Abstract: In a change-speed gearing unit including an extension housing formed at its rear end portion with an upright projection located in the upper opening of the housing, and a shift-and-select lever shaft slidably and rotatably supported at its rear end portion by an axial bearing hole in the upright projection, a lubricating device comprises a pair of laterally upright walls formed on the rear end portion of the housing between both faces of the upright projection and both opposed inner walls of the upper opening portion of the housing to form an oil well in open communication with the axial bearing hole, the oil well being supplied with lubricating oil picked up by the rearmost gears of the change-speed gearing unit.

Abstract: A gear-teeth protector for a change-speed gearing unit in which a pair of upper and lower change-speed gears of high meshing rate and arranged adjacent to an upright wall in a housing for the gearing unit. The gear-teeth protector comprises a shroud plate secured to the upright wall at one side of the change-speed gears to enclose the meshing engagement portion of the gears in forward operation of the gearing unit, the shroud plate being in the form of a side wall extending adjacent to the lower teeth portion of the upper change-speed gear and to the upper teeth portion of the lower change-speed gear.

Abstract: A lubrication mechanism in a change-speed gearing unit in which an oil transfer trough is suspended in a fore-and-aft direction at one side of the inner wall of an extension housing secured at its front end to a transmission casing. The trough is fixed at its front end to the upper portion of the extension housing in such a way as to open toward the upper interior space of the transmission casing and fixed at its rear end to the rear portion of the side wall of the extension housing by means of a hollow bush of elastic material which is pressedly mounted within an axial groove in the rear portion of the side wall of the extension housing. The hollow bush is formed with a closed tubular portion coupled over the rear end of the trough and an outlet portion laterally extending from the tubular portion and opening toward the interior space above an oil well in the extension housing.

Abstract: A fastening arrangement for removably securing a gear or hub to a shaft by means of a spring wire clip which clip includes a curved portion formed by radially and circumferentially bending an intermediate portion of the clip for resilient engagement with an axial groove formed in a central bore of the gear, a pair of loop portions extending from opposite ends of the curved intermediate portion and arranged to be fitted around the shaft for engagement with either side surface of the gear, and a pair of detent pin portions formed by radially inwardly bending the end of each of the loop portions for engagement with a pair of radial holes formed in the shaft.

Abstract: A die-cast transmission extension housing has an outer peripheral wall or whell and an integral bearing supporting partition wall provided transversely of the longitudinal axis of the shell between the open forward end and the closed rear end thereof. The partition wall supports at least a bearing for the transmission output shaft extending through the open forward end, the bearing on the partition wall and the closed end. The inner surfaces of the shell forwardly of the rear surface of the partition diverge to the open end of the shell so that the inner space defined by these inner surfaces and the partition can be moulded by a die-casting mould part which is slidable out of the inner space through the open end of the shell after the extension housing is die-cast. The upper wall of the extension housing is formed therein with an upper opening adapted to be closed by a shift lever retainer.

Abstract: A gear structure for a manual transmission for an automobile which has a shaft rotatably supported in a transmission case, a clutch hub rotatable with the shaft and having a spline on its outer periphery, a clutch hub sleeve splinedly engaged with the spline of the clutch hub and movable in its axial direction by shifting operation of the transmission, a speed change gear freely rotatably mounted on the shaft and having a boss contacting the clutch hub and a gear spline formed independently of the speed change gear and fixed on the boss of the speed change gear. The gear spline has spline teeth on its outer periphery, and the clutch hub sleeve is splinedly engageable with the gear spline upon the shifting operation of the transmission.

Abstract: A device for supporting a shift lever in a manual transmission for an automobile which includes the shift lever having a large spherical portion and a small spherical portion, a shift lever retainer supporting the large spherical portion of the shift lever, a resin bush having a cylindrical outer surface spherically engaging with the small spherical portion of the shift lever and a shift lever housing fixed to an operation lever shaft extending toward the transmission. The device comprises a cylindrical vibration preventing bush interposed between the cylindrical outer surface of the resin bush and the inner surface of a hole in the shift lever housing.

