks can then be coupled to the gates for shifting. The gates and shift forks are not visible in Fig. 2.

[0035] The same applies to the second shift shaft 200, which can also have a screw drive that translates a rotational movement into an axial movement of the second shift shaft 200. Alternatively, the second gear 210 can also be non-rotatably coupled to the second shift shaft 200. In this case, shift drums can again be formed on the second shift shaft 200 to translate the rotational movement of the second shift shaft 200 into axial displacements. The axial displacements can ultimately be used for shifting movements by shift forks.

[0036] Fig. 2 also shows a bracket or housing assembly 400 that provides appropriate support for the first shift shaft 100, the second shift shaft 200, the rotary actuator 300, and the various gears 110, 120, 210.

[0037] The holder 400 comprises, for example, cylindrical through-bores arranged parallel to one another, in which the first shift shaft 100 and the second shift shaft 200 extend offset from one another, for example to trigger the shifting operations there. The first shift shaft 100 and the second shift shaft 200 can thus extend into different transmission areas. According to exemplary embodiments, the drive shaft 320 comprises an axially extending groove (not visible in Fig. 2) along which the drive gear 310 is axially displaceable. Therefore, the drive shaft 320 or the corresponding rotor in the exemplary electric actuator 300 can be arranged axially fixed, so that the axial movement is merely a relative movement between the drive gear 310 and the drive shaft 320.

[0038] In the illustrated embodiment, a shift lever 500 is also provided, which couples to the drive gear 310. This coupling can be achieved, for example, by engaging a groove along the circumferential direction. The shift lever 500 can axially displace the drive gear 310 relative to the drive shaft 320 via an axial displacement parallel to the drive shaft 320, thus enabling the two coupling options to the first gear 110 or the second gear 210.

[0039] This axial displacement can be performed manually, for example, or by a linear actuator. The linear actuator can be, for example, a solenoid that couples to the shift lever 500 and exerts the force there. The shift lever 500 is designed, for example, as a fork at one or both ends, into which, for example, a piston of the exemplary linear actuator can engage to provide the axial movement.

[0040] Embodiments offer the advantage that many gears can be shifted not only via a single shift shaft, but that multiple shift shafts are available for shifting a multitude of gears. According to embodiments, only a single torque actuator is required for this, which can be selectively coupled to various shift shafts. The number of required components can thus be reduced to a necessary minimum.

[0041] The features of the invention disclosed in the description, the claims, and the figures may be essential for the realization of the invention, both individually and in any combination. LIST OF REFERENCE SYMBOLS

[0042] 100 first shift shaft

[0043] 200 second shift shaft 110 first gear

[0044] 120 additional gears

[0045] 210 second gear

[0046] 300 rotary actuator (electric motor)

[0047] 310 Drive gear 320 Drive shaft

[0048] 400 bracket

[0049] 500 gearshift levers

[0050] D0 drive torque

[0051] D1 , D1 torques transmitted to the selector shafts

Claims

PATENT CLAIMS 1 . Switch for selectively coupling different switching shafts (100, 200) of a transmission actuator, characterized by - a first selector shaft (100) with a first gear (110); - a second selector shaft (200) with a second gear (210); - a rotary actuator (300) having a drive gear (310) on a drive shaft (320) to provide a torque (DO), wherein the drive gear (310) is axially displaceably mounted on the drive shaft (320) to selectively couple the rotary actuator (300) to the first gear (110) or to the second gear (320).

2. Changeover switch according to claim 1, characterized in that the first gear (110) is fixed to the first switching shaft (100) in a rotationally fixed manner or via a converter in order to transmit a rotational movement of the first gear (110) to the first switching shaft (100) or to convert it into a first axial movement of the first switching shaft (100).

3. Changeover switch according to claim 1 or claim 2, characterized in that the second gear (120) is fixed to the second switching shaft (200) in a rotationally fixed manner or via a converter in order to transmit a rotational movement of the second gear (210) to the second switching shaft (200) or to convert it into a second axial movement of the second switching shaft (200).

4. Switch according to one of the preceding claims, characterized by a holder (400) which holds the first switching shaft (100) and the second switching shaft (200) parallel and spaced from one another in order to use different switching shafts for switching gears by means of the transmission actuator.

5. Changeover switch according to one of the preceding claims, characterized by a switching lever (500) which is coupled to the drive gear (310) in order to axially displace the drive gear (310) upon actuation of the switching lever (500).

6. A changeover switch according to claim 5, characterized by a linear actuator coupled to the switching lever and configured to provide a force that axially displaces the drive gear (310) between the first gear (110) and the second gear (320).

7. Switch according to one of the preceding claims, characterized in that the drive gear (310) couples directly or indirectly to the first gear (110) or to the second gear (210) in order to transmit a torque (D1, D2) with the same sign or opposite sign or a different strength.

8. Changeover switch according to one of the preceding claims, characterized in that the drive shaft (320) has an axially extending groove and the drive gear (310) has a projection within a cylindrical opening, wherein the projection engages in the axially extending groove and is displaceable along the axially extending groove.

9. Gear actuator, characterized by a changeover switch according to one of claims 1 to 8.

10. Commercial vehicle, in particular a truck, characterized by a transmission actuator according to claim 9.

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