Europäisches Patentamt *EP000722402B1* (19) European Patent Office Office européen des brevets (11) EP 0 722 402 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.7: B62M 13/00, B62M 19/00, of the grant of the patent: F16D 33/00 02.01.2002 Bulletin 2002/01 (86) International application number: (21) Application number: 94930652.6 PCT/US94/11395 (22) Date of filing: 07.10.1994 (87) International publication number: WO 95/10443 (20.04.1995 Gazette 1995/17) (54) FLUID COUPLING FOR SMALL ENGINE WITH DIRECT WHEEL DRIVE FLÜSSIGKEITSKUPPLUNG FÜR KLEINE MASCHINE MIT DIREKTANTRIEB COUPLEUR HYDRAULIQUE POUR PETIT MOTEUR A ENTRAINEMENT DIRECT DE ROUE (84) Designated Contracting States: (72) Inventor: WITTHAUS, Charles, Allison AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL Hayward, CA 94545 (US) PT SE (74) Representative: Morgan, James Garnet et al (30) Priority: 13.10.1993 US 136440 Manitz, Finsterwald & Partner GbR Martin-Greif-Strasse 1 (43) Date of publication of application: 80336 München (DE) 24.07.1996 Bulletin 1996/30 (56) References cited: (73) Proprietor: PATMONT MOTOR WERKS, INC. US-A- 2 139 107 US-A- 2 294 994 Pleasanton, CA 94566 (US) US-A- 3 339 659 US-A- 4 821 832 Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 0 722 402 B1 Printed by Jouve, 75001 PARIS (FR) 1 EP 0 722 402 B1 2 Description attached eccentrically mounted toroidal plug for causing helical rotation of fluid about the plug. A turbine mates [0001] This invention relates to a fluid coupling or to the pump and includes rotating vanes within the other torque converter for a small engine which finds use with half of the toroidal path, these vanes being shaped a direct wheel drive. The fluid coupling of this invention 5 around the toroidal plug of the pump. The toroidal plug can be mounted in a cantilevered support from a small and toroidal volumes are eccentrically mounted one with engine to directly drive the rear wheel of a small scooter respect to another to cause high velocity flow on the out- or alternately to a beam type support in which the out- side diameter of the pump and turbine with low velocity board bearing of the fluid coupler is supported from a flow in the inside diameter of the pump and turbine. Flu- strut, such as a plate reinforcing gas tank mounting. 10 id, typically oil, is confined to the pump and turbine by appropriate seals and causes torque conversion be- BACKGROUND OF THE INVENTION tween the pump and turbine. In the preferred embodi- ment, a fuel tank for the engine is mounted overlying the [0002] In U.S. Patent 4,821,832 entitled MOTOR driven wheel so as to shield the interface of the wheel SCOOTER HAVING A FOLDABLE HANDLE AND 15 and driving spindle. At the same time, the exterior of the FRICTION DRIVE of Steven J. Patmont Issued April 18, driven pump is supplied with vanes to generate appro- 1989, there is disclosed a hydraulic fluid coupling or priate air cooling at the fluid coupling. A preferred em- torque converter. This fluid coupling includes an inner bodiment is disclosed wherein the mount of the fluid motor driven shaft, an outer wheel driving shaft, and a coupler includes a bearing on the outboard end of the fluid couple between the driven and driving shafts for 20 fluid coupler. producing in a motor scooter a fluid drive. From US-A-2 294 994 a combination according to the BRIEF DESCRIPTION OF THE DRAWINGS preamble of claim 1 is known. This document shows a fluid drive for motorcycles. This known fluid drive is pro- [0007] vided with a driven shaft being connected to the engine 25 of the motorcycle wherein a pump wheel of a fluid cou- Fig. 1 is a perspective elevation of a scooter having pling is connected to the output shaft. The fluid coupling the drive of this invention at the rear wheel; further comprises a turbine wheel which is coupled Fig. 2 is a an expanded perspective section of the through a hydraulic fluid with the pump wheel and which fluid coupling illustrating the engine and fluid cou- is connected to an outer driving shaft coupled to the rear 30 pling suspended with respect to the driven wheel, wheel of the motorcycle. the scooter chassis and wheel axle being omitted; [0003] In what follows, an improvement on this com- Fig. 3 is an exploded view of the fluid coupling rel- bination is disclosed. ative to the engine from