Claw clutch with overrunning clutch function and driving device

Abstract

The invention relates to a dog clutch (7) having the function of an overrunning clutch, consisting of an inner element (6a) which is provided on the end face with a traction dog (13) and an outer element (6b) which at least partially surrounds the inner element (6a) radially and which is provided on the end face thereof with a push dog (12), 12) have opposite wedge-shaped structures, and wherein the inner element (6a) and the outer element (6b) can be moved axially towards a counterpart element (6c) having a ring gear (14) via a shift pawl (7) or a shift bolt (7 ') having a respective pawl.

Description

Technical Field

[0001] The invention relates to a claw clutch with an overrunning clutch function, which is composed of an inner element and an outer element, wherein the inner element is provided with a traction claw at the end side, and the outer element radially at least partially surrounds the inner element and is provided with a push claw at its end side.

[0002] The invention also relates to a drive device for an electrically driven vehicle, which has two gears and a claw clutch with an overrunning clutch function. Background Art

[0003] In electric vehicles that obtain their power from electric motors, hybrid vehicles that obtain their power by switching between internal combustion engines and electric motors, and vehicles that are driven only by the driving power of electric motors, the power transmission from the electric motor to the axle side is usually performed only through a reduction gearbox in which the rotation speed of the electric motor is reduced to a rotation speed of the axle whose value is suitable for operation, without providing another gearbox. This is because the electric motor can generate driving torque from a low speed range, has a large speed range that can be used for operation, and has a simple structure, which is an important selling point for electric vehicles.

[0004] However, it is also advantageous to use a transmission in an electric vehicle. Even for an electric motor, it is difficult to achieve high efficiency over the entire speed range of the vehicle. Because the rotation speed of the electric motor is higher, especially in the high speed range of the vehicle, the efficiency of the electric motor decreases. As an improved plan, a two-stage transmission is provided between the electric motor and the reduction transmission, and the side with a low reduction ratio in the two-stage transmission is used in the driving range of the vehicle with a high vehicle speed, and the lower rotation speed of the electric motor can be used to perform the driving operation of the vehicle with a high vehicle speed, which widens the use range of the electric motor with high efficiency. As such a two-stage transmission, JP 2016-017632A proposes a transmission with a planetary gear transmission mechanism for executing a two-stage transmission. The planetary gear transmission mechanism includes three rotating elements, and the three rotating elements are a planetary carrier, a sun gear and a ring gear that pivotably supports a plurality of pinions. If the vehicle is traveling in a low speed range, when the dog clutch is engaged, the friction clutch is not engaged, and the ring gear is fastened to the housing by the engagement of the dog clutch. If the vehicle is traveling in the high-speed range, when the dog clutch is not engaged, the friction clutch is engaged, the ring gear is released from the housing and rotates together with the sun gear and the planet carrier, and the transmission ratio is 1.0 (constant speed (constant speed movement)). The transmission ratio in the driving range with high vehicle speed is set so that the transmission ratio is lower than the transmission ratio in the driving range with low vehicle speed, which causes the rotation speed of the electric motor to be relatively reduced in the driving range with high vehicle speed. Correspondingly, in the driving range with high vehicle speed, the efficient driving range of the electric motor is widened, and driving with high vehicle speed is performed with high efficiency. When switching from the second gear to the first gear (speed reduction), a transmission shock (Getriebeschock) occurs due to the structure of the dog clutch, because the clutch is engaged in accordance with the relative rotation of the engaged gear surface, and the dog clutch transitions from the non-engaged state to the engaged state.

[0005] DE 10 2020 202 788 B3 shows a powertrain with a two-speed transmission, which has an electric motor, a transmission input shaft and a transmission for configuring a first gear and a second gear, wherein the first gear is provided with an overrunning clutch and the second gear is provided with a centrifugal force-controlled friction clutch, wherein the first clutch connects the shifting gear of the first gear with the transmission input shaft and the second clutch connects the shifting gear of the second gear with the transmission input shaft.

