Abstract: An internal combustion engine with a torque converter for extending the temperature range of a hydraulic fluid allowing the function of the torque converter toward lower temperatures. A crankshaft is formed with an oil passage extending there along, an inlet hole for supplying a hydraulic fluid to the torque converter and an outlet hole for discharging the hydraulic fluid. The crankshaft includes a shaft bearing for supporting a rotating shaft for the torque converter. The inlet hole is provided at an axial end of the shaft bearing and contacts the shaft bearing. Flow resistance due to the shaft bearing can be greatly reduced to thereby allow a smooth supply of the hydraulic fluid into the torque converter. When the temperature of the hydraulic fluid is low and the viscosity of the hydraulic fluid is high, a quantity of oil at a certain pressure can be supplied to the torque converter.

Abstract: A vehicular transmission has a structure which enables a reverse idle gear to absorb and reduce excessive back torque inputted from drive wheels. At the time of reverse traveling motion, a counter shaft and a reverse gear are connected to each other through the intermediation of a clutch mechanism, whereby the power of the counter shaft is transmitted from the reverse gear, a driven gear, a hollow shaft, and a drive gear to the drive shaft by way of a final gear. When a large back torque is inputted to the final gear from the drive shaft, the inputted back torque is transmitted to the drive gear, and is then further transmitted to the driven gear by way of the hollow shaft. Since the hollow shaft is thin-walled and has reduced rigidity, it undergoes circumferential twisting due to the back torque inputted, whereby the back torque is reduced.

Abstract: In the transmissions of the background art, two larger-diameter gears are mounted on a final shaft thereby causing an increase in weight of the transmission. The present invention reduces the weight of a transmission by mounting only one larger-diameter gear on a final shaft.

Abstract: In the transmissions of the background art, two larger-diameter gears are mounted on a final shaft thereby causing an increase in weight of the transmission. The present invention reduces the weight of a transmission by mounting only one larger-diameter gear on a final shaft.

Abstract: An internal combustion engine with a hydraulically operated automatic transmission includes a crankcase that is divided on a plane perpendicular to a crankshaft and an outer face of the crankcase in a direction of the crankshaft is covered with a crankcase cover. A transmission gear ratio of the transmission is automatically changed over by control of oil pressures to remove a valve body for readily controlling oil pressures and for raising the accessibility of maintenance.

Abstract: To enhance productivity and maintainability of an internal combustion engine for a vehicle with a torque converter. An internal combustion engine with a torque converter includes a single feed pump for supplying both a working oil for a torque converter and a lubricating oil for the engine with an oil filter in communication with a discharge port of the feed pump being fitted to a crankcase cover. An outlet oil passage of the oil filter is branched into a low-pressure oil passage provided with an orifice and an oil passage for supplying a high-pressure control oil to changeover valves of a transmission. The high-pressure oil passage is provided concentratedly in the crankcase cover.

Abstract: A dry-sump lubrication unit for an internal combustion engine for a vehicle. A crankshaft of the vehicle is disposed so as to be parallel with the direction of travel of the vehicle, and in a position offset from a center of the vehicle when viewed from the front or back of the vehicle. A transmission shaft is disposed on the other side thereof. An oil tank is disposed in a crankcase located substantially at the lower center of the crankcase when viewed from the front or back of the vehicle on the rear side with respect to the traveling direction, and/or in a space between the crankcase and a rear case cover. Oil pumps are disposed forwardly of the oil tank. An oil injection pipe extends from the oil tank toward the side surface thereof on the transmission side. The resulting configuration prevents variations in liquid surface of lubricating oil of the vehicle internal combustion engine due to shaking of the vehicle body, and makes it possible to downsize the entire power unit.

Abstract: An automatic transmission in a power unit with a torque converter and a hydraulic clutch to be engaged and disengaged for the switching of speed-change gears. Hydraulic pressure is applied to the clutch and is increased only when operating the clutch during acceleration of a vehicle. A pressure control valve is provided at a discharge port of an oil pump for supplying hydraulic oil to the hydraulic clutch. The pressure control valve includes a valve body, a valve element is axially slidably provided in the valve body, and a spring is provided between the valve element and the valve body in a sliding direction of the valve element for adjusting a set pressure for opening/closing of the pressure control valve. The valve element is urged in its closing direction by a repulsive force applied to a stator in the torque converter.

