AUTOMOTIVE POWER DRIVE ARRANGEMENT

Abstract: The present power drive arrangement is mounted on the frame of a rear wheel drive car to replace the usual drive shaft extending from the transmission to the differential on the rear axle. It includes a speed change device (10) having step-up gearing between an input shaft (21) and an output shaft (35) extending coaxially behind the input shaft. The input shaft (21) of the speed change device is connected to the output of the transmission (13) through a universal joint (20). The output shaft (35) of the speed change device (10) is connected through a second universal joint (39) to the front end of a drive shaft (40) whose rear end is connected to the input of the differential (14) through a third universal joint (41).

Description: ■ 1 - AUTOMOTIVE POWER DRIVE ARRANGEMENT TECHNICAL FIELD This invention rela-ces to a fuel saving power drive arrangement to replace the usual drive shaft between the transmission and the differential of a rear wheel drive automotive vehicle, particularly a passenger car. BACKGROUND OF THE INVENTION There is a critical need to save fuel since the oil resources of the world are diminishing and fuel costs are increasing rapidly. * SUMMARY OF THE INVENTION In accordance with the present invention, a speed • change device having step-up gearing is supported from the frame of the vehicle directly behind the transmission. The speed change device has a rotary input shaft coupled to the output of the transmission and a rotatable output shaft located coaxially behind the input shaft. A drive shaft behind the speed change device couples the latter's output shaft to the input of the diff rential. The step-up gear- ing in the speed change device causes the input to the dif¬ ferential to be at a substantially higher rotational speed than the output from the transmission. Appreciable fuel savings result from this arrangement. A principal object of this invention is to provide a novel fuel saving power drive arrangement for an automotive vehicle having a conventional rear wheel drive. Another object of this invention is to provide such a Λ CMΠ -2- power drive arrangement which may be substituted for the usual drive shaft extending from the transmission to the differential on a rear wheel drive automotive vehicle. Further objects and advantages of this invention will be apparent from the following detailed description of a presently preferred embodiment thereof, shown in the accom¬ panying drawing. DESCRIPTION OF THE DRAWING Figure 1 is a bottom view of the present power drive arrangement installed between the transmission and the differential on a passenger car; Figure 2 is a side elevation taken along the line 2—2 in Figure 1; Figure 3 is a front end view of the speed change de- vice in this power drive arrangement, taken along the line 3—3 in Figure 1; Figure 4 is a horizontal longitudinal section through the speed change device ? Figure 5 is a cross-section taken along the line 5—5 in Figure 4; and Figure 6 is a cross-section taken along the line 6—6 in Figure 4. DETAILED DESCRIPTION Referring to Figure 1, the frame of the automobile has opposite longitudinal side members 11 and 12 extending generally horizontally from front to back. The usual trans¬ mission 13, which may be either a manual or an automatic transmission, is located toward the front of the vehicle midway between its opposite sides. The usual differential 14 is on the rear axle midway between the rear wheels. In the usual rear wheel drive vehicle, a long drive shaft ex¬ tends from the transmission 13 back to the differential 14 to impart the drive from the transmission to the differen¬ tial. In accordance with the present invention, a speed change device 10 and a shorter drive shaft 40 are interposed between the transmission 13 and the differential 14 to provide a speed step-up between them, so that the input -3- speed to the differential will be substantially greater than the output speed of the transmission. The speed chan device 10 and drive shaft 40 may be connected as shown after first removing the usual long drive shaft extending 5 from the transmission 13 to the differential 14 on an exis ing car. The housing of the speed change device 10 is bol to intersecting, obliquely disposed, horizontal I-beams 15 and 16 whose opposite ends are bolted to the side members 11 and 12 of the frame of the vehicle. The front of the 0 speed change device 10 is in close proximity to the rear end of the transmission 13. As best seen in Figure 2, the rotary output shaft 19 of the transmission is connected through a universal joint 20 to the input shaft 21 of the speed change device 10. 5 Both of these shafts are horizontal and extend longitudina of the vehicle along its centerline. Referring to Figure 4, the input shaft 21 extends rea ward ' into the speed change .device through a seal .22 carrie by the bolted-on front plate 23 of the housing of the spee 0 change device. This front plate at the inside carries an anti-friction bearing 24 which rotatably supports the inpu shaft 21. The housing has an internal transverse wall 25 which carries another anti-friction bearing 26 rotatably supporting the inner end of the input shaft 21. Between 5 the two bearings 24 and 26 the input shaft 21 carries an input gear 27. A rotatable intermediate shaft 28 extends parallel to the input shaft 21 inside the housing of the speed change device 10. The intermediate shaft is rotatably supported 0 at its opposite ends by anti-friction bearings 29 and 30 which are mounted respectively on the inside of the front wall 23 and the bolted-on back wall 31 of the housing of t speed change device. Shaft 28 carries a first intermediat gear 32 which meshes with the input gear 27 and is smaller 5 than the input gear, so that the intermediate shaft 28 wil be rotated at a higher speed than the input shaft 21. Just inside the back wall 31 of the housing the inter- -4- mediate shaft 28 carries a second intermediate gear 33 which meshes with a smaller output gear 34. The output. gear is mounted on an output shaft 35 which extends coaxially behind the input shaft 21. The output shaft is rotatably supported by anti-friction bearings 36 and 37 which are carried re¬ spectively by the internal wall 25 and the back wall 31 of the housing of the speed change device. Because of the gear ratio between gears 33 and 34, the output shaft 35 rotates at a substantially higher speed than the intermediate shaft 28. All four gears 27, 32, 33 and 34 in the speed change device 10 are spur gears. The interior of the housing is filled with a suitable lubricant through an opening in the side of the housing which is normally closed by a screw- threaded plug 45 (Figure 6) . A similar drain plug 46 on the bottom of the housing may be removed to drain the lubri¬ cant from the housing. The output shaft 35 of the speed change device 10 ex¬ tends through a seal 38 carried by the back wall 31 of the housing, and behind the housing it is connected through a universal joint 39 to the front end of the relatively short drive shaft 40 (Figures 1 and 2) . The rear end of this drive shaft is connected through a universal joint 41 to the input of the differential 14. As shown in Figure 4, the output shaft 35 carries a bevel gear 42 directly behind the housing back wall 31. This bevel gear meshes with a smaller bevel gear 43 on the end of a flexible cable 44 which leads to a tachometer (not shown) on the dashboard of the vehicle. It will be understood that the unitary assembly of the speed change device 10, supporting beams 15 and 16, and the short drive shaft 40 may be installed on a previously used automobile after first removing the original long drive shaft which extends from the transmission to the differential. After this has been done, the speed change device 10 may be connected to the transmission output shaft 19 by the universal joint 20 and the drive shaft 40 may be -5- connected to the differential by the universal joint 41. The speed change device 10 is mounted on the frame of the automobile by the cross beams 15 and 16 which carry it. Because the input and output shafts 21 and 35 of the speed change device 10 are aligned with each other, there is no problem of aligning the transmission output shaft 19 with the short drive shaft 40 and the input to the differential 14. ' For a given speed of the transmission output shaft 19, a substantially higher speed is imparted to the input of the differential 14 because of the step-up gearing in the speed change device 10. At some reduction in the torque delivered to the rear wheels of the vehicle, the speed step-up in the present power drive arrangement produces a remarkable decrease in the engine's fuel consumption per mile of vehicle travel. This is extremely advantageous fro the standpoint of energy conservation. While somewhat re¬ duced, the vehicle's acceleration is acceptable under typical driving conditions, both in stop-and-go city traffi and on the highway.

