a device for rotating at least one shaft, a machine tool and a rolling machine equipped with such a device

Abstract

The invention relates to a device (1) for driving in rotation of at least one shaft (2) comprising in addition to said shaft (2), an electric motor (3) comprising a stator (4) and a rotor (5) with two directions of rotation, the rotor (5) for driving in rotation of said shaft (2) being traversed by said shaft (2).The device (1) comprises: - a first configuration in which the shaft (2) and the stator (4) are, independently of any rotational movement of the rotor (5), arranged axially fixed relative to each other, and - a second configuration in which, depending on the rotational movement of the rotor (5), the shaft (2) and the stator (4) are mounted, relative to each other, axially movable in a direction parallel to the longitudinal axis of the shaft (2) to move from one relative axial position between the stator (4) and the shaft (2) to another relative axial position between the stator (4) and the shaft (2), each relative axial position between the stator (4) and the shaft (2) being a stable position. Figure for the abbreviation: Fig. 1.

Description

Title of the invention: a device for rotating at least one shaft, a machine tool, and a rolling vehicle equipped with such a device

[0001] The present invention relates to a device for rotating at least one shaft, a machine tool and a rolling machine equipped with such a device.

[0002] It relates in particular to a drive device for rotating at least one shaft, this drive device comprising in addition to said shaft, an electric motor comprising a stator and a rotor with two directions of rotation, the rotor for driving the rotation of said shaft being traversed by said shaft.

[0003] Numerous shaft rotation drive devices used for diverse and varied applications are on the market. Manufacturers of such devices are constantly seeking solutions to make these drive devices more versatile without compromising their simplicity and compactness.

[0004] One object of the invention is to propose a device of the aforementioned type whose design allows in a simple way the obtaining of a more versatile device.

[0005] To this end, the invention relates to a device for rotating at least one shaft, this drive device comprising, in addition to said shaft, an electric motor comprising a stator and a rotor with two directions of rotation, the rotor for rotating said shaft being traversed by said shaft, characterized in that the device comprises: - a first configuration in which the shaft and the stator are, independently of any rotational movement of the rotor, arranged axially fixed relative to each other, and - a second configuration in which the shaft and stator are, depending on the rotational movement of the rotor, mounted relative to each other and axially movable in a direction parallel to the longitudinal axis of the shaft, moving from one relative axial position between the stator and the shaft to another relative axial position between the stator and the shaft, each relative axial position between the stator and the shaft being a stable position. It should be noted that the expression "stable position" is the opposite of the expression "unstable position." A stable position, within the meaning of the invention, is a position that can be maintained after the motor is stopped in the unpowered state of said device. Conversely, an unstable position is a position that cannot be maintained in the unpowered state of the device. Such a shaft rotation drive device therefore has a second configuration in which the shaft and the stator Depending on the rotor's rotational movement, that is, under the action of the rotor's rotation, the components are mounted relative to each other and are axially movable in a direction parallel to the shaft's longitudinal axis. In this second configuration, the rotor's rotational drive allows for a relative axial displacement of the stator and shaft, the direction of this relative axial displacement depending on the rotor's direction of rotation. Thus, rotating the rotor in a first direction causes a relative axial displacement of the shaft and stator in that first direction, while rotating the rotor in a second direction opposite to the first causes a relative axial displacement of the shaft and stator in the opposite direction.In the first configuration, conversely, the shaft and stator are, independently of any rotational movement of the shaft—that is, in both the driven and undriven states—fixed axially relative to each other. Thus, both the rotational drive of the shaft and its axial displacement can be controlled by the rotational drive of the rotor, which is therefore versatile. The direction of rotation, the operating time, and the angular range of rotor displacement thus control the relative axial displacement of the shaft and stator. This results in a simple device where the rotor, in all configurations, acts as the driving element for controlling the relative rotational drive of the shaft and rotor and / or the relative displacement of the shaft and stator; that is, it influences this displacement according to its direction of rotation, speed, and operating time.

[0006] According to one embodiment of the invention, the device comprises at least one element threaded onto the shaft, this rotating element being fixed to the shaft in rotation at least in the first configuration and fixed in rotation in the second configuration, and the shaft and the element are axially movable relative to each other in the second configuration. The fixed mounting of the element and the shaft in rotation can be achieved by screwing the element onto the shaft or by the cooperation of complementary shapes of the shaft and the element or by any other means.

