Automatic fluid draining from a hydraulic system component of an automatic transmission
First Claim
1. A hydraulic system of an automatic transmission for draining fluid from a portion of the hydraulic system, comprising:
- a fluid source for supplying fluid to the system;
an oil cooler through which hydraulic fluid flows;
a circuit hydraulically connecting the fluid source to the oil cooler;
a reservoir for containing fluid at relatively low pressure; and
a valve hydraulically connected by the circuit to the oil cooler, the fluid source and the reservoir, the valve having a first state at which a hydraulic connection through the valve between the fluid source and the reservoir is closed, and a hydraulic connection between the oil cooler and the reservoir is open, and a second state at which a hydraulic connection through the valve between the oil cooler and the fluid source is open.
2 Assignments
0 Petitions
Accused Products
Abstract
In a hydraulic system for an automatic transmission, a method for automatically draining fluid from an oil cooler and related hydraulic lines when power is off to prevent fluid leakage, escape and outflow when they are disconnected from the system. A control system includes a source of relatively high pressure when power is on, an oil cooler, fluid circuit lines for supplying transmission oil to the cooler, a source of low pressure for containing fluid, such as an oil sump, and a valve hydraulically connected to the circuit, high pressure source, and low pressure source, the valve having a first state at which a hydraulic connection through the valve between the circuit and the source of low pressure is closed when power is on, and a second state at which a hydraulic connection through the valve between the circuit and the low pressure source is open when power is off.
21 Citations
12 Claims
-
1. A hydraulic system of an automatic transmission for draining fluid from a portion of the hydraulic system, comprising:
-
a fluid source for supplying fluid to the system;
an oil cooler through which hydraulic fluid flows;
a circuit hydraulically connecting the fluid source to the oil cooler;
a reservoir for containing fluid at relatively low pressure; and
a valve hydraulically connected by the circuit to the oil cooler, the fluid source and the reservoir, the valve having a first state at which a hydraulic connection through the valve between the fluid source and the reservoir is closed, and a hydraulic connection between the oil cooler and the reservoir is open, and a second state at which a hydraulic connection through the valve between the oil cooler and the fluid source is open. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A hydraulic system for an automatic transmission of a motor vehicle having a power source, for draining fluid from a component hydraulically connected to the system, comprising:
-
a fluid source supplying pressurized fluid to the system when the power source is operating;
a reservoir located at a first elevation, for containing fluid at relatively low pressure;
an oil cooler located at a higher elevation than the first elevation;
a circuit hydraulically connecting the fluid source to the cooler; and
a valve hydraulically connected by the circuit to the cooler, the fluid source, and the reservoir, the valve having a first state at which first state a hydraulic connection through the valve between the fluid source and the reservoir is closed, and a hydraulic connection between the oil cooler and the reservoir is open, and a second state at which second state a hydraulic connection through the valve between the cooler and the fluid source is open. - View Dependent Claims (8, 9, 10, 11, 12)
-
Specification