# US 10,118,624 B2 · Torque converter having variable pitch stator and bypass clutch

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- Number: US 10,118,624 B2
- Document ID: US10118624B2
- Status: Granted
- Kind: B2
- Application number: 15/044,136
- Filed: 2016-02-16
- Published: 2016-06-09
- Granted: 2018-11-06
- Earliest claimed: 2014-08-12
- Assignees: Ford Global Technologies, LLC
- Applicants: Ford Global Technologies, LLC
- Inventors: John Edward Brevick; Steven Anatole Frait; Vincent Patrick LaVoie; Norman Jerry Bird
- Web page: https://patentgrep.com/patent/US10118624B2

## CPC

- B60W 30/19: Improvement of gear change, e.g. by synchronisation or smoothing gear shift
- B60W 10/02: including control of driveline clutches
- B60W 10/10: including control of change-speed gearings
- F16D 48/08: Regulating clutch take-up on starting
- F16H 41/26: Shape of runner blades or channels with respect to function
- F16H 45/02: with mechanical clutches for bridging a fluid gearing of the hydrokinetic type (control of torque converter lock-up clutches F16H61/14)
- F16H 61/143: {using electric control means}
- F16H 61/56: to change the blade angle
- B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16H: GEARING

## Abstract

A transmission includes a torque converter with both a variable pitch stator and a bypass clutch. These are controlled in two modes to maintain a target slip speed. In a first mode, the bypass clutch is fully released and slip is controlled by varying the pitch of the stator blades. In a second mode, the stator is held in the tightest position and slip is controlled by varying the torque capacity of the bypass clutch. The target slip is calculated based on a variety of different input signals depending on what type of vehicle maneuver is being performed.

## Claims

### Claim 1

A transmission comprising:
a torque converter having an impeller, a turbine, a variable pitch stator, and a bypass clutch; and
a controller programmed to
in a first mode, adjust a bypass clutch torque capacity to maintain a target slip between the turbine and the impeller while maintaining the stator at a pitch setting corresponding to a tightest torque converter characteristic;
transition to a second mode in response to the torque capacity decreasing to zero;
in the second mode, adjust the stator pitch to maintain the target slip while maintaining the torque capacity at zero; and
return to the first mode in response to the stator pitch reaching the pitch setting.

### Claim 2 (depends on 1)

The transmission of claim 1 wherein the controller is further programmed to, during a vehicle launch event, compute the target slip based on a pedal position and a vehicle speed.

### Claim 3 (depends on 2)

The transmission of claim 2 wherein the target slip is further based on a manifold pressure.

### Claim 4 (depends on 2)

The transmission of claim 2 wherein the target slip is further based on an atmospheric pressure.

### Claim 5 (depends on 2)

The transmission of claim 2 wherein the target slip is further based on a road gradient.

### Claim 6 (depends on 2)

The transmission of claim 2 wherein the target slip is further based on a vehicle mass.

### Claim 7 (depends on 1)

The transmission of claim 1 wherein the controller is further programmed to, during a shift event, compute the target slip based on an engine torque.

### Claim 8 (depends on 7)

The transmission of claim 7 wherein the target slip is further based on an elapsed time.

### Claim 9 (depends on 1)

The transmission of claim 1 wherein the controller is further programmed to, during a torque reversal event, compute the target slip based on an engine torque.

### Claim 10

A method of controlling a transmission comprising:
repetitively measuring a slip speed between a turbine and an impeller;
while a stator pitch is in a fully tight condition, adjusting a torque capacity of a bypass clutch based on the slip speed; and
while the bypass clutch is fully disengaged, adjusting the stator pitch based on the slip speed.

### Claim 11 (depends on 10)

The method of claim 10 wherein adjusting the torque capacity of the bypass clutch and adjusting the stator pitch both comprise varying a current to a single solenoid.

### Claim 12 (depends on 10)

The method of claim 10 wherein adjusting the torque capacity of the bypass clutch comprises varying a first current to a first solenoid and adjusting the stator pitch comprises varying a second current to a second solenoid.

### Claim 13

A method of accelerating a vehicle comprising:
adjusting a stator pitch based on a target slip derived from a pedal position and a vehicle speed and on a measured slip between a turbine and an impeller while a bypass clutch is fully released; and
in response to the stator reaching a tightest condition, adjusting a torque capacity of the bypass clutch based on the target slip and the measured slip.

### Claim 14 (depends on 13)

The method of claim 13 wherein the target slip is further derived from a manifold pressure.

### Claim 15 (depends on 13)

The method of claim 13 wherein the target slip is further derived from an atmospheric pressure.

### Claim 16 (depends on 13)

The method of claim 13 wherein the target slip is further derived from a road gradient.

### Claim 17 (depends on 13)

The method of claim 13 wherein the target slip is further derived from a vehicle mass.