GB2070727A - Motor mounting - Google Patents

Abstract

A motor mounting 10 enabling a drive such as belting 28 driven by a motor 11, to be kept under tension when the belting 28 stretches, comprises a platform 12 mounted for pivotal movement about an axis therebeneath and biassing means 13, 13 connecting the platform 12 to support structure and urging the platform 12 to tend to pivot about the axis to apply tension to the belting 28. <IMAGE>

Description

SPECIFICATION Motor mounting This invention relates to a mounting for a motor which is used to drive apparatus via a drive, such as one or more V-belts, a timing belt or one or more chains. The motor can be an electric or hydraulic motor, internal com bustion engine or the like. Most drives are liable to stretch whilst in use, and to maintain sufficient driving tension in the drive con nected between a motor and driven apparatus it is usual for a motor to be mounted to enable it to be movable to apply the necessary tension, the driven shaft of the driven appa ratus usually not being amenable to such movement, and the provision of extra tension ing pulleys being an undesired expense.

In one common known motor mounting for this purpose, a motor bearing plate is sup ported on slides and can be moved by means of a lead screw. The problem with this ar rangement, however, is that the amount of adjustment is limited. After the lead screw has been turned sufficiently to achieve desired drive tension, only a limited amount of use is possible before further adjustment is neces sary. Such an arrangement may need adjust ment once every three days on a machine in regular use, and this naturally increases main tenance time.

An object of the present invention is to provide an improved motor mounting.

Accordingly the invention provides a motor mounting in the form of a platform supported for pivotal movement about an axis there beneath, and biassing means for urging the platform to pivot about the axis.

The platform may be a simple plate having apertures by means of which a motor can be bolted thereto. Alternatively it can be a frame or other suitable structure.

Preferably the axis is centrally disposed be neath the plate.

The axis can be defined by the coincident axes of a pair of assemblies which constitute the biassing means. Each assembly can com prise a first member secured to the plate, and a second member united with the first mem ber for resilient pivotal movement and secura 'ble to support structure.

One of the members of each assembly can be a short rectangular tube and the other member can include a short rectangular bar disposed in the tube to define therewith four triangular recesses, each substantially filled by a prestressed resilient insert of rubber or plas tics material. The rectangular bar can be se cured to a cylindrical block clampable to other structure in any desired angular position to apply biassing to the first member.

The cylindrical block can be clampable by a bracket to a support structure, or to a foot forming part of the mounting.

The invention will be described further, by way of example, with reference to the accompanying drawings, which illustrate a preferred embodiment thereof, it being understood that the following description is illustrative and not limitative of the scope of the invention. In the drawings: Figure lis a side elevation of a preferred embodiment of motor mounting of the invent tion showing a motor positioned thereon; Figure 2 is a plan view of the mounting; Figure 3 is an end elevation of the mounting; and Figure 4 is an enlarged, fragmentary, exploded view showing one tensioning assembly of the mounting of the invention.

A preferred embodiment of mounting 10 of the invention for an electric motor 11 comprises a platform in the form of a steel plate 1 2 supported by a pair of assemblies 1 3 which define an axis 1 4 beneath the plate 1 2 about which the plate 1 2 is pivotable.

Each assembly 1 3 (Fig. 4) comprises a first member 1 5 in the form of a short squaresection tube fastened to the plate 1 2 by screws 1 8 securing a complementary bracket 1 6. Accommodated within member 1 5 is a second member 1 7 in the form of a squaresection bar disposed to define with the tube four triangular spaces 1 9 each of which has had inserted therein a cylindrical body 20 of resilient rubber or plastics material. Each body 20 has, by its insertion been compressed to be prestressed and to achieve a generally triangular cross-section. United with each second member 17, by screws 21, are a first cylindrical block 22 and a second, similar block 23.

The first block 22 enables a biassing force to be applied by the assembly 1 3 and to this end can be secured, as by screws 24 passing through apertures in feet of a clamping bracket 25, to one of two baseplates 26 of the mounting 10 (not shown in Fig. 4). Because the block 22 is cylindrical and the clamping bracket 25 has a generally cylindrical interior the block 22 can be held at any desired angular position relative to the bracket 25.

