GB2471526A

GB2471526A - Mounting assembly for a sensor

Info

Publication number: GB2471526A
Application number: GB0911605A
Authority: GB
Inventors: Andy Anthony
Original assignee: MONITRAN Ltd
Current assignee: MONITRAN Ltd
Priority date: 2009-07-03
Filing date: 2009-07-03
Publication date: 2011-01-05
Also published as: GB0911605D0

Abstract

A mounting assembly includes a first component (2) and a second component (4) that are constructed and arranged to be releasably interconnected. The first component (2) includes a male connector (6) and the second component (4) includes complementary female connector (8) that is constructed and arranged to receive the male connector by insertion in the direction of a first axis. 'The male connector (6) and the female connector (8) include complementary locking formations that are inclined relative to the first axis. The second component (4) includes a releasable locking element (26) that is constructed and arranged to engage the male connector (6) when the first and second components are interconnected and to urge the male connector in a direction that is substantially perpendicular to the first axis. The first and second components are locked together by interaction of the inclined locking formations.

Description

MOUNTING ASSEMBLY

The present invention relates to a mounting assembly and in particular, but not exclusively, to a mounting assembly for a sensor, for example an accelerometer.

Accelerometers are used in wide variety of situations to monitor vibrations or other movements. For example, they may be used for monitoring vibrations in bearings used in heavy machinery, wind turbines, paper-making machines and so on.

* : : In order to monitor vibrations accurately, the accelerometer must be mounted rigidly to the * component that is to be monitored. Various mounting methods are used, including * 10 adhesives and magnetic mounts, but in the majority of cases a threaded mount is used. The * thread may be provided either directly on the accelerometer casing so that is screwed directly to the monitored component, or it can be provided on a mounting stud or adaptor *..: that is used to attach the accelerometer to the monitored component. In some cases, a very *, coarse screw thread having typically only one half to three quarters of a turn may be used to provide a quick-fit mount that can be secured and released relatively quickly.

One problem with using a threaded mount is that rotating the accelerometer sensor can cause the attached signal cable to twist and possibly break. There is therefore a risk of damaging the accelerometer both during installation and also in any subsequent maintenance operation. This applies both to sensors with an integral cable and also, in some circumstance, to sensors with a releasable cable connection. However, threaded mounts are often preferred, as they ensure both accuracy of mounting and also a reliable, rigid connection to the monitored component.

It is an object of the present invention to provide a mounting assembly, and in particular but not exclusively a mounting assembly for an accelerometer sensor, that mitigates at least some of the aforesaid disadvantages.

According to the present invention there is provided a mounting assembly including a first component and a second component that are constructed and arranged to be releasably interconnected, wherein the first component includes a male connector, the second component includes a complementary female connector that is constructed and arranged to receive the male connector by insertion in the direction of a first axis, the male connector and the female connector include complementary locking formations that are inclined relative to the first axis, and the second component includes a releasable locking element that is constructed and arranged to engage the male connector when the first and second components are interconnected and to urge the male connector in a direction that is substantially perpendicular to the first axis such that the first and second components are locked together by interaction of the inclined locking formations.

The mounting assembly comprises two components that can be locked together rigidly and *::: : securely. No relative rotation of the two components is required, thus avoiding any risk of *::: :* damaging a cable or similar element attached to either of the components. The components can be locked together quickly and easily, simply by use of a single locking element. Precise alignment of the components when locked is ensured.

Advantageously, the male and female connectors are each at least partially tapered, the tapered parts of the male and female connectors thus providing the locking formations.

* : This arrangement provides a particularly secure connection and ensures accurate alignment of the components. Preferably, the male connector is at least partially frusto-conical and the female connector includes a bore that is at least partially frusto-conical, the frusto-conical parts of the male and female connectors forming the locking formations.

Advantageously, the female connector includes a bore having a first part that is frusto-conical and a second part that is enlarged relative to the first part, the first and second parts being located on opposite sides of a plane that extends substantially parallel to a longitudinal axis of the bore. This allows the male connector to be inserted into and removed from the female connector.

Advantageously, the locking element comprises a threaded member, for example a grub screw. Advantageously, the locking element extends substantially radially through a circumferential wall of the female connector.

Advantageously, the male and female connectors each include an end face, which are constructed and arranged to abut one another when the first and second components are fully engaged. This prevents relative movement in the axial direction and provides a secure connection between the components.

Advantageously, the first component and the second component each include a longitudinal axis, said longitudinal axes being substantially coaxial when the first and second components are fully engaged. This ensures good transmission of vibrations and movements through the assembly.

Advantageously, at least one of the first and second components includes a fastener for fastening the assembly to an external component. Preferably, the fastener comprises a *..S .. : threaded fastener, although other types of fastener may alternatively be used. *...

s.' Advantageously, the fastener is provided on the first component, which may comprise a * : : :* stud for attachment to the external component.