[0006] US11 408 488 B2 relates to a two-stage transmission, which is arranged along the output shaft of the electric motor in a vehicle that uses an electric motor for wheel drive, and the two-stage transmission has: a planetary gear transmission mechanism, the planetary gear transmission mechanism includes three rotating elements, the rotating elements include a planetary carrier that pivotally carries a plurality of pinions and a plurality of gears with different numbers of teeth and engaged with the pinions, and the planetary gear transmission mechanism uses a first speed mode, in which a first rotating element selected from the three rotating elements is fastened on the housing side and power transmission is performed using the following transmission ratio, the value of the transmission ratio is 1.0 and the transmission ratio is obtained between the second rotating element and the third rotating element, and the planetary gear transmission mechanism uses a second speed mode, in which force transmission is performed using the following transmission ratio in the second speed mode, the value of the transmission ratio is 1.0 and the The transmission ratio is obtained by inputting and outputting from one of the second rotating element and the third rotating element to the one rotating element or by the integral rotation of one of the second rotating element and the third rotating element with the first rotating element; a dog clutch, which is coupled to the rotating element of the planetary gear transmission mechanism so as to select a side speed mode with a relatively low transmission ratio between the first speed mode and the second speed mode; a friction clutch, which is coupled to the rotating element of the planetary gear transmission mechanism so as to select a side speed mode with a relatively high transmission ratio between the first speed mode and the second speed mode; and a one-way ratchet clutch, so as to prevent torque drop when switching between the first speed mode and the second speed mode, wherein the engagement section of the dog clutch and the ratchet engagement section of the one-way ratchet clutch are arranged at the same rotational phase position.

[0007] If the ratchet clutch overruns, it can be a disruptive noise source.

[0008] DE 699 635 A shows a lockable overrunning clutch, in which the force transmission takes place via surfaces abutting against each other. The lockable overrunning clutch is essentially characterized by two claw clutches arranged concentrically in one another for connecting a drive shaft to a driven shaft, the immovable parts of which are located on one shaft, while the movable parts can be moved relative to each other, but are prevented from rotating relative to each other. The claws of the clutch to be engaged first are designed in a known manner so that they can only drive or be driven in one direction of rotation, but slide away from each other over their entire length in the other direction of rotation, and the other claw clutch to be engaged subsequently cancels the overrunning clutch effect of the first claw clutch.

[0009] DE 10 2012 015 863 A1 relates to a multi-stage transmission for a motor vehicle, the multi-stage transmission having a transmission input that can be connected to a drive motor and a transmission output that can be connected to a driven shaft of the motor vehicle, wherein the multi-stage transmission is designed to configure at least a first gear and a further gear, wherein in the first gear, the force transmission from the transmission input to the transmission output takes place via a first clutch device, wherein in the further gear, the force transmission from the transmission input to the transmission output takes place via a second clutch device, and wherein the second clutch device has a power shift clutch. Due to the overrunning clutch, actuation is not required, in which a pressure overlap of two power shift clutches is required.

[0010] The object of the present invention is to provide an improved embodiment of a claw clutch with an integrated overrunning clutch, which allows fast and quiet shifting operations but is of small construction. Summary of the invention

[0011] The object is achieved by means of a claw clutch with an overrunning clutch function, which consists of an inner element and an outer element, the inner element being provided with a traction claw on the end side, the outer element radially at least partially surrounding the inner element and being provided with a push claw on its end side, wherein the traction claw and the push claw have opposite wedge-shaped structures, and wherein the inner element and the outer element can be axially moved toward a matching element with a gear ring via a shift fork with corresponding claws.

[0012] The combination of the claw clutch and the overrunning clutch function saves components and can ensure fast gear shifting. It is also possible that the push pawl and the traction pawl are geometrically interchangeable, that is, at the corresponding end sides of the inner element or the outer element, the push pawl is placed inside and the traction pawl is placed outside.

[0013] A claw clutch with overrunning clutch function has a one-piece shift fork which actuates both an inner element and an outer element, wherein the relative movement of the two elements relative to one another is limited by a collar of the inner element which is arranged on the side of the inner element facing away from the counterpart.

[0014] Advantageously, the shift fork resting against the inner element is elastically guided on the shift drum track via a spring device.

[0015] Advantageously, the locking spring engages in an inner groove of the inner element.

[0016] A dog clutch with overrunning clutch function combined with a friction clutch allows upshifting and downshifting without interruption of traction.

[0017] The dog clutch with overrunning clutch function allows at least a fast and easily controlled upshift process.

[0018] In one embodiment, a fast and easy to control downshift process is also possible.

[0019] The object is also achieved by means of a drive device having an electric machine, a clutch, two gears and a claw clutch with an overrunning clutch. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A view showing a claw clutch with overrunning clutch function,

[0021] Figure 2 An embodiment not in accordance with the present invention showing the dog clutch in a fully closed state,

[0022] Figure 3 An embodiment of a dog clutch not in accordance with the invention is shown, in which the traction dog is closed,

[0023] Figure 4 An embodiment of a dog clutch not in accordance with the invention is shown, in which the clutch is fully opened.