[0007] According to one embodiment of the invention, the device comprises an activatable / deactivatable system for rotationally immobilizing said element relative to the stator, in that the first configuration of the device corresponds to the configuration in which the activatable / deactivatable system for rotationally immobilizing the element is in the deactivated state, and in that the second configuration of the device corresponds to the configuration in which the activatable / deactivatable system for rotationally immobilizing the element is in the activated state. The device is therefore configured to switch from the first configuration to the second configuration by activating the activatable / deactivatable system for rotationally immobilizing the element and the second The first configuration involves disabling the element's rotational immobilization system. This results in simpler operation of the device. In the second configuration, the relative axial displacement between the shaft and the stator is achieved by rotating the rotor in conjunction with the element's rotational immobilization system. In other words, the relative axial displacement between the shaft and the stator in the second configuration, with the element's rotational immobilization system activated, is achieved by rotating the rotor.

[0008] According to one embodiment of the invention, the rotation-locking system for the element comprises at least one part that is rotationally fixed to the element and one part that is independent of the element. These parts are mounted to move inward or outward, and in the activated state of the rotation-locking system, they are in a position close to each other. In this close position, the parts thus form a means of rotationally locking the element. The part of the rotation-locking system that is independent of the element is generally mounted on the stator, particularly for reasons of compactness. This part of the rotation-locking system that is independent of the element, and therefore separate from the element, is preferably mounted in a fixed position on the stator.

[0009] According to one embodiment of the invention, the rotation-locking system for the element is an electromagnetic system comprising at least one coil and an armature or core. Generally, the coil and the armature or core are formed, respectively, by the portion of the rotation-locking system that is fixed to the element and rotates with it, and by the portion of the rotation-locking system that is independent of the element, this independent portion preferably being mounted on the stator. These portions are thus mounted to move towards each other when the coil is energized. Generally, the portion of the rotation-locking system that is independent of the element is mounted on the device that is fixed and rotates with respect to the stator.

[0010] According to one embodiment of the invention, the shaft is a threaded shaft over at least part of its length and the element and / or the rotor include a tapping in permanent contact with the thread of the shaft.

[0011] According to an embodiment of the invention, in which the rotor comprises a tapped hole permanently engaged with the shaft thread, the element is mounted rotationally fixed to the rotor in the first configuration and the element is, with the shaft, mounted fixed in rotation relative to the rotor in the second configuration. It should be noted that in the second configuration, in which the shaft and stator move axially relative to each other, the shaft does not rotate relative to the stator during this axial movement. Thus, in the second configuration, when driven by the rotor, the shaft and stator are mounted axially mobile relative to each other, and the shaft is mounted fixed in rotation relative to the stator and rotor. The element and the shaft are in permanent engagement, either directly or indirectly, for a fixed rotational mounting.

[0012] According to one embodiment of the invention, the element is ring-shaped with one of its faces facing the rotor. This face has protruding or recessed portions adapted to cooperate with complementary shaped portions of the rotor for a rotationally fixed mounting of the element and the rotor in the first configuration. This element is axially movable in the direction of rotor separation when the element's rotation-locking system transitions from the deactivated to the activated state. This arrangement prevents accidental loosening of the rotor shaft in the first configuration. Thus, the angular position of the shaft and the rotor is securely maintained, and a precise relative axial displacement of the shaft and the stator can be controlled in the second configuration.The fact that the element is mounted axially in the direction of rotor displacement when the element's rotational immobilization system switches from the deactivated to the activated state allows for independent rotation of the rotor and shaft in the second configuration. The recessed and raised parts of the rotor and the element do not cooperate in the second configuration.

[0013] According to one embodiment of the invention, in which the element comprises a thread permanently engaged with the shaft thread, the rotor and the shaft are, directly or indirectly, permanently engaged for a rotationally fixed and axially free mounting, and the element is axially fixed in a direction parallel to the longitudinal axis of the shaft relative to the stator. It should be noted that in the second configuration, in which the shaft and the stator move axially relative to each other, the shaft rotates relative to the stator during said axial movement. Thus, in the second configuration, when the rotor is driven in rotation, the shaft and the stator are axially movable relative to each other, and the shaft is rotationally movable relative to the stator and rotationally fixed to the rotor.

[0014] According to one embodiment of the invention, the element is a so-called locking nut equipped with a permanently acting brake on the nut. The brake is configured to prevent accidental loosening of the nut. Indeed, the brake is active by constriction to prevent accidental loosening of the nut from the shaft. Thus, the axial position of the shaft is The nut is securely held in place, and precise axial relative displacement of the shaft can be controlled. The brake is therefore configured to increase the stress between the screw thread and the nut's thread. This brake creates a resisting torque between the screw thread and the nut's thread. This resisting torque limits the risk of accidental nut loosening. The switchable nut locking system is configured, when activated, to generate a rotational locking force greater than the stress between the screw thread and the nut's thread, thus allowing the nut to be separated from the shaft.Due to the design of the rotationally immobilizable nut, said nut and the shaft are mounted rotationally fixed in the first configuration and are rotationally unfixed in the second configuration so that the shaft can rotate independently of the nut in the second configuration.

