# US 2017/0284533 A1 · Drive unit with an electromotive power unit and a transmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0284533 A1 - Document ID: US20170284533A1 - Status: Published application - Kind: A1 - Application number: 15/476,451 - Filed: 2017-03-31 - Published: 2017-10-05 - Earliest claimed: 2016-03-31 - Assignees: Schaeffler Technologies AG & Co. KG - Applicants: Schaeffler Technologies AG & Co. KG - Inventors: Thorsten BIERMANN; Philipp STORNER; Robert SCHIECK - Web page: https://patentgrep.com/patent/US20170284533A1 ## CPC - F16H 57/029: characterised by means for sealing the gearboxes, e.g. to improve airtightness - B60K 1/00: Arrangement or mounting of electrical propulsion units (B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00) - B60K 17/165: {provided between independent half axles (B60K17/18, B60K17/20 take precedence)} - B60K 17/354: having separate mechanical assemblies for transmitting drive to the front or to the rear wheels or set of wheels - F16J 15/3204: with at least one lip - H02K 5/124: Sealing of shafts - H02K 7/116: with gears - B60K 2001/001: {one motor mounted on a propulsion axle for rotating right and left wheels of this axle} - B60Y 2200/90: Vehicles comprising electric prime movers - B60Y 2400/73: Planetary gearings - F16H 1/46: Systems consisting of a plurality of gear trains each with orbital gears, {i.e. systems having three or more central gears} - F16H 2057/02034: {Gearboxes combined or connected with electric machines} - F16H: GEARING - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES - F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY ## Abstract A drive unit includes a housing having first and second chambers. An electromotive drive is disposed in the first chamber and including a hollow rotor shaft. A transmission is disposed in the second chamber and includes an output shaft extending through the rotor shaft such that a gap is formed. The transmission further includes a gearing arrangement that operably couples the output shaft to the rotor shaft and reduces a speed ratio between the rotor shaft and the output shaft so that the output shaft rotates slower than the rotor shaft when operating. The gearing arrangement includes a first element fixed to the rotor shaft and a second element that rotates slower than the first element when operating. An annular clearance is defined between the first and second elements. An annular seal has a first portion engaging with the first element and a second portion engaging with the second element. ## Claims ### Claim 1 A drive unit comprising: an electromotive drive including a rotor shaft defining an axis; a transmission including: a first planetary gear set supported for rotation about the axis and having a first input element coupled to the rotor shaft and a first output element operably coupled to the first input element such that a rotational speed of the first output element is slower than the first input element when the first planetary gear set is rotating, a second planetary gear set supported for rotation about the axis and having a second input element coupled to the first output element and a second output element operably coupled to the second input element such that a rotational speed of the second output element is slower than the second input element when the second planetary gear set is rotating, and an output shaft supported for rotation about the axis and operably coupled to the second output element; and a seal disposed between the first input element and the output shaft and having a first portion engaging with the first input element and a second portion engaging with one of the first output element and the second input element. ### Claim 2 (depends on 1) The drive unit of claim 1, wherein the second portion of the seal engages with the second input element. ### Claim 3 (depends on 1) The drive unit of claim 1, wherein the first and second input elements are sun gears, and the first and second output elements are planet carriers. ### Claim 4 (depends on 1) The drive unit of claim 1, wherein the first input element, the second input element, and the first output element are arranged such that an annular clearance is defined between the first input element and the second input element and between the first input element and the first output element, and wherein a gap is formed between the rotor shaft and the output shaft, and wherein the seal blocks a fluid path between the clearance and the gap to prevent fluid from entering into the gap. ### Claim 5 (depends on 1) The drive unit of claim 1, wherein the second input element defines a sealing surface and the seal is seated on the sealing surface. ### Claim 6 (depends on 1) The drive unit of claim 1, wherein the first input element is fixed to the rotor shaft, and the first output element is fixed to the second input element. ### Claim 7 (depends on 1) The drive unit of claim 1, wherein the first portion of the seal is fixed to the first input element. ### Claim 8 (depends on 1) The drive unit of claim 1 further comprising a second seal having a first portion engaging the output shaft and a second portion engaging the second input element. ### Claim 9 (depends on 8) The drive unit of claim 8, wherein the second seal is seated in the second input element. ### Claim 10 (depends on 8) The drive unit of claim 8, wherein the seal and the second seal are coaxial and are supported for rotation about the axis. ### Claim 11 (depends on 1) The drive unit of claim 1, wherein the first portion of the seal is seated in the first input element. ### Claim 12 (depends on 1) The drive unit of claim 1 further comprising a second seal engaging between the rotor shaft and the first input element. ### Claim 13 (depends on 1) The drive unit of claim 1 further comprising a differential operably coupled to the second output element and including a gear fixed to the output shaft. ### Claim 14 A drive unit comprising: a housing having an interior and a radially extending wall that divides the interior into a first chamber and a second chamber; an electromotive drive disposed in the first chamber and including a rotor shaft defining an axis, wherein the rotor shaft is hollow and defines a bore; a transmission disposed in the second chamber and including an output shaft extending through the bore such that a gap is defined between the bore and the output shaft, the transmission further including a gearing arrangement that operably couples the output shaft to the rotor shaft and reduces a speed ratio between the rotor shaft and the output shaft so that the output shaft rotates slower than the rotor shaft when operating, wherein the gearing arrangement includes a first element fixed to the rotor shaft and a second element that rotates slower than the first element when operating, wherein an annular clearance is defined between the first element and the second element and concentric with the axis; and an annular seal supported for rotation about the axis and having a first portion engaging with the first element and a second portion engaging with the second element to inhibit fluid flow between the gap and the annular clearance. ### Claim 15 (depends on 14) The drive unit of claim 14 further comprising a second seal supported for rotation about the axis and having a first portion engaging with a third element of the gearing arrangement and a second portion engaging with the output shaft to prevent fluid flow between first chamber and the second chamber. ### Claim 16 (depends on 15) The drive unit of claim 15, wherein the output shaft rotates slower than the third element. ### Claim 17 (depends on 14) The drive unit of claim 14, wherein the gearing arrangement is at least one planetary gear set. ### Claim 18 (depends on 17) The drive unit of claim 17, wherein the first element is a sun gear and the second element is a planet carrier, and the first and second elements are part of a same planetary gear set.