Cycloidal gear unit and electric bicycle drive unit with cycloidal gear unit

Abstract

The present disclosure relates to a cycloidal gear (CG), an electric bicycle drive unit (DU) with cycloidal gear (CG), an axial freewheel device (FA) for the drive unit (DU), and a speed sensor device (TMS) for the drive unit. The cycloidal gear (CG) comprises a drive shaft assembly (DSD), an eccentric assembly (AE) and an output shaft assembly (SO), as well as at least one cycloidal disc assembly (DC1, DC2) with cycloidal gear arrangements (CT1, CT2) and at least one counter-cycloidal assembly (OC1, OC2) with counter-gear arrangements (OT1, OT2). In contact areas (CD1, CD2) of cycloidal disc device (DC1, DC2) and counter-cycloid device (OC1, OC2), drive forces (FD1, FD2) in the circumferential direction of the cycloidal gear (CG) can be transmitted by means of drive contact between cycloidal discs (PC1, PC2) of the cycloidal gear arrangements and counter-cycloidal (PO1, PO2) of the at least one counter-cycloid device (OC1, OC2) at least within a respective load flank sub-area (AL1, AL2). At least one of the cycloidal gear arrangements (CT1, CT2) and / or at least one of the counter-gear arrangements (OT1, OT2) has a relief contour (PR1, PR2) that is reduced in size along a relief area (AC1, AC2) arranged outside its load flank sub-area (AL1, AL2) of the respective contour (PC1, PC2, PO1, PO2) compared to the respective contour (PC1, PC2, PO1, PO2). This results in improvements to the cycloidal gear in terms of efficiency, heat and noise generation, wear and service life as well as manufacturing costs, while simultaneously reducing installation space and mass.