Claims: -6- I CLAIM: 1. For use on an automotive vehicle having a frame, and a rear wheel drive including a differential on the rear axle and a transmission spaced forward from the differentia a power drive arrangement which comprises: a speed change device having a rotary input shaft at the front, a rotary output shaft at the rear coaxial with said input shaft, step- up gearing acting between said input and out- put shafts to drive said output shaft from said input shaft at a substantially higher speed than the input shaft, and " a housing ro¬ tatably supporting said input and output shafts and enclosing said gearing; rigid support members carrying said housing of the speed change device and attachable to the frame of the vehicle to position said speed change device closely behind he transmission; coupling means for connecting said input shaft of the speed change device to the output of the transmissio ; a drive shaft extending rearward from the speed change device to the differential; coupling means for connecting the front end of said drive shaft to the output shaft of said speed change device; and coupling means for connecting the rear end of said drive shaft to the input of the differ- ential. -7- 2. A power drive arrangement according to claim 1, .wherein each of said coupling means is a universal joint: 3. A power drive arrangement according to claim 1, wherein said step-up gearing comprises: an input gear on said input shaft; an intermediate shaft mounted for rotation paralle 5 to said input and output shafts; a first intermediate gear fastened to said inter¬ mediate shaft and meshing with said input gear, said first intermediate gear being smaller in diameter than said input gear; 10 a second intermediate gear fastened to said inter¬ mediate shaft and meshing with said output gear, said second intermediate gear being larger in diameter than said output gear. 4. A power drive arrangement according to claim 3, wherein each of said coupling means is a universal joint. 5. A power drive arrangement according to claim 1, wherein said support members extending laterally outward from said speed change device and have outer ends which are attachable to longitudinal side members of the frame of the 5 vehicle. 6. A power drive arrangement according to claim 5, wherein said step-up gearing comprises: an input gear on said input shaft; an intermediate shaft mounted for rotation par- 5 allel to said input and output shafts; a first intermediate gear fastened to said inter¬ mediate shaft and meshing with said input gear, said first intermediate gear being smaller in diameter than said input gear; 0 a second intermediate gear fastened to said inter¬ mediate shaft and meshing with said output -8- gear, said second intermediate gear being larger in diameter than said output gear. 7. A power drive arrangement according to claim 6, wherein each of said coupling means is a universal joint. - ' ^ --^.

Inventors: AIDAR NORBERT
Applicants: ACT INVESTMENT & DEV CORP
Application year: 1981
Main classification: F16H3
IPC codes: B60K17, F16H1