Second block 23 is apertured at 27 and serves merely to enable block 22 to be turned. It could be replaced simply by a noncircular, e.g. square or hexagonal boss protruding from block 22. Alternatively block 23 could be discarded and a hexagonal socket or the like provided in block 22 to enable it to be turned.

In use the mounting 10 is used to support motor 11 and apply tension to belting 28 passing around a pulley 29 fastened to a shaft 30 of the motor 11. With the baseplates 26 secured to support structure the motor 11 is secured to plate 1 2 and the belting 28 attached. If they have already been tightened, set screws 24 are slackened and a tommy bar or similar tool is inserted in aperture 27 and block 23 (and thus block 22 and member 1 7 therewith) is turned in an anticlockwise direction (in Fig. 1) which applies an appropriate torque to the plate 1 2 via the bodies 20 and member 1 5. The motor pivots with plate 1 2 until prevented from doing so by the tension in belting 28.Pivoting of member 22 is, however, continued some way past this point, compressing the bodies 20. Next the screws 24 are tightened to clamp block 22 in position.

Thus, the tension in the belting 28 is raised to a desirable value. When the belting 28 stretches (as it usually does in use) the tension is not lost immediately, because the bodies 20 continue to urge member 1 5 and thus plate 1 2 in an anti-clockwise direction and so maintain the tension until they have relaxed to a sufficient degree. When this happens the block 22 can be slackened and bias re-applied to the plate 1 2 as described above. Naturally, as the belting 28 lengthens due to stretching the plate 1 2 will tilt more and more to the right (Fig. 1). Thus it is desirable if the support 10 is installed and positioned so that when initial tension is applied the plate 1 2 is tilted to the right.When the full movement of the plate 1 2 has occurred, either the support must be moved or, more likely, new belting will be required.

The support of the invention greatly facilitates the maintenance of tension in belting engaged with a motor, and the adjustment (of members 22 to re-apply bias to the two assemblies 13) may need to be carried out at intervals of a few months rather than a few days as has been necessary with some known previous supports.

The invention is not limited to the precise details of the foregoing and variations can be made thereto within the scope of the following claims. For example, the platform can be a frame or other suitable arrangement replacing plate 1 2. The baseplates 26 can be dispensed with if desired and the brackets 25 secured directly to supporting structure.

The assemblies 1 3 need not be as described and each could incorporate a windable spring arrangement. Any convenient mechanism can be used to apply the bias to urge the platform to pivot about the axis.

Claims (11)

1. A motor mounting in the form of a platform supported for pivotal movement about an axis therebeneath, and biassing means for urging the platform to pivot about the axis.

2. A mounting as claimed in claim 1, wherein the platform is a plate.

3. A mounting as claimed in claim 1, wherein the platform is a frame.

4. A mounting as claimed in claim 1, 2 or 3, wherein the axis is disposed centrally beneath the platform.

5. A mounting as claimed in any preceding claim, wherein the axis is defined by the coincident axes of a pair of assemblies which constitute the biassing means.

6. A mounting as claimed in claim 5, wherein each assembly comprises a first member secured to the platform, and a second member united with the first member for resilient pivotal movement and securable to support structure.

7. A mounting as claimed in claim 6, wherein one of the members of each assembly is a short rectangular tube and the other member is a short rectangular bar disposed in the tube to define therewith four triangular recesses, each substantially filled by a pres tressed resilient insert of rubber or plastics material.

8. A mounting as claimed in claim 1, wherein the bar is secured to a cylindrical block clampable to other structure in any desired angular position.

9. A mounting as claimed in claim 8, wherein the cylindrical block is clampable by a bracket to one of two baseplates of the mounting.

10. A motor mounting substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

11. A motor mounting as claimed in any preceding claim in combination with a motor attached to the platform and connected to a drive, the biassing means urging the platform to pivot about the axis to urge the motor to move in a direction tending to apply tension to the drive.

1 2. A combination as claimed in claim 11 and substantially as hereinbefore described with reference to and as illustrated in Fig. 1 of the accompanying drawings.