Coupling device

Abstract

The invention relates to a coupling arrangement having two shaft sections (17, 19) which can be coupled by means of a claw coupling (21) which has a sliding claw (37) which is arranged on one of the shaft sections (19) in a rotationally fixed but axially displaceable manner, said sliding claw (37) being arranged on the other of the shaft sections (19) in a specific operating state, in particular in the event of a fault. The sliding claw (37) is adjusted in a direction opposite to the closing direction by means of a rebound movement (R). According to the invention, a damping element (45) is provided for reducing kinetic energy, in particular impact energy, and the sliding claw (37) impinges on the damping element during the rebound movement (R).

Description

Technical Field

[0001] The invention relates to a coupling arrangement according to the preamble of claim 1 . Background Art

[0002] This type of coupling device has a first shaft section and a second shaft section that can be connected by means of a claw coupling. The claw coupling has a sliding claw that is arranged on the first shaft section in a manner that is non-rotatable but axially movable. In addition, the claw coupling has a fixed claw that cooperates with the sliding claw and is arranged on the second shaft section in a manner that is non-rotatable and axially fixed.

[0003] The normal closing process takes place when the speed difference between the two shaft sections is small, that is, when the two shaft sections are almost synchronous, for example, when the speed difference is 10 rpm. In this normal closing process, the actuator-operated coupling sleeve first brings the sliding claw into axial contact with the fixed claw in a tooth-to-tooth manner with the overload spring connected in between. From the time tooth-to-tooth contact is reached, the coupling sleeve is further adjusted into its closed position, more precisely, when an overload spring force acts axially on the claw. As soon as the tooth-to-gap contact is established with a small rotational angle deviation, the two claws achieve a positive locking connection when the overload spring force is reduced.

[0004] In the event of a fault when the speed difference is too large, the actuator can mistakenly adjust the coupling sleeve into its closed position, and the sliding claw can rebound against the deflection contour of the fixed claw. This creates an axial force, by which the sliding claw can rebound against the deflection contour of the fixed claw in the axial direction in the opposite direction of the closing direction, and then rebounds again in the closing direction into tooth-to-tooth contact, specifically when an impact is applied to the fixed claw (that is to say to the deflection contour of the fixed claw). If the impact energy is high enough, the sliding claw can accidentally (despite the presence of the deflection contour) be connected to the fixed claw in a form-locking manner, which can impair the operational safety of the claw coupling.

[0005] A profile device for elastically absorbing shocks in a vehicle is known from DE 103 39 125 A1. A spring and damping element with a filler consisting of rubber particles is known from DE 201 06 540 U1. A device for holding a rack is known from DE 10 2008 040 508 A1. A vibration damping device for a steam turbine engine is known from EP 3 608 517 A1. A torsion bar with particle damping is known from EP 3 708 491 A1. Summary of the invention

[0006] The object of the invention is to provide a coupling arrangement whose operational reliability can be increased in a simple manner compared to the prior art.

[0007] This object is achieved by the features of claim 1. Preferred embodiments of the invention are disclosed in the dependent claims.

[0008] The invention relates to a coupling device having a first shaft section and a second shaft section which can be connected by means of a claw coupling. The claw coupling has a sliding claw which is arranged on one of the shaft sections in a manner that is non-rotatable but axially movable. Under certain operating conditions, in particular in the event of a fault, the sliding claw can suddenly be adjusted in a rebound movement in a direction opposite to the closing direction. According to the characterizing part of claim 1, a damping element can be provided for attenuating the kinetic energy, in particular the impact energy, of the sliding claw. During the rebound movement, the sliding claw can hit the damping element with reduced kinetic energy.

[0009] In one technical implementation, the claw coupling can have a fixed claw. The fixed claw is arranged on the other shaft section in a manner that it cannot rotate relative to each other and is preferably fixed in an axial position. The sliding claw can be adjusted to a closed position or an open position by means of an adjustment unit operated by an actuator, in particular a coupling sleeve. An overload spring can be supported between the adjustment unit (that is, the coupling sleeve operated by the actuator) and the sliding claw.