[0015] According to one embodiment of the invention, the device comprises one or more limit stops for the relative axial displacement of the shaft and the stator. These limit stops are mechanical stops. When a stop is under load, a current surge, also called a current peak, can be detected.

[0016] According to one embodiment of the invention, the device comprising several, namely at least two end stops for the axial relative displacement of the shaft and the stator, said stops are selectively activatable depending on the direction of rotation of the rotor.

[0017] According to one embodiment of the invention, the device comprises at least one rotor angular position sensor and a rotor control unit. The control unit is configured to acquire the data provided by the rotor angular position sensor(s) and to control the rotor to achieve a predetermined axial relative positioning of the shaft and stator based on at least the data provided by the rotor angular position sensor(s). The rotor angular position sensor(s) is generally mounted on the stator and may consist of a set of Hall effect sensors provided on the stator to detect the rotor's angular position.The rotor angular position sensors are therefore versatile and also provide information to the rotor control unit to control the relative axial displacement of the shaft and stator. The control unit is further configured to acquire data relating to the current consumed by the motor and to stop the axial displacement of the shaft based on the data provided. Thus, when the rotor is under load at a stop, a current surge, also called a current peak, can be detected by the control unit, and the control unit is configured to stop the axial displacement according to the data provided.

[0018] According to one embodiment of the invention, the device comprises a working tool, and the working tool is coupled to the rotor or shaft of said device. The working tool may be a cutting tool, such as a trimmer blade.

[0019] The invention further relates to a rolling machine comprising a shaft drive device, characterized in that the shaft drive device, which includes a working tool coupled to the rotor or shaft of said device, is of the aforementioned type. The rolling machine may be a mowing machine and the working tool a mowing blade, such that the device, in a second configuration, acts as a cutting height adjustment device.

[0020] The invention further relates to a working machine comprising a device for rotating a shaft, characterized in that the device for rotating a shaft which includes a working tool coupled to the rotor or to the shaft of said device is of the aforementioned type. Brief description of the drawings

[0021] The invention will be better understood upon reading the following description of exemplary embodiments, with reference to the accompanying drawings in which:

[0022] [Fig-1] represents an exploded perspective view of the elements constituting a device for rotating at least one shaft according to the invention;

[0023] [Fig.2] represents in cross-sectional views of the drive device in rotation of at least one shaft of the [Fig.1] the different configurations of the device and the relative axial positions of the shaft and the stator in the different configurations;

[0024] [Fig.3] represents two cross-sectional views of the rotation drive device of at least one shaft of the [Fig.1] in the second configuration in two relative axial positions of the shaft and the stator;

[0025] [Fig.4] represents a partial perspective view of the ring-shaped element, of the rotor and the shaft to illustrate the possible engagement of the element with the rotor;

[0026] [Fig.5] represents a partial perspective view of the ring-shaped element, the rotor and the shaft;

[0027] [Fig.6] represents an exploded perspective view of the constituent elements of a rotational drive device for at least one shaft according to the invention;

[0028] [Fig.7] represents in cross-sectional views of the drive device in rotation of at least one shaft of the [Fig.6] the different configurations of the device and the relative axial positions of the shaft and the stator in the different configurations;

[0029] [Fig.8] represents two cross-sectional views of the rotation drive device of at least one shaft of the [Fig.6] in the second configuration in two relative axial positions of the shaft and the stator;

[0030] [Fig.9] represents a partial perspective view of the nut-shaped element, the rotor and the shaft to illustrate in particular the permanently acting brake of the nut;

[0031] [Fig. 10] represents a partial cross-sectional view of the element in the form of a nut and the shaft;

[0032] [Fig. 11] represents in the form of two cross-sectional views associated with a detail view of variants of a rotational drive device of at least one shaft according to the invention;

[0033] [Fig. 12] represents two cross-sectional views of a rotational drive device of at least one shaft according to the invention in two different relative axial positions of the shaft and the stator;

[0034] [Fig. 13] represents a partially perspective view of a rolling machine equipped with a rotation drive device for at least one shaft according to the invention;

[0035] [Fig. 14] represents a partially perspective view of a machine tool equipped with a rotational drive device for at least one shaft according to the invention.