Abstract: Many vehicles designed for running on rough terrain include an automatic transmission for performing speed change by connecting or disconnecting an oil hydraulic clutch provided alongside each speed change gear. However, depending on the posture of the driver, it may be impossible to step on the brake. As a result, it may be impossible to achieve creep prevention with a creep preventive mechanism dependent on a brake signal. Therefore, a creep preventive mechanism which operates independently from a brake signal is required. The present invention provides an oil pressure control system operating independently from a brake signal. The system includes an oil pressure supply source with a linear solenoid valve for supplying working oil or interrupting the supply of the working oil to the oil hydraulic clutches. The supply of the working oil to the clutches is interrupted when the vehicle is stopped under an idling condition of an engine.

Abstract: In an automatic transmission includes a main shaft and a counter shaft which are parallel to a crankshaft with the rotation of a torque converter on the crankshaft being transmitted to the main shaft through gears. A two-state speed change is conducted by gears provided on the main shaft and the counter shaft. An oil hydraulic clutch is operatively provided for connection and disconnection between the gear for reducing the spacing between the crankshaft and the transmission and to contrive a reduction in size of a power unit. A tubular auxiliary main shaft rotatable relative to the main shaft is provided at the outer circumference of the main shaft with a first-speed drive gear and a rearward-running drive gear are fixed on the auxiliary main shaft. First and second oil hydraulic clutches are provided for enabling contact and separation between the main shaft and the auxiliary main shaft.

Abstract: A compact transmission for an internal combustion engine in a saddle ride type vehicle for operating on wasteland that effectively utilizes space and enables members to be laid out freely. A transmission for internal combustion engine, includes a crankshaft disposed in parallel to the operating direction of a vehicle body. A forward-running/backward-running changeover mechanism is provided wherein the supply sources of a working oil and a lubricating oil for an automatic transmission are arranged concentratedly on the side of a front crankcase cover. The changeover mechanism is provided between a rear crankcase and a rear crankcase cover. A forward-running/backward-running changeover shift drum is disposed on the upper side of a plane containing the axis of a main shaft and the axis of a counter shaft of the transmission. One end portion of a shift spindle projects from the rear crankcase cover at a position on a lateral side of the shift drum.

Abstract: A hydraulic clutch and a torque converter, a crank web or an alternator provided in separate locations, except opposite positions, for avoiding interference. A crankcase is provided in a transmission for transmitting the revolution of the torque converter to a crankshaft to a main shaft via a gear. Shifting speed in three steps is achieved by a gear provided on the main shaft and a counter shaft and the hydraulic clutch for connecting or disconnecting the gear. One hydraulic clutch is arranged on a main shaft outside a pair of supports for supporting the main shaft, two gears are fixed to the main shaft inside the supports for supporting the main shaft and on both sides close to the support. The two gears engaged with the two gears and hydraulic clutches for connecting or disconnecting each gear are arranged between the two gears.

Abstract: In the transmissions of the background art, two larger-diameter gears are mounted on a final shaft thereby causing an increase in weight of the transmission. The present invention reduces the weight of a transmission by mounting only one larger-diameter gear on a final shaft.

Abstract: In an automatic transmission includes a main shaft and a counter shaft which are parallel to a crankshaft with the rotation of a torque converter on the crankshaft being transmitted to the main shaft through gears. A two-state speed change is conducted by gears provided on the main shaft and the counter shaft. An oil hydraulic clutch is operatively provided for connection and disconnection between the gear for reducing the spacing between the crankshaft and the transmission and to contrive a reduction in size of a power unit. A tubular auxiliary main shaft rotatable relative to the main shaft is provided at the outer circumference of the main shaft with a first-speed drive gear and a rearward-running drive gear are fixed on the auxiliary main shaft. First and second oil hydraulic clutches are provided for enabling contact and separation between the main shaft and the auxiliary main shaft.