[0010] In this arrangement, the following normal closing process is obtained: the clutch sleeve operated by the actuator first presses the sliding claw in the closing direction in the axial direction with the overload spring connected in between. If the shift claws of the sliding claw and the fixed claw are axially opposite each other in the manner of teeth against gaps, the form-locking connection is smoothly carried out. However, it is more likely that during the closing process, the shift claws of the sliding claw and the fixed claw first abut against each other in the manner of teeth against teeth. From the time when the tooth-to-tooth abutment is reached, the clutch sleeve is further adjusted until it enters its closed position, so that an overload spring force is formed in the overload spring that acts axially on the claws. As soon as the tooth-to-gap abutment is established by a small relative angular rotation when the speed difference between the two shaft sections is small, the two claws achieve a form-locking connection when the overload spring force is reduced.

[0011] Different from the above-mentioned normal closing process, the following describes a fault situation in which the damping element according to the present invention can be used. In the case of a fault when the speed difference between the shaft sections is too large, the actuator mistakenly adjusts the coupling sleeve to its closed position. Due to the excessive speed difference, the positive locking engagement of the claw cannot be smoothly achieved. On the contrary, the sliding claw can only be made to abut against the fixed claw in a tooth-to-tooth manner. At this time, the sliding claw preloaded by the spring is rebounded in the opposite direction of the closing direction at the deflection profile of the fixed claw. In this way, an axial force is formed, through which the sliding claw is adjusted in the opposite direction of the closing direction by the deflection profile of the fixed claw in the axial direction in a rebound movement, and then rebounds again in the closing direction until the tooth-to-tooth abuts, specifically when the fixed claw is subjected to an impact. In order to reduce or attenuate the impact energy, the sliding claw hits the damping element in its rebound movement. In this way, the kinetic energy (that is, the impact energy) of the sliding claw is attenuated when the damping element is deformed. Thus, it is possible to prevent the claw coupling from accidentally closing due to the excessive impact energy of the sliding claw. In contrast, if no damping element is provided, the sliding pawl could rebound with excessive impact energy until it abuts tooth against tooth and could inadvertently engage in a positive-locking manner with the securing pawl.

[0012] In a specific embodiment, the sliding claw can extend annularly around the outer circumference of the first shaft section. In this case, the sliding claw can abut the damping element with its end side facing away from the claw. In order to achieve a defect-free functionality, it is advantageous if the damping element extends annularly around the outer circumference of the first shaft section and can abut the sliding claw continuously when viewed in the circumferential direction.

[0013] Preferably, the damping element can consist of an elastically and / or plastically deformable damping body. The damping body can be connected to a support element, which can be fastened at the first shaft section. Preferably, the damping element can consist of a rubber material or an elastomeric material. Particularly preferably, the damping element can be a hollow profile element, the cavity of which is filled with a damping material, for example a damping gel or damping particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Embodiments of the present invention will be described below with reference to the accompanying drawings.

[0015] in:

[0016] Figures 1 to 11 A view is shown in each case for explaining the coupling arrangement. DETAILED DESCRIPTION

[0017] exist Figure 1 In the embodiment, the claw coupling 21 is installed in the electrically driven front axle VA of the electrically operated vehicle. The front axle VA is equipped with an electric motor EM, which drives the left and right drive shafts 7 and 9 of the right and left front wheels 5 through the front axle differential 3. Figure 1 It is also known that the right front drive shaft 9 is divided into a wheel-side shaft section 17 and an axle-side shaft section 19. The two shaft sections can be coupled by means of a claw coupling 21 for drivingly connecting the electric machine EM to the wheels 5 during driving operation. Alternatively, the shaft sections 17, 19 can be decoupled from each other in order to avoid drag losses during driving operation and when the electric machine EM is deactivated.

[0018] Therefore, in driving operation, when the claw coupling 21 is disconnected, the differential bevel gear 29 in the front axle differential 3 only maintains a load-free balancing movement. On the contrary, the rest of the drive unit (that is, the reducer and the motor) is at rest, thereby significantly reducing drag losses.