[0036] As mentioned above, the invention relates to a device 1 for rotating at least one shaft 2 intended to be equipped with a working tool 21, as illustrated in the figures. This working tool 21 may be a cutting tool, a drilling tool, or other. This rotating drive device 1 comprises, in addition to said shaft 2, as illustrated for example in Figures 1 and 6, an electric motor 3. This electric motor 3 comprises a stator 4 and a rotor 5 with two directions of rotation. This rotor 5 is centrally hollowed out to define a through-passage through said shaft 2, which forms the drive shaft of said electric motor 3. The through-passage of this motor may be threaded as illustrated in [Fig. 2], the thread being shown in 83, or smooth, as illustrated in [Fig. 7].

[0037] The rotor 5 is generally formed by a stack of sheets and by magnets arranged near the periphery of the rotor in order to be attracted by a rotating magnetic field generated at the stator.

[0038] In each of the examples shown, the rotor 5 also includes internally a sleeve or tube delimiting this through passage. The sleeve or tube is surrounded by a stack of laminations which, together with the sleeve and the magnets, form a rigid assembly that rotates securely.

[0039] The stator 4 is formed of laminations interacting with a winding to form an electromagnetic part and of a frame at least partially enclosing the electromagnetic part of the stator 4 and the rotor in a manner known per se. The enclosure of this frame has at least one opening from which the shaft 2 protrudes. This The frame, which encloses the rotor, the stator, and at least part of the shaft, may also define one or more cavities housing components of the rotating drive device 1, which will be described below. The rotor 5 is a two-way rotor capable of rotating clockwise and counterclockwise.

[0040] The electric motor 3 comprising the stator 4 and the rotor 5 can be a direct current or alternating current motor. This motor can be of the brushless type.

[0041] Characteristically to the invention, the device 1 comprises a first configuration in which the shaft 2 and the stator 4 are, independently of a rotational movement of the rotor 5, i.e. including in the state driven in rotation of the rotor 5, arranged fixed axially relative to each other.Device 1 further includes a second configuration in which the shaft 2 and the stator 4 are, depending on the rotational movement of the rotor 5, mounted relative to each other, axially movable in a direction parallel to the longitudinal axis of the shaft 2 to move from one relative axial position between the stator 4 and the shaft 2 to another relative axial position between the stator 4 and the shaft 2, each relative axial position between the stator 4 and the shaft 2 being a stable position, i.e. maintained after the motor's rotational drive has stopped, including in the state of the motor and the entire device 1 not being supplied with electricity, or maintained after the deactivation of the switchable / switchable system for immobilizing the rotation of the element, which will be described below.

[0042] The device 1 further comprises at least one element threaded onto the shaft 2. This element, shown as 71 or 72 in the figures, is a rotating element mounted fixed to the shaft 2 in rotation, at least in the first configuration. This rotating element 71 or 72 is mounted fixed in rotation in the second configuration, and the shaft 2 and the element 71, 72 are mounted axially movable relative to each other in the second configuration.

[0043] To enable this fixed rotation of element 71 or 72 in the second configuration, device 1 includes an activatable / deactivatable system 9 for rotationally immobilizing element 71 or 72 relative to stator 4. The first configuration of device 1 corresponds to the configuration in which the activatable / deactivatable system 9 for rotationally immobilizing element 71 or 72 is in the deactivated state, and the second configuration of device 1 corresponds to the configuration in which the activatable / deactivatable system 9 for rotationally immobilizing element 71 or 72 is in the activated state. The transition of device 1 from the first to the second configuration is therefore achieved by simply activating the activatable / deactivatable system 9 for rotationally immobilizing element 71 or 72 relative to stator 4.The transition of device 1 from the second to the first configuration is achieved by simply deactivating the activatable / deactivatable immobilization system 9. in rotation of element 71 or 72 relative to stator 4. In the activated state of the switchable / switchable rotation-locking system 9, the element, represented as 72 in some embodiments and as 71 in others, is locked in rotation. It therefore cannot rotate around shaft 2.

[0044] Regardless of the design of the shaft 2, the element 71 or 72, and the rotor, the shaft 2 and the element 71 or 72 are mounted axially movable, that is, in a direction parallel to the longitudinal axis of the shaft 2 in the second configuration. The switchable / switchable system 9 for preventing the rotation of the element 71 or 72 comprises at least a part 10 fixed in rotation to the element 71 or 72 and a part 11 independent of the element 71 or 72, this independent part being mounted on said stator. The said parts 10 and 11 are mounted movable in the direction of a coming together or a moving apart from each other and are, in the activated state of the system 9 activable / deactivatable of the rotation immobilization of the element 71, 72, in a position close to each other to ensure, in a position close to each other, by friction contact, a rotation immobilization of the element 71.

