TIGHTENING DEVICE FOR A DEVICE FOR CONVEYING FLUID AND A DEVICE FOR CONVEYING FLUID

Abstract

A tightening device for applying a preload to a fastening element, wherein the fastening element is suitable for fastening a diaphragm pump head part to a drive system for impressing movement on a diaphragm of the diaphragm pump head part in a device for conveying fluid. The tightening device has a support with support surface for supporting a bearing surface of the fastening element, wherein the support has a threaded bore through which a screw element penetrates. The screw element has a contact surface at its front end, wherein the contact surface of the screw element and the support surface of the support face opposite directions, and the distance between the contact surface of the screw element and the support surface of the support can be changed by screwing in or unscrewing the screw element.

Claims

1. A tightening device for applying a preload to a fastening element configured for fastening a pump to a drive system, comprising: a support having a support surface for supporting a bearing surface of the fastening element, and a threaded hole for receiving a screw element; a screw element adapted to penetrate the threaded hole, the screw element having a contact surface at its front end; wherein the contact surface of the screw element and the support surface of the support face opposite directions and are separated by a given distance; and wherein the given distance between the contact surface of the screw element and the support surface of the support is adjustable by screwing in or unscrewing the screw element.

2. The tightening device of claim 1, wherein the fastening element is configured to fasten a diaphragm pump head part to a drive system for impressing movement on a diaphragm of the diaphragm pump head part in a fluid conveying device.

3. A method for generating a preload on at least one bolt of a device for conveying fluid having a diaphragm pump head part and a drive system for impressing movement on a diaphragm of the diaphragm pump head part, the method comprising: fastening the at least one bolt at one end to a housing of the drive system so that said bolt penetrates a through-hole through the housing of the diaphragm pump head part, and at a second end to a support element of a tightening device so that the at least one bolt penetrates a pressure plate located between an outer portion of said diaphragm pump housing and said support element, and wherein said at least one bolt has a bearing surface supported by a support surface of the support element; inserting a screw element having a contact surface into a threaded through hole of the support element; and rotating the screw element within the threaded through hole to cause a change in distance between the contact surface of the screw element and the support surface of the support element; whereby rotating the screw element in one direction causes the contact surface to act on the pressure plate to cause movement of said pressure plate in the direction of the diaphragm pump head part along a longitudinal axis of the diaphragm pump head part, and rotation in an opposite direction causes the contact surface to act on the pressure plate to cause movement in the direction away from the diaphragm pump head part along said longitudinal axis.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0054] The invention is explained in more detail below with reference to drawings illustrating an example embodiment of the invention. Shown therein:

[0055] FIG. 1 a sectional view through a drive system chamber section and a diaphragm pump head part;

[0056] FIG. 2 a device for conveying fluid in an isometric view;

[0057] FIG. 3 the device for conveying fluid corresponding to FIG. 2 in a partially exploded view;

[0058] FIG. 4 an exploded view of a handling element with a screw element mounted on the handling element;

[0059] FIG. 5 a pressure element in a sectional view along its longitudinal axis; and

[0060] FIG. 6 a front view of the handling element with an enlarged break-out view.

DETAILED DESCRIPTION

[0061] FIG. 1 shows a device for conveying fluid, which is designed as a diaphragm pump 1. The diaphragm pump 1 has a drive system 2, of which a drive system head part designed as a drive system chamber section 3 is shown in FIG. 1, and a diaphragm pump head part 4.

[0062] The diaphragm pump head part 4 essentially has a diaphragm housing part 5, a valve plate 7 situated between the diaphragm housing part 5 and a diaphragm housing cover 6, a diaphragm plate 8, and a swash plate 9.

[0063] As can be gathered by way of example from FIGS. 2 and 3, the diaphragm housing part 5 has an inlet 10. The diaphragm housing part 5 also has an outlet 11.

[0064] Between the diaphragm housing part 5 and the diaphragm housing cover 6, the valve plate 7 is located in a stepped recess 12 of the diaphragm housing part 5.

[0065] The valve plate 7 has four inlet valves 13, the valve channels of which are connected on one side to an annular inlet chamber 14 and on the other side to pump chambers 15 covered externally by the valve plate 7. The valve plate 7 has four outlet valves 16, wherein a central outlet valve body is provided. The valve channels of the outlet valves 16 are connected on one side to a central outlet chamber 17 and on the other side to the pump chambers 15. The pump chambers 15, which are open towards the diaphragm housing cover 6, are each closed or restricted by a pump diaphragm that is designed as a section of the diaphragm plate 8. The pump diaphragms are clamped between the valve plate 7 and the diaphragm housing cover 6 and seal the respective pump chamber 15 by means of an annular bead that runs in a groove circumscribing the pump chamber 15.

[0066] The drive system head part has a drive system chamber part 3 with a drive system chamber 18, which is located in front of the diaphragm housing cover 6. When the diaphragm pump head part 4 is placed on the drive system head part, the swash plate 9 located on the diaphragm pump head part 4 is situated in the drive system chamber 18. The swash plate 9 is slipped over a ball bearing 19 that is located on a pin 20 of a drive shaft connected to the drive system 2. The pin 20 is thereby angled with respect to the longitudinal axis of the drive shaft in order to generate a wobbling motion of the swash plate 9.