[0019] exist Figure 1 In the embodiment, the electric motor EM of the front axle VA is connected to the external gear 25 on the input side of the front axle differential 3 via the reduction gear 23. On the output side of the front axle differential 3, the axle bevel gear 27 is connected to the two drive shafts 7 and 9. The axle bevel gear 27 and the differential bevel gear 29 meshing therewith are positioned in the differential housing 31 of the axle differential 3.

[0020] According to the following Figure 2 The structure and working principle of the claw coupling 21 are described. Therefore, the shaft section 19 on the axle side is connected (at Figure 2 The axle section 19 on the axle side is rotatably supported by its outer axial end in a plug-in shaft leading to the front wheel 5, which forms the wheel-side shaft section 17. Figure 2 In FIG. 2 , the claw clutch 21 has an axle-side shifting claw 33 and a wheel-side shifting claw 35 , which are connected to one another in a form-locking manner when the claw clutch 21 is closed. Figure 2 In the embodiment, the shift claw 35 on the wheel side is a component of the fixed claw 36, which is arranged on the wheel side shaft section 17 in a manner that cannot rotate relative to each other and is fixed in axial position. The shift claw 33 on the axle side is a component of the sliding claw 37, which is arranged on the spline / gear part (steckverzahnung) of the axle side shaft section 19 in a manner that cannot rotate relative to each other but can move axially. The annular coupling sleeve 38 is arranged on the outer periphery of the sliding claw 37 in a manner that cannot rotate relative to each other but can be adjusted axially. The coupling sleeve 38 can be moved in the closed position ( Figure 4 and Figure 5 ) and the open position ( Figure 3 ) are axially adjusted between the coupling sleeve 38 and the axle-side shift claw 33 of the sliding claw 37 . According to the drawings, an overload spring 42 is supported between the coupling sleeve 38 and the axle-side shift claw 33 of the sliding claw 37 .

[0021] In the event of a fault, which will be described later, the sliding claw 37 can use its end side 43 ( Figure 2 ) against the damping element 45. The damping element 45 extends annularly around the outer circumference of the axle-side shaft section 19. Furthermore, the damping element 45 is designed in two parts, namely, it consists of a substantially plastically deformable damping body 47 and a rigid supporting element 49, to which the damping body 47 is connected. The supporting element 49 is fastened to the axle-side shaft section 19.

[0022] According to the following Figures 3 to 5 Describe the various working conditions of the claw coupling 21. Figure 3 In the embodiment, the actuator-actuated clutch sleeve 38 is in its open position, in which the shifting claws 33, 35 are disengaged. Figure 4 In the process, the coupling process (that is, the closing process) of the claw coupling 21 is carried out, in which the shift claws 33, 35 on the wheel side and the shift claws 33, 35 on the axle side are facing the gaps 53 with their teeth 51 (only in Figure 7 When the actuator 39 is activated, the coupling sleeve 38 together with the sliding claw 37 coupled to its movement is moved from Figure 4 The open position shown in FIG. 1 is pushed into a closed position in which the wheel-side shift claw and the axle-side shift claw 33 , 35 are smoothly engaged.

[0023] and Figure 4 On the contrary, in a normal closing process, it is more likely that the wheel-side shift claw and the axle-side shift claw 33, 35 are not axially opposite each other in the closing process, with teeth 51 facing gaps 53, but with teeth 51 facing teeth 51, as in Figure 5 In this case, during the closing process, the wheel-side shift claw and the axle-side shift claw 33, 35 first abut against each other with teeth 51 against teeth 51. From the time when teeth 51 against teeth 51 are abutted, the actuator 39 continues to adjust the clutch sleeve 38 within the overload travel until it reaches its closed position, more precisely, after the spring force F of the overload spring 41 is formed. F ( Figure 7 ), the spring force acts on the sliding claw 37. As soon as the tooth 51 faces the gap 53 through a small relative angle rotation and a small speed difference Δn between the two shaft sections 17, 19, the overload travel is exhausted and the spring force F of the overload spring 41 is released. F In the event of a reduction, the sliding claw 37 is suddenly connected to the fixing claw 36 in a form-locking manner.

