Actuator for pneumatic linear drive and method for assembling the actuator

Abstract

The invention relates to an actuator (100) for a pneumatic linear drive, comprising: a first housing (110), a working space (120) arranged in the first housing (110), a second housing (150) arranged in the first housing (110), and an electronics space (160) arranged in the second housing (150). The electronics space (160) is pneumatically sealed relative to the working space (120) and is accessible from outside the first housing (110) by means of an access channel (230). The invention also relates to a method for assembling an actuator (100) according to the invention, comprising the following steps: providing an assembly opening (130) in the first housing (110), providing an end cap (140), inserting the second housing (150) into the first housing (110) through the assembly opening (130), and closing the assembly opening (130) by means of the end cap (140).

Description

Technical Field

[0001] The invention relates to an actuator for a pneumatic linear drive, which comprises a first housing and a working space arranged in the first housing. In addition, the invention also relates to a method for assembling the actuator. Background Art

[0002] Such actuators are well known in the prior art. Many such actuators include electronic components for operating and / or monitoring the actuator, for example, for monitoring the operating state of the actuator. These components are arranged in or on the housing of the actuator. This has the disadvantage that, when the electronic components are arranged on the housing, additional installation space is required or, when the electronic components are arranged in the first housing or the working space, the electronic components cannot be accessed or are only difficult to access. Summary of the invention

[0003] It is therefore an object of the present invention to provide an improved actuator so as to overcome at least one of the disadvantages of the prior art.

[0004] According to the invention, this object is achieved with respect to an actuator and with respect to a method for assembling an actuator by the subject-matter of the appended claims.

[0005] Advantageous and expedient embodiments of the actuator according to the invention are specified in the appended claims.

[0006] The invention is based on the idea that the actuator comprises a second housing arranged within a first housing and an electronics space arranged within the second housing, wherein the electronics space is pneumatically sealed relative to the working space and is accessible from outside the first housing by means of an access channel.

[0007] The advantage of the actuator according to the invention is that the electronics space is arranged with its second housing inside the first housing, which saves space. In addition, the electronics space is non-pressurized due to its pneumatic sealing relative to the working space, thereby protecting the electronic components arranged in the electronics space or not subjecting them to large pressure loads. Since the electronics space is accessible via the access channel, the electronic components can also be configured by the user at any time, also during operation of the actuator, or can be maintained and replaced by the user. This is mainly due to the fact that the electronics space can be accessed without opening the working space, which may just be under pressure.

[0008] Furthermore, the linear drive is preferably a controllable linear drive, also called DFPI. Particularly preferably, it is a controllable linear drive standardized according to ISO 15552, also called DFPI-NB3P. Such a linear drive is used, for example, to control the level in a flotation chamber. In this case, a displacement measuring system connected to a valve terminal is integrated into the linear drive.

[0009] According to a preferred embodiment, the first housing has an assembly opening and an end cap closing the assembly opening, wherein the second housing is arranged at the end cap to be directly accessible through the assembly opening. The second housing and thus the electronic device space can be introduced into the first housing through the assembly opening in the last assembly step before it is closed with the end cap. The proximity of the second housing to the end cap allows the second housing and thus the electronic components located in the electronic device space to be replaced simply and quickly.

[0010] On this basis, the access channel is preferably constructed by means of a cover opening in the end cap and an access channel opening in the second housing. Here, the access channel opening is preferably constructed in such a way that the second housing has an open side facing the end cap. In other words, preferably no wall of the second housing is arranged between the end cap and the electronic instrument space. Therefore, the electronic instrument space can be reached through the cover opening. Since the cover opening is arranged in the end cap that closes the assembly opening, an access channel to the electronic instrument space is realized through the assembly opening, whereby no additional opening is required in the first housing in addition to the assembly opening to provide the access channel. Therefore, a standard housing can be used for the first housing, which brings cost advantages.

