Speed changer and clutch assembly

Abstract

A clutch assembly is disclosed that combines a positively engaging dog clutch and one way clutch. The two devices are design such that the one way clutch never interferes with the engagement or disengagement of the dog clutch. In one embodiment, the one way clutch transmits torque in particular rotational positions and the dog teeth are circumferentially placed such that they do not engage in any of these positions. In another embodiment, the dog clutch piston, to which the teeth are secured, is permitted to rotate enough to accommodate any interference between dog teeth during engagement. In either embodiment, the teeth faces that transmit torque in the same direction as the one way clutch may be angled such that torque in that direction tends to disengage the dog clutch.

Description

technical field [0001] The present disclosure relates to the field of automatic transmissions for motor vehicles. More specifically, the present disclosure pertains to clutch assemblies combining positively engaging dog clutches with passive one-way clutches. Background technique [0002] Some vehicles are used over a wide range of vehicle speeds that includes both forward and reverse motion. However, certain types of engines are only capable of operating efficiently within a narrow range of vehicle speeds. Therefore, transmissions capable of transmitting power at multiple speed ratios are often employed. Some vehicle transmissions utilize sets of clutches and establish specific speed ratios by engaging subclutch sets within those clutches. However, a disengaged clutch may exert some parasitic drag torque. Due to the power loss associated with these disengaged clutches, the engine must generate additional power, which increases fuel consumption. Thus, a transmission clu...

AI Technical Summary

Problems solved by technology

However, a low-drag clutch will not be suitable if it interferes with the ability to transition reliably and smoothly between rev ratios

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