Transmission control system

• US 4,209,985 A
• Filed: 12/11/1978
• Issued: 07/01/1980
• Est. Priority Date: 12/11/1978
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Americas Company (Caterpillar Incorporated)
• Inventors: Master, Ralph E.
• Primary Examiner(s): Geoghegan, Edgar W.
• Application Number:
  US05/973,047
• Time in Patent Office: 568 Days
• Field of Search: 60/337, 60/357, 60/358, 60/456, 60/DIG. 5, 60/361, 60/494
• US Class Current: 60/337
• CPC Class Codes: F16H 41/30 relating to venting, lubrication, cooling, circulation of the cooling medium
• CPC Class Codes: Y10S 60/912 Cooling means

Abstract

A transmission control system (10) for a transmission including a torque converter (66) has fluid inlet and fluid outlet passages (64,80) connected to the torque converter (66), a pressure regulating valve (20) for relieving fluid from a pressure source (12,16) to the inlet passage (64) of the torque converter (66), and a flow limiting passage (96) directly connecting the inlet and outlet passages (64,80) for continually bypassing fluid past the torque converter (66) and controlling the pressure drop thereacross.

Claims

1. In a transmission control system (10) for a transmission including a torque converter (66), and of the type having fluid inlet and outlet passages (64,80) leading respectively to and from the torque converter (66), a source of fluid pressure (16), and a pressure regulating valve (20) for relieving fluid from the source (16) at a preselected pressure to the fluid inlet passage (64), the improvement comprising:

a flow limiting passage (96) directly connecting said fluid inlet and outlet passages (64,80) to said torque converter (66).

2. The transmission control system (10) of claim 1 wherein said torque converter (66) includes a turbine element (74), a rotary shaft (76) connected to the turbine element (74), and a tubular member (72) surrounding the rotary shaft (76), the flow limiting passage (96) being defined in said tubular member (72).

3. The transmission control system (10) of claim 2 wherein said torque converter (66) has a reactor element (70) and said tubular member (72) is connected to said reactor element (70).

4. A transmission control system (10) comprising:

a hydrodynamic torque converter (66);

fluid inlet and outlet passages (64,80) connected to said torque converter (66);

a fluid pressure source (12,16);

pressure regulating valve means (20) for relieving fluid from said source (12,16) at a first preselected pressure to said inlet passage (64);

pressure relief valve means (88) for relieving fluid from said inlet passage (64) at a second preselected pressure above said first preselected pressure; and

a flow limiting passage (96) directly connecting said fluid inlet and outlet passages (64,80) and being of a construction sufficient for continually and controllably bypassing fluid around said torque converter (66).

5. The transmission control system (10) of claim 4 wherein said torque converter (66) includes a tubular member (72), said inlet and outlet passages (64,80) are located radially interiorly and exteriorly of said tubular member (72), and said flow limiting passage (96) is defined through said tubular member (72).