Static hydraulic pressure type continuously variable transmission
First Claim
1. A static hydraulic pressure type continuously variable transmission having a hydraulic closed circuit formed between a swashplate type hydraulic pump and a swashplate type hydraulic motor, wherein a pump cylinder of said hydraulic pump and a motor cylinder of said hydraulic motor are integrally coupled to an output shaft, a number of cylinder bores are arranged annularly in said pump cylinder, a number of cylinder bores are also arranged annularly in said motor cylinder, an annular high pressure oil passage and an annular low pressure oil passage are disposed concentrically with each other between the pump cylinder bores and the motor cylinder bores, the high pressure oil passage communicating with all the pump cylinder bores via exhaust valves, the low pressure oil passage communicating with all the pump cylinder bores via intake valves, wherein a number of distribution valves are disposed in a radial arrangement so as to conduct reciprocating movements between a radially outward position and a radially inward position for placing said number of motor cylinder bores into alternate connection with said high pressure oil passage and said low pressure oil passage, respectively, an eccentric ring is disposed to surround from outside the distribution valves and engage with outer ends thereof so as to impart reciprocating motion to respective distribution valves in response to rotation of said pump cylinder and motor cylinder, and wherein a replenishing pump for replenishing working fluid to said low pressure oil passage is provided to have a discharge side thereof connected to inner end surfaces of the distribution valves so as to hydraulically bias the distribution valves in an engaging direction with the eccentric ring.
0 Assignments
0 Petitions
Accused Products
Abstract
A static hydraulic pressure type continuously variable transmission having a hydraulic closed circuit formed between a swashplate type hydraulic pump and a swashplate type hydraulic motor, in which a high pressure oil passage is communicated through exhaust valves with a number of cylinder bores annularly disposed in a pump cylinder of the hydraulic pump, a low pressure oil passage is communicated through intake valves with the cylinder bores, and a number of distribution valves capable of being reciprocated are radially disposed so as to provide an alternate communication between a number of cylinder bores annularly disposed in a motor cylinder of the hydraulic motor and the high and low pressure oil passages. An eccentric ring for imparting reciprocation to each distribution valve is provided and a discharge side of a replenishing pump is communicated with an inner end surface of each distribution valve to hydraulically urge the distribution valve in a direction of engagement with the eccentric ring.
43 Citations
12 Claims
- 1. A static hydraulic pressure type continuously variable transmission having a hydraulic closed circuit formed between a swashplate type hydraulic pump and a swashplate type hydraulic motor, wherein a pump cylinder of said hydraulic pump and a motor cylinder of said hydraulic motor are integrally coupled to an output shaft, a number of cylinder bores are arranged annularly in said pump cylinder, a number of cylinder bores are also arranged annularly in said motor cylinder, an annular high pressure oil passage and an annular low pressure oil passage are disposed concentrically with each other between the pump cylinder bores and the motor cylinder bores, the high pressure oil passage communicating with all the pump cylinder bores via exhaust valves, the low pressure oil passage communicating with all the pump cylinder bores via intake valves, wherein a number of distribution valves are disposed in a radial arrangement so as to conduct reciprocating movements between a radially outward position and a radially inward position for placing said number of motor cylinder bores into alternate connection with said high pressure oil passage and said low pressure oil passage, respectively, an eccentric ring is disposed to surround from outside the distribution valves and engage with outer ends thereof so as to impart reciprocating motion to respective distribution valves in response to rotation of said pump cylinder and motor cylinder, and wherein a replenishing pump for replenishing working fluid to said low pressure oil passage is provided to have a discharge side thereof connected to inner end surfaces of the distribution valves so as to hydraulically bias the distribution valves in an engaging direction with the eccentric ring.
-
10. A static hydraulic pressure type continuously variable transmission comprising:
-
a hydraulic pump having a pump cylinder; a hydraulic motor having a motor cylinder; and a hydraulic closed circuit between said hydraulic pump and motor; said pump cylinder and said motor cylinder being connected together to form a cylinder block which is disposed on a transmission shaft; said pump cylinder having a plurality of pump cylinder bores therein; said motor cylinder having a plurality of motor cylinder bores therein; said hydraulic closed circuit being integrally formed with the cylinder block between the pump cylinder and the motor cylinder and including a high pressure oil passage and a low pressure oil passage; said pump cylinder bores and motor cylinder bores being capable of communicating with said high pressure oil passage and low pressure oil passage, respectively, via a distribution device; wherein said distribution device comprises a distribution valve means having outer and inner ends, said distribution valve means being rotatable in response to rotation of said cylinder block and serving to establish alternate connection of the respective cylinder bores with said high pressure oil passage and said low pressure oil passage, the outer end of the distribution valve means projecting from an outer periphery of the cylinder block and being operably engaged by a valve operating means disposed around the outer periphery of the cylinder block, the inner end of the distribution valve means receiving an oil pressure urging the valve toward engagement with said valve operating means, a low pressure within said low pressure oil passage being added to said oil pressure.
-
-
11. A static hydraulic pressure type continuously variable transmission comprising:
-
a hydraulic pump; a hydraulic motor; and a hydraulic closed circuit between said pump and motor and including a first annular oil passage as a high pressure oil passage and a second annular oil passage as a low pressure oil passage; one of the first and second oil passages encircling the other, said first oil passage being placed in communication with said hydraulic pump during discharge strokes of the pump and said second oil passage being placed in communication with the pump during suction strokes thereof; wherein a clutch valve meas is disposed radially in said hydraulic closed circuit, said clutch valve means being radially movable to assume at least a first position at which a pressure in said high pressure oil passage is maintained at a high level providing a clutch ON state and a second position at which the pressure in said high pressure oil passage is reduced to a low level to provide a clutch OFF state, said clutch valve means permitting the oil pressure in said high pressure oil passage to be reduced gradually when moving from said first position to said second position.
-
-
12. A static hydraulic pressure type continuously variable transmission comprising:
-
a hydraulic pump; a hydraulic motor; and a hydraulic closed circuit between said pump and motor and including a first annular oil passage as a high pressure oil passage and a second annular oil passage as a low pressure oil passage, one of the first and second oil passages encircling the other, said first oil passage being placed in communication with said hydraulic pump during discharge strokes of the pump and said second oil passage being placed in communication with the pump during suction strokes thereof, wherein a clutch valve means is disposed radially in said hydraulic closed circuit, said clutch valve means being radially movable to assume at least a first position at which a pressure in said high pressure oil passage is maintained at a high level and a second position at which the pressure in said high pressure oil passage is reduced to a low level; and wherein said clutch valve means has opposite ends and engages at one of the opposite ends with a clutch actuating means and at the other end communicates with the low pressure oil passage of said hydraulic closed circuit to receive an oil pressure urging the clutch valve means toward the clutch actuating means.
-
Specification