Abstract: An automatic transmission in a power unit with a torque converter and a hydraulic clutch to be engaged and disengaged for the switching of speed-change gears. Hydraulic pressure is applied to the clutch and is increased only when operating the clutch during acceleration of a vehicle. A pressure control valve is provided at a discharge port of an oil pump for supplying hydraulic oil to the hydraulic clutch. The pressure control valve includes a valve body, a valve element is axially slidably provided in the valve body, and a spring is provided between the valve element and the valve body in a sliding direction of the valve element for adjusting a set pressure for opening/closing of the pressure control valve. The valve element is urged in its closing direction by a repulsive force applied to a stator in the torque converter.

Abstract: A compact transmission for an internal combustion engine in a saddle ride type vehicle for operating on wasteland that effectively utilizes space and enables members to be laid out freely. A transmission for internal combustion engine, includes a crankshaft disposed in parallel to the operating direction of a vehicle body. A forward-running/backward-running changeover mechanism is provided wherein the supply sources of a working oil and a lubricating oil for an automatic transmission are arranged concentratedly on the side of a front crankcase cover. The changeover mechanism is provided between a rear crankcase and a rear crankcase cover. A forward-running/backward-running changeover shift drum is disposed on the upper side of a plane containing the axis of a main shaft and the axis of a counter shaft of the transmission. One end portion of a shift spindle projects from the rear crankcase cover at a position on a lateral side of the shift drum.

Abstract: To enhance productivity and maintainability of an internal combustion engine for a vehicle with a torque converter. An internal combustion engine with a torque converter includes a single feed pump for supplying both a working oil for a torque converter and a lubricating oil for the engine with an oil filter in communication with a discharge port of the feed pump being fitted to a crankcase cover. An outlet oil passage of the oil filter is branched into a low-pressure oil passage provided with an orifice and an oil passage for supplying a high-pressure control oil to changeover valves of a transmission. The high-pressure oil passage is provided concentratedly in the crankcase cover.

Abstract: Supplying fluids different in pressure from one end of a revolving shaft without providing a diagonal hole in the revolving shaft for supply holes for feeding hydraulic fluid and lubricating oil. The time for manufacturing and the cost of providing a hydraulic fluid feeder to the revolving shaft is reduced. A hydraulic fluid feeder includes a central hole provided on the centerline of the revolving shaft. Hollow tubes having a smaller outside diameter than the inside diameter of the central hole are concentrically inserted into the central hole and the central hole is partitioned. Either of the passages formed by partitioning functions as a hydraulic fluid supply passage for the hydraulic equipment and the other functions as a hydraulic fluid supply passage for another piece of hydraulic equipment or a lubricating oil supply passage for a bearing provided on the revolving shaft.

Abstract: Many vehicles designed for running on rough terrain include an automatic transmission for performing speed change by connecting or disconnecting an oil hydraulic clutch provided alongside each speed change gear. However, depending on the posture of the driver, it may be impossible to step on the brake. As a result, it may be impossible to achieve creep prevention with a creep preventive mechanism dependent on a brake signal. Therefore, a creep preventive mechanism which operates independently from a brake signal is required. The present invention provides an oil pressure control system operating independently from a brake signal. The system includes an oil pressure supply source with a linear solenoid valve for supplying working oil or interrupting the supply of the working oil to the oil hydraulic clutches. The supply of the working oil to the clutches is interrupted when the vehicle is stopped under an idling condition of an engine.

Abstract: A hydraulic clutch and a torque converter, a crank web or an alternator provided in separate locations, except opposite positions, for avoiding interference. A crankcase is provided in a transmission for transmitting the revolution of the torque converter to a crankshaft to a main shaft via a gear. Shifting speed in three steps is achieved by a gear provided on the main shaft and a counter shaft and the hydraulic clutch for connecting or disconnecting the gear. One hydraulic clutch is arranged on a main shaft outside a pair of supports for supporting the main shaft, two gears are fixed to the main shaft inside the supports for supporting the main shaft and on both sides close to the support. The two gears engaged with the two gears and hydraulic clutches for connecting or disconnecting each gear are arranged between the two gears.