Drive device
By designing the flywheel as a multifunctional component, which serves both as vibration isolation and position detection, the problem of difficult position detection caused by the small rotational inertia of the vibration damping device in the drive unit is solved, thus achieving accurate output shaft position detection and a simplified position detection device design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SCHAEFFLER TECHNOLOGIES AG & CO KG
- Filing Date
- 2025-10-13
- Publication Date
- 2026-05-12
AI Technical Summary
In existing drive devices, the small rotational inertia of the vibration damping device leads to the encoder disk being designed with a thin and light structure, making it difficult to accurately detect the output shaft position and affecting the accuracy of ignition timing and fuel injection control.
The flywheel is designed as a multifunctional component, serving both as vibration isolation and as part of a position detection device. By setting an incremental sensor detection structure on the flywheel, precise positioning of the output shaft position can be achieved.
It achieves precise positioning of the output shaft with a simple structure, improves vibration isolation, and simplifies the design of the position detection device.
Smart Images
Figure CN122014809A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a drive device, comprising at least one drive unit having an output shaft and a drive shaft connected to the output shaft via a vibration damping device, wherein the vibration damping device comprises a housing housing an arc spring assembly comprising a plurality of arc springs, the housing being connected to the drive shaft via a hub flange, the vibration damping device further comprising a flange connected to the arc springs, the flange being connected to one end of the output shaft, wherein an additional mass in the form of a flywheel is disposed at the other end of the output shaft. Background Technology
[0002] DE102017127525A1 discloses such a drive unit, which is presented in the form of a hybrid drive unit. In motor vehicles, for example, those having a hybrid drive unit comprising an internal combustion engine and an electric motor, there is a need to transmit torque, particularly generated by the internal combustion engine, to the transmission in a low-vibration manner. This process is achieved by means of a torque transmission device, which can be implemented as a damping device or includes such a device, specifically capable of damping the sometimes vibrating torque provided by the internal combustion engine to the drive shaft leading to the transmission. This damping device includes an input section and an output section, which can be relatively restricted to rotation under the opposite force to an energy storage device constructed as an arc spring acting circumferentially, absorbing kinetic energy and retransmitting it to the transmission system in the process. This damping device can also be implemented as a conventional dual-mass flywheel, including a primary section with a corresponding arc spring, the primary section being threadedly connected to the output shaft of the drive unit (e.g., the crankshaft of the internal combustion engine). The secondary section is connected to the drive shaft (i.e., the transmission input shaft) via a corresponding anti-torsional connection (usually a hub). Alternatively, as disclosed in DE102017127525A1, a damping device called a "reverse damper" can be used, in which the primary and secondary sections are structurally or arranged in opposite ways. In this design, the housing that houses the arc spring is the secondary section, which is connected to the drive shaft via a hub flange. The primary section, connected to the output shaft (e.g., crankshaft), is implemented as a simple flange, which is connected to the arc spring via a corresponding drive mechanism. As disclosed in DE102017127525A1, to balance the relatively small moment of inertia of the damping device implemented as a "reverse damper" or its primary section, and to improve the vibration isolation effect of the output shaft (e.g., crankshaft), a flywheel is non-rotatingly mounted on the other side of the output shaft.
[0003] Furthermore, it is known that the position of the output shaft (i.e., the crankshaft) needs to be determined in order to obtain the ignition timing based on measurements. This value is also incorporated into fuel injection control and other parameters that allow for optimized operation of the internal combustion engine. For this purpose, the crankshaft position must be accurately detected, as the crankshaft position indirectly reflects the position of each piston. This allows the control device to determine when the first cylinder is at top dead center, thereby accurately determining the ignition timing and firing order. This necessitates a position detection device, typically implemented as an incremental encoder. An incremental encoder usually includes an encoder gear with a correspondingly large diameter connected to the crankshaft, and a suitable incremental sensor. The incremental sensor is fixed in position and scans the encoder gear rotating past it. The encoder gear is typically implemented as a correspondingly large disk, i.e., with a correspondingly large diameter. However, because the moment of inertia of the encoder disk is large compared to the small moment of inertia of the damping device, this encoder disk, connected to the damping device implemented as a "reverse damper," can only adopt a thin structure or be designed with a very small diameter. Summary of the Invention
[0004] Therefore, the technical problem to be solved by the present invention is to provide an improved driving device compared to the present invention.
[0005] To solve the above-mentioned technical problems, according to the present invention, the following technical solution is proposed in the drive device of the above type: the flywheel is part of a position detection device for detecting the rotational position of the output shaft.
