Compact gear motor

Abstract

The present invention relates to an electric motor having a cylindrically wound stator assembly forming a free internal space and a rotor assembly guided inside the internal space (6), wherein a gear motor is inside a housing integral with the stator assembly and has an assembly of movable gears, the output of the movable gears being integrated with a motion output shaft, the input element of the movable gears being driven by the rotor assembly extending inside the housing, the gear motor having guiding elements for the output shaft, the output shaft extending inside the motor to guiding elements arranged at least partially inside the rotor assembly, the rotor assembly being guided by guiding means arranged between the inner surface of the rotor assembly and the surface of the output shaft.

Description

Technical Field

[0001] The present invention relates to the field of rotary gear motors, which combine a brushless electric motor and a mechanical reduction gear, such as a trochoid type or an epicyclic type, having significant axial compactness, in an integrated manner.

[0002] Preferably but not exclusively, the present invention finds privileged use in various automotive applications, such as for the operation of valve flaps, such as needles for regulating the flow rate of liquids, camshaft phasers, etc.

Background Art

[0003] Documents presenting gear motors integrating motor and reduction gear functions within the same housing are already known in the prior art. For example, documents US2018022397 and US9303728 present the association of a brushless electric motor and a reduction gear of the trochoid (or cycloid) type. In these solutions, the output shaft is separated from the shaft of the electric motor and is arranged downstream of the motor. The motor shaft is guided by providing bearings at the rear and front of the motor, and the output shaft is guided by rolling bearings and main bearings. Therefore, in these solutions, several large rolling bearings (single and double) are required, and these are hardly compact.

[0004] Document US9041259, which shows the association of an epicyclic (or planetary) reduction gear and a brushless motor, is also known, which particularly clearly presents an output shaft passing upstream of the motor to enable position detection and guide this shaft on the upstream side of the motor. This solution is more compact than the prior art, but requires two rolling bearings for guiding the motor shaft and a rolling bearing and a main bearing for guiding the output shaft. This results in significant production complexity and suboptimal compactness.

Summary of the Invention

[0005] [Problems not solved by conventional technology] These devices of the conventional technology are not economically satisfactory and involve numerous components to ensure the guidance of several rolling bearings and main bearings, which increase the cost of the solution and produce suboptimal axial sizes due to the relatively large size of these guide elements.

[0006] In particular, in known solutions, one output shaft and the other rotor assembly are guided by rolling bearings supported by the motor housing. This introduces a risk of concentric defects, particularly those resulting from manufacturing tolerances, which can adversely affect the performance of the motor and reduction gears, especially efficiency, reversibility, and wear of the reduction gears. [Purpose of the invention] The main objective of this invention is to propose a more economical and compact solution for gear motors by minimizing the size and number of dedicated guide elements such as main bearings and rolling bearings, and supporting this function with elements already present in the gear motor. It also aims to ensure perfect coaxiality between the output shaft and the rotor.

[0007] Conventional solutions result in overstatic systems where misalignment of the rolling bearings in the output shaft and rotor assembly can prevent or degrade the system's operation (performance, noise, reduced lifespan). [Means for solving the problem]

[0008] For this purpose, the present invention relates more particularly to a gear motor having an electric motor and a mechanical reduction gear, wherein the electric motor has a cylindrical winding stator assembly forming a free internal space and a rotor assembly guided inside the internal space, the reduction gear is located inside a housing fixed to the stator assembly and has a movable gear assembly, the output of the movable gear is fixed to a motion output shaft, the input element of the movable gear is driven by the rotor assembly extending inside the housing, the gear motor has a guide element for the output shaft, the output shaft extends inside the motor to a guide element at least partially located inside the stator assembly, and the rotor assembly is guided by a guide means positioned between the inner surface of the rotor assembly and the surface of the output shaft.