[0011] According to the invention, it is advantageous if the end cap is fastened to the first housing, preferably by means of a screw connection. By means of the screw connection, the end cap is designed to be removable from the first housing. As a result, the second housing can be easily and quickly reached and replaced. Alternatively, it is conceivable that the end cap is non-detachably fastened to the first housing, for example by means of welding, caulking or soldering.

[0012] According to a preferred embodiment, the end cap is made of a lightweight material, preferably aluminum. As a result, the end cap is particularly easy to construct, which results in a reduced weight of the actuator.

[0013] Furthermore, the assembly opening is preferably closed by means of the second housing. As a result, the second housing assumes the function of an end cap and thus fulfills a dual function. It provides an electronics space for the electronic components and also closes the assembly opening of the first housing. As a result, the actuator has a particularly good or effective use of the structural space. Furthermore, possible requirements on the end cap, such as its stability, are reduced, which can lead to material savings.

[0014] In another embodiment, a sealing element is arranged between the first housing and the second housing, which seals the inlet channel pneumatically relative to the working space. Here, the second housing is preferably configured to be arranged on the assembly opening or to close the assembly opening. As a result, the end cover only has the function of retaining the second housing and / or covering the electronic instrument space. The sealing element is preferably configured as a sealing ring. The pneumatic sealing of the inlet channel by means of the sealing element protects the electronic instrument space from undesirable gas exchange with the working space. Conversely, of course, the working space is also protected from undesirable gas exchange with the electronic instrument space. This improves the operational safety of the actuator.

[0015] On this basis, it is preferred that an additional sealing element is arranged between the first housing and the end cover so that the working space is pneumatically sealed relative to the external environment of the first housing. By means of this additional pneumatic sealing of the working space relative to the external environment of the first housing, the sealing element fulfills a dual function. The actuator is thus constructed particularly efficiently. Particularly preferably, the sealing element is arranged on the assembly opening or along the entire edge of the assembly opening. This has the advantage that other points or surfaces of the sealing end cover that are to be abutted or already abutted against the first housing are no longer required. In particular, the following bolted joints should be mentioned here, with which the end cover can be fastened on the first housing, and these bolted joints can now be constructed without sealing elements. It is particularly advantageous here to place the bolted joint radially outside the sealing element arranged along the entire edge of the assembly opening.

[0016] In addition, the working space can also be sealed relative to the electronic device space and relative to the environment of the first housing by means of two sealing elements. Here, for example, the first sealing element is arranged between the first housing and the end cap, and the second sealing element is arranged between the second housing and the end cap.

[0017] According to a preferred embodiment, the outer wall of the second housing at least partially bears against the inner wall of the first housing in a form-fitting manner. In this case, the inner wall is particularly preferably the inner wall of the assembly opening. As a result, the second housing has a particularly good fit in the first housing, thereby avoiding costly stabilization and / or fastening.

[0018] In another preferred embodiment, at least one electronic component, preferably a position feedback module, is arranged in the electronic instrument space. The position feedback module is used to feedback the position of the working mechanism arranged in the working space. This position feedback is carried out by an analog output or feedback signal, and is carried out at a distance of up to 30 meters. For this reason, the position feedback module is constructed to have at least one voltage-to-current converter or measuring transducer. According to the basic standard DIN 1319, the measuring transducer is a measuring mechanism that transforms or converts an input variable into an output variable corresponding to a fixed relationship. Here, the measuring transducer specifically converts an input signal or a constant voltage into a feedback signal of 4 to 20 mA or a current signal proportional to the displacement of the working mechanism. The feedback signal provides the user with higher reliability and simpler diagnosis when the actuator or linear drive is running. In addition, the position feedback module is arranged in the electronic instrument space in a space-saving and well-protected manner and is therefore arranged within the first housing of the actuator.