[0006] According to the present invention, the flywheel, used to improve vibration isolation, is also used as a multifunctional component in the position detection device; that is, the flywheel is also part of the position detection device. On the one hand, the size of the flywheel is designed according to the vibration damping device, meaning its weight is adjusted accordingly. On the other hand, the flywheel is fixedly connected to the output shaft (e.g., the crankshaft of an internal combustion engine) without relative rotation, so the flywheel rotates with the output shaft, and the flywheel is arranged at the corresponding end of the output shaft, which is typically located outside the housing of the drive unit (i.e., the internal combustion engine); therefore, the flywheel is also necessarily located outside the housing. This design allows the flywheel to be utilized as part of the position detection device, thus giving the flywheel a dual function. This design, on the one hand, applies the vibration damping device designed as a "reverse damper" in a simple manner, and on the other hand, realizes a position detection device with a simple construction.
[0007] The flywheel itself preferably has a structure that can be detected by a sensor element that can be positioned by a position detection device. This sensor element (i.e., an incremental sensor) detects the corresponding structure and provides a corresponding sensor signal, which is evaluated for position detection.
[0008] The structure itself is preferably designed as protrusions and / or recesses equidistantly arranged around the flywheel circumference, i.e., designed as a three-dimensional geometry that is easily identifiable by incremental sensors.
[0009] For example, the structure can be implemented as a toothed form, meaning the outer circumference of the flywheel has radial teeth and the incremental encoder detects the teeth and tooth clearances rotating past it. Alternatively, the structure can also be implemented as a series of through holes, for example, on an axially oriented annular flange. It is conceivable that the structure can also be implemented as axially extending fingers, which initially extend radially during flywheel manufacturing and are subsequently bent axially. Both the through-hole and finger structures produce a "hole pattern" that is easily recognized by the incremental sensor.
[0010] At least one drive unit is typically an internal combustion engine (Brennkraftmaschine), i.e., a combustion engine (Verbrennungsmotor).
[0011] Alternatively, the drive unit can be designed as a hybrid drive unit, comprising another drive unit in the form of an electric motor, wherein a clutch device is provided, through which the internal combustion engine can be reversibly connected to the drive shaft. In such a hybrid drive unit, the torque transmitted to the transmission can be provided solely by the electric motor, solely by the internal combustion engine, or both. The internal combustion engine can be reversibly engaged or disengaged via the clutch device depending on whether it is running. For example, to start the internal combustion engine via the electric motor (through the corresponding engagement of the clutch device) or similar purposes, the electric motor can be fixedly connected to the drive shaft. It is well known that the structure of such a hybrid drive unit can be designed in various ways. Attached Figure Description
[0012] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. The accompanying drawings are schematic diagrams, in which:
[0013] Figure 1 A schematic diagram of the driving device designed according to the present invention;
[0014] Figure 2 : Figure 1 A detailed schematic diagram of the driving device structure. Detailed Implementation
[0015] Figure 1 A schematic diagram of a drive unit 1 according to the present invention is shown. The drive unit 1 includes a drive unit in the form of an internal combustion engine 2 (i.e., a multi-cylinder engine). The internal combustion engine 2 has an output shaft 3 (i.e., a crankshaft), one end of which is connected to a vibration damping device 4, which includes a primary portion 5 and a secondary portion 6. (The following is a continuation of the previous paragraph.) Figure 2As described, the primary portion 5 is implemented as a simple flange, while the secondary portion 6 is implemented as a housing with a hub flange housing an arc spring assembly. The primary portion 5 is fixedly connected to the output shaft 3, and the secondary portion 6 is connected to the drive shaft 7. A flywheel 8 is provided on the other side of the internal combustion engine 2 (i.e., the other end of the output shaft 3). The flywheel 8 is part of a position detection device 9, which further includes a sensor element 10 in the form of an incremental sensor 10. The sensor element 10 is communicatively connected to a control device 11, through which the operation of the internal combustion engine 2 is controlled.
[0016] In addition, an electric motor 12 is provided, which includes a rotor and a stator. In the illustrated example, the electric motor 12 is fixedly connected to the transmission 13. The rotor is also connected to the drive shaft 7 so that the torque of the rotor can be transmitted to and from the drive shaft 7 to the transmission 13. The transmission 13 is finally connected to the drive shaft 14. That is, the drive unit 1 is implemented as a hybrid drive unit.
[0017] Through a disengagement clutch 15, the internal combustion engine 2 can be connected to or disconnected from the drive shaft 7 as needed, so that the torque generated by the internal combustion engine can be transmitted to or not transmitted to the drive shaft 7 as needed.