[0045] In the examples shown in figures 1 to 10 and 12, said parts 10 and 11 are mounted to move axially in a direction parallel to the longitudinal axis of the shaft 2 when switching from the deactivated state to the activated state of said system 9 which can be activated / deactivated for immobilizing the rotation of the element 71 or 72, this movement occurring in the direction of bringing said parts closer together.

[0046] In the example shown in [Fig. 11], parts 10 and 11 are mounted to move radially in a direction orthogonal to the longitudinal axis of shaft 2 during the transition from the deactivated state to the activated state of said activatable / deactivatable rotational immobilization system 9 of the element, this movement occurring in the direction of a bringing said parts closer together.

[0047] Generally, and as illustrated in the figures, the switchable / switchable system 9 for preventing the rotation of element 71 or 72 is an electromagnetic system comprising at least one coil 91 and an armature 92 or a core. The coil 91 may form at least partially one part of the system 9, and the armature 92 of the core may form at least partially the other part of the system 9. These parts are mounted to move towards or away from each other by switching the system 9 on or off. Switching the system 9 on or off for preventing the rotation of element 71 or 72 is achieved by supplying or interrupting the power supply to at least one part of the system 9. Thus, such a system may be formed by a solenoid, an electromagnetic brake, or other means.The movable part of the system 9, which can be activated / deactivated for immobilizing the rotation of element 71 or 72, can also take the form of a movable finger capable of moving from one to another. position to another in the activated state of system 9 to come into contact with a part of the system provided on element 71 or 72.

[0048] In this embodiment, as illustrated in [Fig. 11], the portion of the system 9 formed on the element can have notches or recesses into which the finger forming the portion of the system 9 independent of the element is able to fit in the active position of the system 9. The movement of this finger can be radial, as illustrated in [Fig. 11]. The portion 11 of the system 9, independent of the element 71 or 72, can be mounted on the stator housing. This portion 11 of the system 9 is mounted fixed against rotation relative to the shaft 2.

[0049] Element 71 or 72 can, independently of the design of the activatable / deactivatable rotational immobilization system 9 of said element, also affect a large number of shapes. Examples are given in [Fig. 1] and [Fig. 6].

[0050] Regardless of the design of element 71 or 72, shaft 2 is threaded along at least part of its length. The thread of said shaft 2 is shown as 6 in the figures. In the example shown in Figures 1 to 5, rotor 5 includes a tapped hole 83 permanently engaged with the thread 6 of shaft 2. Thus, rotor 5 is traversed by shaft 2, which is screwed into the threaded through-hole of rotor 5. The tapped hole 83 of rotor 5 is permanently engaged with the thread 6 of shaft 2 (first or second configuration). Element 72 is mounted rotationally fixed to rotor 5 in the first configuration; in the second configuration, element 72, along with shaft 2, is fixed rotationally relative to rotor 5. Element 72 and shaft 2 form a rotationally fixed assembly in both the first and second configurations.Thus, element 72 includes longitudinal ribs 82 extending parallel to the longitudinal axis of shaft 2, these ribs fitting into grooves in shaft 2. This rotationally fixed assembly of element 72 and shaft 2 also allows free axial mounting along a direction parallel to the longitudinal axis of shaft 2 of element 72 and shaft 2.

[0051] In the examples shown in figures 1 to 5, the system 9 and the element 72 are housed inside the engine casing which forms the envelope of the device 1.

