HYDRAULIC ACCUMULATOR

Abstract

A hydraulic accumulator, in particular in the form of a piston accumulator, comprising an accumulator housing (10) and a separating element (20) arranged therein, in particular in the form of a piston, which separates a fluid side (22) from a gas side (24), is characterized in that at least the gas side (24) can be inspected, at least in part, by means of at least one sight glass (34, 36) which is fixed in the accumulator housing (10).

Claims

1. A hydraulic accumulator, in particular in the form of a piston accumulator, comprising an accumulator housing (10) and a separating element (20) arranged therein, in particular in the form of a piston, which separates a fluid side (22) from a gas side (24), characterized in that at least the gas side (24) can be inspected, at least in part, by means of at least one sight glass (34, 36), which is fixed in the accumulator housing (10).

2. The hydraulic accumulator according to claim 1, characterized in that for manufacturing the sight glass (34, 36) a metal material surrounding the glass material is heated together with the glass material to a temperature at which the glass material is liquid and runs to the metal material while in contact therewith, such that upon subsequent cooling, the glass material solidifies while forming a sight glass and is clamped in an annular manner by the metal material.

3. The hydraulic accumulator according to claim 1, characterized in that the metal material consists of materials of the accumulator housing (10) or of an independent metal ring (44, 46), preferably consisting of a corrosion-resistant stainless steel, which is inserted into the accumulator housing (10).

4. The hydraulic accumulator according to claim 1, characterized in that the sight glass (34, 36) is a laminated safety glass, a soda lime glass, a borosilicate glass, a glass ceramic, or a quartz glass or sapphire glass.

5. The hydraulic accumulator according to claim 1, characterized in that the sight glass (34, 36) is cut and preferably polished at its exposed front faces (56, 58).

6. The hydraulic accumulator according to claim 1, characterized in that the sight glass (34, 36) is provided with optical properties such as magnification, coating and/or prismatic properties.

7. The hydraulic accumulator according to claim 1, characterized in that the metal ring (44, 46) surrounding the sight glass (34, 36) has an outer thread (48, 50) fixing the metal ring (44, 46) to the accumulator housing (10) via an inner thread (52, 54) of the accumulator housing (10).

8. The hydraulic accumulator according to claim 1, characterized in that two sight glasses (34, 36) are fixed in the accumulator housing (10), of which one sight glass (34, 36) is used to supply light, preferably from an external light source, and the other sight glass (34, 36) is used for optical observation.

9. The hydraulic accumulator according to claim 1, characterized in that both sight glasses (34, 36) are arranged side-by-side and are fixed to the accumulator housing (10) such that their longitudinal axes (L1, L2) extend in parallel to the longitudinal axis (R) of the accumulator housing.

10. The hydraulic accumulator according to claim 1, characterized in that the location of installation of the two sight glasses (34, 36) is an end cover (16), arranged on the front side, as part of the accumulator housing (10).

Description

[0027] The only FIGURE shows a longitudinal sectional of a hydraulic accumulator according to the invention, having a separating element arranged therein and two sight glasses arranged on the front end of an upper end cover.

[0028] The only FIGURE shows a longitudinal section of a hydraulic accumulator having an accumulator housing 10, which has a hollow cylindrical main part 12 having a bottom part 14 at the bottom and an end cover 16 at the top. The bottom part 14 and the end cover 16 are inserted into the main part 12 of the accumulator housing 10 from the respective front end and are sealed against the latter in a fluid-tight manner using sealing elements 18. A separating element 20 is arranged in the accumulator housing 10 and can be moved linearly. The separating element 20 has the shape of a pot-shaped piston, separating a liquid or oil side 22, assigned to the bottom part 14, from a gas side 24 assigned to the end cover 16. Furthermore, the separating element 20 has a pot-shaped opening facing the gas side 24.

