Low oil level detection system and method

摘要

A hydraulic system for a hybrid module which is located between an engine and a transmission includes a parallel arrangement of a mechanical pump and an electric pump. Each pump is constructed and arranged to deliver oil from a sump to other portions of the hydraulic system depending on the operational mode. A load on the electric pump corresponds to a current draw on the electric pump motor. This current draw is used to indicate when there is a low oil level in the sump.

主权项

1. A low level detection system for a fluid reservoir of a vehicle, said low level detection system comprising:
a supply of fluid retained in said fluid reservoir, said supply of fluid having an upper surface which defines the depth of said supply of fluid; a primary fluid pump having a fluid inlet and being constructed and arranged for drawing fluid from said fluid reservoir and delivering at least a portion of said fluid to a location which is downstream from said primary fluid pump, wherein the fluid inlet of said primary fluid pump is positioned in said fluid reservoir at a first depth relative to said upper surface; a secondary fluid pump having a fluid inlet and being constructed and arranged for drawing fluid from said fluid reservoir and delivering at least a portion of said fluid to a location which is downstream from said secondary fluid pump, said secondary fluid pump having an ON operational state and an OFF operational state, wherein the fluid inlet of said secondary fluid pump is positioned in said fluid reservoir at a second depth relative to said upper surface, wherein when said supply of fluid is sufficient to cover the fluid inlet of said secondary fluid pump, the fluid inlet of said secondary fluid pump is closer to said upper surface than is the fluid inlet of said primary fluid pump; monitoring and control means constructed and arranged for monitoring the operational state of said secondary fluid pump and for switching an OFF operational state of said secondary fluid pump to an ON operational state for said secondary fluid pump; and sensor means constructed and arranged for reading the current draw of said secondary fluid pump when in said ON operational state.