02 Tour Inside Torque Converter

[Music] the torque converter is mounted on the input side of the automatic transmission it takes the place of the clutch found on standard shift vehicles the transmission bail housing is bolted to the rear of the engine block you one end of the torque converter is bolted to the engine flex plate to transfer power to the transmission the combined mass of a torque converter and flex disc acts like a flywheel to smooth out the power pulses produced by the engine the flexplate also allows for a slight alignment tolerance between the engine and torque converter assembly the pilot hub at the front of the torque converter fits into a recess in the crankshaft so they will be centered to each other the converter should fit tightly into the crankshaft but still seed fully and turn freely a test fit between the two components is a good idea before installing the transmission the other end of the torque converter is used to drive the transmission oil pump the torque converter is filled with automatic transmission fluid and transmits the engine torque to the transmission you oil pump body provides support for the torque converter stator shaft the torque converter transmits the engine torque to the driving devices clutches through the turbine shaft by engaging the clutch torque is transmitted to planetary gear sets the major components of the torque converter are impeller turbine stator and lock-up clutch [Music] [Music] the converter housing with the impeller is attached to the flex plate that is bolted to the engine crankshaft in its simplest form a single-stage torque converter has three elements the impeller the turbine and stator all three have angled or curved vanes and are separated from each other by thrust bearings [Music] [Music] the impeller is integrated with the torque converter case and many curved vanes that are radially mounted inside a guide ring is installed on the inn of the veins to provide a path for smooth fluid flow the impeller hub is used to drive the transmission oil pump Hiller is driven by the engine crankshaft the fluid in the impeller rotates with it when the impeller speed increases centrifugal force causes the fluid to flow outward toward the turbine [Music] [Music] the turbine is located inside the converter case but is not connected to it the turbine is similar in construction to the impeller but with more veins and with a greater curvature the direction of curvature of the turbine vanes is opposite to that of the impeller vanes the turbine is fitted with a torus or guide ring this helps to secure the vanes in position it also reduces turbulence at the center to improve efficiency the hump of the turbine is spline so that it can drive a turbine shaft the turbine shaft transfers engine torque to the transmission gearing when the fluid coming from the impeller rotates the turbine the turbine shaft also rotates [Music] the stator has a small set of curved blades attached to a central hub and is positioned between the impeller and the turbine the veins of the stator catch the fluid as it leaves the turbine vanes and redirects it so that it strikes the back of impeller vanes giving the impeller an added boost or torque the central hump is mounted on a one-way clutch spline to a state of support shaft and fixed to the transmission case [Music] [Music] the central hub is mounted on a one-way clutch you the one-way clutch allows the stator to rotate only in the same direction as the impeller and locks the stator in the opposite direction you therefore the stator is rotated or locked depending on the direction from which the fluid strikes against the vanes [Music] [Music] State Fair locking action is produced by using either a roller or a Spragg one-way clutch you in the roller type one-way clutch the inner race is splined to the stator support the outer race has wedge-shaped segments which remain the rollers in each segment a wave compression spring pushes each roller towards the narrow end of the wedge you a force on the stator blades against engine rotation locks the outer race onto the rollers which between the two races turning the stator with the engine rotation eases the wedging and the stator rotates with the impeller and turbine you in the Spragg type one-way clutch the inner race has a central spline it locates on the stator support shaft to hold the race stationary the outer race is part of a stator hub it turns with the stator in the direction of engine rotation equally spaced prax between the two races produce a wedging action to stop the stator rotating in Reverse the sprags are held in place by a spring-loaded gauge the one-way action is produced by the different radii of the sprags and the curvature at their outer edges this gradually increases from the shorter radius to the larger when the stator is turned against engine rotation at pivots thus prax towards the larger radius and wedges them between the two races locking them together when the effort to the stator is reversed the ridges pivot towards the smaller radius and the outer race collides freely over them in the direction of engine rotation you torque converter stall is when the turbine is held stationary while the converter housing and impeller are spinning the impeller is driven by the engine and turns at crankshaft speed centrifugal force throws fluid between the impeller vanes outward surround the back of the guide ring in a forward direction engine accelerates higher impeller speed discharges the fluid across and against the turbine vanes with greater force this exerts a turning effort against the back of the turbine vanes which absorbs energy in the fluid causing the turbine to rotate the stator redirects the fluid it reenters the impeller in the same direction as impeller rotation the secret of torque multiplication lies in the use of stator the job of the stator is to intercept the oil thrown off by the turbine and redirect the path of this oil so it will enter the pump smoothly torque multiplication exists only when there is a difference in speed between the impeller and the turbine the magnitude of torque multiplication depends unload when the turbine is stalled it has a maximum value of about 2.2 to 1 this multiplication tapers off as the turbine commences to turn and increases in speed this subjects that fluid in the turbine passages to centrifugal force which slows down the circulation between impeller and turbine when turbine speed reaches around nine of impeller speed torque multiplication Falls to zero torque transfer from impeller to turbine is then about one-to-one this is known as the coupling point at coupling point fluid flow from the turbine veins is relatively low but it is at high speed in the direction of rotation the rapidly turning turbine discharges its fluid against the back of the stator blades this force unlocks the stator and all three elements rotate as one unit unlocking the stator prevents turbulence in the fluid and any braking effect on the engine lock up clutches engaged just after coupling phase the impeller causes the fluid to flow to the and transfers torque through the fluid medium and then passes the stator and back to the impeller but there are times when this flow is quicker and more powerful than at other times and there are times when this flow is almost non-existent centrifugal force causes circular flow stator changes direction of flow to multiply to work opposing centrifugal forces stop circular fluid flow stator free wheels and no torque multiplication of fluid flow within the converter one is vortex flow and the other is rotary flow Hillar carries the fluid with it inside the converter casing that fluid is rotating around the axis of the converter this is known as the rotary flow at the same time centrifugal force moves the fluid outwards away from the converter axis during torque multiplication the shape of the converter case makes the fluid flow in a circular motion through the impeller turbine and stator this is known as the vortex flow combining these two fluid flows produces a progressive circular or spiraling motion this is known as the spiral flow in a lock-up converter the impeller and turbine are locked together when conditions are suitable to provide a one-to-one Drive from the engine to the transmission turbine shaft a lock-up clutch eliminates slippage between the impeller and turbine during the coupling phase and helps to reduce the heat generated in the fluid and improves fuel mileage the parts of lock-up clutch assembly our converter cover clutch plates apply piston clutch hub and backplate you the converter cover holds all other clutch components you use plastic hammer to free play piston from converter cover the piston is made of steel with the seal ring groups around the outer and inner diameter the piston is operated hydraulically it moves axially in front cover convened cover the inner clutch disks friction disks are spline to lock up clutch hub and the outer clutch disks steel discs are spline to mount to front cover use a straightedge to check that the outer and inner clutch discs are flat and not distorted you use a feeler gauge to measure the play between the last inner clutch disc and the end disc the splines on the outside of the lockup clutch hub which connected with turbine hub mate with the splines on the inner plates you lockup torque converter may use a damper assembly to dampen torsional vibration the damper assembly is made of several coil springs designed into the piston plate or clutch disc or clutch hub to transmit driving torque and absorb shock you pressure to apply the lock-up clutch enters between pissed front cover through the center of the turbine shaft [Music] [Music]

Channel: Kansow Vehicle Engineering

Views: 42,250

Keywords: Torque Converter, محول العزم, lockup clutch, automatic transmission, الفتيس الاتوماتيك

Id: GQTYMMlRZ84

Length: 18min 7sec (1087 seconds)

Published: Mon Jun 03 2019