GB2184611A - Improvements in or relating to fixing elements for electric motors - Google Patents

Abstract

A fixing element for mounting an end flange (10) of a motor 6 in a cradle 7 in such a way as to be freely rotable, formed by a single piece of plastics material provided with a circular aperture to permit the passage therethrough of the motor shaft 24, a lower support surface for engagement with the semicircular seating 9 on arm 8 of the cradle 7, first 12 and second 17, 23 means for damping relative movement of the motor and cradle, and latching means 18, 19 for engaging corresponding projections 22 on the cradle in resilient opposition to the elements 23 of the second damping means. The assembly may be employed in laundry machine and arranged to automatically tension the drive belt. <IMAGE>

Description

SPECIFICATION Improvements in or relating to fixing elements for electric motors The invention concerns an elementforfixing an electric motor, in particular for an electric drive motor in a drum-type laundry drying machine for domestic use.

In that type of machine, the electric motor is generally fixed on a metal support cradle which in turn is anchored to the base of the casing for transmitting the motion both to the drum for the laundry and to the fan for the drying air circuit, by means of conventional belt-type transmission means.

Besides performing those functions, the motor is frequently also so arranged as to participate in tensioning the transmission means of flexible belt type. For that purpose, the motor is also fixed to the support cradle in such a way as to be capable of oscillating movement and a belt-tensioning pulley is connected to the external shielding thereof in such a way as to come into operative engagement when the rotor is driven.

In particular, the most widely used construction provides that the end flanges of the drive shaft are shaped (with teeth and shoulders) to receive and lock in respect of rotary movement corresponding rubber damper rings, the purpose of which is to reduce the vibration and noise caused by the eccentricity of the rotary members and the structural and assembly tolerances.

Mounted then on the above-mentioned rubber rings are metal ferrules or bushes which are suitably shaped to provide for oscillating support for the motor between corresponding semicircular seatings which are provided in the two vertical arms of the support cradle. Finally, by means of clamping clips of screw type or with steel blade springs, the assembly is fixed within the corresponding seatings in the arms of the support cradle.

It will be appreciated that such a construction is disadvantageous because it requires a high number of components of different shapes and a corresponding number of assembly operations.

Besides that, some components such as the rubber rings or the steel blade springs are excessively expensive.

An alternative solution provides that the terminal flanges of the motor shaft are supported in bores provided in the support cradle, with the interposition of rings of anti-friction and selflubricating material. That construction necessarily requires a support cradle which can be dismantled in a plurality of components in such a way that the arms thereof can be individually mounted to the flanges of the motor and subsequently anchored to each other and to the base of the casing by means of screw systems. In that case, the large number of screw-type connections required for assembly of the support cradle compromise the axial relationship of the unit and correct positioning of the rotating parts of the assembly.

According to the present invention there is provided an element for fixing the drive motor of a laundry dryer machine, in particular for fixing, in such a way as to be freely rotatable, an end flange of the motor to the open support seatings of a conventional one-piece metal cradle which is anchored to the base of the casing of a domestic laundry dryer, the said apparatus being formed by a single piece of plastic material provided in itself with: a circular aperture and a seating around same, which are respectively arranged to permit the passage therethrough of an end of the motor shaft and to house freely rotatably an end flange of the motor; a lower support surface whose profile corresponds at least in part to the edge of the support seatings of the cradle; first and second means for damping the oscillations of the motor; means for positioning and retaining the element on the respective seating of the cradle; and latching means capable of engaging corresponding projections on the cradle in resilient opposition to said second damping means.

The invention further provides a fixing element for mounting an end flange, conforming to a cylindrical surface, of a motor in a supporting cradle, the mounting element being in the form of an annular structure and having a cylindrical socket therein for accommodating said end flange in a manner which permits free relative rotation of the mounting element and motor end flange, first and second means for damping relative movement of the motor and cradle, means providing a lower support surface for engaging a seating edge of the cradle for mounting the mounting element on the cradle, means for positioning and retaining the element on the seating edge of the cradle and latching means for engaging corresponding means on the cradle in resilient opposition to the second damping means.

As will become apparent from the following description, the illustrated embodiment of the invention provides for fixing of the motor on a conventional one-piece support cradle by means of a reduced number of components and in such a way as to simplify mounting operations and to reduce the costs thereof. Another aim of the invention is to effect that type of fixing while maintaining if not improving the level of reliability of the support and damping arrangements which are in use at the present time.

The advantages of the fixing element according to the invention will be better appreciated from the following description and the accompanying diagrammatic drawings in which: Figure 1 is a front view of the fixing element according to the invention, Figure 2 is a view of the fixing element in longitudinal section taken along line Il-Il in Figure 1, Figure 3 is a front view of the element according to the invention in the position of fixing the motor on the support cradle, and Figure 4 is a partly sectioned side view of the arrangement illustrated in Figure 3.

The fixing element 5 shown in the drawings makes it possible to fix an electric motor 6 (see Figures 3 and 4) on a conventional one-piece metal cradle 7 which is anchored to the base of the casing of a domestic laundry dryer.

The support cradle 7 has two vertical arms 8 and provided on the free end of each of the arms 8 is a respective semicircular seating 9 for supporting the end flanges 10 of the motor 6 (see Figure 4).

The fixing element 5 is made in one piece from injection-moulded thermoplastic material (for example an anti-friction and self-lubricating acetal copolymer such as Hostaform, a registered trademark of Hoechst AG).

The element 5 is of a substantially annular shape with a circular aperture 31 for permitting the end 24 of the motor shaft to pass therethrough (see Figure 4). Provided around the aperture 31 is a circular zone 11 of L-shaped profile, for freely rotatably housing the respective end flange 10 of the electric motor 6 (see Figures 1 and 2).

