DE19546113A1 - Double acting diaphragm cylinder for pump - Google Patents

Abstract

The cylinder has a rolling diaphragm between the piston and cylinder walls for radial guidance of the piston in axial movement and separation of the upper and lower cylinder chambers. The diaphragm (1) has an annular hollow body defining an inner volume (4) filed with liquid through an opening (3). The diaphragm forms a bearing rolling between the piston skirt and cylinder bore and the size of the bearing faces does not alter. The diaphragm can be installed in a separate guide in the inner or outer section of the cylinder.

Description

The invention relates to a double-acting roll diaphragm cylinder according to the preamble of claim 1.

Membrane cylinders are generally used for lifting loads, for controlled movements processes, used in pumps, compressors, etc.

Rolling membranes or rolling bellows as a single element are used as a separating element for e.g. B. stick Material / oil used in storage, as well as independent lifting or suspension elements in Vehicles and machinery.

All these designs have in common that the elastic membranes and bellows are not for Alternating loads are suitable, since the volume in the chamber changes when the load is reversed change suddenly, d. H. a vacuum is created in a chamber that the membrane contracts, the stroke reversal is inflated again, which in a short time their destruction leads and also makes regulated behavior impossible (cf. patent DT 19 52 124 C3; DE 31 28 666 A1). Metal membranes are partly for load reversal suitable, but only allow a small stroke and require an additional one Exertion of force for elastic bending of the metal.

The invention specified in claim 1 is based on the object pressure waves with a precisely specified stochastic course with a constant zero crossing d. H. Generate change from overpressure to underpressure and vice versa, whereby noise and Rei exercise should be kept to a minimum.

This object is achieved by the features listed in claim 1.  

The advantages of the invention are that the rolling diaphragm cylinder is almost noisy. and works smoothly and requires no lubrication.

The pressurized roll membrane, the wall thickness z. B. can be 0.1 mm and the has a minimal stretch, is subjected to an internal pressure that is significantly higher than the pressure curves to be generated in the cylinder chamber, so that at the point of reversal Piston movement d. H. at the zero crossing of the pressure there is no kink in the pressure curve.

The roll diaphragm cylinder is simple and inexpensive to manufacture and does not require any narrow Tolerances.

The piston is precisely guided through the large contact surface of the rolling membrane, tolerates high Lateral forces as well as tilting. The roll membrane has a vibration dampening and soundproof.

Changed when rolling the rolling membrane on the piston skirt and the cylinder bore the size of the contact surface does not, so that there is a good sealing effect, even without additional sealing in the non-lifting central area of the roll membrane.

Advantageous embodiments of the invention are given in claims 2 to 5 ben.

The development according to claim 2 enables that when arranging further roll membranes inside or outside the cylinder on friction and smear dependent additional guides can be omitted.

Claim 3 allows the dead weight of the piston including the additional masses to be compensated for by an upward thrust of the piston by the ring gap width (b2; Fig. 1b) between the piston ( 5 ) and cylinder tube ( 6 ) in the upper region of the rolling membrane ( 1 ) is larger than the annular gap width (b1) in the lower region of the rolling membrane.

Claim 4 enables a compact unit of roller diaphragm cylinder and linear drive ( 12 ; Fig. 1) which is preferably a servo-hydraulic, hydrostatically mounted cylinder, which also takes over the leadership of the piston rod.

Claim 5 allows normal operation of the roll diaphragm cylinder as a working cylinder ( Fig. 5) by the movement of the piston ( 5 ) by supplying and removing a pressure medium around the openings ( 18 ).

Claim 6 allows the formation of an elastic joint ( Fig. 6) by the rolling membrane ( 1 ) between a cylindrical part in the central part ( 5 ) and a housing ( 6 ) with a cylindrical bore is attached, in a further embodiment ( Fig. 6a ) the cylindrical body ( 5 ) is mounted on rolling elements ( 19 ).

Embodiments of the invention are shown in the drawings and are in the fol described in more detail.

Fig. 1 shows a roll diaphragm cylinder which is coupled to a pressure chamber ( 11 ) in the interior ( 10 ) of which pressure fluctuations are generated. The rolling diaphragm ( 1 ), the interior ( 4 ) of which is to be connected via a conventional valve to the threaded connector ( 2 ) through the bore ( 3 ) with a pressure medium, so that the rolling diaphragm ( 1 ) automatically on the cylinder jacket ( 7 ) and creates and seals the surface of the cylinder bore ( 8 ). The upper cylinder chamber ( 9 ) contains ambient air pressure. The linear cylinder ( 12 ) - controlled by means of a closed control loop - carries out the lifting movements, the target value coming from an external computer, magnetic tape or the like, the actual value from a pressure sensor in the pressure chamber ( 10 ). Test persons or objects to be tested can be located in the pressure chamber ( 10 ).

