Patent Description:
It is known that such motors may be controlled by electronic control boards which are arranged in proximity to the motor and connected to the motor by means of electric cables. Such an arrangement may be disadvantageous from the construction and installation point of view, since it requires wiring to establish a connection between the motor and the relative electronic control board.

<CIT> discloses a mounting configuration, in which a board holder is configured to be snap-fitted to an electric motor which may be a brushed motor. The board holder is fitted axially to the motor. <CIT> discloses a brushed motor mounted to an electronic board.

An object of this invention is to provide a solution for integrating the electronic control board directly on the motor. Such a solution would make it possible to avoid the use of wiring, with a consequent reduction in costs.

The subject matter of the invention is a configuration for mounting an electronic control board on a brushed electric motor as defined in the independent claim <NUM>.

Further embodiments of the invention are defined in the dependent claims <NUM> - <NUM>.

According to the invention, the coupling face comprises a first snap tooth protruding from the coupling face and engaging an anchoring formation made on the motor head and a second snap tooth protruding from the coupling face and engaging an edge of the stator housing. This arrangement allows for a particularly effective solution for anchoring the board holder to the motor and requires only a minimum adaptation of the structure of the electric motor. In particular, said first and second tooth may be opposite to each other and facing away from each other.

According to an embodiment, the coupling face further comprises a centering formation projecting from the coupling face and configured to be inserted in a seat formed in the anchoring formation of the motor head. This arrangement makes it possible to achieve precise alignment between the board holder and the electronic board on the one hand, and the electric motor (i.e., stator housing and motor head) on the other.

Preferably, the centering formation comprises at least one longitudinal rib and at least one transverse rib oriented orthogonally to the longitudinal rib. With this arrangement it is possible to obtain an alignment between the parts with respect to two orthogonal directions.

According to an embodiment, the coupling face further comprises at least one stand projection which rests on the edge of the stator housing. In particular, said at least one stand projection may have an abutment surface which cooperates with the second snap tooth to grip a wall of the edge of the stator housing between the snap tooth and the abutment surface. Preferably, there are two abutment surfaces arranged on opposite sides of the coupling face with respect to the second snap tooth. These arrangements allow for the play/tolerances between the components to be compensated, possibly in cooperation with the other arrangements described above.

According to the invention, the coupling face further comprises at least one pair of leaf spring projections configured to engage a side surface of the stator housing. In particular, the leaf spring projections may be opposed to each other and extend from the coupling face divergently from each other. Preferably, the leaf spring projections are arranged according to an alignment direction orthogonal to an alignment direction of said first and second snap tooth. These arrangements allow for the play/tolerances between the components to be compensated, possibly in cooperation with the other arrangements described above.

Further features and advantages of the mounting configuration according to the invention will become clearer from the following detailed description of an embodiment of the invention, made in reference to the accompanying drawings, provided purely for illustrative and non-limiting purposes, wherein:.

With reference to <FIG> and <FIG>, a brushed electric motor <NUM> is shown. Overall, it is a conventional brushed electric motor, comprising a stator with permanent magnets and a rotor provided with windings which are powered by means of brushes.

The figures show a cylindrical stator housing, indicated with <NUM> and made of metallic material, which supports the magnets and forms a magnetic circuit for the electric motor. In the illustrated example, the stator housing <NUM> has the shape of a cylinder or prism with a circular cross section, but more generally it could have the shape of a cylinder or prism with a more complex-shaped cross section.

The figures also show a motor head made of plastic material, indicated with <NUM> and fixed to the stator housing <NUM>. The motor head <NUM> provides at one end of the electric motor <NUM> support for a shaft <NUM> of the electric motor <NUM>. The motor head <NUM> also carries the brushes, the relevant brush holders, and therefore also the motor terminals <NUM> which are connected to the brushes. In the illustrated example, the terminals <NUM> are formed as male terminals, and are two in number.

As will be clarified below, the motor head <NUM> is adapted to allow direct mounting of an electronic control board.

With reference to <FIG>, an electronic control board is indicated as a whole with <NUM>. This board is of the conventional type and may comprise, for example, a speed regulator. However, the circuit configuration of the electronic control board <NUM> is not essential for the purposes of the invention. The electronic control board <NUM> comprises a connector <NUM> configured to be connected to a control system (not shown), for example to the control system of an air conditioning unit of a vehicle. On the opposite face, the electronic control board <NUM> comprises a plurality of board terminals <NUM>, shown in <FIG>, which are configured to be coupled to the terminals <NUM> of the electric motor <NUM>. In the illustrated example, the board terminals <NUM> are made as female terminals, and are two in number as are the male terminals.