[0052] In the examples shown in Figures 1 to 5, the element 72 is ring-shaped with one of its faces 721 facing the rotor 5. As mentioned above, the inside of the ring has longitudinal ribs 82 that engage with longitudinal grooves in the shaft 2 for a rotationally fixed mounting of the element 72 and the shaft 2, regardless of the configuration (first or second configuration) of the device 1. The element 72 and the shaft 2 are therefore, by design, permanently fixed in rotation. In other words, the rotating element 72 is rotationally fixed to the shaft 2 in both the first and second configurations. The element 72 and the shaft 2 are axially movable. relative to each other, that is, the shaft 2 and the element 72 are mounted axially movable along a direction parallel to the longitudinal axis of said shaft. Due to the aforementioned mounting, when the shaft 2 rotates, the element 72 rotates. The face 721 of the ring forming the element 72 has protruding or recessed portions 122 adapted to cooperate with complementary portions 51 of the rotor 5 for a rotationally fixed mounting of the element 72 and the rotor 5 in the first configuration. In the example shown, teeth forming the protruding portions 122 extend beyond the face of the ring to engage with recesses provided in the rotor 5 in the first configuration of the device 1.Element 72 is axially movable in the direction of the rotor 5's displacement, i.e., parallel to the longitudinal axis of shaft 2, when the rotation-locking system 9 of element 72 switches from the deactivated to the activated state. This allows for independent rotation of the rotor and shaft 2 in the second configuration. Thus, element 72 ensures that shaft 2 and rotor 5 remain fixed in rotation in the first configuration, preventing any angular displacement of shaft 2, which is screwed into rotor 5.In the second configuration of device 1, corresponding to the activated state of the switchable / switchable rotation-locking system 9 for element 72, element 72 is moved away from the rotor so that the rotor can rotate while the shaft is held fixed in rotation by element 72, which is itself prevented from rotating by the switchable / switchable rotation-locking system 9 for said element. When element 72 is moved away from the rotor 5, the recessed and protruding parts of element 72 and rotor 5 no longer cooperate. As a result, in this second configuration, when the rotor rotates, the shaft screwed into the rotor moves axially, that is, parallel to its longitudinal axis. Thus, in the case where the shaft is equipped with a rotating working tool 21, such as a cutting tool, this cutting tool can rotate in the first configuration and move axially relative to the stator in the second configuration.If such a device 1 is mounted on a wheeled machine 22, such as a robotic mower, as illustrated in [Fig. 13] or on a lawnmower, this shaft drive device 1 allows for adjustment of the cutting height. Thus, when the wheeled machine 22 is a mower and the working tool 21 is a cutting blade, the shaft drive device 1, as described above, acts as a drive for the rotation of the working tool 21 in the first configuration and as a cutting height adjustment device in the second configuration, these functions being achieved when the rotor is in rotation. It matters little whether the working tool 21 is coupled to the rotor 5 or to the shaft 2 of the device 1. Thus, when the rolling machine is a mowing machine, the device 1 for rotating a shaft is of the aforementioned type and the working tool 21 is coupled to the rotor. or to shaft 2 of device 1 is a mowing blade, the drive device 1 has the function of a mowing cutting height adjustment device in the second configuration and the function of a mowing blade rotation drive device in the first configuration.

[0053] Figures 6 to 12 illustrate another embodiment of the element shown as 71 in said figures. In this embodiment, the element 71 is a nut. This element 71 comprises a threaded hole 81 permanently engaged with the thread 6 of the shaft 2. The element 71 is therefore screwed onto the shaft 2. In this embodiment, the rotor 5 and the shaft 2 are, directly or indirectly, permanently engaged for a fixed mounting in rotation and free in axial movement. The element 71 is mounted axially fixed in a direction parallel to the longitudinal axis of the shaft 2 with respect to the stator 4.

[0054] In the examples shown, the means for a rotationally fixed and axially free mounting of the shaft 2 and the rotor 5 include a pin 13 connecting the rotor 5 and the shaft 2. This pin 13 passes through the shaft 2 and is inserted into two diametrically opposed longitudinal grooves in the rotor 5, as illustrated in [Fig. 8]. The element 71 and the shaft 2 are rotationally fixed in the first configuration. To prevent accidental loosening of the element 71 on the shaft 2 in this first configuration, the element 71 is a so-called locking nut equipped with a brake 121 that acts permanently on the nut. This brake is active by constriction and here takes the form of a spring washer surrounding a radially deformable portion of the nut.Indeed, the nut is a partially radially deformable nut, and the brake 121 of said nut is a constricting element of said nut configured to generate an internal radial deformation of the radially deformable portion of said nut. In the example shown, this brake is formed of elastic washers surrounding the radially deformable portion of the nut. Alternatively, the brake could also take the form of a tension spring whose two ends are connected to form a torus; this torus is then mounted on the deformable portions of the nut. The nut is also mounted axially fixed in a direction parallel to the longitudinal axis of the shaft relative to the stator.

[0055] In this embodiment, the device 1 again comprises an activatable / deactivatable system 9 for rotationally immobilizing the element 71 relative to the stator 4. The first configuration of the device 1 corresponds to the configuration in which the activatable / deactivatable system 9 for rotationally immobilizing the element 71 is in the deactivated state, and the second configuration of the device 1 corresponds to the configuration in which the activatable / deactivatable system 9 for rotationally immobilizing the element 71 is in the activated state. Thus, the shaft 2 and the element 71 are rotationally uncoupled in the second configuration so that the shaft 2 can, engaged with the rotor, rotate independently of element 71 in this second configuration.

