HYDRAULIC PUMP FOR BRAKE SYSTEM
Disclosed is a hydraulic pump for a brake system including a piston installed in a bore formed in the modulator block having an inlet and an outlet such that the piston can reciprocate and having a channel communicating with the inlet, a plug installed in the bore for dividing the inside of the bore into a pressure chamber, in which the piston is located, and a discharge chamber communicating with the outlet and having an orifice communicating the pressure chamber and the discharge chamber with each other, and a discharge valve installed in the discharge chamber for opening and closing the orifice, wherein a filter for filtering oil, fed into the bore through the inlet, is installed in the bore, and surrounds the outer surface of the piston so as to guide the piston. Since the filter for filtering the oil serves as a guide member guiding the piston as well as a filtering member, the hydraulic pump reduces the number of components and reduces an occupied space.
1 . A hydraulic pump for a brake system comprising a piston installed in a bore formed in the modulator block having an inlet and an outlet such that the piston can reciprocate and having a channel communicating with the inlet, a plug installed in the bore for dividing the inside of the bore into a pressure chamber, in which the piston is located, and a discharge chamber communicating with the outlet and having an orifice communicating the pressure chamber and the discharge chamber with each other, and a discharge valve installed in the discharge chamber for opening and closing the orifice,
wherein a filter for filtering oil, fed into the bore through the inlet, is installed in the bore, and surrounds the outer surface of the piston so as to guide the piston.
2 . The hydraulic pump according to claim 1 , wherein the filter includes a frame surrounding the outer surface of the piston and having openings for communicating the inlet and the channel of the piston, and a filtering member installed in the openings for filtering oil fed into the frame through the openings.
3 . The hydraulic pump according to claim 1 , wherein a sealing part having an increased thickness, which surrounds the piston, is provided on the frame so as to guide and seal the piston simultaneously.
4 . The hydraulic pump according to claim 3 , wherein a sealing member for sealing the piston is provided at both upstream and downstream ends of the filter or any one of upstream and downstream ends of the filter.