To allow direct mounting of the electronic control board <NUM> on the electric motor <NUM>, a board holder is provided, indicated with <NUM> in the figures. In <FIG>, the board holder <NUM> is shown alone, without the electronic control board.

The board holder <NUM> comprises a body made of plastic material, in particular a monolithic body, in which a seat <NUM> is formed, configured to receive the electronic control board <NUM>, and made substantially as a tray. The electronic control board <NUM> may be attached to the seat <NUM> according to different methods known in the art, for example by snap, interference, by means of screws, etc. Preferably, the seat <NUM> is subjected to a potting process to embed the electronic control board <NUM> in a material so as to protect the electronic control board <NUM> from shocks and vibrations and to insulate the board with respect to water, humidity and corrosive agents.

On the board holder <NUM>, on the side opposite to the seat <NUM>, a coupling face <NUM> is formed, configured to be snap-fitted to the electric motor <NUM> and to establish an electrical connection between the motor terminals <NUM> and the electronic control board <NUM>. The coupling face <NUM> is shown in particular in <FIG>.

The coupling face <NUM> of the board holder <NUM> comprises hollow projections <NUM> configured to respectively accommodate the board terminals <NUM> of the electronic control board <NUM>. The hollow projections <NUM> are therefore made as tubular projections which extend from the coupling face <NUM>, and the inner cavities of which are in communication, through a bottom wall 31a of the seat <NUM>, with the cavity of the seat <NUM> in which the electronic control board <NUM> is placed. The hollow projections <NUM> are provided with open ends 34a with windows configured to allow the insertion of the motor terminals <NUM> when the board holder <NUM> is assembled on the electric motor (see in particular <FIG> and <FIG>). Preferably, a respective gasket is arranged inside each hollow projection <NUM> to prevent liquid penetration.

The coupling face <NUM> comprises a first snap tooth <NUM> protruding from the coupling face <NUM>. In the illustrated example, the first snap tooth <NUM> is arranged between the hollow projections <NUM> and is equidistant therefrom. The first snap tooth <NUM> comprises a resilient tab 35a extending from the coupling face <NUM> and a toothed head 35b formed on the free end of the tab 35a.

The coupling face <NUM> also comprises a second snap tooth <NUM> protruding from the coupling face <NUM>. In the example of <FIG>, this second snap tooth <NUM> comprises a resilient tab 36a extending from the coupling face <NUM> and a toothed head 36b obtained on the free end of the tab 36a. <FIG> show a variant where the second snap tooth <NUM> comprises a resilient tab 36a extending towards the coupling face <NUM> and a toothed head 36b obtained on the free end of the tab 36a.

The first and second snap tooth <NUM>, <NUM> are opposite and aligned with each other in a direction parallel to the shaft <NUM> of the electric motor, which will be referred to hereinafter as the longitudinal direction. The first and second snap tooth <NUM>, <NUM> are arranged facing away from each other, i.e., with the respective toothed ends 35b, 36b not facing each other.

The first snap tooth <NUM> is configured to engage - in the assembled condition - an anchoring formation <NUM> formed, in particular as a single piece, on the motor head <NUM>. The anchoring formation <NUM> protrudes radially from the motor head <NUM> and is shaped so as to define a frontal seat 45a facing in a radial direction and a side window 45b facing in a longitudinal direction and communicating with the frontal seat 45a. In the illustrated example, the anchoring formation <NUM> is arranged between the motor terminals <NUM> and is equidistant therefrom.

In particular, in the assembled condition shown in <FIG> the tab 35a of the first snap tooth <NUM> is inserted in the frontal seat 45a of the anchoring formation <NUM> and the toothed head 35b of the first snap tooth <NUM> is inserted in the side window 45b, abutting against one edge of this window.

The second snap tooth <NUM> is configured to engage - in the assembled condition - an end edge 11a of the stator housing <NUM> adjacent to the motor head <NUM>. In particular, in the assembled condition shown in <FIG> and <FIG> the toothed head 36b of the second snap tooth <NUM> abuts against a radially inner surface 11b of the terminal edge 11a of the stator housing <NUM>. The snap tooth of the variant of <FIG> is configured to couple with a stator housing having a larger diameter than the stator housing engaged by the snap tooth of the example of <FIG>.