Advantageously, at least one of the first and second components includes a holder for a * 45 sensor, for example an accelerometer. Preferably, the holder comprises a bore into which * : the sensor fits, although it may alternatively take any other suitable form. Advantageously, the holder is provided on the second component, which may comprise an adaptor.

Alternatively, at least one of the first and second components may include a sensor: that is, the sensor may be an integral part of that component, rather than a separate component. In this case, the second component preferably includes the sensor.

According to another aspect of the invention there is provided a mounting assembly according to any one of the preceding statements of invention, for mounting an accelerometer on a machine or structure to sense vibrations or movements in the machine or structure.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a top view of a mounting stud; Figure 2 is a sectional side view of an adaptor; Figure 3 is an end view of the adaptor from the left, and Figure 4 is an end view of the adaptor from the right, Figure 5 is a partial sectional side view illustrating a construction method, and Figure 6 is an end view of the adaptor from the right illustrating the construction method.

The mounting assembly comprises two components: a stud 2 shown in Figure 1 for attachment to a component that is to be monitored (not shown), and an adaptor 4 shown in Figures 2 to 4 that receives an accelerometer sensor (not shown) and is releasably attached to the stud 2. The stud 2 includes a male connector 6 that is received in a complementary female connector 8 in the adaptor 4. Both parts of the mounting assembly are made of a to suitable rigid material, preferably stainless steel. It should be appreciated that any other suitable material may be used, including for example other metals, plastics or ceramics. * ..

The stud 2 shown in Figure 1 is a one-piece component having a male connector body 6 at one end (shown as the left end in the drawings) and a fastener 10 at other end (shown as * : *.: the right end). In this example, the fastener 10 comprises a short shaft with a male screw * : * * thread, which can be screwed into a corresponding female threaded bore in the monitored component (not shown). The fastener also includes a hexagonal nut 12, which allows the stud to be fastened tightly to the monitored component with a spanner.

It should be understood that any other suitable fastener may be used to fasten the stud 2 to ---the monitored component. For example, the stud 2 may include a bore with a female thread for attachment to a male threaded fitting on the monitored component.

Alternatively, the stud 2 may be attached to the monitored component by any other suitable method, for example by being welded, riveted or attached with adhesive to the component.

The male connector body 6 of the stud 2 is circular in cross-section and at least partially frusto-conical. In this example, the connector body is in two parts, the first part 6a that is closer to the fastener 10 being cylindrical while the second part 6b that is further from the fastener is frusto-conical. The walls 14 of the frusto-conical part 6b are inclined outwards relative to the longitudinal axis 16 of the stud, for example at an angle of approximately 8°, so that the diameter of the connector body 6 increases towards the outer end face 18 of the connector body. The frusto-conical part 6b of the connector body is considerably longer than the cylindrical part 6a: in this example the frusto-conical part 6b of the connector body has a length of 8mm, and the cylindrical part 6a has a length of 1mm. The circular end face 18 of the connector body is substantially flat.

The adaptor 4 shown in Figures 2 to 4 is externally substantially cylindrical in shape. At the left-hand end of the adaptor 4 as shown in the drawings a cylindrical axial bore 20 is provided. This forms a holder to accommodate the accelerometer sensor (not shown). The shape and size of this bore 20 may be adapted to fit the accelerometer sensor. Preferably, the bore 20 is designed so that the accelerometer sensor has a push-fit. If necessary, fastening means (not shown) may be provided for securing the sensor within the bore, *:::. which may for example be mechanical, magnetic or adhesive. 0***

At the right-hand end of the adaptor 4 as shown in the drawings, the female connector 8 is * * : :* provided: this comprises a second axial bore, which is shaped to receive the tapered male connector body 6 of the stud. As can be seen in Figure 2, the bore 8 has a tapered portion 8a that forms the upper part of the bore and a cylindrical portion 8b that forms the lower * :" part of the bore. The tapered portion 8a is matched to the shape of the frusto-conical male * : * connector 6 of the stud. The cylindrical lower part 8b of the bore is enlarged relative to the tapered upper part, allowing the frusto-conical male connector 6 to be inserted and removed. The bore 8 is surrounded by a circumferential wall 22 and is terminated by a substantially flat end face 24.

A grub screw 26 is provided within a threaded bore 28 that extends radially through the lower part of the circumferential wall 22 into the second bore 8. When the male connector body 6 of the stud 2 has been inserted into the female connector bore 8 of the adaptor 4, the grub screw 26 can be tightened against the male connector body 6 to press the inclined wall 14 of the connector body against the inclined inner surface of the wall 22 in the upper part of the adaptor. This provides a rigid connection between the stud and the adaptor, the inclined wall 14 of the stud being pressed against the corresponding inclined wall 22 of the adaptor, and the end face 18 of the stud being pressed against the end face 24 of the bore in the adaptor. When the two parts are fully engaged, the longitudinal axes of the stud 2 and the adaptor are aligned 4.