[0024] Figure 5 An embodiment according to the invention is shown, in which the fully closed

[0025] Figure 6 An embodiment not in accordance with the invention is shown, in which the fully opened

[0026] Figure 7 shows the course of a shifting movement for an embodiment not in accordance with the invention,

[0027] Figure 8 An embodiment not in accordance with the invention is shown, wherein the external element is opened,

[0028] Fig. 9 An embodiment not in accordance with the invention is shown, wherein the components are opened,

[0029] Fig.10 Shown in Fig. 9 The position of the shift movement in the case shown in

[0030] Fig.11 An embodiment not in accordance with the invention is shown, in which the elements are closed,

[0031] Fig.12 Show according to Fig.11 The shift position,

[0032] Fig.13An exemplary transmission is shown with a friction fit in a first gear,

[0033] Fig.14 The same exemplary transmission is shown in a second gear with a friction fit. DETAILED DESCRIPTION

[0034] Fig.13 and Fig.14 By way of example, a drive device 10 is shown which comprises a friction clutch 5 and form-fitting elements 7, 6. Hitherto, a dog clutch 7 and a conventional overrunning clutch 6 have been combined in the transmission architecture in order to enable energy recovery and reverse driving via shifting with the aid of the dog clutch 7 and at the same time to enable fast and simple shifting operations under traction conditions via the overrunning clutch 6.

[0035] In the embodiment selected, the electric motor 4 drives the input shaft 3, on which there are a first gear set for the first gear 1 and a second gear set for the second gear 2. The friction clutch 5 is introduced adjacent to the second gear 2. The output shaft 9 is connected to the drive gear set 8 via an intermediate shaft 11. In addition to the gear sets for the two gears, the shifting claw 7 and the overrunning clutch 6 are also mounted on the intermediate shaft 11.

[0036] exist Fig.13 The force flow for the first gear 1 is shown in FIG. The friction clutch 5 is open and the claw clutch 7 is closed. Fig.14 The force flow for the second gear 2 is shown in FIG. The friction clutch 5 is closed, the claw clutch 7 is open, and the overrunning clutch 6 is overrunning, ie, no torque is transmitted.

[0037] Figure 1 A view of two parts of a claw clutch with overrunning clutch function 6, which consists of an inner element 6a and an outer element 6b. The inner element 6a has a traction pawl 13 along its end face. In the embodiment shown, there are six traction pawls 13. In contrast, the outer element 6b has a push pawl 12 extending along the end face. The push pawl 12 differs from the traction pawl 13 in the direction in which the teeth point and thus in the direction in which the torque can be transmitted.

[0038] The pulling claw 13 and the pushing claw 12 are designed asymmetrically in a wedge shape and protrude from the corresponding end faces of the inner and outer elements. The wedge-shaped design is produced in that the claw protrudes from the annular surface of the end face. As a result, the claw transmits torque in one direction, while no torque is transmitted in the other direction. The inner element 6a and the outer element 6b are arranged in opposite directions with respect to their orientation with respect to the torque transmission.

[0039] The inner element 6a transmits torque in the pulling direction, while the outer element 6b transmits torque in the pushing direction. Figure 2 If two elements are engaged simultaneously as shown in FIG, torque can be transmitted in two directions, as is the case with conventional claw clutches.

[0040] exist Figure 2 The construction of a claw clutch with an overrunning clutch function which does not conform to the invention is shown more precisely in FIG.

[0041] The inner element 6a is radially surrounded by the outer element 6b. The elements 6a and 6b can be axially moved and are connected to each other in a rotationally fixed manner. The inner element 6a has a flange 17 and an inner groove 18. The outer element 6b shows a groove 16 on the outer diameter. The matching element 6c can be seen on the output side, in which the traction pawl 13 and the push pawl 12 can be engaged. The shift fork 7' shows a fork element 7a for the inner element 6a and a fork element 7b for the outer element 6b. The fork element 7b for the outer element 6b is engaged in the groove 16 of the outer element 6b. The fork element 7a for the inner element 6a is attached to the flange 17 of the inner element 6a from the outside. In the closing function of the overrunning clutch corresponding to the claw clutch, not only the inner element 6a but also the outer element 6b is engaged with the toothed ring 14 of the matching element 6c.

