초록 ▼

A hydraulic coupling arrangement used for a 4WD vehicle for imparting a drive torque of an engine to auxiliary drive wheels based on a first rotational difference between main and auxiliary drive wheels. A first rotary shaft is coupled to the main drive wheel and a second rotary shaft is coupled to

A hydraulic coupling arrangement used for a 4WD vehicle for imparting a drive torque of an engine to auxiliary drive wheels based on a first rotational difference between main and auxiliary drive wheels. A first rotary shaft is coupled to the main drive wheel and a second rotary shaft is coupled to the auxiliary drive wheel. A hydraulic pump of the coupling arrangement is adapted to be driven according to a second rotational difference between the first and second rotary shafts for generating an oil pressure corresponding to the second rotational difference. A clutch connects the first rotary shaft with the second rotary shaft based on the oil pressure generated by the hydraulic pump. A first oil passage extends to the clutch. First and second ports are formed in the hydraulic pump and function as inlet and outlet ports or vice versa based on the second rotational difference and a rotational direction of the first rotary shaft. One of the ports is communicated with the first oil passage and the other port is communicated with an oil chamber defined in the coupling arrangement for normally holding the working oil.

대표청구항 ▼

[ What is claimed is:] [1.] A hydraulic coupling arrangement used in a vehicle having a main drive wheel and an auxiliary drive wheel for imparting a drive power to the main and auxiliary drive wheels based on a rotational difference between the main and auxiliary drive wheels, comprising:a first ro

[ What is claimed is:] [1.] A hydraulic coupling arrangement used in a vehicle having a main drive wheel and an auxiliary drive wheel for imparting a drive power to the main and auxiliary drive wheels based on a rotational difference between the main and auxiliary drive wheels, comprising:a first rotary shaft coupled to the main drive wheel;a second rotary shaft coupled to the auxiliary drive wheel;a hydraulic pump adapted to be driven according to the rotational difference for generating an oil pressure corresponding to the rotational difference;an oil chamber defined in the hydraulic coupling arrangement;a clutch for connecting the first rotary shaft with the second rotary shaft based on the oil pressure generated by the hydraulic pump;a first oil passage extending to the clutch;first and second ports formed in the hydraulic pump and functioning as inlet and outlet ports or vice versa based on the rotational difference, one port being communicated with the first oil passage and the other port being communicated with the oil chamber; anda check valve which is opened when the second rotary shaft rotates faster than the first rotary shaft, for communicating the first oil passage with the oil chamber so that oil pressure from the hydraulic pump is not applied to the clutch. [4.] A hydraulic coupling arrangement used in a vehicle having main drive wheels and auxiliary drive wheels for imparting a drive torque to the main and auxiliary drive wheels based on a rotational difference, the rotational difference being obtained by subtracting a rotational speed of the auxiliary drive wheels from a rotational speed of the main drive wheels, comprising:a first rotary shaft coupled to the main drive wheels;a second rotary shaft coupled to the auxiliary drive wheels;a hydraulic pump adapted to be driven according to the rotational difference for generating an oil pressure corresponding to the rotational difference;an oil chamber defined in the hydraulic coupling arrangement;a clutch for connecting the first rotary shaft with the second rotary shaft based on the oil pressure generated by the hydraulic pump;a first oil passage extending to the clutch; andfirst and second ports formed in the hydraulic pump and functioning as inlet and outlet ports or vice versa based on the rotational difference, one port being communicated with the first oil passage and the other port being communicated with the oil chamber, and wherein the drive torque transmitted to the auxiliary drive wheels is proportional to the square of the rotational difference when the rotational difference is in a first range, a lower limit of the first range being greater than zero, and the drive torque transmitted to the auxiliary drive wheels is generally proportional to the rotational difference when the rotational difference is in a second range, a lower limit of the second range being greater than an upper limit of the first range.