Torque converter with lock-up clutch and torque converter operating method
Torque converter arrangements and operating methods are provided herein. In one example, the torque converter includes a first attachment interface designed to rotationally couple to a prime mover and a second attachment interface designed to rotationally couple to a transmission. The torque converter further includes a lock-up clutch with an engagement spring embedded in an actuation piston, a plurality of separator plates supported by one or more guiding pins that extend through the plurality of separator plates and into a casing, and a plurality of friction plates interleaved with the plurality of separator plates, where the plurality of separator plates and friction plates are axially captured between the actuation piston and an end plate.
1. A torque converter, comprising:
a first attachment interface rotationally coupled to an input shaft and designed to rotationally couple to a prime mover;
an impeller rotationally coupled to the input shaft;
a second attachment interface designed to rotationally couple to a transmission; and
a lock-up clutch including:
an engagement spring embedded in an actuation piston, wherein an opening in the actuation piston circumferentially surrounds the engagement spring;
a seal circumferentially surrounding the actuation piston and sealing pressurized fluid in a cavity of a lock-up hub;
a plurality of separator plates supported by one or more guiding pins that extend through the plurality of separator plates and into a casing; and
a plurality of friction plates interleaved with the plurality of separator plates;
wherein the plurality of separator plates and the plurality of friction plates are axially captured between the actuation piston and an end plate; and
wherein the end plate is spaced away from a radially outer interior surface of the casing.
2. The torque converter of claim 1 , wherein the one or more guiding pins each extend axially through a corresponding opening in the plurality of separator plates and into a recess in a section of the casing.
3. The torque converter of claim 1 , wherein the engagement spring is positioned radially inward from the one or more guiding pins.
4. The torque converter of claim 1 , wherein radial ends of the plurality of separator plates are spaced away from the radially outer interior surface of the casing.
5. The torque converter of claim 4 , wherein the plurality of separator plates do not include splines that attach the casing to the plurality of separator plates.
6. The torque converter of claim 1 , wherein the engagement spring is a wave spring.
7. The torque converter of claim 1 , wherein the engagement spring is a disc spring.
8. The torque converter of claim 1 , further comprising a torsional damper positioned radially between the lock-up hub and a central shaft.
9. The torque converter of claim 1 , wherein the prime mover is an electric motor.
10. A method for operation of a torque converter, comprising:
selectively engaging a lock-up clutch in the torque converter, wherein the torque converter includes:
an input shaft rotationally coupled to an engine;
an output shaft coupled to a transmission;
an impeller rotationally coupled to the input shaft; and
a turbine rotationally coupled to the output shaft;
the lock-up clutch comprising:
an engagement spring embedded in an actuation piston;
a seal circumferentially surrounding the actuation piston and sealing pressurized fluid in a cavity of a lock-up hub;
a plurality of separator plates supported by one or more guiding pins that extend through the plurality of separator plates and into an end plate and a casing; and
a plurality of friction plates interleaved with the plurality of separator plates;
wherein the plurality of separator plates and the plurality of friction plates are axially captured between the actuation piston and the end plate;
wherein an opening in the actuation piston circumferentially surrounds the engagement spring; and
wherein the end plate is spaced away from a radially outer interior surface of the casing.
11. The method of claim 10 , wherein selectively engaging the lock-up clutch, includes engaging the lock-up clutch when a speed variance between the input shaft and the output shaft is smaller than a threshold value.
12. The method of claim 11 , wherein engaging the lock-up clutch includes moving the actuation piston to induce frictional engagement between the plurality of separator plates and friction plates and wherein the plurality of separator plates axial travel along the one or more guiding pins during lock-up clutch engagement.
13. The method of claim 11 , wherein during lock-up clutch engagement, the engagement spring reduces a sensitivity of a lock-up clutch filling.
14. The method of claim 11 , further comprising dampening vibration via a torsional damper included in the torque converter when the lock-up clutch is engaged.
15. The method of claim 10 , wherein the plurality of separator plates include outer radial ends that are spaced away from the radially outer interior surface of the casing and do not include splines that mate with the casing.
16. A torque converter, comprising:
an input attachment interface rotationally coupled to an input shaft and designed to rotationally couple to a flexplate or flywheel of an engine;
an output attachment interface rotationally coupled to an output shaft and designed to rotationally couple to a transmission;
a turbine rotationally coupled to the output shaft;
a lock-up clutch including:
an engagement spring embedded in an actuation piston;
a seal circumferentially surrounding the actuation piston and sealing pressurized fluid in a cavity of a lock-up hub;
a plurality of separator plates supported in a housing by one or more guiding pins that extend through the plurality of separator plates and into a casing and an end plate; and
a plurality of friction plates interleaved with the plurality of separator plates;
wherein the plurality of separator plates and the plurality of friction plates are axially captured between the actuation piston and the end plate;
wherein an opening in the actuation piston circumferentially surrounds the engagement spring; and
wherein the end plate is spaced away from a radially outer interior surface of the casing.
17. The torque converter of claim 16 , wherein the engagement spring is positioned radially inward from the one or more guiding pins and wherein radial ends of the plurality of separator plates are spaced away from the radially outer interior surface of the casing.
18. The torque converter of claim 16 , further comprising a torsional damper configured to dampen vibration and wherein the lock-up clutch is a hydraulically actuated wet clutch.
19. The torque converter of claim 16 , wherein the transmission is a powersplit transmission, a powershift transmission, or a hydrostatic transmission.
20. The torque converter of claim 16 , wherein the engagement spring is a wave spring or a disc spring.