Abstract: A synchro-mesh type gear transmission includes a clutch hub rigidly mounted on an output power shaft. The clutch hub is provided with axial slots in which springs are axially inserted. The springs urge a synchronizer ring against a conically tapered surface of a driven shift gear which is mounted on the output power shaft so as to be rotatable. Thus, the synchronizer ring exerts a frictional resistance against rotation of the driven shift gear. A cylindrical sleeve is rigidly inserted in each of the guide slots. Each spring is inserted in a respective cylindrical sleeve so as to be prevented from being deformed in the direction in which the synchronizer ring rotates. A guide rod may be inserted in the cylindrical coil spring disposed in the cylindrical sleeve as a further support against deformation.

Abstract: A roller bearing assembly including a surface of a shaft serving as an inner race for rolling bodies, the surface having a diameter smaller than the outer diameter of a gear formed integrally with the shaft, a cylindrical outer race of a larger inner diameter than the outer diameter of the gear, and a cage for the rolling bodies composed of two halves formed by splitting the cage radially of the shaft, whereby the gear of a small outer diameter can be formed integrally with the shaft of a large diameter to thereby increase the rigidity of the shaft.

Abstract: A synchro-mesh type gear transmission includes a clutch hub rigidly mounted on an output power shaft. The clutch hub is provided with axial slots in which springs are axially inserted. The springs urge at least one synchronizer ring against a conically tapered surface of a driven shaft gear which is mounted on the output power shaft so as to be rotatable. The synchronizer ring exerts frictional resistance against rotation of the driven shift gear. At least a portion of the inner wall of each guide slot is located in a spline-toothed flange portion of the clutch hub. The inner wall portion of the guide slot which is in the flange portion provides an additional guide for the spring. The spring is thereby prevented from being deformed in the direction in which the synchronizer ring rotates.

Abstract: A power transmission unit comprises a transmission casing shaped to conform with a change-speed gearing contained therein, the change-speed gearing including an output mainshaft rotatably supported from the rear end wall of the casing, and an extension housing secured in a fluid-tight manner to the rear end wall of the casing to form a lubricant chamber in open communication with the interior of the casing through the upper portion of the wall. In the transmission unit, an oil flow control device is provided in the bottom wall of the transmission casing to transfer lubricating oil into and from the lubricant chamber.

Abstract: A reverse shift mechanism for a power transmission unit comprises a plurality of fork shafts slidably supported from a transmission casing in parallel with each other to be shifted by an operator's shift lever, a shift head fixed to one of the fork shafts, a shift arm rotatably supported by the shift head at its intermediate portion and being pivoted at its lower end on a portion of the transmission casing, and a shift fork slidably mounted on another one of the fork shafts and being rotatably supported by the upper end of the shift arm, the shift fork receiving thereon a reverse idler gear to shift it toward and away from a reverse drive gear and a reverse output gear.

Abstract: The counter shaft of a constant-meshed type manual transmission is fixed at both its ends in the transmission casing, with a counter gear member formed as a hollow shaft being rotatably supported at both its ends upon the counter shaft through ball bearings at one end and through needle roller bearings at its opposite end. The invention is particularly directed to the means whereby the inner and outer races of the ball bearings are mounted between adjacent ends of the counter shaft and counter gear member.

Abstract: There is disclosed a fixing device for a speed meter driven gear which comprises a sleeve attached to a transmission casing or an extension housing thereof in an automobile, a rotary shaft rotatably disposed within the sleeve, and a speed meter driven gear fixedly mounted on part of the rotary shaft in a manner to be maintained in meshing relation to a speed meter drive gear of an output shaft. A resilient clip is secured to the aforesaid rotary shaft and sleeve, so as to restrain the axial directional movement of the rotary shaft within the sleeve.A slit is provided in the aforesaid sleeve, and an annular groove is provided in the aforesaid rotary shaft in a manner to correspond with the slit, so that a locking portion of the aforesaid resilient clip may be locked in the slit and annular groove, and a retaining portion thereof is resiliently retained by the aforesaid sleeve.