[0042] Input side speed n AN and the output speed n AB are the same.

[0043] exist Figure 3 and Figure 4 The process during a fast traction upshift is shown in FIG.

[0044] The outer element 6b is primarily designed for a fast traction upshift. The outer element 6b is unloaded here, since the traction torque is transmitted via the inner element 6a. To this end, the shift fork 7' moves the fork element 7b for the outer element away from the counterpart element 6c, see Figure 3 .

[0045] After the torque has been superimposed on the second gear by closing the friction clutch 5, the speed ratio at the dog clutch 7 changes. The drive side reduces its speed n AN , and as long as the drive speed n AN Lower than driven speed n AB The inner element 6a of the claw clutch is automatically pushed out due to the design of the traction claw 13 of the inner element 6a.

[0046] The locking spring 15 then engages in the inner groove 18 of the inner element 6 a in order to support the separation process up to the end position and prevent the claw from rattling.

[0047] The shift fork 7' simultaneously actuates two elements, namely the inner element 6a and the outer element 6b. This allows both the push pawl 12 and the pull pawl 13 to be engaged simultaneously. For decoupling, two positions are provided for the shift fork 7'. Figure 3 As shown in FIG, in the first position, only the outer element 6 b is separated by means of the push claw 12. In the second position, as in Figure 4 As shown in FIG, the outer element 6b is also actively disengaged. The shift fork 7 is Figure 3 and Figure 4 6a is in the same position in the figure. Only 6b is actively disengaged. The disengagement of 6a is achieved by pushing out at the corresponding speed ratio with the support of the locking spring. The active disengagement of 6a by the shift fork is not shown in the figure.

[0048] But it is feasible by the second shift fork position more on the left in the accompanying drawings. Here, the outer element 6b slides further to the left and drives the inner element 6a at the flange 17 places.

[0049] Figure 5 An embodiment according to the invention of a claw clutch with overrunning clutch functionality is shown.

[0050] The shift fork 7 ′ is replaced by a shift fork 7 ′ having only one fork element which engages in the groove 16 of the outer element 6 b.

[0051] The outer element 6b radially surrounds the inner element 6a, wherein the collar 17 of the inner element 6a is axially displaceable in a recess 20 of the outer element. The elements 6a and 6b are connected to one another in a rotationally fixed manner.

[0052] The entrainer / fixing ring 19 forms a stop for the axial movement of the inner element 6a in the recess 20. The simplified shift fork 7' is used to realize an entrainer function which enables the first gear to be disengaged or engaged when stationary.

[0053] Even in the original variant, it is possible to actively separate the two elements, for example when stationary. In both cases, this is achieved via the second position of the shift fork "further to the left".

[0054] Figure 5 The advantage of the variant in is a more compact and more cost-effective design. The shift fork requires only one fork element, and the overall length of the clutch can be expected to be reduced because the two elements are completely nested in each other.

[0055] In the variants described so far, the pulling pawl and the pushing pawl engage simultaneously during the engagement process. In this case, the initial direction of action when the pawl engages is dependent on the sign of the speed difference during the engagement process. If the drive speed n ANLower than driven speed n AB , the pushing claw 12 acting in the pushing direction first transmits the torque. If the driving speed is greater than the driven speed, the traction claw 13 acting in the traction direction first transmits the torque.

[0056] In practice, due to inaccuracies in the data acquisition or dynamic effects, the sign of the rotational speed difference is not always known exactly.

[0057] Therefore, the third embodiment which does not conform to the present invention is an improved solution.

[0058] Alternatively, the mechanical design of the actuation system can be designed so that, in addition to the disengagement process, the claw is also engaged via two separately actuatable shift bolts or shift claws in sequence.

[0059] The design can simplify the design of the regulator and the mechanical design and have a positive effect on the shifting time and the shifting comfort. In order to control the components consisting of the motor, the clutch and the shifting system, the following situation should be used: the traction pawl 13 acting in the traction direction always transmits the load first. As long as the traction pawl 13 acting in the traction direction is engaged and the driving torque is transmitted, the pushing pawl 12 acting in the pushing direction can be engaged without load. In addition, the elasticity introduced in the actuation system of the traction pawl 13 by the spring mechanism 21 realizes the overrunning clutch functionality. This can be advantageous in particular for downshifting, in order to compensate for the inaccuracy of the "clutch" component in particular, thereby further improving the shifting time and the shifting comfort. The working mode of the overrunning clutch is used here.

