Oil pan structure and separator for partitioning oil pan

A separator provided in an oil pan including a reservoir configured to store oil circulated in a power unit and returned to the reservoir, extending vertically, configured to partition the reservoir into a first reservoir and a second reservoir such that oil always flows to the lowermost portion of the reservoir, and including

• an opening/closing means capable of establishing or cutting off communication between the first reservoir and the second reservoir, wherein
• an oil passageway configured to allow oil to return from the power unit is provided above the first reservoir,
• the separator is configured to separate an inside of the oil pan in which when the first reservoir has a temperature lower than a given temperature the opening/closing means cuts off communication between the first reservoir and the second reservoir such that oil in the power unit returns only to the first reservoir, and when the first reservoir has a temperature equal to or higher than the given temperature, the opening/closing means establishes communication between the first reservoir and the second reservoir such that oil in the power unit returns to the second reservoir through the first reservoir,
• the first reservoir includes a suction-member-placement region in which a member for sucking oil from the reservoir toward the power unit is provided at a bottom of the first reservoir, and
• the separator has an oil guide surface located at a surface toward the first reservoir and configured to have a top located below a downstream end of the oil passageway and a bottom located close to the suction-member placement region to allow oil dropping from the oil passageway to flow toward the suction-member placement region.