HYDRAULIC PUMP DEVICE

PROBLEM TO BE SOLVED: To appropriately lubricate an engagement portion between a drive gear and a first driven gear and an engagement portion between the drive gear and a second driven gear with lubricating oil stored in a gear housing. SOLUTION: The upper surface 25 of the gear housing 21 is formed with an inner surface 25A opposed to the drive gear, a first inner surface 25B opposed to the driven gear, and a second inner surface 25C opposed to the driven gear, and a clearance 28 formed between the inner surface 25A opposed to the drive gear and the drive gear 11 is set smaller than a clearance 29 formed between a first inner surface 25D opposed to the engagement portion and the drive gear 11. Thereby, when the lubricating oil L flowing in the rotating direction of the drive gear 11 passes from the clearance 29 through the clearance 28 along the first inner surface 25D opposed to the engagement portion, a Venturi effect is provided. By the Venturi effect, the large amount of lubricating oil L is led out in the rotating direction of the drive gear 11 to appropriately lubricate the engagement portion between the drive gear 11 and the second driven gear 13. COPYRIGHT: (C)2011,JPO&INPIT