[0018] Figure 2 An enlarged view of the vibration damping device 4 is shown. The figure shows a primary mass 5 implemented as a simple flange, with an inner flange section 16 connected to one end face of the output shaft 3 via a suitable threaded connector 17. The primary mass 5 has multiple radially protruding drive portions 18, which engage between arc springs 19. The other ends of the arc springs 19 are supported on corresponding support sections of the housing 20 of the secondary mass 6, wherein the housing 20 is a multi-part structure. The housing 20 includes a cover 21 on one side and a hub flange 22 on the other. The hub flange 22 extends radially inward and has a toothed hub 23 that meshes with the teeth 24 of the drive shaft 5. The torque generated by the output shaft 3 (i.e., the crankshaft of the internal combustion engine 2 in this embodiment) is directly transmitted to the primary mass 5 (i.e., the flange), which transmits the torque to the elastic arc spring assembly via the engagement of the drive portions 18. The arc spring assembly then dampens the torque and transmits it to the secondary mass 6.
[0019] A flywheel 8 is mounted at the other end of the output shaft 3. The flywheel 8 has a structure 25, which is in the form of radial teeth 26. The radial teeth 26 are mounted adjacent to a fixedly mounted sensor element 10 (i.e., an incremental encoder). The incremental encoder detects the teeth 26 rotating past it and provides sensor signals by continuously detecting the teeth and tooth gaps. The control device 11 processes these sensor signals to accurately determine the working position of the output shaft 3.
[0020] The flywheel 8 is designed to have a relatively small diameter and light weight to match the small moment of inertia of the primary mass 5. The flywheel 8 serves to isolate the torsional vibration of the output shaft 3. Simultaneously, the flywheel 8, due to its structure 25 (here, teeth 26) for position detection, also functions as part of the position detection device 9.
[0021] In addition to the teeth 26, the structure 25 can also adopt other design forms, such as being designed as axially bent, circumferentially equidistant fingers so that the fingers and gaps can be detected by the sensor element 10, or being designed as a similar structure.
[0022] List of reference numerals
[0023] 1. Drive unit
[0024] 2. Internal Combustion Engine
[0025] 3 Output shaft
[0026] 4 Vibration damping device
[0027] 5. Primary Quality
[0028] 6 Secondary quality
[0029] 7 drive shafts
[0030] 8 Flywheel
[0031] 9. Position detection device
[0032] 10 Sensor Components
[0033] 11 Control device
[0034] 12 Electric motors
[0035] 13. Transmission
[0036] 14 drive shafts
[0037] 15 Disengage the clutch
[0038] 16 Flange Section
[0039] 17 Threaded fasteners
[0040] 18. Driving Department
[0041] 19. Curved Spring
[0042] 20. Housing
[0043] 21. Cover
[0044] 22 Wheel hub flange
[0045] 23-inch wheels
[0046] 24 teeth
[0047] 25 Structure
[0048] 26 teeth
Claims
1. A drive device comprising at least one drive unit having an output shaft (3) and a drive shaft (5) connected to the output shaft (3) via a vibration damping device (4), wherein, The vibration damping device (4) has a housing (20) that houses an arc spring assembly including a plurality of arc springs (18). The housing (20) is connected to the drive shaft (5) via a hub flange (22). The vibration damping device (4) also has a flange connected to the arc springs (18) and the flange is connected to one end of the output shaft (3). An additional mass in the form of a flywheel (8) is disposed at the other end of the output shaft (3). The flywheel (8) is part of a position detection device (9) for detecting the rotational position of the output shaft (3).
2. The driving device according to claim 1, characterized in that, The flywheel (8) has a structure (25) that can be detected by a sensor element (10) of the position detection device (9) whose position is fixedly set.
3. The driving device according to claim 2, characterized in that, The structure (25) is implemented as circumferentially equidistant protrusions and / or recesses surrounding the flywheel (8).
4. The driving device according to claim 3, characterized in that, The structure (25) is implemented in the form of teeth (26), through holes, or axially extending fingers.
5. The driving device according to any one of the preceding claims, characterized in that, The at least one drive unit is an internal combustion engine (2).
6. The driving device according to any one of the preceding claims, characterized in that, The drive unit is a hybrid drive unit, which includes another drive unit in the form of an electric motor (12), wherein a clutch device (15) is provided, and the internal combustion engine (2) can be reversibly connected to the drive shaft (5) through the clutch device (15).