Fig. 1a shows the rolling membrane ( 1 ) with positive locking ( 13 ), which allows a fixation and possibly an additional seal.

Fig. 1b shows the piston ( 5 ) with different diameters or gap widths (b1; b2) whereby the rolling membrane ( 1 ) receives a larger pressure area at the upper end and thus generates the thrust for weight compensation.

In Fig. 1c, the roll membrane cylinder is equipped with 2 roll membranes ( 1 ) one behind the other.

Fig. 1d shows the piston ( 5 ) in its upper position.

In Fig. 2, the piston rod ( 17 ) is supported by an additional roller membrane ( 1 ) and a Zylin derrohr ( 16 ).

Fig. 3 shows a roll diaphragm cylinder with a roll diaphragm ( 1 ) separated in the middle as well as the likewise separate pistons ( 5 ) and the cylinder tube ( 6 ) which are sealed or fixed at the separation points by ring elements ( 15 ).

In Fig. 3a, the roller membrane ( 1 ) consists of a part open only on one side, which engages for fixing in a groove ( 14 ) on the cylinder circumference and can be glued there if necessary. This roll membrane design is advantageous if suitable closed roll membranes are not available.

Fig. 4 contains a separate guide element with a rolling membrane ( 1 ) a piston-like body ( 5 ) and an outer bearing housing ( 6 ) with a cylindrical bore.

Fig. 5 shows a normal synchronous working cylinder with piston surfaces of the same size on both sides. The lifting movements are carried out by supplying and removing the pressure medium at the openings ( 18 ).

Fig. 6 shows an elastic joint, consisting of a central cylindrical bolt ( 5 ) with mounting holes at the ends. The housing ( 6 ) has a cylindrical bore and threaded connection for further load transfer. The rolling membrane ( 1 ) between the pin ( 5 ) and the housing ( 6 ) allows the pin ( 5 ) to be tilted and damped in accordance with the internal pressure in the rolling membrane ( 1 ). With a roller bearing ( 19 ; Fig. 6a) additional rotational movements between the bolt ( 5 ) and the housing ( 6 ) are possible.

Claims (6)

1.Double-acting roll diaphragm cylinder as a linear drive controllable compression and decompression device for the generation of negative and positive pressures in a pressure chamber, with at least one roll diaphragm between the piston and the cylinder wall, the radial guidance of the piston during its axial displacement, and the seal between the upper and Lower cylinder chamber takes over, characterized in that the rolling diaphragm ( 1 ) forms an annular hollow body, the interior ( 4 ) of which is filled with a pressure medium via an opening ( 3 ), that the rolling diaphragm ( 1 ) during stroke movements on the Kolbenman tel ( 7 ) and the cylinder bore ( 8 ) rolls and the sizes of the contact surfaces do not change. 2. Double-acting roll diaphragm cylinder according to claim 1, characterized in that the roll diaphragm ( 1 ) is constructed in a separate guide element inside ( Fig. 2) or outside ( Fig. 4) of the roll diaphragm cylinder. 3. Double-acting roll diaphragm cylinder according to one of claims 1 to 2, characterized in that the annular gap width (b2; Fig. 1b) between the piston ( 5 ) and Zy cylinder tube ( 6 ) in the upper region of the roll membrane ( 1 ) is larger than the annular gap width (b1) in the lower area of the rolling membrane. 4. Double-acting roll diaphragm cylinder according to one of claims 1 to 3, characterized in that the linear drive ( 12 ; Fig. 1) for the piston ( 5 ) forms a unit with the roll diaphragm cylinder, and takes over the leadership of the piston rod ( 17 ). 5. Double-acting roll diaphragm cylinder according to one of claims 1 to 4, characterized in that the movement of the piston ( 5 ; Fig. 5) takes place by supplying and removing a pressure medium at the openings ( 18 ). 6. Double-acting roll diaphragm cylinder according to one of claims 1 to 5, characterized in that the roll diaphragm ( 1 ; Fig. 6) is in a joint in which the piston-like inner part consists of a cylindrical bolt ( 5 ) with connection holes to the introduction of load and radial loads can also be introduced into the housing ( 6 ) with a cylindrical bore, the insertion of rolling elements ( 19 ; FIG. 6a) allowing rotational movements between the bolt ( 5 ) and the housing ( 6 ).