The vertical side of the above-mentioned Lshaped configuration is provided with resilient tongue portions 12 which are bent over towards the region for accommodating the flange 10, in order to damp any horizontal oscillations of the motor 6.

Provided in the lower region of the element 5 are three straps orfiaps 13,14and 15 which extend vertically downwardly and which define therebetween a passage 16 which permits the element 5 to be connected to the metal cradle 7, and a surface 20 of semicircular configuration for supporting the element Son the corresponding semicircular seating 9 on the cradle 7.

The flaps 13, 14 and 15 are provided with resilient tongue portions 17 which are bent over towards the passage 16 for damping any oscillations of the element 5 with respect to the support frame 7.

Further damping tongue portions 23 which are bent over downwardly are provided on the semicircular surface 20 in order to absorb longitudinal oscillations of the element 5 with respect to the support cradle 7.

In order to ensure the connection thereof to the metal cradle 7, the element 5 is provided with two lateral limb portions 18 and 19 which are turned over downwardly and which are provided with a slot 21 for engagement onto projections 22 provided at the sides of the semicircular seating 9 of the cradle 7.

The operation for fixing the motor 6 begins with superpositioning of the seatings 11 of the elements 5 around the respective end flanges 10 of the motor.

After that, the passage 16 in each element 5 is positioned astride the respective seating 9 of the cradle 7, with the central strap or flap 14 positioned on the outward side of the arm 8 of the cradle 7 and with the two side straps or flaps 13 and 15 positioned on the inward side thereof.

Finally, it is only necessary to apply a pressure to the elements 5 to cause the lateral limb portions 18 and 19 to come into latching or clasping engagement with the corresponding projections 22 on the cradle 7, against the resilient reaction of the tongue portions 23. That therefore attains the main aim of the present invention, namely substantially to reduce the number of components necessary for fixing the motor 6 on a conventional one-piece metal cradle 7.

Furthermore, by virtue of the element Sin accordance with the invention which is provided in itself with slidable support seats, damper means and means for latching engagement with the cradle 7, the costs derived from construction and assembly of a number of parts of different and inexpensive materials are advantageously eliminated.

Finally, also eliminated are any shaping operations to be carried out on the end flanges 10 of the motor 6 to make them suitable for connection to damping and fixing means and to the support cradle 7.

Claims (12)

1. An element for fixing the drive motor of a laundry dryer machine, in particular for fixing, in such a way as to be freely rotable, an end flange of the motor to the open support seatings of a conventional one-piece metal cradle which is anchored to the base of the casing of a domestic laundry dryer, the said apparatus being formed by a single piece of plastic material provided in itself with: a circular aperture and a seating around same, which are respectively arranged to permit the passage therethrough of an end of the motor shaft and to house freely rotatably an end flange of the motor; a lower support surface whose profile corresponds at least in part to the edge of the support seatings of the cradle; first and second means for damping the oscillations of the motor; means for positioning and retaining the element on the respective seating of the cradle; and latching means capable of engaging corresponding projections on the cradle in resilient opposition to said second damping means.

2. An element according to claim 1 wherein said seat which is capable of freely rotatably housing an end flange of the motor is formed by a circular region of L-shape profile and said first damping means comprise resilient tongue portions provided in the vertical side of said L-shaped configuration and which are bent over towards the region for housing the flange of the motor.

3. An element according to claim 1 or 2 wherein said retaining means comprise three straps which extend vertically downwards and which define therebetween a passage for positioning of the element on the cradle and said surface of semicircular configuration for supporting the element on the corresponding semicircular seating of the cradle.

4. An element according to claim 1, 2 or 3 wherein said second damping means comprise resilient tongue portions which are respectively provided in the straps and in the semicircular surface and which are respectively bent over towards the passage and downwardly to absorb oscillations of the element with respect to the support cradle.

5. Apparatus according to any one of the preceding claims wherein said latching means comprise two lateral limb portions which are turned over downwards and which are provided with a slot capable of latching onto projections provided at the sides of the semicircular seating of the cradle.

6. A fixing apparatus constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

7. A drive assembly for a laundry dryer comprising an electric motor having end flanges at opposite ends thereof, a "C"-shaped cradle between the limbs of which the motor is mounted, the motor being secured to the cradle by means of a pair of fixing elements according to any one of the preceding claims.

8. A fixing element for mounting an end flange, conforming to a cylindrical surface, of a motor in a supporting cradle, the mounting element being in the form of an annular structure and having a cylindrical socket therein for accommodating said end flange in a manner which permits free relative rotation of the mounting element and motor end flange, first and second means for damping relative movement of the motor and cradle, means providing a lower support surface for engaging a seating edge of the cradle for mounting the mounting element on the cradle, means for positioning and retaining the element on the seating edge of the cradle and latching means for engaging corresponding means on the cradle in resilient opposition to the second damping means.

9. An element according to Claim 8, in which said first damping means comprise resilient tongue portions provided in the longitudinal end wall of the cylindrical socket which are bent towards the region for housing the end flange for damping relative longitudinal movement of the motor.

10. An element according to Claim 8 or 9, in which said means providing a lower support surface for engaging a seating edge of the cradle comprises three straps, alternately at opposite sides of, and defining a groove on the edge of the element for positioning the mounting element on the cradle, and a part circular surface for supporting the element on the corresponding part circular seating of the cradle.

11. An element according to claims 8 to 10, in which said second damping means comprise resilient tongue portions respectively provided in said straps and said part circular surface which are respectively bent into the slot and towards the edge of the element for damping relative movement of the fixing element and the cradle.

12. An element according to claims 8 to 11, in which said latching means comprise two lateral limb portions which are turned downwards, each of which is provided with a slot into which projections provided at the sides of the semicircular seating protrude.