Transmission Mechanism

Abstract

The disclosure relates to a transmission mechanism with at least two gearwheels that can be brought into form-fitting engagement with one another. One of the gearwheels is designed as a movable gear and, in a disengaged position, is arranged in a freely rotatable manner on a transmission shaft. The other of the gearwheels is designed as a fixed gear and is arranged non-rotatably on a further transmission shaft, the movable gear is connectable non-rotatably to the transmission shaft by a clutch unit and at least one transmission gear can be engaged if a clutch toothing of the clutch unit engages in a form-fitting manner in a toothing of the movable gear in a tooth-on-tooth-gap position. A sensor device detects a rotational speed signal incoming into the other transmission shaft and a rotational speed signal outgoing from the transmission shaft.

Claims

1. A transmission mechanism for a transmission, the transmission mechanism comprising: a transmission shaft; a further transmission shaft; at least two gearwheels that can be brought into form-fitting engagement with one another, one of the gearwheels designed as a movable gear and, in a disengaged position, arranged in a freely rotatable manner on the transmission shaft, the other one of the gearwheels designed as a fixed gear and arranged non-rotatably on the further transmission shaft, the movable gear connectable non-rotatably to the transmission shaft by a clutch unit and at least one transmission gear can be engaged if a clutch toothing of the clutch unit engages in a form-fitting manner in a toothing of the movable gear in a tooth-on-tooth-gap position; a sensor device detecting a rotational speed signal incoming into the transmission shaft and a rotational speed signal outgoing from the other transmission shaft; a control unit coupled to the sensor device, the control unit: determining and storing a time stamp for each detected edge in the respective rotational speed signal, after an initial engagement of the at least one transmission gear, determining an angular position of the toothing of the movable gear relative to the transmission shaft, and assigning the angular position to the time stamp, and determining an absolute angular relationship between the toothing of the movable gear and the clutch toothing based on the time stamp and the angular position assigned to the time stamp.

2. The transmission mechanism of claim 1, wherein the control unit activates the clutch unit based on the determined absolute angular relationship.

3. The transmission mechanism of claim 2, wherein the control unit determines a tooth-on-tooth-gap position between the toothing of the movable gear and the clutch toothing based on the absolute angular relationship.

4. The transmission mechanism of claim 3, wherein the tooth-on-tooth-gap position is determined continuously or in an event-controlled or time-controlled manner.

5. The transmission mechanism of claim 1, wherein the sensor device has at least two rotational speed sensors.

6. The transmission mechanism of claim 5, wherein the sensor device includes: one rotational speed sensor arranged at or on a transmission input shaft, and another rotational speed sensor arranged at or on a transmission output shaft.

7. The transmission mechanism of claim 6, wherein the rotational speed sensors are each designed as a Hall sensor.

8. The transmission mechanism of claim 1, wherein the clutch unit is designed as a claw clutch.

9. The transmission mechanism as claimed in claim 8, wherein the clutch unit is formed in two parts and has a first claw element and a second claw element, the first claw element is connected non-rotatably to the transmission shaft and the second claw element is formed integrally with the movable gear.

10. The transmission mechanism of claim 1, wherein the transmission is a vehicle transmission.

Description

DESCRIPTION OF DRAWINGS

[0018] FIG. 1 schematically shows a transmission with a transmission mechanism.

[0019] FIG. 2 schematically shows a detail of a top view of a form-fitting connection between a movable gear and a claw element of the transmission.

[0020] Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

[0021] FIG. 1 schematically shows a transmission 1 with a transmission mechanism GM. The transmission 1 has a transmission input shaft 2 coupled to a drive unit (not shown specifically), for example an internal combustion engine. The transmission input shaft 2 forms the drive shaft and thus the drive side of the transmission 1.

[0022] As shown, the transmission 1 is a vehicle transmission and is based on an automated transmission in which a second transmission shaft 4 running parallel to a first transmission shaft 3 is arranged. The first transmission shaft 3 is also referred to as a countershaft and is arranged coaxially with respect to the transmission input shaft 2. The transmission input shaft 2 and the first transmission shaft 3 are depicted integrally as shown. Alternatively, these can also be formed separately and connected to each other. The second transmission shaft 4 forms the output shaft of the transmission 1 and is arranged coaxially with respect to a transmission output shaft 5. The second transmission shaft 4 and the transmission output shaft 5 are also depicted integrally. Alternatively, these can also be formed separately and connected to each other.

[0023] The transmission input shaft 2 and the second transmission shaft 4 are mechanically coupled to each other by a first pair of gearwheels ZP1, including the gearwheels Z1, Z2. As shown, the transmission 1 has a total of four pairs of gearwheels ZP1 to ZP4 and thus four engageable transmission gears G1 to G4, also referred to as transmission stages or gear stages. Alternatively, the transmission 1 can also have fewer than four or more than four engageable transmission gears G1 to G4.