[0024] Based on the above Figure 5 The described normal closing process takes place when the rotational speed n of the wheel-side shaft section 17 is Rad The speed n of the axle-side shaft section 19 achs The speed difference Δn between them is less than or equal to the theoretical value Δnsoll By way of example, the speed difference may be 10 revolutions per minute.

[0025] According to the following Figure 5 and Figure 6 A fault situation is described in which the damping element 45 according to the invention is used. soll ), the actuator 39 erroneously actuates the clutch sleeve 38 into its closed position. Since the speed difference Δn is too large, the shifting claws 33 and 35 cannot achieve a positive lock with each other. Instead, the sliding claw 37 is deflected by the deflection contour 55 ( Figure 7 ) rebound.

[0026] according to Figure 7 The deflection contour 55 is an oblique introduction side surface at the axial outer end of the claw recess 53 of the fixing claw 36. Figure 7 In the example, the rotational speed n of the wheel-side shaft section 17 is Rad is greater than the speed n of the axle-side shaft section 19 achs During this (practically impermissible) closing process, the shifting claw 33 of the sliding claw 37 comes into sliding contact with the oblique introduction side of the deflection contour 55, thereby generating an axial force component F acting on the sliding claw 37. ax ( Figure 7 In this way, an axial dynamic force is generated, by which the spring force F of the overload spring 41 is generated in the form of a rebound movement R in the opposite direction of the closing direction. F In the case of the sliding claw 37 being adjusted, the sliding claw 37 then springs back in the closing direction again until tooth 51 abuts against tooth 51 (that is to say against the tooth deflection contour 55 ), specifically when an impact S is applied to the fixing claw 36 .

[0027] During its rebound movement R, the sliding claw 37 strikes the damping element 45, thereby reducing the kinetic energy in the sliding claw 37 when the damping element 45 is plastically deformed. Accordingly, the sliding claw impact S in the closing direction acts with reduced impact energy on the fixed claw 36. Inadvertent closing of the claw coupling 21 due to excessive impact energy of the sliding claw 36 is thus prevented.

[0028] In contrast, without the damping element 36, in the above-mentioned fault situation, the sliding claw 37 is rebounded in an undamped manner by the annular shoulder 57 of the axle-side shaft section 19 and springs back from there in the closing direction with an excessive impact energy at a high initial speed and with a reduction in the spring force stored in the overload spring 41. Due to the excessive impact energy, there is a risk that the closing claw 37 will run over the deflection contour 55 of the fixing claw 36 and cause an unintentional form-locking engagement between the sliding claw 37 and the fixing claw 36.

[0029] exist Figure 8 and 9 In the embodiment, according to the first embodiment variant, the damping element 45 is constructed as a supporting element 49 by an annular angle plate. An elastomeric material is vulcanized on the angle plate as a damping body 47, which is subjected to a force load F( Figure 8 ) thereafter, the elastomeric material partially elastically recovers its original shape again.

[0030] Alternatively, in Fig.10 and 11 In the embodiment, the damping body 47 has a flexible hollow profile element 59, the cavity of which is filled with a damping material 61, for example, damping particles. The damping body 47 constructed in this way mainly undergoes plastic deformation, so that when subjected to a force load F( Fig.10 ) after which the damping body 47 still maintains its deformed state ( Fig.11 ).