[0019] The actuator is therefore designed to have a displacement sensor function in particular. Preferably, a potentiometer is used here, which is supplied with the above-mentioned input signal or a constant voltage by a measuring transducer. A potentiometer is a resistance element whose resistance value can be changed mechanically, in this case specifically by means of a displacement of a working element. The described embodiment of the actuator is particularly well suited for such a displacement sensor.

[0020] With regard to a method for assembling an actuator according to one of the aforementioned embodiments, this object is achieved by the features of the attached claims. The method according to the invention has similar advantages as the actuator according to the invention and comprises the following steps: providing an assembly opening in a first housing, providing an end cap, inserting the second housing through the assembly opening into the first housing, and closing the assembly opening by means of the end cap. Assembly can be carried out particularly efficiently.

[0021] According to a preferred embodiment, when providing the end cap, a cover opening is also provided in the end cap. As already mentioned, access to the electronic space is thus already achieved via the assembly opening, and no further opening in the first housing is required. In addition to increasing the assembly efficiency, the use of a standard housing for the first housing and the resulting cost savings are advantageous.

[0022] In a particularly preferred embodiment, the pneumatic sealing of the working space relative to the electronic device space and relative to the external environment of the first housing is already carried out when the second housing is installed. Here, the sealing element of one of the above-mentioned embodiments is preferably used. As already mentioned, the second housing realizes a dual function by providing the electronic device space for the electronic components and also closing the assembly opening of the first housing. As a result, the actuator has a particularly good or effective structural space utilization, and additional assembly steps can be saved.

[0023] In another embodiment, the end cap is screwed together with the first housing during closing. As already mentioned, the screw connection required for this determines the detachable structure of the end cap from the first housing. The second housing is thus easily and quickly accessible and replaceable. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Exemplary embodiments of the invention are shown in the drawings and are described in detail below.

[0025] In the figure:

[0026] Figure 1 A perspective exploded view showing an actuator according to the invention in a possible embodiment, and

[0027] Figure 2 Show Figure 1 Details of II. DETAILED DESCRIPTION

[0028] Figure 1 An actuator 100 in the form of a linear actuator in a possible embodiment of the invention is shown. The actuator 100 comprises a first housing 110, which surrounds a working space 120. The first housing 110 has an assembly opening 130 leading to the working space 120. The assembly opening 130 can be closed with an end cap 140, which is shown here in an exploded view. A second housing 150 is arranged in the working space 120 and at the assembly opening 130. The second housing 150 surrounds an electronic instrument space 160 and further has an access channel opening 170. An electronic component 180, in particular a position feedback module, is arranged in the electronic instrument space 160.

[0029] A section of the inner wall 190 of the first housing 110 is arranged in a form-fitting manner against a section of the outer wall 200 of the second housing 150. A sealing element 210 is arranged between the inner wall 190 and the outer wall 200 and at the assembly opening 130 in order to pneumatically seal the working space 120 relative to the electronics space 160 and also relative to the external environment of the actuator 100.

[0030] The end cover 140 further comprises a cover opening 220 or an openable cover section which together with the access opening 170 forms an access 230 to the electronics space 160 . Furthermore, the end cover 140 is fixed to the first housing 110 by means of a screw connection 240 in order to close the assembly opening 130 .

[0031] The electronics space 160 can be reached at any time from outside the actuator 100 or from outside the first housing 110 via the access channel 230. During operation of the actuator 100, the user can also reach the electronics 180 located in the electronics space 160 through the access channel 230 to maintain or replace them. This is achieved in particular by making the electronics space 160 accessible without having to open the working space 120, which may be under pressure.

[0032] Figure 2 Again shown in full and in perspective Figure 1 The electronic device 180 or position feedback module in FIG. Figure 2 In this case, the positioning plate 250 and the two measuring transducers 260 , 270 arranged on the positioning plate 250 can be seen more clearly.

