摘要:
A pump device (1) is provided comprising: a shaft (2), rotor means (3a, 3b) fixed to said shaft (2) in rotational direction, said rotor means (3a, 3b) having pressure chambers (5a, 5b) the volume of which varying during a rotation of said rotor means (3a, 3b), port plate means (15a, 15b) having a through going opening (16a, 16b) for each of said pressure chambers (5a, 5b) and being connected to said rotor means (3a, 3b) in rotational direction, and valve plate means (17a, 17b) cooperating with said port plate means (15a, 15b). It is intended to pressurize a high volume of fluid, in particular water, within a limited space. To this end said rotor means (3a, 3b) comprise a first rotor (3a) and at least a second rotor (3b), both rotors being fixed to said shaft (2) in rotational direction, said first rotor (3a) having at least a first pressure chamber (5a) and said second rotor (3b) having at least a second pressure chamber (5b), said port plate means (15a, 15b) having a first port plate (15a) and at least a second port plate (15b), said first port plate (15a) having a through going opening (16a) for said first pressure chamber (5a) and being connected to said first rotor (3a) in rotational direction, said second port plate (15b) having a through going opening (16b) for said second pressure chamber (5b) and being connected to said second rotor (3b) in rotational direction, said valve plate means (17a, 17b) having a first valve plate (17a) and at least a second valve plate (17b), said first valve plate (17a) cooperating with said first port plate (15a), and said second valve plate (17b) cooperating with said second port plate (15b), wherein at least one of said first rotor (3a) and said second rotor (3b) comprises force generating means (19) pressing said second port plate (15b) against said second valve plate (17b) even in absence of hydraulic pressure in said second pressure chamber (5b).
摘要:
A pump arrangement (1) is provided comprising a driving shaft (2), cylinder drum means (3a, 3b) fixed to said shaft (2) in rotational direction and having a plurality of cylinders (6a, 6b), and a piston (7a, 7b) in each cylinder, each piston (7a, 7b) having a slide shoe (8a, 8b) in contact with driving surface means (8a, 8b). Such a pump arrangement should produce a pressure with low undulations. To this end said cylinder drum means (3a. 3b) comprise at least a first cylinder drum (3a) and a second cylinder drum (3b), said cylinder drums (3a, 3b) being fixed to said common shaft (2) in rotational direction, wherein the cylinder drums (3a, 3b) are offset with respect to each other in rotational direction.
摘要:
The invention concerns a valve arrangement (7) comprising a flow path (11) connecting an inlet (9) and an outlet (10), a closing means (12) arranged in said flow path (11), a resetting means and a first pressure in a first pressure chamber (14) acting in a closing direction on said closing means (12), a pressure of said outlet (10) and a second pressure in a second pressure chamber (18) corresponding to a pressure of said inlet (9) when said closing means (12) is closed acting in opening direction on said closing means (12), said first pressure chamber (14) being connectable to the outlet (10) via an auxiliary valve (13). It is intended to keep small a pressure pulse when opening the valve arrangement (7). This is achieved in that the closing means (12) having a first opening state (A) and a second opening state (B), a flow resistance of said closing means (12) in said first opening state (A) being larger than a flow resistance of said closing means in said second opening state (B).
摘要:
A water-hydraulic machine (1) is disclosed with at least two parts which are movable relative to one another, of which one has a surface composed of a plastic (5, 12, 13, 15, 19) with friction-reducing properties. Improvement of friction-reducing properties is achieved by injection molding a composite material on the surface of at least one of the two parts, wherein the composite comprises a basic polymer resin, preferably PEEK, and ceramic filler particles, the particles having a dimension of up to 1 μm. The friction-reducing surface treatment may be utilised for any parts in relative motion in the water-hydraulic machine, such as cyilnder liner, sliding shoe for swash plates, wear rings in general or bearing surfaces. With such a design the wear in case of a water-hydraulic machine should be kept low.
摘要:
An add-in device for a hydraulic control arrangement provides a function unit (24) to be arranged between successive modules, which function unit takes the connection between the pump channels of the preceding and the subsequent module by way of at least one function slide valve (117, 217) which is arranged to be displaced into several positions. In its positions this function slide valve initiates different functions, by which fluid under pressure is arranged to be admitted to the subsequent control module in at least two different amounts and/or in at least two different levels of pressure. In this manner operation of the subsequent control modules can be better matched to the particular operating conditions that obtain.