[0009] According to different modifications taken separately or in all technically feasible combinations, the guide means is composed of rolling bearings. The aforementioned guide means is composed of a sliding bearing, The guiding means includes a coaxial combination of a rolling bearing and the tubular sleeve (coupling, shaft sheath) of a flange fixed to the stator assembly. The stator assembly is overmolded from an injection-molded plastic material, forming support elements for guiding the output shaft within the internal space. The support element is a cylindrical bore that receives a rolling bearing or main bearing, through which the output shaft is guided. The support element is a cylindrical bore that directly guides the output shaft. The support element for guiding is a sliding bearing obtained by a cylindrical bore directly formed in the overmolding of the stator assembly. The support element for guidance is an insert bearing, The housing and the overmolding extend laterally by corresponding mounting eyelets, The molded stator is located inside the flange, and the housing and flange extend laterally by corresponding mounting eyelets. The input element has a sawtooth shape around it that mechanically cooperates with the sawtooth shape mounted and fixed to the housing, The gear motor has a sawtooth-shaped internal structure that is mounted and fixed in the housing. The sawtooth-shaped internal shape mounted in the housing is generated within the housing to form a single identical part. The sawtooth-shaped internal profile mounted in the housing is directly formed within the housing material or within the overmolding of the stator assembly. A ring made of a very hard material is inserted around the outer circumference of the aforementioned sawtooth-shaped internal structure. The gear motor has a sawtooth internal shape formed on an output disc fixed to the output shaft, and the sawtooth shape cooperates with a gear wheel having an axial extension or cavity that cooperates with a cavity or axial extension fixed to the housing to enable eccentric rotational motion of the gear wheel. The mechanical reduction gear is of the trochoidal type. The input element of the movable gear is a gear wheel having a sawtooth shape around it that mechanically cooperates with the sawtooth internal shape. The mechanical reduction gear is of the epicyclic type. The mechanical reduction gear is of the elliptical or distorted wave type. The output element of the movable gear is an output disc fixed to the output shaft, and the output disc and the gear wheel are fixed axially using hooks. The output element of the movable gear is an output disc fixed to the output shaft, and the rotor assembly and the output disc are pre-stressed in the axial direction. The rotor and disk assembly is pre-stressed in the axial direction. The geared motor comprises a printed circuit arranged between the stator and the bottom of the housing or the flange at the rear of the stator assembly, said circuit comprising a position sensor, for example a magnetic sensitive probe, a Hall probe, cooperating with a magnet attached to the output shaft, The magnetic actuator inserted into the internal space brakes the rotational movement of the rotor assembly which is regulated by its power supply (power supply), The magnetic actuator prevents the rotational movement of the rotor assembly in case of failure of its power supply, The magnetic actuator allows the rotor assembly to rotate freely in case of failure of its power supply.

[0010] The invention and its features and advantages will be better understood, for example given, by reading the embodiments illustrated in the appendix shown below.

Brief Description of the Drawings

[0011] [Figure 1] It is a cross-sectional view of a first embodiment of a geared motor according to the invention. [Figure 2] It is an exploded perspective view of the embodiment shown in FIG. 1. [Figure 3] It is a cross-sectional view of a second embodiment of a geared motor according to the invention. [Figure 4] It is a cross-sectional view of a third embodiment of a geared motor according to the invention. [Figure 5] It is a cross-sectional view of a fourth embodiment of a geared motor according to the invention. [Figure 6] It is a cross-sectional view of a fifth embodiment of a geared motor according to the invention. [Figure 7] It is a cross-sectional view of a sixth embodiment of a geared motor according to the invention. [Figure 8] It is a cross-sectional view of a seventh embodiment of a geared motor according to the invention. [Figure 9] It is a cross-sectional view of an eighth embodiment of a geared motor according to the invention. [Figure 10]Cross-sectional view of the ninth embodiment of the gear motor according to the present invention. [Figure 11a] Cross-sectional view of the tenth embodiment of the gear motor according to the present invention. [Figure 11b] Cross-sectional view of the tenth embodiment of the gear motor according to the present invention. [Figure 12] Exploded perspective view of the embodiment shown in FIG. 11. [Figure 13] Cross-sectional view of the eleventh embodiment of the gear motor according to the present invention. [Figure 14] Exploded perspective view of the embodiment shown in FIG. 13. [Figure 15] Cross-sectional view of the twelfth embodiment of the gear motor according to the present invention. [Figure 16] Exploded perspective view of the embodiment shown in FIG. 15. [Figure 17a] Perspective view of a partial cross-section. [Figure 17b] Exploded perspective view of a partial cross-section of the thirteenth embodiment. [Figure 18a] Exploded perspective view of a partial cross-section. [Figure 18b] Exploded perspective view of a partial cross-section. [Figure 18c] Axial cross-sectional view of the fourteenth embodiment. [Figure 18d] Radial cross-sectional view of the fourteenth embodiment. [Figure 19] Exploded perspective view of the fifteenth embodiment of the gear motor according to the present invention.

Mode for Carrying Out the Invention

[0012] Generally, a gear motor comprises an electric motor (200) associated with a mechanical reduction gear (201), the electric motor (200) consisting of a stator assembly (2), a rotor assembly (26), and a mechanical reduction gear (210) having a movable gear assembly, the output element of the movable gear being secured to a movement output shaft (19), and the input element of the movable gear being driven by the rotor assembly (26).

[0013] Figures 1 and 2 show a first embodiment of a gear motor according to the present invention. In this example, the gear motor comprises a flange (1) in which a brushless electromechanical stator assembly (2) is housed, which here takes the form of an assembly of ferromagnetic laminates overmolded into a plastic material to facilitate the retention of electric windings (3). The electric windings have connectors (4) at press-fit type ends that allow power to be supplied to the windings from a printed circuit (5) located at the rear of the stator assembly (2). This circuit includes, for example, a magnetic position measuring probe (24) for a Hall probe, located on an extension of the output shaft (19). The printed circuit (5) may include all or some electronic components that enable control of the motor. This embodiment is not limiting to the present invention, and the coupling of motor coils can be done, for example, using copper wire tracks (or "lead frames") if the required power is high. The printed circuit (5) can then be removed or retained if it is necessary to have one or more position sensors intended to measure the position of the output shaft (19) of the movable gear assembly or rotor assembly (26). The layout of the printed circuit (5) between the stator assembly (2) and the flange (1) allows for a very compact integration while using the flange (1) to facilitate the dissipation of the calories generated by the printed circuit (5).