[0067] FIG. 2 shows the fastening of the diaphragm pump head part 4 on the drive system in an isometric view. A handling element 21, which can be rotated about the longitudinal axis L of the diaphragm pump head part 4, is provided for fastening. The handling element 21 is profiled around the circumference.

[0068] In FIG. 3 is an exploded view of the components provided for fastening the diaphragm pump head part 4 to the drive system 2. Around the circumference of the drive system chamber section 3, bores are provided for bolts 22 that can be screwed to the drive system chamber section 3. Four bolts 22 are provided, which are temporarily fastened to the drive system chamber section 3 at the edge at equidistant angles.

[0069] The diaphragm pump head part 4 has through-holes 23 that are adapted to the outer diameter of the bolts 22 and through which the bolts 22 can be guided. The diaphragm pump head part 4 can essentially be placed on the drive system chamber section 3 along the longitudinal axis L of the diaphragm pump head part 4, the bolts 22 being guided through the corresponding through-holes 23.

[0070] A pressure plate 24 is placed on the outside of the diaphragm pump head part 4, which is spaced apart from the drive system 2, the pressure plate 24 having slotted holes 25 formed around the circumference, through which the bolts 22 can be guided. The pressure plate 24 can be placed on the four bolts 22 and moved in the direction of the diaphragm pump head part 4 along the longitudinal axis L of the diaphragm pump head part 4.

[0071] A support 26, which can also be referred to as a bayonet plate, is fastened to the bolts 22, the position of which is fixed relative to the longitudinal axis L of the diaphragm pump head part 4, or the effective direction of the fastening of the diaphragm pump head part 4 to the drive system 2. The connection between the support 26 and the bolts 22 occurs in the form of a bayonet-type connection in that the support is pushed onto the bolts 22 and rotated relative to them about the longitudinal axis L of the diaphragm pump head part 4. As a result, the head of the bolt 22 comes into contact with the bearing surface of the support 26. The bearing surface faces away from the diaphragm pump head part 4. An undercut on the head of the bolt 22, which faces the direction of the diaphragm pump head part 4, comes into contact with this bearing surface. The support 26 and the pressure plate 24 are connected to one another by means of four screws 27.

[0072] The support 26 has a central through-hole 28 with internal thread. The internal thread is matched to the external thread of a screw element 29 (FIG. 4), and the screw element 29 can penetrate the through-hole 28 and be rotated in the internal thread. By rotating the screw element 29 in the through-hole 28, a contact surface on the front end 30 of the screw element 29 directed towards the pressure plate 24 can act on the pressure plate 24. The screw element 29 is supported on the support 26 by means of the thread engagement and can press the pressure plate 24 and the diaphragm pump head part 4 in the direction of the drive system 2.

[0073] The screw element 29 is mounted centrally in the handling element 21, which can also be referred to as a handwheel. The longitudinal axis of the screw element 29 essentially coincides with the longitudinal axis L of the diaphragm pump head part 4. At the end opposite the end 30, the screw element 29 has a head 31, which is in contact with the handling element 21. A depression 32 is formed in the handling element 21, which at least partially receives the head 31. Recesses 33 are formed circumferentially around the head 31 of the screw element 29, into which the pressure elements 34 are inserted.

[0074] According to FIG. 5, which shows a sectional view of the pressure elements 34, the pressure elements 34 have a sleeve 35, a spring 36, and an engagement piece 37. The screw element 29 is supported on its circumferential side by the handling element 21 via the pressure elements 34, six of which are provided at equidistant angles around the circumference of the head 31 of the screw element 29.

[0075] A retaining element 38 is fastened to the handling element 21 by means of screws 39. The engagement pieces 37 of the pressure elements 34 are engaged with the inner contour of the retaining element 38. An inner contour in the form of a profile is formed on the retaining element 38 as shown in FIG. 6, which shows a front view of the handling element 21 with an enlarged break-out view, which is illustrated again in Detail Z in FIG. 4. The profile 40 has a recess 41 for each engagement piece 37, in which the engagement piece 37 is engaged. For each of the pressure elements 34 in FIG. 4, a recess 41 is provided in the profile 40 of the retaining element 38 at a corresponding point. The recesses 41 are designed identically.

[0076] FIG. 6 shows a different effect when rotating the handling element 21 due to the asymmetrically configured profile 40. Regarding recess 41, the profile 40 is designed asymmetrically in such a way that a driver surface 42 for rotation in the clockwise direction, as is shown schematically in FIG. 6, is angled with respect to the radial line of the handling element 21. Due to the angle, the profile 40 acts functionally like a slip clutch when rotated clockwise together with the pressure element 34. From a certain torque acting on the screw element 29, the engagement piece 37 of the pressure element 34 disengages from the recess 41 with continued rotation. The engagement piece 37 can slip out of the recess 41, which is enabled by the angled driver surface 42.

[0077] When the handling element 21 is rotated counterclockwise, the engagement piece 37 is engaged with a driver surface 43 of the profile 40, which runs essentially parallel to the radial line of the handling element 21. Upon counterclockwise rotation of the handling element 21, it is possible—unlike when it is rotated clockwise—to ensure a constant transmission of force. The engagement piece 37 cannot leave the recess 41 upon counterclockwise rotation.