Claims

[1] Cycloidal gear (CG) for an electric bicycle drive unit (DU), the cycloidal gear (CG) comprising - a drive shaft device (DSD) with an eccentric arrangement (AE) and an output shaft device (SO), wherein the drive shaft device (DSD) and output shaft device (SO) are arranged concentrically to each other and to a central axis (AC) of the cycloidal gear (CG), - at least one cycloidal disk device (DC1, DC2) with together at least two at least approximately cycloidal or cylindrical cycloidal toothing arrangements (CT1, CT2) and - at least one counter-cycloid device (OC1, OC2) with at least two at least approximately cycloidal or cylindrical counter-toothing arrangements (OT1, OT2), wherein the at least one cycloid disk device (DC1, DC2) and the at least one counter-cycloid device (OC1, OC2) are arranged for a torque-transmitting positive mutual engagement, and wherein the at least one cycloidal disc device (DC1, DC2) and / or the at least one counter-cycloidal device (OC1, OC2) can be brought into an eccentric-cycloidal relative rolling movement (MC) relative to the central axis (MA) by means of a rotary drive by means of the eccentric arrangement (AE), by means of which, in contact areas (CD1, CD2), drive forces (FD1, FD2) can be transmitted in the circumferential direction of the cycloidal gear (CG) by means of drive contact between cycloid disk (PC1, PC2) of the cycloid toothing arrangements (CT1, CT2) of the at least one cycloid disk device (DC1, DC2) and counter-cycloid (PO1, PO2) of the counter-toothing arrangements (OT1, OT2) of the at least one counter-cycloid device (OC1, OC2) at least within a respective load flank partial area (AL1, AL2) of the respective contour (PC1, PC2, PO1, PO2) of the respective toothing arrangement, characterized by , that at least one of the cycloidal toothing arrangements (CT1, CT2) and / or at least one of the counter-toothing arrangements (OT1, OT2) has a free-cut contour (PR1, PR2) that is set back (PRS) relative to the contour (PC1, PC2, PO1, PO2) along a free-cut area (AC1, AC2) arranged outside the respective load flank partial area (AL1, AL2) of the respective contour (PC1, PC2, PO1, PO2) of the respective toothing arrangement (CT1, CT2, OT1, OT2). [2] Cycloidal gear (CG) according to claim 1, characterized by that the free-cut contour (PR1, PR2) forms a smooth transition at transitions to the contour (PC1, PC2, PO1, PO2) and / or at transitions to the load flank sub-areas (AL1, AL2). [3] Cycloidal gear (CG) according to claim 1 or 2, characterized by that an arc length of the free-cut contour (PR1, PR2), based on the arc length of the contour (PC1, PC2, PO1, PO2) is between 60% and 85%, particularly preferably between 65% and 80%. [4] Cycloidal gear (CG) according to one of claims 1 to 3, characterized by that the cycloidal gear (CG) is a single-disk or multi-disk cycloidal gear (CG) with one or more cycloidal disc devices (DC1, DC2) and with two counter-cycloidal devices (OC1, OC2). [5] Cycloidal gear (CG) according to one of claims 1 to 3, characterized by that the cycloidal gear is a Compur gear (CM) with at least one inner cycloid disk device (DCI), at least one outer cycloid disk device (DCO) and a cam disk (DI) as a counter cycloid device (OC1, OC2) between the (PC1, PC2) of the inner cycloid disk device (DCI) and the outer cycloid disk device (DCO) which rotates eccentrically in a form-fitting manner with the (PC1, PC2), wherein at least one of the inner cycloid disk device (DCI) and the outer cycloid disk device (DCO) is rotatable about the central axis (AD) of the cycloidal gear. [6] Cycloidal gear (CG) according to one of claims 1 to 3, characterized by that the cycloidal gear (CG) is a Cyclo-Acbar gear (CA) with at least two rotationally rigidly connected cycloid disk devices (DC1, DC2) and two counter-cycloid devices (OC1, OC2), wherein at least one of the counter-cycloid devices (OC1, OC2) is rotatable about the central axis (AD) of the cycloidal gear (CG). [7] Cycloidal gear (CG) according to one of claims 4 to 6, characterized by that one of the counter cycloid devices (OC1, OC2) forms a rotary output or drive of the cycloidal gear (CG) which is in engagement with a first cycloidal disc device (DC1, DC2), and the second counter cycloid device (OC2, OC1) forms a torque counter support (HDT) which is in engagement with the second cycloidal disc device (DC2, DC1) and is preferably connected to a housing (TH) of the cycloidal gear (CG). [8] Cycloidal gear (CG) according to one of claims 1 to 7, characterized by that contact areas (CD1, CD2) of at least one of the counter-toothing arrangements (OT1, OT2) comprise polymer material to increase the elasticity during torque transmission between the cycloid disk device (DC1, DC2) and the counter-cycloid device (OC1, OC2). [9] Electric bicycle drive unit (DU) for arrangement in a bottom bracket area of ​​a bicycle frame, the drive unit (DU) comprising - a bottom bracket spindle (SB) for mounting pedal cranks, - an electric motor device (MD) with a stator device (SD) and a rotor device (AR) arranged on a rotor shaft (SR), wherein the rotor shaft (SR) is arranged coaxially to the bottom bracket shaft, - a freewheel arrangement with at least one freewheel device (FA), - a sensor arrangement with at least one sensor device (SSP, STM, TS), - at least one electronic device (AP1, AP2) for controlling the motor device (MD) and / or for processing signals from the sensor device (SSP, STM, TS), - an output shaft (SO) for transmitting drive power to a bicycle drive train (TP), and - a transmission device (CG) with a cycloidal transmission (CG) according to one of claims 1 to 7 or according to the preamble of claim 1, characterized by that the cycloidal gear (CG) is at least liquid-tightly encapsulated relative to the motor device (MD). [10] Drive unit (DU) according to claim 9, characterized by that the cycloidal gear (CG) is encapsulated at least liquid-tight with respect to several or all of the motor device (MD), freewheel arrangement, sensor arrangement and electronic device (AP1, AP2). [11] Drive unit (DU) according to claim 9 or 10 or according to the preamble of claim 9, characterized bythat the rotor shaft (SR) is mounted exclusively in the cycloidal gear (CG), wherein the rotor device (AR) is arranged on the rotor shaft (SR) in the region of a flying end of the rotor shaft (SR). [12] Drive unit (DU) according to claim 11, characterized by that the gearbox-side end of the rotor shaft (SR) is mounted inside a gearbox output shaft (SO). [13] Drive unit (DU) according to one of claims 9 to 12 or according to the preamble of claim 9, characterized by an axial freewheel device (FA) with coupling elements (DR, CL, DO) for decoupling the output shaft (SO) from the transmission device (CG), wherein the axial freewheel device (FA) is essentially disc-shaped and is designed to transmit a transmission torque (TM2) through the coupling elements (DR, CL, DO) in the axial direction, relative to the bottom bracket shaft (SB). [14] Drive unit (DU) according to claim 13, characterized bythat at least one of the coupling elements (DR, CL, DO) of the axial freewheel device (FA) consists essentially of a polymer material. [15] Drive unit (DU) according to claim 13 or 14, characterized by that the axial freewheel device (FA) comprises a control device (RDD, RDC, DMN, FPP) for the active movement of at least one of the coupling elements (DR, CL, DO) depending on the direction of rotation. [16] Drive unit (DU) according to one of claims 9 to 15 or according to the preamble of claim 9, characterized by a speed sensor device (TMS) with a speed sensor element (STM) and a tachometer element (TE) connected to the bottom bracket shaft (SB) for contactless measurement of the speed of the bottom bracket shaft (SB), wherein the tachometer element (TE) and the speed sensor element (STM) are arranged on opposite sides of a wall (DA) of an output shaft section through which a transmission torque (TM2) of the drive unit (DU) can flow. [17] Drive unit (DU) according to one of claims 13 to 15 and according to claim 16, characterized by that the speedometer element (TE) is arranged in an inner area of ​​the axial freewheel device (FA). [18] Drive unit (DU) according to one of claims 9 to 17 or according to the preamble of claim 9, characterized by that one of the electronic devices (AP1, AP2) comprises at least two of the three sensor devices 1. speed sensor device (TMS) with a speed sensor element (STM) for measuring the speed of the bottom bracket shaft (SB), 2. torque sensor device with a torque sensor element (CC, TS) for measuring an elastic deformation of a deformation element (ED) of an output shaft section, and 3. speed sensor device with a speed sensor element (SSP) for measuring a speed of a bicycle wheel (WB). [19] Drive unit (DU) according to claim 18, characterized bythat the electronic device (AP1, AP2) comprises a circular ring-shaped or circular ring-segment-shaped circuit board device on which essentially all electronic assemblies and electronic components of the at least two sensor devices are arranged. [20] Axial freewheel device (FA) for a drive unit (DU) according to one of claims 9 to 19, characterized by Features of one of claims 9 to 19 relating to the axial freewheel device (FA). [21] Speed ​​sensor device (TMS) for a drive unit (DU) according to one of claims 9 to 19, characterized by features of one of claims 9 to 19 relating to the speed sensor device (TMS).

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