WO2006027807A1

WO2006027807A1 - Valve

Info

Publication number: WO2006027807A1
Application number: PCT/IT2005/000096
Authority: WO
Inventors: Giuseppe Rossetti; Artemio Guerrini
Original assignee: So.Ge.Mi. S.P.A.
Priority date: 2004-09-10
Filing date: 2005-02-22
Publication date: 2006-03-16
Also published as: ITMC20040113A1

Abstract

The present invention refers to a valve with oscillating gate (2) for aeriform fluid ducts, actuated by a stepping motor (7) that drags into rotation a gear assembly (A, B) comprising two worms with gears, directly supported on the frame where the gate is pivoted and the opening closed by the gate is situated.

Description

VALVE

Description

This patent application refers to a valve with oscillating gate for aeriform fluid ducts actuated by an electric micromotor, of the type normally used in ventilated refrigerators for domestic use, in which the thermal exchanger walls are touched by an air flow capable of preventing the formation of frost and ice on the walls.

The air flow travels in a suitable duct provided with ventilation jets and valves with gates to intercept or deviate the air flow.

Although it has been specifically designed to be used in the aforementioned models of domestic refrigerators, the valve of the invention can be advantageously installed in all types of ventilated machines equipped with valves with oscillating gate actuated by electric micromotors. For a better understanding of the advantages of the invention, the description continues with the structural configuration of traditional valves with oscillating gates actuated by a micromotor, for which the valve of the invention intends to be an alternative solution with equivalent efficacy and reduced cost.

First of all, it must be noted that the gear motor assembly that is currently used comprises a bearing box with cover, which houses and supports both the elecri micromotor and all the gears that form the reduction gear, with the last gear being adjusted on a shaft that protrudes from the box and ends with a faceted ending pin suitable to be inserted into the faceted hub of the gate. The gate is pivoted to a box-shaped bearing base, whose bottom features the opening covered by the gate, while the two transversal opposite walls feature the supporting housings for the pivoting pins of the gate, which are normally obtained from one moulded piece with the gate. One of the pin has a faceted hub where the faceted pin that protrudes from the assembly box of the gear motor assembly is inserted, with the box being engaged and fixed in external position to the box-shaped base. In view of the above, the installation of a similar valve on board the machine includes three different operations and assembly stages:

- assembly of the gear motor assembly, which comprises the bearing box with cover, gear assembly and electric micromotor; - assembly of the valve assembly, which comprises the gate with pivoting pins and the box-shaped base;

- assembly of the gear motor assembly in external position on one of the transversal walls of the box-shaped base.

A critical analysis of the structural configuration and assembly modes of the aforementioned type of valves with oscillating gates has shown that the production cost is considerably affected by the high number of parts that form the gear motor assembly and consequently by the time needed for assembly, with the addition of the time needed to fix the gear motor assembly in external position on the box-shaped base that houses the gate to be moved. The purpose of the present invention is to reduce the said cost by designing a valve with oscillating gate for aeriform fluid ducts, actuated by a micromotor characterised by a small number of parts and simple, rapid assembly. In particular, the valve of the invention makes use of an electric stepping micromotor to actuate a reduction gear formed of two reduction stages, each of them using a worm that engages with a gear with helical tines.

According to the valve of the invention, the reduction gear is fixed directly in external position on one of the two transversal walls of the box-shaped base and contained in a protection case, on which the electric micromotor is fixed in external position. Because of the aforementioned solutions, the number of parts of the gear motor assembly is reduced to the following parts:

- reduction gear composed of three parts, since one of the worms is directly obtained on the shaft of the rotor of the micromotor;

- stepping micromotor; - protection cover of reduction gear.

The following parts have been therefore eliminated with respect to traditional valves with oscillating gates: - series of reduction gears

- the box with cover that houses and supports the reduction gears.

For major clarity, the description of the valve with gate of the invention continues with reference to the enclosed drawings, which are only intended with an illustrative purpose, and not in a limiting sense, whereby:

- Fig. 1 is an exploded axonometric view of all parts of the valve of the invention, showing the internal compartment of the protection cover of the reduction gear;

- Fig. 2 is an exploded axonometric view of all parts of the valve of the invention, showing the external wall of the protection cover where the electric micromotor is fixed.

- Fig. 3 is a cross-sectioned view of the cover, showing the small number of parts of the reducer gear in mutually engaged position.