[0060] Figure 6 The shift fork 7' is shown engaging in the groove 16. Separately from the shift fork 7', a second shift fork 7" for the inner element 6a is provided, which second shift fork surrounds the flange 17 of the inner element. The dog clutch is fully open and the vehicle moves in the second gear. Figure 7 The outline of the shift drum is shown schematically in FIG. It can be seen that the shifting claw can occupy four areas by being guided in the shift drum. The fully open position is Figure 7 It is marked by two dots.

[0061] Figure 8 and Fig. 9The situation is shown during the engagement phase of downshifting from the second gear to the first gear. During the engagement of the traction pawl 13, the traction pawl automatically transmits torque if the speed on the drive side is greater than the speed on the driven side. This is taken into account when designing the speed regulator for the motor and the clutch and when actuating the traction pawl 13. By utilizing the overrunning clutch functionality, the shift fork 7″ of the traction pawl 13 can be moved into the engagement position before the target speed is reached. As long as the drive side rotates slower than the driven side, the traction pawl 13 is pushed away. When the same speed and the pawl-to-pawl clearance position are reached, the traction pawl 13 automatically engages via the spring mechanism 21.

[0062] As a result, the requirements for the accuracy of the clutch control and the control of the electric machine 4 are significantly reduced. As a result, the shifting time for engaging the claw clutch is also reduced.

[0063] In this embodiment, the elasticity in the actuation system of the traction pawl 13 is introduced into the shift drum, such as Fig.10 Here, the section 22 of the shift drum track 23 is designed to be elastically axially displaceable in order to create a free space for movement for the shifting claw 7 ″ and thus for the drag claw 13 in this region for the overrunning clutch function.

[0064] Fig.11 A fully closed claw clutch is shown, wherein the inner element 6a and the outer element 6b are fully connected to the counterpart element. In this case, driving in the first gear is possible.

[0065] Fig.12 The position of the shift dog relative to the track in the shift drum is shown again.

[0066] Reference numerals list

[0067] 1 Gear set for first gear

[0068] 2 Gear set for second gear

[0069] 3 Input shaft

[0070] 4 Motor

[0071] 5 Friction clutch

[0072] 6 Overrunning clutch

[0073] 6a Internal components

[0074] 6b External Components

[0075] 6c Mating element

[0076] 7-dog clutch

[0077] 7', 7" Shift Fork

[0078] 7a Fork element for inner element

[0079] 7b Fork element for external element

[0080] 8 Drive gear set

[0081] 9 Driven shaft

[0082] 10 Powertrain

[0083] 11 Intermediate shaft

[0084] 12 Push claw

[0085] 13 Traction claw

[0086] 14 Gear ring

[0087] 15 Locking spring

[0088] 16 slots

[0089] 17 Flange

[0090] 18 Inner groove

[0091] 19 Driving parts

[0092] 20 concavity

[0093] 21 Spring mechanism

[0094] 22 Sections

[0095] 23 Shift drum track

Claims

1. A claw clutch (7) with an overrunning clutch function, the claw clutch consisting of an inner element (6a) and an outer element (6b), the inner element being provided with a traction claw (13) on the end side, the outer element radially at least partially surrounding the inner element (6a) and being provided with a push claw (12) on its end side, wherein the traction claw and the push claw (13, 12) have opposite wedge-shaped structures and can also be exchanged with each other, and wherein the inner element (6a) and the outer element (6b) can be axially moved via a shift fork (7') with claws towards a matching element (6c) with a toothed ring (14), It is characterized in that The shift fork (7') engages in a groove (16) of the outer element (6b), and the inner element (6a) can be moved relative to the outer element (6b) in a recess (20) of the outer element (6b) up to a carrier (19) which is arranged on a side of the inner element (6a) facing away from the counterpart element (6c).

2. The claw clutch (7) with overrunning clutch function according to claim 1, characterized in that: The locking spring (15) engages in an inner groove (18) of the inner element (6a).

3. A claw clutch (7) with overrunning clutch function according to any one of the preceding claims, characterized in that: Achieve upshifts without interruption of traction.

4. A claw clutch (7) with overrunning clutch function according to any one of the preceding claims, characterized in that: Enables downshifting without interruption of traction.

5. A drive device comprising an electric motor (4), a clutch (5), two gears (1, 2) and a claw clutch (7) with an overrunning clutch according to any one of the preceding claims.

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