[0014] The stator assembly (2) is cylindrical around the rotational axis of the electromachine and defines a free internal space (6) in which the rotor assembly (26) is positioned, and is typically, but not limited to, a magnetic ring (8) fixed to a support (9) which may or may not have magnetic properties. This embodiment of the rotor assembly (26) is not limited to the present invention, and other embodiments conventionally used by those skilled in the art are envisioned, such as an embodiment without magnets, or an embodiment having magnets inserted in or on a ferromagnetic yoke, the magnets may also be positioned entirely or partially on the stator portion. The support (9) extends toward the front of the rotor assembly (26) by a shaft (10) to which the inner ring of a rolling bearing (11) is fixed, and the rotational axis of the rolling bearing is eccentric with respect to the rotational axis of the rotor assembly (26). The outer ring of the rolling bearing (11) is fixed to a disc-shaped gear wheel (12) having a serrated shape (13) around its periphery. Of course, the present invention is not limited to a rotor assembly (26) that is arranged throughout the interior of a stator assembly (2), but extends to any type of configuration that a person skilled in the art might consider. For example, the rotor assembly (26) may have a bell shape so as to house the stator assembly (2) inside while remaining guided by an output shaft (19) passing through the stator assembly (2). An axial bundle configuration well known to a person skilled in the art can also be imagined in which the magnetically active parts of the stator assembly (2) and the rotor assembly (26) face each other in the axial direction of the motor, and nevertheless the rotor assembly (26) remains guided inside the stator assembly (2).

[0015] The stator assembly (2), fixed to the flange (1), is inserted into the housing (14) to form a single integrated unit. The housing (14) has a sawtooth internal shape (15) that cooperates with the sawtooth shape (13) of the gear wheel (12), so that the gear wheel (12) performs cycloidal motion when driven by the rotor assembly (26) via the eccentric rolling bearing (11). Embodiments having multiple wheels (12) are also conceivable but are not shown. The sawtooth shape (15) of the housing is preferably generated directly in the material of the housing (14) forming a single part as shown herein, or it can be generated as a separate part added to the housing (14) if, for example, for robustness requirements, the sawtooth shape must be generated from a material having better mechanical strength than the housing (14). The gear wheel (12) has a set of cavities (16) in which an axial extension (17) of an output disc (18) is positioned. The output disc (18) is guided in rotational motion around the rotational axis of the electromachine by an output shaft (19). Due to the cycloidal motion of the gear wheel (12) and the rotational guidance of the output disc (18), the output disc (18) is driven in rotational motion according to a mechanical reduction ratio imposed by the number of teeth of a serrated shape (13, 15) cooperating according to the teachings of the prior art relating to trochoidal type reduction gears. As will be apparent to those skilled in the art, the axial extension (17) may alternatively be fixed to a housing (14), so that the housing (14) functions as a support for the gear wheel (12). Therefore, the gear wheel (12) describes a circular orbital motion, and the sawtooth shape (15) and the output disc (18) are consequently rigidly coupled or form one identical part. Similarly, the gear wheel (12) may have two non-coplanar profiles (13), one cooperating with the sawtooth shape (15) and the other cooperating with a second sawtooth shape rigidly coupled to the output disc, with the axial extension (17) and cavity (16) being removed.

[0016] The housing (14) has radial extensions complementary to the radial extensions of the flange (1) and has mounting eyelets (36) intended for fixing the gear motor according to the present invention to any external member relevant to the application.

[0017] Accordingly, the housing (14) has a guide section (20) at the front of the gear motor that receives a rolling bearing (21) which guides the output shaft (19) in rotational motion around the rotation axis of the machine, and the output shaft extends at the front to any external member relevant to the application of the gear motor by a connecting shaft (22). The output shaft (19) extends toward the rear of the gear motor so as to pass inside and through the internal space (6) of the rotor assembly (26). The output shaft (19) is guided at the rear of the gear motor by a main bearing (bearing) (25) formed by an extension of the overmolded stator assembly (2) which performs this guiding function directly without the addition of a guide element. In this embodiment, the output shaft (19) of the movable gear assembly is connected to the external member by a connecting shaft (22), but this direct connection mode is not limited to the present invention, and any kind of indirect modification that would be apparent to those skilled in the art is assumed. For example, the output shaft (19) of a movable gear assembly can be coupled to the input wheel of a second movable gear assembly that articulates around an axis parallel to or perpendicular to the output shaft (19), and the output of this second movable gear assembly can be fixed to a means for connecting to an external member.