[0024] The first transmission shaft 3 is also mechanically coupled to the second transmission shaft 4. For this purpose, further gearwheels Z3, Z5, Z7 are arranged on the second transmission shaft 4, the further gearwheels being in constant engagement in pairs with further gearwheels Z4, Z6, Z8 arranged on the first transmission shaft 3 and thus providing different transmission ratios for the transmission gears G1 to G4.

[0025] In each pair of gearwheels ZP1 to ZP4, the gearwheels Z2, Z4, Z6, Z8 are each arranged non-rotatably on the first transmission shaft 3 and are therefore referred to further as fixed gears Z2, Z4, Z6, Z8. The other gearwheels Z1, Z3, Z5, Z7 are each arranged in a freely rotating and axially fixed manner on a section of the second transmission shaft 4 designed as a hollow shaft and are therefore referred to below as movable gears Z1, Z3, Z5, Z7.

[0026] A first clutch unit K1 is arranged between the movable gears Z1, Z3. Furthermore, a second clutch unit K2 is arranged between the movable gears Z5, Z7. The clutch units K1, K2 are used for shifting, such as, engaging the transmission gears G1 to G4, and are each designed as what is referred to as a claw clutch.

[0027] The clutch units K1, K2 each have a first claw element K1.1, K2.1 which is arranged non-rotatably on the second transmission shaft 4. For example, the first claw element K1.1, K2.1 is arranged in such a way that it rotates together with the second transmission shaft 4, but is axially displaceable relative to the latter.

[0028] The clutch units K1, K2 furthermore each have two second claw elements K1.2, K2.2 which are each arranged coaxially opposite the first claw element K1.1, K2.1 on the second transmission shaft 4. Furthermore, the second claw elements K1.2 and K2.2 are formed integrally with the movable gears Z1, Z3, Z5, Z7.

[0029] Those surfaces of the first claw element K1.1, K2.1 which each face the movable gears Z1, Z3, Z5, Z7 have a clutch toothing KV which is illustrated abstractly in FIG. 1 and in sections in FIG. 2. Likewise, a corresponding toothing VZL is formed on those surfaces of the second claw elements K1.2, K2.2 which each face the first claw element K1.1, 2.1, and therefore the first claw elements K1.1, K2.1 can be brought into engagement with the second claw elements K1.2, K2.2 and thus with the movable gears Z1, Z3, Z5, Z7 in a form-fitting manner.

[0030] In some implementations, both clutch units K1, K2 are illustrated in an open state. That is, the transmission 1 is in a neutral position, with none of the movable gears Z1, Z3, Z5, Z7 being connected to the second transmission shaft 4.

[0031] To engage a first transmission gear G1, the first clutch unit K1 is moved in the direction of the movable gear Z1 for the first transmission gear G1. The clutch toothing KV arranged on the first claw element K1.1 is brought into engagement in a form-fitting manner with the toothing VZL of the second claw element K1.2, which is formed integrally with the movable gear Z1, in a tooth-on-tooth-gap position ZLS (shown in FIG. 2).

[0032] As a result, the movable gear Z1 is connected non-rotatably to the second transmission shaft 4 and the second transmission shaft 4 is functionally coupled to the transmission input shaft 2 by the first pair of gearwheels ZP1. Thus, the second transmission shaft 4 is driven starting from the transmission input shaft 2 via the first pair of gearwheels ZP1.

[0033] By shifting the following transmission gears G2 to G4, a torque is transmitted from the first transmission shaft 3 to the second transmission shaft 4. This torque is then transmitted via a transmission output shaft 5, which is arranged coaxially with respect to the second transmission shaft 4, to an output unit (not illustrated) which, for example, includes a differential transmission which drives axle drive shafts for drive wheels of the vehicle, for example front drive wheels.

[0034] The form-fitting connection between the toothing VZL of the second claw element K1.2, K2.2 and the clutch toothing KV on the first claw element K1.1, K2.1 takes place in what is referred to as a tooth-on-tooth-gap position ZLS (see FIG. 2), in which, for example, a tooth of the clutch toothing KV engages in a form-fitting manner in a tooth gap of the toothing VZL. If, on the other hand, two teeth (one of the toothing VZL and one of the clutch toothing KV) meet, this can lead to the toothings VZL jamming or to a delayed form-fitting connection. This is noticeable in the driving mode by a prolonged and noisy shifting operation.

[0035] To reduce such problems, the transmission mechanism GM provides a sensor device 6 and a control unit 7 which is coupled thereto and by way of which an absolute angular relationship WB between the toothing VZL of the movable gear Z3, Z5, Z7 and the clutch toothing KV can be determined and, resulting therefrom, so too can a clutch position between the toothing VZL and the clutch toothing KV, for example, a tooth-on-tooth-gap position ZLS or a tooth-on-tooth position (not shown) be determined. In some examples, a clutch region between the toothing VZL and the clutch toothing KV can thus be monitored for their clutch position, for example, as to whether their teeth are in the tooth-on-tooth-gap position ZLS or in a tooth-before-tooth position. In some examples, the sensor device 6 and the control unit 7 detect and/or determine whether the first claw element K1.1, K2.1 and the second claw element K1.2, K2.2 are positioned in a tooth-on-tooth-gap position ZLS with respect to one another.