[0056] In the examples shown, the switchable / switchable rotational immobilization system 9 for element 71 comprises a portion 10 that is rotationally fixed to element 71 and a portion 11 that is independent of element 71. This portion 11 of the system 9, independent of element 71, is at least partially mounted fixed relative to the stator 4. In the example shown in Figures 6 to 10, this portion 11 of the system 9, independent of element 71, extends around shaft 2 and is traversed by shaft 2. This portion 11 is mounted fixed in rotation relative to shaft 2. The portions 10 and 11 are mounted, by activation of the switchable / switchable rotational immobilization system 9 for element 71, to move towards each other in order to ensure, in a position close to each other, contact. friction, a rotational immobilization of element 71.Parts 10 and 11 are therefore separated from each other in the deactivated state of system 9 and brought closer together in the activated state of system 9.

[0057] This switchable / switchable system 9 for preventing the rotation of element 71 can be an electromagnetic system comprising at least one coil and an armature or core. The coil and the armature can be formed, respectively, by the portion of the switchable / switchable system 9 for preventing the rotation of element 71 that is integral with element 71, and by the portion 11 of the switchable / switchable system 9 for preventing the rotation of element 71 that is mounted on the stator 4. The activation and deactivation of system 9 are achieved by supplying and de-supplying the coil.

[0058] Due to the design of the device 1, as described above, in the second configuration in the state driven in rotation of the rotor and immobilized in rotation of the element 71, the shaft and the stator are animated by a relative axial displacement.

[0059] In the example shown in [Fig. 8], it is the shaft 2 that moves axially, that is, along its longitudinal axis. In this case, the device 1 can be equipped with a working tool 21 coupled to the shaft 2. Conversely, in [Fig. 12], where the element 71 is also a nut, it is the stator / rotor assembly that moves axially, that is, in a direction parallel to the longitudinal axis of the shaft relative to the shaft 2, which is axially fixed. In this embodiment, the working tool 21 is coupled to the rotor. The case as illustrated in [Fig. 12], where it is the stator / rotor assembly that moves relative to the fixed shaft, requires an additional enclosure surrounding at least part of the motor and the shaft, with the rotor protruding from said additional enclosure. Again, such a device 1, as described above, can be installed on a rolling machine 22, such as a mowing machine on a machine tool 20 or other.

[0060] Regardless of its embodiment, the device 1 comprises at least one or more limit stops for the relative axial displacement of the shaft 2 and the stator. These limit stops are represented as 14 and 15 in the figures. Generally, the device comprises at least two limit stops 14 and 15 for the relative axial displacement of the shaft 2 and the stator 4. Said limit stops 14 and 15 are selectively active depending on the direction of rotation of the rotor 5. These limit stops can take on a wide variety of shapes. These limit stops can be implemented as mechanical stops as illustrated in the figures. Thus, each limit stop can, in its active state, be in contact with a portion of the shaft. This limit stop can be provided on the element or at a specific location on the stator. The said stops are, in the end-of-stroke position of the shaft, one or the other in contact with the shaft.The shaft comes to a position driven in rotation in one direction against one of the stops and to a position driven in rotation in the opposite direction against the other stop. In the example illustrated in [Fig. 2], the shaft has a washer disposed at the end of said shaft, this washer extending radially from the body of the shaft. This washer bears against the inside of the stator housing forming a first stop in a first end position of the shaft's travel and against element 72 forming a second stop in a second end position of the shaft's travel.

[0061] In the example shown in figures 9 and 10, the stops 14 and 15 are provided on the element 71 in a manner offset axially with respect to the shaft on said element 71.

[0062] In the activated state of a shaft end stop, a current peak can be detected and recorded in a working memory 19 which will be described below.

[0063] Finally, regardless of the embodiment of device 1, device 1 includes at least one sensor 16 for detecting the angular position of the rotor 5 and a control unit 18 for the rotor 5. The sensor 16 for detecting the angular position of the rotor 5 may include a set of hall effect sensors mounted fixed on their stator and arranged on a circle opposite a polarized disk 17 coaxial to the shaft 2 and detected by the sensors and fixed in rotation to the rotor.

[0064] The control unit 18 is in the form of an electronic and computer system which includes, for example, a microprocessor and a working memory 19. In one particular aspect, the control unit 18 can be in the form of a programmable logic controller (PLC). In other words, the functions and steps described can be implemented as a computer program or via hardware components (e.g., programmable gate arrays). In particular, the functions and steps performed by the control unit 18 or its modules can be carried out by instruction sets or computer modules implemented in a processor or controller, or by dedicated electronic components or FPGA or ASIC type components. It is also possible to combine computer parts and electronic parts. When it is specified that the unit or means or modules of said control unit 18 are configured to perform a given operation, this means that the control unit 18 includes computer instructions and the corresponding means of execution which enable said operation to be performed and / or that the control unit 18 includes corresponding electronic components.