[0031] List of Reference Numerals

[0032] 3Front axle differential

[0033] 5Front wheel

[0034] 7.9 Drive shaft of the front axle

[0035] 17 Axle section on the wheel side

[0036] 19 Axle section on the axle side

[0037] 21 claw coupling

[0038] 23 reduction gear

[0039] 25 External gear

[0040] 27 Axle bevel gear

[0041] 29 Differential bevel gear

[0042] 31 Differential housing

[0043] 33 Shift claw on axle side

[0044] 35 Shift claw on wheel side

[0045] 36 fixed claws

[0046] 37 Sliding claw

[0047] 38 coupling sleeve

[0048] 39 Actuator

[0049] 41 Overload Spring

[0050] 43 Sliding claw end side

[0051] 45 Damping element

[0052] 47 Damping body

[0053] 49 Support element

[0054] 51 teeth

[0055] 53 Gap

[0056] 55 Deflection Profile

[0057] 57 Circular Shoulder

[0058] 59Hollow Profile Components

[0059] 61 Damping material

[0060] Δn speed difference

[0061] Δn soll Theoretical value

[0062] n rad Speed ​​of the wheel-side shaft section 17

[0063] n achs Speed ​​of axle-side shaft section 19

[0064] R rebound movement

[0065] S-Shock

[0066] F ax Axial force component

[0067] F F Spring force

Claims

1. A coupling device, comprising two shaft sections (17, 19) which can be coupled by means of a claw coupling (21), the claw coupling having a sliding claw (37) which is arranged on one of the shaft sections (19) in a manner that is non-rotatable but axially displaceable relative to one another, wherein: Under certain operating conditions, in particular in the event of a fault, the sliding claw (37) is adjusted in a rebound movement (R) in a direction opposite to the closing direction, characterized in that a damping element (45) is provided for attenuating kinetic energy, in particular impact energy, and in the rebound movement (R) the sliding claw (37) impacts on the damping element.

2. The coupling device according to claim 1, characterized in that: The claw coupling (21) has a fixed claw (36) which is arranged on another shaft section (17) in a manner that cannot rotate relative to each other and preferably has a fixed axial position, and / or a sliding claw (37) can be adjusted to a closed position or an open position by means of a coupling sleeve (38) operated by an actuator, in particular an overload spring (41) is supported between the coupling sleeve (38) operated by the actuator and the sliding claw (37).

3. The coupling device according to claim 2, characterized in that: During the normal closing process, the actuator-operated coupling sleeve (38) first adjusts the sliding claw (37) in the axial direction with the overload spring (41) connected in the middle until the teeth (51) of the fixed claw (36) are in contact with each other. From the time when the teeth (51) are in contact with each other, the coupling sleeve (38) is further adjusted until it enters its closed position, specifically, when the overload spring force (F) acting axially on the claws (36, 37) is generated. F ) and especially once the speed difference (Δn ≤ Δn soll ) is small, the tooth (51) is established against the gap (53), so that the two claws (36, 37) are under the overload spring force (F F ) is reduced to achieve a positive locking connection.

4. The coupling device according to claim 2 or 3, characterized in that: The speed difference between the shaft sections (17, 19) is too large (Δn>Δn soll ), the coupling sleeve (38) is incorrectly adjusted to its closed position, so that the sliding claw (37) is in contact with the fixed claw (36) in a tooth (51)-to-tooth (51) manner, thereby generating an axial force, by which the sliding claw (37) is rebounded at the deflection contour (55) of the fixed claw (36) and adjusted axially in a rebound movement (R) in the direction opposite to the closing direction, and then rebounds again in the closing direction until the teeth (51) are in contact with the teeth (51), specifically when an impact (S) is applied to the fixed claw (36).

5. A coupling device according to any one of the preceding claims, characterized in that In order to attenuate the impact energy, the sliding claw (37) strikes the damping element (45), and / or the kinetic energy or impact energy in the sliding claw (37) is attenuated when the damping element (45) is plastically deformed, thereby preventing the claw coupling (21) from accidentally closing due to excessive impact energy of the sliding claw (37), especially in the event of a fault.

6. A coupling device according to any one of the preceding claims, characterized in that The sliding claw (37) extends annularly around the outer circumference of the first shaft section (19) and / or the sliding claw (37) can abut against the damping element (45) with its end side (43) facing away from the claws (33, 35).

7. A coupling device according to any one of the preceding claims, characterized in that The damping element (45) extends annularly around the outer circumference of the first shaft section (19).

8. A coupling device according to any one of the preceding claims, characterized in that The damping element (45) consists of an elastically and / or plastically deformable damping body (47) which is connected to a support element (49) which can be fastened to the first shaft section (19).

9. A coupling device according to any one of the preceding claims, characterized in that The damping element (45) or the damping body (47) is made of a rubber material or an elastomeric material, or the damping element (45) or the damping body (47) has a preferably flexible hollow profile element (59), the cavity of which is filled with a damping material (61), for example a damping gel or damping particles.

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