[0018] According to the main features of the present invention, the output shaft (19) guides the rotor assembly (26) of the apparatus in rotational motion by using two needle-shaped rolling bearings (23) inside the stator assembly (2). In this way, the rotor assembly (26) has effective guidance provided by the output shaft (19) over most of its length.

[0019] The output shaft (19) supports a magnet (7) facing axially at its rear, which is used to detect the angular position of the output shaft (19) with a magnetically sensitive detection probe (24). Position detection is not limited to the magnet / probe pair, and other embodiments such as inductive detection (not shown) may be envisioned.

[0020] In another embodiment not shown herein, to obtain compactness and / or resistance, the inner and / or outer guide tracks of the rolling ball guide element, rolling bearing (11), or needle rolling bearing (23) can be generated directly within a support component, which may optionally be an output shaft (19), a support (9), or a gear wheel (12).

[0021] Figure 3 shows a second embodiment of the gear motor according to the present invention, which is very similar to the first embodiment shown in Figures 1 and 2. This modification differs from the first embodiment in two elements. In fact, at the rear of the gear motor and output shaft (19), an additional guide element (251) of the rolling bearing type is inserted between the main bearing (25), which here acts as a bore for receiving the additional guide element (251), and the output shaft (19). In addition, guidance of the rotor assembly (26) on the output shaft (19) is achieved by sliding the rotor assembly (26) on the output shaft (19), and in this embodiment, then dispensing the needle rolling bearing (23) of the first embodiment. Any additional guide element (251) other than a rolling bearing can be envisioned, as will be selected by those skilled in the art depending on functional constraints.

[0022] Figure 4 shows a third embodiment of the gear motor according to the present invention, which is very similar to the first embodiment shown in the previous figure. This modification differs from the embodiment shown in the previous figure in that the rolling bearing (23) described above is removed. In this modification, the rear of the output shaft (19) is guided by an extension of the overmolding that forms the main bearing (25), as shown in Figure 1, and the rotor assembly (26) is guided by the output shaft (19) by sliding, as shown in Figure 3. This minimal, simple, and most economical configuration is particularly preferred when cost constraints are significant and when the lateral forces and torques applied to the output shaft are not of paramount importance.

[0023] Figure 5 shows a fourth embodiment of the gear motor according to the present invention, which is very similar to the first embodiment shown in Figures 1 and 2. This modification differs from the first embodiment in that the rear needle rolling bearing (23) is removed, and the rear guidance of the rotor assembly (26) by the output shaft (19) is achieved by sliding the rotor assembly (26) on the output shaft (19) to propose an interesting cost and performance compromise, and the guidance by the rolling element at the eccentric portion absorbs most of the radial force passing through the reduction gear.

[0024] Figure 6 shows a fifth embodiment of the gear motor according to the present invention, which is very similar to the first embodiment shown in Figures 1 and 2. This modification differs from the first embodiment in that the printed circuit (5) and flange (1) have openings through which the output shaft (19) passes and emerges at the rear end of the gear motor, in order to provide a double exit. In this embodiment, the magnet (7) is a ring fixed to the output shaft (19) and also radially faces a magnetically sensitive probe (24) used to detect the angular position of the output shaft (19), such as in patent WO2007057563A1 or WO2007099238A1. In the present invention, position detection is not limited to the magnet / probe pair and includes other embodiments that can be envisioned by those skilled in the art in axial or radial configurations, such as inductive detection or detection by optical sensors.

[0025] Figure 7 shows a sixth embodiment of the gear motor according to the present invention, which is very similar to the first embodiment shown in Figures 1 and 2. This modification differs from the first embodiment in that the output shaft (19) is not extended by a connecting shaft (22), and the output disc (18) is directly mounted to a system controlled using a screw inserted into a tapped hole (32) in the output disc (18). This embodiment allows for the absorption of greater lateral forces as well as transmitted torque and tilt torque on the output shaft (19) than in the first embodiment. For this purpose, this embodiment replaces the rolling bearing (21) with a double row of larger diameter rolling bearings (33).

[0026] Figure 8 shows a seventh embodiment of the gear motor according to the present invention, which is very similar to the second embodiment shown in Figure 3. This modification has a failure prevention function commonly referred to as "fail-safe". In this embodiment, this function is obtained by the action of a spring (28) housed in a guide (20). The spring (28) is fixed to the housing at one end (30) and to the output disc (18) at the other end (29). Advantageously, in the event of a gear motor failure, the action of the spring (28) has the effect of returning the output shaft (19) to a selected angular position. However, the incorporation of the spring limits the full angular movement of the output shaft (19) of the gear motor described by the present invention.