[0033] The electronic device 180, which is designed as a position feedback module, is used to provide feedback about the position of a working element (not shown here) arranged in the working space of the actuator. The feedback or position feedback is carried out via an analog feedback signal. For this purpose, the position feedback module 180 is designed with two measuring transducers 260, 270, which convert the input voltage into a feedback signal. The feedback signal provides the user with greater reliability and simpler diagnosis during the operation of the actuator or linear drive.

[0034] All features explained and shown in conjunction with individual embodiments of the invention may be provided in various combinations in the subject matter according to the invention in order to simultaneously achieve their advantageous effects.

[0035] The scope of protection of the present invention is given by the claims and is not limited by the features described in the description or shown in the drawings.

[0036] Reference numerals list

[0037] 100 actuators

[0038] 110 first shell

[0039] 120 workspaces

[0040] 130 Assembly opening

[0041] 140 end cap

[0042] 150 Second Shell

[0043] 160 Electronic Instrument Space

[0044] 170 Access channel opening

[0045] 180 Electronic Devices

[0046] 190 Inner wall of the first shell

[0047] 200 outer wall of the second shell

[0048] 210 sealing element

[0049] 220 Cover opening

[0050] 230 Access Channel

[0051] 240 bolt joint

[0052] 250 positioning plate

[0053] 260 Measurement Transducer

[0054] 270 measuring transducers.

Claims

1. An actuator (100) for pneumatic linear drive, comprising: A first housing (110), a working space (120), the working space being arranged within the first shell (110), a second housing (150), the second housing being arranged inside the first housing (110), and an electronic instrument space (160), the electronic instrument space being arranged within the second housing (150), wherein the electronics space (160) is pneumatically sealed relative to the working space (120) and is accessible from outside the first housing (110) via an access channel (230), The first housing (110) has an assembly opening (130) and an end cover (140) closing the assembly opening (130), wherein the second housing (150) is arranged on the end cover (140) in order to be directly accessible through the assembly opening (130), The inlet channel (230) is constructed by means of a cover opening (220) in the end cover (140) and an inlet channel opening (170) in the second housing (150).

2. The actuator (100) according to claim 1, characterized in that The end cover (140) can be fastened to the first housing (110) by means of a bolt connection (240).

3. The actuator (100) according to claim 1 or 2, characterized in that: The end cover (140) is made of a lightweight material.

4. The actuator (100) according to claim 1 or 2, characterized in that: The end cover (140) is made of aluminum.

5. The actuator (100) according to claim 1 or 2, characterized in that: The mounting opening (130) is closed by means of the second housing (150).

6. The actuator (100) according to claim 1 or 2, characterized in that: A sealing element (210) is arranged between the first housing (110) and the second housing (150), which seals the inlet channel (230) pneumatically with respect to the working space (120).

7. The actuator (100) according to claim 6, characterized in that A further sealing element (210) is arranged between the first housing (110) and the end cover (140), so that the working space (120) is pneumatically sealed relative to the external environment of the first housing (110).

8. The actuator (100) according to claim 1 or 2, characterized in that: The outer wall (200) of the second housing (150) at least partially abuts against the inner wall (190) of the first housing (110) in a form-fitting manner.

9. The actuator (100) according to claim 1 or 2, characterized in that: At least one electronic component (180) is arranged in the electronics space (160).

10. The actuator (100) according to claim 1 or 2, characterized in that: A position feedback module is arranged in the electronic instrument space (160).

11. A method for assembling an actuator (100) according to any one of claims 1 to 10, comprising the following steps: - providing a mounting opening (130) in the first housing (110), - providing an end cap (140), - inserting the second housing (150) into the first housing (110) through the assembly opening (130), and The assembly opening (130) is closed by means of the end cap (140).

12. The method according to claim 11, characterized in that When the end cap (140) is provided, a cap opening (220) in the end cap (140) is also provided.

13. The method according to claim 11 or 12, characterized in that: When the second housing (150) is installed, the working space (120) is already pneumatically sealed relative to the electronics space (160) and the external environment of the first housing (110).

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