Transmission and hydraulic control system

Patent metadata

Field	Value
Publication number	US-9732847-B2
Application number	US-201414533213-A
Country	US
Kind code	B2
Filing date	Nov 5, 2014
Priority date	Jun 16, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A hydraulic control system for an automatic transmission with a torque converter includes two regulator valves controlled by a single variable force solenoid (VFS). A bypass clutch regulator valve increases the pressure to a bypass clutch apply chamber as the VFS pressure increases. A converter charge regulator valve decreases the pressure in a converter charge circuit as the VFS pressure increases. The converter charge circuit is in series with a lubrication circuit. An orifice restricts the flow through these circuits such that they can be supplied from the line pressure circuit rather than a lower priority circuit. In one embodiment, an on/off solenoid opens a flow control valve to bypass the orifice when additional flow is required. In another embodiment, an electric pump supplements the flow in these circuits when required. This later embodiment includes a switch valve such that the electric pump also supports stop/start operation.

First claim

What is claimed is:

1. A transmission comprising:
a first pump configured to provide fluid to a line pressure circuit in response to rotation of a transmission input shaft;
a second pump driven by an electric motor; and
a switch valve configured to direct fluid from the second pump alternately to only one of the line pressure circuit and a torque converter charge circuit, the choice based on an electric current to an on/off solenoid.

2. The transmission of claim 1 further comprising:
a torque converter defining a torque converter chamber; and
a first regulator valve configured to adjust a pressure in the torque converter charge circuit based on an electric current supplied to a first variable force solenoid wherein the torque converter charge circuit is in fluid communication with the torque converter chamber.

3. The transmission of claim 2 wherein the first regulator valve adjusts the pressure in the torque converter charge circuit by adjusting a size of a valve opening connecting the line pressure circuit to the torque converter charge circuit.

4. A transmission comprising:
a first pump driven by a transmission input shaft and configured to provide fluid to a line pressure circuit;
a second pump driven by an electric motor; and
a switch valve configured to direct fluid to the line pressure circuit in response to an electric current being less than a threshold and to a torque converter charge circuit in response to the electric current being greater than the threshold.

5. A transmission comprising:
a first pump configured to provide fluid to a line pressure circuit in response to rotation of a transmission input shaft;
a second pump driven by an electric motor;
a torque converter defining a torque converter chamber;
a switch valve configured to direct fluid from the second pump alternately, based on an electric current to an on/off solenoid, to either the line pressure circuit or to a torque converter charge circuit in fluid communication with the torque converter chamber;
a torque converter bypass clutch having an apply chamber;
a first regulator valve configured to adjust a pressure in the torque converter charge circuit based on an electric current supplied to a first variable force solenoid; and
a second regulator valve configured to adjust a pressure in a bypass clutch apply circuit in fluid communication with the bypass clutch apply chamber based on the electric current supplied to the first variable force solenoid.

6. The transmission of claim 5 further comprising:
a third regulator valve configured to adjust a pressure in the line pressure circuit based on an electric current supplied to a second variable force solenoid.

7. The transmission of claim 5 further comprising a lubrication circuit in series with the torque converter charge circuit wherein the lubrication circuit is in fluid communication with a balance chamber of the bypass clutch.

Assignees

• Ford Global Tech Llc

Inventors

• Frait Steven Anatole

Classifications

• F16H2306/00

  Shifting · CPC title

• F16H61/14 Primary

  Control of torque converter lock-up clutches · CPC title

• F16H61/0021

  Generation or control of line pressure · CPC title

• F16H41/30

  relating to venting, lubrication, cooling, circulation of the cooling medium · CPC title

• F16H57/0434

  relating to lubrication supply, e.g. pumps; Pressure control · CPC title