which the fluid coupling is [0004] Known fluid couplings, particularly torque con- mounted; verters, have been utilized in all kinds of machinery, es- 35 Fig. 4 is a side elevation section of the pump, turbine pecially automobiles. With these torque converters, it is and pump cover; common to include, a driven shaft, a pump, a turbine, Fig. 5 is a perspective disassembled view taken and a driving shaft. Commonly, these units are aligned with the axis of the assembled fluid coupling folded serially one behind another. Thus, the entire power path disclosing the relative locations of the respective from the engine to the driven part of the engine con- 40 assembled parts of the fluid coupling; sumes a considerable linear distance needed for the flu- Fig. 6 is a perspective view of an assembled scooter id coupling between the serially aligned driven and driv- at the driving wheel showing the fluid coupler with ing paths. a gas tank covering the coupler; Fig. 7 is a perspective view of the gas tank removed SUMMARY OF THE INVENTION 45 and the fluid coupler reinforced by a bearing at- tached to a plate; and, [0005] The invention is defined by claim 1. Fig. 8 is a perspective view of the plate removed [0006] A fluid coupling is disclosed for the direct drive from the fluid coupler illustrating location of a bear- of a wheel from a small engine. The fluid coupling is ing at the distal end of the coupler from the motor. mounted in cantilevered support or two ended bearing 50 support from a small engine and has a small diameter DESCRIPTION OF THE PREFERRED EMBODIMENT inner driven shaft and a larger diameter out wheel driv- ing shaft for contacting and directly driving a wheel. The [0008] Referring to Figs. 1 and 2, fluid coupling C is inner driven shaft connects to a pump having a relatively disclosed for the direct drive of wheel W from a small larger outer diameter than either the driven or driving 55 engine E. The fluid coupling is mounted in cantilevered shaft. This pump is mounted on the opposite side of the support from small engine E, Fig.1 showing the engine driven wheel from the engine and preferably includes and rear end of the scooter and Fig. 2 showing wheel rotating vanes within one half a toroidal path having an and engine alone. 2 3 EP 0 722 402 B1 4 [0009] Referring to the exploded view of Fig. 3, fluid pler remote from engine E. coupling C has a small diameter inner driven shaft 14 and larger diameter outer wheel driving shaft 16 for con- tacting and directly driving wheel W. Inner driven shaft Claims 14 connects to pump 18 having a relatively larger outer 5 diameter than either the driven shaft 14 or driving shaft 1. In combination a wheel (W) to be driven, a frame 16. Such connection occurs by bolt 15 threading to driv- mounting said wheel (W) to be driven for rotation en shaft 14. Further, it can be seen that regular ball bear- about an axis, an engine (E), said engine (E) mount- ing 17 and needle bearings 19 provide the necessary ed to said frame and having an output shaft sub- rotating bearings to assure transfer of the rotation. 10 stantially parallel to the axis of rotation of said wheel [0010] Referring back briefly to Figs. 1 and 2, it can (W), and, a fluid coupling (C) connecting said wheel be seen this pump 18 is mounted on the opposite side (W) to be driven and said engine (E), said fluid cou- of the driven wheel W from engine E. pling (C) comprising in combination: [0011] Referring to Fig. 5, it can be seen that pump 15 18 includes rotating vanes VP within one half a toroidal an inner driven shaft (14) connected to said en- path having an attached eccentrically mounted toroidal gine (E) on one side of said wheel (W) to be plug P for causing helical rotation of fluid about the plug. driven; Turbine T mates to pump 18 and includes rotating vanes a pump (18) connected to said driven shaft (14) VT within the other half of the toroidal path, these vanes and rotating with said driven shaft (14); being shaped around the toroidal plug P of the pump. 20 fluid communicated to said pump (18) for re- [0012] Referring to the section of Fig. 4, toroidal plug ceiving rotational energy from said engine (E); P and toroidal volumes between vanes VP and VT are an outer and wheel driving shaft (16) concen- eccentrically mounted one with respect to one another.