[0027] Figure 9 shows an eighth embodiment of the gear motor according to the present invention, which is very similar to the first embodiment shown in Figures 1 and 2. This modification differs from the first embodiment in that the rear needle rolling bearing (23) is removed. The rear guide of the rotor assembly (26) is secured by a rolling bearing (252), the inner portion of which is fixed to the outer circumference of the extension of the overmolding, and the rolling bearing (252) is inserted into the bore of the rear portion of the rotor assembly (26). A spring (108) provides axial prestress to the assembly. Advantageously, this prestress takes up play in the assembly, avoids parasitic tilting of the disc (12), and thus ensures proper engagement of the teeth, thereby preventing the gear motor from wearing out prematurely or even generating parasitic noise. The axial prestress can also be amplified or entirely generated using the magnetic ring (8) of the rotor assembly (26), which is not intentionally positioned axially centered relative to the stator assembly (4), so that an axial magnetic force is generated and the magnetic ring (8) naturally refocuses on the stator assembly (4).

[0028] Figure 10 shows a ninth embodiment of the gear motor according to the present invention, which is very similar to the first embodiment shown in Figures 1 and 2. This modification differs from the first embodiment in that axial compactness is greatly increased. For this purpose, the needle rolling bearings (23) are arranged in series, and the front guide (20) has a disc shape. To offset play and stabilize the potentially noisy elements of the reduction gear, elastic washers (151) are placed between the shoulder of the support (9) of the rotor assembly (26) and the rolling bearing (11), the rolling bearing (11) is slidably mounted on the support (9). The rotor assembly (26) is then pressed against the extension of the overmolded stator assembly (2). Friction washers (150) are then placed between the support (9) and the extension to limit friction loss between these two elements in relative rotational motion. In contrast, the elastic washer (151) compensates for the axial play between the gear wheel (12) and the output disc (18) that causes noise and premature wear of these parts. The output disc (18) then axially contacts the annular extension (153) of the guide (20), the relative speed between these parts is low, and friction is controlled by the appropriate dimensions of the elastic washer (151). This embodiment also differs in that the housing (14) is an integral part of the stator overmolding. Finally, as an example, in this modified embodiment, the rotor assembly consists of a sheet metal package (152) to which the magnet ring (8) is fixed, for example, by adhesive, and this sheet metal package (152) is then fixed to a support (9).

[0029] Figures 11a, 11b, and 12 show a tenth embodiment of the present invention, similar to the first embodiment shown in Figures 1 and 2. This embodiment is a particularly compact modification in the axial direction. This modification differs from the first embodiment in that the needle rolling bearing (23) is removed and the guidance of the rotor assembly (26) by the output shaft (19) is provided by two rolling bearings (37) and (38) inserted into the bore of the hollow shaft (10) of the rotor assembly (26). The rolling bearing (37) receives axial force from a spring (108) whose other end is constrained by a washer (107) fixed to the output shaft (19). This axial force is transmitted by the rolling bearing (37) to the shaft (10) of the support (9) of the rotor assembly (26) via the stopper (109), generating an axial force that ensures prestress on the gear wheel (12) of the rotor assembly (26) fixed to the shaft (10) on the output disc (18) fixed to the output shaft (19). Advantageously, this prestress absorbs the play in the assembly, avoids parasitic tilting of the disc (12), and thus ensures proper engagement of the teeth, preventing premature wear of the gear motor or even the generation of parasitic noise. Similarly, axial play and tilting of the output assemblies (18), (19), and (22) can be limited by restricting the axial play with a stop ring (41) and a friction disc (42) mounted or generated by the housing (14). These modified embodiments also differ in that the connecting shaft (22) provides an interface via a spline cavity (34) and the stator assembly (2) includes a guide flange (35) to ensure rearward guidance of the output shaft (19), but these embodiments are not limiting to the present invention.

[0030] To limit system vibrations, balancing is performed to address the mechanical unbalance inherent in the eccentric rotational motion of the gear wheel (12). In this embodiment, this balancing is achieved by the careful removal of material (40) from the magnetic support (9). This embodiment is not limiting, and other balancing means, such as adding material, should also be considered.

[0031] This alternative embodiment also differs from the first embodiment in that the flange (1) is not secured to the housing (14) by mounting blurrs (36), but rather by screws (31) that are directly housed in an overmolded stator assembly.