[0036] In some implementations, the sensor device 6 includes a first rotational speed sensor 6.1 coupled to the transmission input shaft 2 and a second rotational speed sensor 6.2 coupled to a transmission output shaft 5, which forms the transmission output side. The rotational speed sensors 6.1, 6.2 are each, for example, Hall sensors or inductive sensors and detect a rotational speed of the transmission input shaft 2 or the transmission output shaft 5.

[0037] The rotational speed sensors 6.1, 6.2 are also connected to a control unit 7 which is, for example, a transmission control unit of a vehicle. The control unit 7 evaluates the signals detected by the rotational speed sensors 6.1, 6.2, for example, an incoming rotational speed signal n.sub.in and an outgoing rotational speed signal n.sub.out, which depict the rotational speeds of the transmission input shaft 2 and the transmission output shaft 5.

[0038] During the evaluation of the rotational speed signals n.sub.in, n.sub.out, a time stamp is stored for each edge in the signal. In other words: Each signal edge can be assigned to a fixed point in time.

[0039] During the evaluation of the detected rotational speed signals n.sub.in, n.sub.out, for each stored time stamp of an edge in the rotational speed signal n.sub.in, n.sub.out a position, for example, an angular position WP of the toothing VZL of the movable gear Z3, Z5, Z7, for example, of the second claw element K1.2, K2.2, relative to the second transmission shaft 4 is detected and this angular position WP is assigned to the time stamp. Since, owing to the non-rotatable arrangement of the first claw element K1.1, K2.1 on the second transmission shaft 4, a position of the clutch toothing KV is known with reference to the evaluated rotational speed signals n.sub.in, n.sub.out of the rotational speed sensors 6.1, 6.2, it is consequently possible, after an initial engagement of a transmission gear G1 to G4, for example of the first transmission gear G1, for an absolute angular relationship WB, for example, angular position WP between the toothing VZL of the second claw element K1.2, K2.2 and the clutch toothing KV of the first claw element K1.1, K2.1 to be determined.

[0040] If the control unit 7 determines the tooth-on-tooth-gap position ZLS shown in FIG. 2, the control unit activates the clutch unit K1, K2 for engaging the corresponding transmission gear G1 to G4 such that the first claw element K1.1, K2.1 engages in a form-fitting manner in the second claw element K1.2, K2.2 virtually without interference. If, on the other hand, the control unit 7 determines a tooth-before-tooth position (not shown), the clutch unit K1, K2 is moved relative to the movable gear Z3, Z5, Z7, for example, rotated step by step into the tooth-on-tooth-gap position ZLS.

[0041] The control unit 7 monitors the clutch region between the movable gear Z3, Z5, Z7 and the clutch unit K1, K2, for example, continuously or, in an event-controlled or time-controlled manner. In some examples, the control unit 7 can use the absolute angular relationship WB to determine a tooth-on-tooth-gap position ZLS even after disengaging the previously initially engaged transmission gear G1 to G4.

[0042] FIG. 1 schematically shows a detail from a top view of the tooth-on-tooth-gap position ZLS between the toothing VZL and the clutch toothing KV. For example, the tooth-on-tooth-gap position ZLS between the first claw element K1.1 and the second claw element K1.2 is illustrated. The flanks of the toothings VZL, KV are illustrated vertically here. In addition, the flanks can be provided with an undercut such that they are configured substantially to be dovetail-shaped.

[0043] By way of the described transmission mechanism GM, the clutch unit K1, K2 and therefore the engagement of a transmission gear G1 to G4 can thus be activated depending on the position of the toothing VZL of the movable gear Z1, Z3, Z5, Z7 or of the second claw element K1.2, K2.2 with respect to the clutch toothing KV of the first claw element K1.1, K2.1.

[0044] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.

LIST OF REFERENCE SIGNS

[0045] 1 transmission
2 transmission input shaft
3 first transmission shaft
4 second transmission shaft
5 transmission output shaft
6 sensor device
6.1, 6.2 rotational speed sensor
7 control unit
G1 to G4 transmission gear
GM transmission mechanism
K1, K2 clutch unit
K1.1, K2.1 first claw element
K1.2, K2.2 second claw element
KV clutch toothing
n.sub.in incoming rotational speed signal
n.sub.out outgoing rotational speed signal
VZL toothing
WP angular position
WB angular relationship
Z1 to Z8 gearwheel
Z1, Z3, Z5, Z7 movable gear
Z2, Z4, Z6, Z8 fixed gear
ZP1 to ZP4 pair of gearwheels
ZLS tooth-on-tooth-gap position