[0029] The accumulator housing 10 with the separating element 20 arranged therein is rotationally symmetrical to the longitudinal axis R of the hydraulic accumulator, which is vertically aligned in the representation of the FIGURE. Due to the large extension of the hydraulic accumulator in the direction of the longitudinal axis R, in the FIGURE said hydraulic accumulator is depicted with an interruption.

[0030] To facilitate moving the separating element 20 in the interior of the accumulator housing 10, sliding guides together with sealing rings 26 are formed on the radial outside of the separating element 20. A fluid port 28 is formed in the bottom part 14 and a gas port 30 is formed in the end cover 16, both coaxial to the longitudinal axis R. In the shown functional position of the hydraulic accumulator, the fluid port 28 is open for connection with a fluid line not shown to supply fluid to the fluid side 22 or to discharge fluid therefrom. A plug 32 is used to close the gas port 30 after filling the gas side 24 using a specified pressure.

[0031] To inspect the interior of the accumulator housing 10 on the gas side 24, a first sight glass 34 and a second sight glass 36 are arranged in a first through hole 38 and in a second through hole 40 in the end cover 16. As shown by arrows 42, the two sight glasses 34, 36 permit a view of the gas side 24 of the hydraulic accumulator and a monitoring of the position of the separating element 20 in the accumulator housing 10. The sight glasses 34, are each inserted material-fit into a first metal ring 44 and a second metal ring 46, while forming a viewing glass. For the production of these metal-fused sight glasses 34, 36, a metal material, surrounding the glass material, is heated together with the sight glasses 34, 36 to a temperature, at which the glass material is liquid and runs to a metal material while in contact therewith, such that upon subsequent cooling the glass material solidifies, while forming a respective sight glass, and is clamped annularly by the metal material here the metal rings 44, 46.

[0032] The metal rings 44, 46, surrounding the respective sight glass 34, 36, are preferably made of a corrosion-resistant stainless steel and each have an outer thread 48, 50, with which they are each screwed into an inner thread 52, 54 at the outer end of the respective through-holes 38, 40 and is in this way secured to the accumulator housing 10. The exposed fronts 56, 58 of the two sight glasses 34, 36 are cut and preferably polished and are flush with the associated metal ring 44, 46. The preferred glass material for the respective sight glass 34, 36 is a laminated safety glass, a soda lime glass, a borosilicate glass, a glass ceramic or a quartz glass or sapphire glass. It is advisable that both sight glasses 34, 36 are made of the same material, but it is also conceivable to choose different glass materials. To improve visibility through the sight glasses 34, 36 and the optical effects produced thereby, they may be provided with optical properties such as magnification, coating and/or prismatic properties.

[0033] In the exemplary embodiment shown, two sight glasses 34, 36 are fixed in the accumulator housing 10, but it is also conceivable to provide only one or more than two sight glasses 34, 36, which can also be arranged in the main part 12 and in the bottom part 14. The location of the two sight glasses 34, 36 in the embodiment shown is the end cover 16, arranged on the front side, as part of the accumulator housing 10. The two sight glasses 34, 36 protrude in axial direction with a small projection over a cover front side of the end cover 16. The two sight glasses 34, 36 are arranged side-by-side and are fixed to the accumulator housing 10 such that their longitudinal axes L1, L2 extend in parallel to the longitudinal axis R of the accumulator housing. Advantageously, one sight glass 34 is used to supply light, preferably from an extraneous light source not shown in the FIGURE, and the other sight glass 36 is used simultaneously for optical observation.

[0034] The solution according to the invention permits the observation of the gas side 24 in an accumulator housing 10 of a hydraulic accumulator and the separating element 20 arranged therein and further components via one or more sight glasses 34, 36 in a structurally simple, reliable and cost-effective manner. If the respective sight glasses 34, 36 are integrated into a screw insert in the manner of an insert solution, such screw inserts can be produced in large quantities in a standardized construction and can be inserted into existing hydraulic accumulators in operation in the manner of a retrofit kit. At that preferably the metal ring 44, 46, provided with a corresponding outer thread, is used as the insert holder.