The coupling face <NUM> of the board holder <NUM> further comprises a centering formation <NUM> projecting from the coupling face <NUM> and arranged adjacent to the first lock tooth <NUM>. The centering formation <NUM> is configured to be inserted into the frontal seat 45a formed in the anchoring formation <NUM> of the motor head <NUM>. The centering formation <NUM> comprises at least one longitudinal rib, i.e., extending in the longitudinal direction, and at least one transverse rib oriented orthogonally to the longitudinal rib. In the illustrated example, the centering formation comprises a lattice of longitudinal ribs 37a and transverse ribs 37b connected to each other and arranged in such a way as to define as a whole a shape (in the example, a sort of inverted T) having a cross section that matches the cross section of the frontal seat 45a of the anchoring formation <NUM>.

The coupling face <NUM> of the board holder <NUM> further comprises at least one stand projection configured to rest on the edge 11a of the stator housing <NUM>. In the illustrated example, two internal stand projections <NUM> adjacent to the second lock tooth <NUM> and two external stand projections <NUM> further away from the second lock tooth <NUM> are provided. The stand projections <NUM> and <NUM> are arranged on opposite sides of the coupling face <NUM> with respect to the second lock tooth <NUM>. In the variant of <FIG>, the root of the second lock tooth <NUM> is connected to the free end of the inner stand projections <NUM>.

Each of the outer stand projections <NUM> also has a respective abutment surface 39a which - in the assembled condition - abuts against a radially outer surface 11c of the edge 11a of the stator housing <NUM>. Thus, in the assembled condition, the abutment surfaces 39a cooperate with the second snap tooth <NUM> to tighten a wall of the edge 11a of the stator housing <NUM> between the second snap tooth <NUM> and the abutment surfaces 39a.

The coupling face <NUM> of the board holder <NUM> further comprises a pair of leaf spring projections <NUM>' configured to engage the radially outer surface 11a, hereinafter also referred to as the side surface, of the stator housing <NUM>. The leaf spring projections <NUM>' are opposed to each other and extend from the coupling face <NUM> divergently from each other. In the assembled condition, the leaf spring projections <NUM>' are subject to bending due to the effect of the engagement with the side surface 11c of the stator housing <NUM>. The leaf spring projections <NUM>' are arranged in a transverse alignment direction orthogonal to the longitudinal alignment direction of the first and second snap tooth <NUM>, <NUM>.

Claim 1:
A configuration for mounting an electronic control board (<NUM>) on a brushed electric motor (<NUM>), said configuration comprising
a brushed electric motor (<NUM>), wherein said brushed electric motor comprises a cylindrical stator housing (<NUM>), a motor head (<NUM>) of plastic material fixed to the stator housing (<NUM>) and carrying brushes and relative brush holders, said motor head providing support for a shaft (<NUM>) of the electric motor (<NUM>), and a plurality of motor terminals (<NUM>) carried by the motor head (<NUM>) and connected to said brushes, and
a board holder (<NUM>) configured to support an electronic control board (<NUM>), said board holder comprising a body made of plastic material in which there is formed a seat (<NUM>) configured to receive the electronic control board (<NUM>), and on which there is formed, opposite to the seat (<NUM>), a coupling face (<NUM>) snap-fitted radially to the electric motor (<NUM>) to establish an electrical connection between the motor terminals (<NUM>) and the electronic control board (<NUM>),
wherein the coupling face (<NUM>) of the board holder (<NUM>) comprises hollow projections (<NUM>) configured to receive board terminals (<NUM>) of the electronic control board (<NUM>) and provided with open ends (34a) in which the motor terminals (<NUM>) are inserted,
wherein the coupling face (<NUM>) comprises a first snap tooth (<NUM>) protruding from the coupling face (<NUM>) and engaging an anchoring formation (<NUM>) formed on the motor head (<NUM>) and a second snap tooth (<NUM>) protruding from the coupling face (<NUM>) and engaging an edge (11a) of the stator housing (<NUM>),
and wherein the coupling face (<NUM>) further comprises at least one pair of leaf spring projections (<NUM>') configured to engage a side surface (<NUM>1c) of the stator housing (<NUM>).