[0032] Finally, this modification differs from the first embodiment in that it incorporates a braking and safety locking system. In this modification, this function is ensured by adding it to the internal space (6) of the monostable magnetic actuator (100), but the present invention is not limited to this technique. The magnetic actuator (100) consists of a ferromagnetic bell (101) having an inner annular extension. The inner annular extension is assembled without gap on the guide flange (35) of the stator assembly (2), so that the inner portion of the guide flange (35) that forms the main bearing (25) guides the output shaft (19). The ferromagnetic bell (101) is closed by a ferromagnetic disc portion (103) which is mounted with play on the same outer portion of the overmolded extension and is guided to translate by the axial irregularity (110) of the bell (101) in cooperation with a complementary shape (111). The disc portion (103) has axial teeth (105) on its outer circumference that cooperate with a ring gear (106) which is a ring gear inserted into an annular recess of the shaft (10) and has complementary teeth (115), and when the teeth (105, 115) are nested, the rotational motion of the rotor assembly (26) is blocked. The magnetic actuator (100) is characterized in that, in a dormant or faulty state, the interlocking of the teeth (105, 115) is ensured by a spring (104) inserted into the internal cavity of the bell (101) and coaxial with the output shaft (19), and the spring (104) is located in an axial bearing at one end of the radially unfolded bell (101) and at the other end of the radially unfolded disc portion (103). Advantageously, the annular winding (102), inserted into the cavity of the bell (101) and fixed to the bell, generates an attractive magnetic force between the bell (101) and the disc portion (103) when current flows through it. This magnetic force counteracts the spring force, making it possible to eliminate contact between the two ring gears.Advantageously, the strength of the current passing through the winding (102) allows the magnetic actuator (100) to modulate the friction between the teeth (105, 115) and brake the rotor assembly (26) by the dog clutch.

[0033] Figures 13 and 14 show an eleventh embodiment of the gear motor according to the present invention, which is very similar to the first embodiment shown in Figures 1 and 2. This modification differs from the first embodiment in that the reduction gear is of the epicyclic type. In this embodiment, the rotor assembly (26) no longer drives the gear wheels (12) via rolling bearings (11), but the rotor assembly (26) has a sawtooth shape (27) at its end that cooperates with the sawtooth shape (13) of the multiple gear wheels (12). The multiple gear wheels (12) are guided in rotational motion by an axial extension (17) of an output disc (18) fixed to an output shaft (19). The illustrated examples are not limiting to the present invention, and the number of planets (12) and the type of epicyclic reduction gear (a simple type here) can be changed, and those skilled in the art will also consider integrating composite rows, which are said to be type 2, 3, or 4 or nested rows.

[0034] Figures 15 and 16 show a twelfth embodiment of the gear motor according to the present invention. This embodiment differs from the previous embodiment in that it comprises two different juxtaposed reduction gear modules, the first of which is a trochoidal reduction gear and the second of which is an epicyclic reduction gear. In this embodiment, the rotor assembly (26) is guided by a sliding bearing on the output shaft (19). The shaft (10) of the rotor support (9) guides the gear wheel (12) eccentrically with respect to the rotational axis of the rotor assembly (26). The disc-shaped gear wheel (12) has a serrated shape (13) around its circumference.

[0035] The housing (14) is integrated into the overmolding of the stator assembly (2) and has two sawtooth internal shapes (15, 125), the first sawtooth shape (15) working in cooperation with the sawtooth shape (13) of the gear wheel (12), so that the gear wheel (12), when driven by the rotor assembly (26) via the eccentric guide ring (129), performs cycloidal motion to form a first reduction stage, and the second sawtooth shape (125) working in cooperation with a plurality of planetary gears (122) to form a second reduction stage.

[0036] The gear wheel (12) has a set of cavities (16) in which pins (120) fixed to the planetary carrier (121) are located. Each of the pins guides a planetary gear wheel (122) which has two sawtooth shapes (123, 124) on its outer circumference, the first sawtooth shape (123) cooperating with a second sawtooth shape (125) of the housing (14).

[0037] The output disc (18) has a sawtooth internal shape (126) that cooperates with the second sawtooth shape (124) of the planetary gear wheel (122). In this embodiment, the output disc (18) is overmolded onto the output shaft (19) and guided by sliding bearings (127) on the inner surface of the overmolded stator assembly (2) and guide (20). The output disc (18) also has projections (128) that cooperate with the complementary shape of the controlled member. The complementary shape of the controlled member is guided by the inner surface of the guide (20). The output shaft (19) is guided at the other end of the gear motor, on the one hand by projections of the overmolded stator assembly (2) that form the main bearing (25), and on the other hand by projections of the flange (1) that form the main bearing (130). At its end, the output shaft (19) is fixed to a U-shaped portion (131) by punching. The U-shaped portion (131) has a second means for interfacing with the controlled member.

[0038] In this modified embodiment, the entire guide is generated by sliding bearings, but other alternatives for additional components considered by those skilled in the art are not excluded, for example, the guide ring (129) can be advantageously replaced by a rolling bearing to limit friction in this critical region.

[0039] Finally, in this embodiment, the housing (14) is an integral part of the stator molding and is not connected to the flange (1) by a mounting blinder (36), but is connected to the flange (1) by screws (31) that are housed directly in the overmolded stator assembly, although these screws are not visible here.