With reference to the aforementioned figures, the valve (1 ) of the invention comprises an oscillating gate (2) housed in a bearing base (3) with box- shaped configuration, whose bottom is provided with the opening (4) covered by the gate (2), while the two transversal opposite walls (3a and 3b) feature the housings (5) that support the pivoting pins (2a) of the gate (2), being obtained from one moulded piece with the gate. One of the pins (2a) features a faceted hub (2b) where the pin (6) that exits the reducer gear (R) is inserted to drag the gate (2) into alternate oscillations. As electric motor for the actuation of the gate (2), the valve (1) of the invention uses a traditional stepping motor (7), whose rotor drags into rotation a first worm (8) that engages with a gear, whose supporting shaft (10) features a second worm (11 ) that engages with a toothed section (12), whose supporting shaft (13) ends with the said faceted pin (6) designed to be inserted into the hub (2b) of the gate (2).

In order to reduce the number of part of the reduction gear (R), the gear (9) and the second worm (11) are obtained from a single moulded piece (A) with the supporting shaft (10). Likewise, the shaft (13) is obtained from a single moulded piece (B) with the toothed section (12), meaning that the reduction gear (R) is practically formed of two parts only (A) and (B). The support housings of the two parts (A) and (B) are obtained partially on the external side of one (3a) of the two transversal walls of the box-shaped base (3), which, more exactly, feature three forks (14) that exactly, yet partially house the shaft (10), which is otherwise surrounded and held by additional three forks (15) situated on the internal wall of a protection cover (16) with the centring and supporting pin (17) of the toothed section (12). The cover (16), which is basically shaped has a rectangular tub, is provided with four holes (16a) on the four corners for the screws used to fix it in external position to the transversal wall (3a), having suitable dimensions and shape as to perfectly close the mouth of the cover (16).

The case (7a) of the stepping motor (7) is provided with means (7b) used to fix it in external position directly to the cover (16), which is in turn provided with counter-means (16b) designed to cooperate with the said means (7b), which consist in three peripheral tongues that engage into a corresponding series of three slots (16b).

In view of the above, and with reference to the enclosed drawings, the structural configuration of the valve (1) of the invention with relevant operational modes is now apparent. The actuation of the stepping motor (7) drags into rotation the worm (8), the gear (9), the shaft (10), the worm (11 ), the toothed section (12), the faceted pin (6), the gate (2), whose oscillation direction depends on the rotation direction of the motor (7).

Claims

1 ) Valve with oscillating gate for aeriform fluid ducts, actuated by an electric micromotor, of the type comprising an oscillating gate (2) housed in a bearing base (3) with box-shaped configuration, whose bottom is provided with the opening (4) covered by the gate (2), while the two transversal opposite walls (3a and (3b) feature the housings (5) that support the pivoting pins (2a) of the gate (2), being obtained from one moulded piece with the gate; valve (1) being characterised in that as electric motor for the actuation of the gate (2) it uses a traditional stepping motor (7), whose rotor drags into rotation a first worm (8) that engages with a gear, whose supporting shaft (10) features a second worm (11 ) that engages with a toothed section (12), whose supporting shaft (13) ends with the said faceted pin (6) designed to be inserted into the hub (2b) of the gate (2); it being provided that the external side of one (3a) of the two transversal walls of the box-shaped base (3) features three forks (14) that exactly, yet partially house the shaft (10), which is otherwise surrounded and held by additional three forks (15) situated on the internal wall of a protection cover (16) with the centring and supporting pin (17) of the toothed section (12); it being additionally provided that the cover (16) is fixed in external position to the wall (3a) and acts as support for the motor (7). 2) Valve as defined in claim above, characterised in that the gear (9) and the second worm (11) are obtained from a single moulded piece (A) with the supporting shaft (10), and in that the shaft (13) is obtained from a single moulded piece (B) with the toothed section (12), meaning that the reduction gear (R) is practically formed of two parts only (A) and (B). 3) Valve as defined in any of the above claims, characterised in that the cover (16) is shaped as a rectangular tub and provided with four holes (16a) on the four corners for the screws used to fix it in external position to the transversal wall (3a). 4) Valve as defined in any of the above claims, characterised in that the wall (3a) of the box-shaped base (3) is suitably dimensioned and shaped as to perfectly close the mouth of the cover (16).

5) Valve as defined in any of the above claims, characterised in that the case (7a) of the stepping motor (7) is provided with means (7b) used to fix it in external position directly to the cover (16), which is in turn provided with counter-means (16b) designed to cooperate with said means (7b).

6) Valve as defined in claim 2, characterised in that the worm (8) is obtained on the shaft of the rotor of the micromotor (7).