In use, the stud 2 shown in Figure 1 is first fastened to the component to be monitored (not shown), for example by screwing it into a suitable threaded hole. It is then tightened securely using a spanner.

The accelerometer sensor (not shown) is then inserted into the holder bore 20 in the left-hand end of the adaptor 4. If necessary, the sensor may be fastened within the bore, for example using a suitable adhesive. The accelerometer sensor may have either an integral sigual cable or a connector for a separate cable: in the latter case, the cable may now be connected.

The adaptor 4 is then placed over the stud 2 so that the frusto-conical male connector body 6 of the stud enters the corresponding female connector bore 8 in the right-band end of the adaptor 4. The grub screw 26 is then tightened to attach the adaptor 4 securely to the stud 2. It should be noted that no rotation of the adaptor 4 takes place, thereby avoiding any *:*::* risk of damage to the cable.

A method of making the female connector bore 8 in the adaptor 4 is illustrated in figures 5 & 6. First, a cylindrical axial hole is cut to a first diameter (for example, 13.05mm) and a * first depth (for example 8mm). Second, this hole is bored to provide a taper that increases * in diameter (for example from 13.05mm at the end of the adaptor to 15.00mm at a depth of 8mm). Finally, the size of the hole is increased by using a larger cutter (for example with a diameter of 15.05mm), which is offset from the original axis (for example by 1.0mm).

This provides a hole that is frusto-conical in its upper part and cylindrical in its lower part.

Various modifications of the mounting assembly are possible. The male connector 6 may be only partially frusto-conical, or it may include a simple tapered portion that engages a complementary tapered portion in the female connector 8. The grub screw 26 may be replaced by another locking element that urges the male connector in a direction that is substantially perpendicular to the longitudinal axis of the assembly. The male and female connectors may be reversed, so that the stud 2 provides the female connector and the adaptor 4 carries the male connector. The sensor may form an integral part of the adaptor rather than being held by it. The mounting assembly may also be employed for mounting sensors other than accelerometers, or components that are not sensors. -7.-

Claims

CLAIMS1. A mounting assembly including a first component and a second component that are constructed and arranged to be releasably interconnected, wherein the first component includes a male connector, the second component includes a complementary female connector that is constructed and arranged to receive the male connector by insertion in the direction of a first axis, the male connector and the female connector include complementary locking formations that are inclined *:::: relative to the first axis, and the second component includes a releasable locking *::: :* element that is constructed and arranged to engage the male connector when the first and second components are interconnected and to urge the male connector in a *.*:, direction that is substantially perpendicular to the first axis, such that the first and second components are locked together by interaction of the inclined locking formations. S....

*: .
2. A mounting assembly according to claim 1, in which the male and female connectors are each at least partially tapered.
3. A mounting assembly according to claim 2, in which the male connector is at least partially frusto-conical and the female connector includes a bore that is at least *: :: . partially frusto-conical. * *5*

*t'c'*
4. A mounting assembly according to claim 3, in which the female connector includes : s'* a bore having a first part that is frusto-conical and a second part that is enlarged * relative to the first part, the first and second parts being located on opposite sides of * * * a plane that extends substantially parallel to a longitudinal axis of the bore.
5. A mounting assembly according to any one of the preceding claims, in which the locking element comprises a threaded member.

**...S * .
6. A mounting assembly according to claim 5 in which the locking element extends substantially radially through a circumferential wall of the female connector.
7. A mounting assembly according to any one of the preceding claims, in which the male and female connectors each include an end face, which are constructed and arranged to abut one another when the first and second components are fully engaged.
8. A mounting assembly according to any one of the preceding claims, in which the first component and the second component each include a longitudinal axis, said longitudinal axes being substantially coaxial when the first and second components are fully engaged.
9. A mounting assembly accordin.g to any one of the preceding claims, in which at least one of the first and second components includes a fastener for fastening the : assembly to an external component. S.. * * S S..'
10. A mounting assembly according to claim 9, in which the fastener comprises a * :* : :* threaded fastener.
11. A mounting assembly according to claim 9 or claim 10, in which the fastener is provided on the first component.S'S...

*
12. A mounting assembly according to any one of the preceding claims, in which at least one of the first and second components includes a holder for a sensor.
13. A mounting assembly according to claim 12, in which the holder comprises a bore.

*
14. A mounting assembly according to claim 12 or claim 13, in which the holder is 4** provided on the second component.
15. A mounting assembly according to any one of claims I to 11, in which at least one of the first and second components includes a sensor. * *** .
16. A mounting assembly according to claim 15, in which the second component .: includes the sensor. I *S * ****
17. A mounting assembly according to any one of the preceding claims, for mounting an accelerometer on a machine or structure to sense vibrations or movements in the machine or structure.