[0040] Figures 17a and 17b show a thirteenth embodiment that is very similar to the embodiment shown in Figure 10. This modification differs from the embodiment shown in Figure 10 in that the gear wheel (12) has deformable hooks (50) suitable for clipping onto the surface (53) of the output wheel (18) passing through a cavity (51), so as to eliminate the axial degree of freedom between the gear wheel (12) and the output wheel (18). The axial connection of these two parts prevents the occurrence of vibration and premature wear associated with them and limits misalignment that would disadvantage the operation of the reduction gear. The use of the hook (50) integrated with the gear wheel (12) is not limiting with respect to the present invention, and alternatively the hook (50) may be integrated with the output wheel (18), or alternatively the cavity (51) may be integrated with the gear wheel (12). However, those skilled in the art can also imagine all sorts of solutions aimed at constraining axial displacement between the output wheel (18) and the gear wheel (12) while leaving free movement in the orthogonal plane.

[0041] This embodiment also differs in that a ring (52) made of a very hard material such as steel is inserted around the outer circumference of the housing (14) in the serrated internal shape (15) to compensate for radial deformation of the housing (14) due to forces between the gear wheel (12) and the serrated internal shape (15). This ring (52) is particularly useful when the serrated internal shape (15) is an integral part of the plastic housing (14). Nevertheless, the use of such a ring (52) is not conditional on the use of plastic material, and one can assume that the forces involved are too large and risk deforming the serrated internal shape (15). The use of such a ring (52) is not limited to the presented embodiment and can be mounted around the stator assembly (2) when the serrated internal shape (15) is produced directly in its overmolding process.

[0042] Figures 18a, 18b, 18c, and 18d show a 14th embodiment, which differs from the previous embodiments in that it includes an external rotor motor and a so-called distorted wave or elliptical reduction gear. In this embodiment, the rotor assembly (26) is sandwiched by the stator assembly (2), which also functions as an overmolded housing (14), although this embodiment is not limiting, and the housing can be a separate part and attached to the stator assembly. The rotor assembly (26), more specifically the magnetic ring (8), magnetically cooperates with the magnetic field generated by the coils (3) of the stator assembly (2) on the radial outer circumference of the stator. Furthermore, the rotor assembly (26) is at least partially guided within the internal space (6) of the stator assembly (2) by rolling bearings (37) or sliding bearings inserted between the support (9) of the rotor assembly (26) and the output shaft (19). The output shaft (19) is guided by a sliding bearing (25) or by a rolling element (not shown). The shaft (10) of the rotor support (9) guides an elliptical plate (300) consisting of an elliptical hub (301) that supports a special rolling bearing (302) that deforms an external deformable toothed bush (303) that meshes with the inner ring gear (304). The latter can be mounted, molded, or form an integral part of the stator assembly (2) or housing (14). The elliptical plate (300), driven in rotational motion, deforms a toothed bush (303) that has slightly fewer teeth than the inner ring gear (304), typically two fewer teeth. As shown here, the inner ring gear (304) is normally stationary, and the reduced output motion is absorbed by a deformable bush (sleeve, bearing cylinder) (bush) (303), which is connected to a connecting shaft (22) forming a large diameter plate, thereby controlling the transmission of high loads to the member and enabling the actuator to close.Alternatively, as will be apparent to those skilled in the art, the bush (303) can be locked in rotational motion, and the output motion can then be transmitted by the ring gear (304). The connecting shaft (22) is here guided by a large diameter rolling bearing (21) which is advantageously positioned near the meshing plane of the reduction gear to seal the system directly (or via a dynamic seal (not shown)). The shaft (19) shown herein is hollow for the purpose of reducing the mass of the system. Alternatively, if the flange (1) and printed circuit (5) (or lead frame) are perforated, the hollow shaft (19) can allow output to be obtained on each side of the actuator and / or allow the passage of fluid, cables, shafts, etc. through the actuator. Those skilled in the art may use other types of reduction gears, such as trochoidal or epicyclic reduction gears, or other types of motors with internal rotors, as described in other embodiments, but also those with axial flux, as taught, for example, in the applicant's patent WO1992011686.

[0043] Figure 19 shows an exploded view of the 15th embodiment. This is a modification of the first embodiment, in which the gear wheel (12) has an axial extension (17) that cooperates with a cavity (16) created within an insert (401) rigidly connected to the stator assembly (2). Thus, the eccentric shaft (10) drives the disc (12) in circular translational motion, and the reduced rotational motion is captured by a sawtooth internal shape (15), which is then rigidly connected to an output disc (18) to form a single part, the latter which, here advantageously, surrounds and reinforces the sawtooth shape (15) and limits its elliptic deformation under load. As will be apparent to those skilled in the art, the cavity (16) can be created directly within the disc (12) or via one or more inserts, and the axial extension (17) can be created by the insert (401). Alternatively, the insert (401) can be clipped, screwed, or molded to the housing (14) or stator assembly (2), and the cavity (16) or axial extension (17) can be directly produced by overmolding the disc (12) or stator assembly (2).

[0044] In this variant, the rotor assembly (26) is generated by a magnet block (8) inserted into a ferromagnetic yoke (9), which is driven or molded on an axis (10).

[0045] This variant also includes an encoder (405), which may be of magnetic, ferromagnetic, or optical barrier type, used herein to obtain the position of the rotor assembly (26) via a probe or sensor (not shown) connected to or independently positioned in the printed circuit (5).

[0046] Finally, a variation of this embodiment uses a seal (406) that enables a seal between the housing (14) and the rotor assembly (2) formed therein.

Claims

1. It is a gear motor, It has an electric motor (200) and a mechanical reduction gear (210), The electric motor (200) comprises a cylindrical wound stator assembly (2) that forms a free internal space (6), and a rotor assembly (26) that is guided into the internal space (6). The reduction gear (210) is located inside a housing (14) fixed to the stator assembly (2), and has a movable gear assembly. The output element of the movable gear is fixed to the motion output shaft (19), The input element of the movable gear is driven by the rotor assembly (26) which extends inside the housing (14), The gear motor has guide elements (25, 251) for the output shaft (19) supported by the stator assembly (2), and the guide elements (25, 251) are at least partially located inside the stator assembly (2). The output shaft extends inside the gear motor to the guide elements (25, 251), The rotor assembly (26) is guided by guide means positioned between the inner surface of the rotor assembly (26) and the surface of the output shaft (19), The stator assembly (2) is overmolded from an injection-molded plastic material, the plastic material forming the guide elements (25, 251) for guiding the output shaft (19) within the internal space (6), The guide elements (25, 251) for guiding are characterized by being either sliding bearings or insert bearings having cylindrical bores overmolded from the plastic material of the stator assembly. A gear motor characterized by the following features.

2. The gear motor according to claim 1, characterized in that the guiding means is composed of a rolling bearing or a sliding bearing.

3. The gear motor according to claim 1, wherein the guiding means includes a rolling bearing and a tubular sleeve of a flange (1) fixed to the stator assembly (2), and the rolling bearing and the tubular sleeve are arranged coaxially with respect to each other.

4. The gear motor according to claim 1, characterized in that the housing (14) and the overmolded stator assembly (2) extend radially by corresponding mounting eyelets.

5. The overmolded stator assembly (2) is located inside the flange (1), The gear motor according to claim 1, characterized in that the housing (14) and the flange extend radially by corresponding mounting eyelets.

6. A gear motor according to any one of claims 1 to 5, characterized in that it has a sawtooth-shaped internal shape (15) that is mounted and fixed in the housing (14).

7. The gear motor according to claim 6, characterized in that the sawtooth-shaped internal shape (15) mounted on the housing (14) is integrally provided within the material of the housing (14) or within the overmolding of the stator assembly (2).

8. The gear motor according to claim 6, characterized in that a ring (52) is inserted on the outer circumference of the sawtooth-shaped internal shape (15).

9. The gear motor according to claim 6, comprising an output disc (18) fixed to the output shaft (19), wherein the output disc (18) has a sawtooth-shaped internal shape (15) that cooperates with a gear wheel (12), and the gear wheel (12) has an axial extension (17) that cooperates with a cavity (16) fixed to the housing (14) so ​​as to enable eccentric rotational motion of the gear wheel (12).

10. The mechanical reduction gear (210) is of the trochoidal type, The gear motor according to claim 9, characterized in that the input element of the movable gear is a gear wheel (12) having a sawtooth shape (13) around it that mechanically cooperates with the sawtooth internal shape (15).

11. The gear motor according to claim 9 or 10, characterized in that the mechanical reduction gear (210) is of the epicyclic type.

12. The gear motor according to claim 9 or 10, characterized in that the mechanical reduction gear (210) is of the elliptical type or the distorted wave type.

13. The output element of the movable gear is an output disc (18) fixed to the output shaft (19), The gear motor according to claim 12, characterized in that the output disc (18) and the gear wheel (12) are fixed in the axial direction using a hook (50).

14. The output element of the movable gear is an output disc (18) fixed to the output shaft (19), The gear motor according to any one of claims 1 to 13, characterized in that the rotor assembly (26) and the output disc (18) are pre-stressed in the axial direction.

15. The gear motor according to claim 3, characterized in that it has a printed circuit (5) disposed between the stator assembly (2) and the rear flange (1) of the stator assembly (2).

16. The gear motor according to claim 15, characterized in that the printed circuit (5) has a magnetically sensitive (24) probe (24) that cooperates with a magnet (7) fixed to the output shaft (19).

17. A gear motor according to any one of claims 1 to 16, characterized in that a magnetic actuator (100) inserted into the internal space (6) brakes the rotational motion of the rotor assembly (26) which is regulated by its power supply.

18. The gear motor according to claim 17, characterized in that the magnetic actuator (100) prevents the rotational motion of the rotor assembly in the event of a power supply failure.

19. The gear motor according to claim 17, characterized in that the magnetic actuator (100) allows the rotor assembly to rotate freely in the event of a power supply failure.

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