[0065] The control unit 18 is configured to acquire data from the rotor 5 angular position sensor 16 to control the rotor 5 for a predetermined relative axial positioning of the shaft 2 and the stator 4, based on at least the data provided by the rotor 5 angular position sensor(s) 16. Indeed, the rotor's rotational drive time, rotational speed, and direction of rotation allow the relative axial displacement of the shaft and stator to be determined. A single sensor can therefore determine the rotor's angular position and assist in controlling the shaft's axial displacement. The desired axial displacement can be entered by the user into the control unit, for example via a human-machine interface, or can be stored. Furthermore, the shaft thread pitch can be stored to control the axial displacement.

[0066] As mentioned above, the applications of such a shaft rotation drive device 1 are diverse and varied. Such a device 1 can be integrated into a wheeled machine 22, as illustrated in [Fig. 13], or into a machine tool 20, as illustrated in [Fig. 14]. When the wheeled machine 22 is a lawnmower, this shaft rotation drive device 1, where the shaft 2 or the rotor 5 is coupled to a working tool 21 formed by the cutting blade of said machine, can be used, in addition to the rotational drive of the cutting blade necessary for performing the cutting operation, to allow, in the second configuration, the adjustment of the cutting height.

[0067] The operation of a shaft rotation drive device 1, as described above, is as follows.

[0068] It is assumed that the switchable / switchable system 9 for preventing the rotation of element 71 or 72 relative to the stator 4 is deactivated. Device 1 is therefore in the first configuration. In this first configuration, in the example shown in Figures 1 to 5, element 72 is mounted rotationally fixed and axially free on the shaft by the cooperation of the ribs and grooves of the element and the shaft. In this embodiment, element 72 is a ring threaded onto the shaft. This element 72 is also, in the first configuration, by means of the ring's portions 122, rotationally fixed to the rotor 5 screwed onto the shaft 2, such that the rotational drive of the rotor generates a rotational drive of the shaft and element 72 without the possibility for the shaft, in this first configuration, to shift angularly relative to to the rotor into which it is screwed. In this first configuration, the shaft 2 and the stator 4 are, including in the state driven in rotation of the rotor 5, arranged fixed axially relative to each other.

[0069] In the example shown in Figures 6 to 12, in the first configuration where the switchable / switchable rotation-locking system 9 for element 71 is deactivated, the shaft 2 and the stator 4 are, even when driven by the rotor 5, axially fixed relative to each other. The element 71, formed by a nut, is screwed onto the shaft 2 and rotates with the shaft 2, while the shaft 2 is mounted by keying or by means of a pin that is fixed and axially free relative to the rotor. Thus, in this first configuration, when the rotor is driven, the shaft 2, the element 71, and the rotor rotate together, with the shaft 2 and the stator 4 being axially fixed relative to each other.

[0070] In the activated state of the switchable / switchable system 9 for immobilizing the rotation of element 71 or 72, the device 1 is in its second configuration. In the example shown in Figures 1 to 5, the activation of the system 9 causes an axial displacement of element 72 in the direction of a separation of element 72 from the rotor and a movement of element 72 towards the independent part 11 of the switchable / switchable system 9 for immobilizing said element. In this second configuration, in the example shown in figures 1 to 5, in the driven state of the rotor, the shaft 2 is prevented from rotating by the element 72 with which it is engaged by the complementary groove / rib shapes, this element 72 being immobilized in rotation due to the activated state of the system 9. In this second configuration, the element 72 is decoupled in rotation from the rotor 5.In particular, the protruding portions 122 of the face of the ring forming part 72 are offset from the rotor so that the rotor can rotate independently of part 72. This results, due to the rotational lock of shaft 2, in an axial displacement of shaft 2 screwed into the rotor when the rotor is driven. The stroke of this axial displacement depends on the data provided by the rotor's angular position sensor 16 and the comparison of this data with a stroke command setpoint that can be entered by the user into the control unit via, for example, a human-machine interface, or that can be stored. Furthermore, the pitch of the shaft thread can be stored to control the axial displacement. This displacement can continue until it makes contact with one of the end stops 14 or 15. This contact is detected by a current surge.Indeed, when the rotor rotates clockwise, shaft 2 moves axially in one direction at most to one of its end-of-stroke positions. When the rotor rotates counterclockwise, shaft 2 moves axially in a second, opposite direction to at most its other end-of-stroke position. Between these... two end-of-stroke positions, as soon as the rotor stops rotating, the shaft stops moving axially and occupies a stable position relative to the stator.

[0071] In the example shown in Figures 6 to 11, in the activated state of the switchable / switchable system 9 for preventing the rotation of element 71, element 71, which is a nut screwed onto the shaft, is prevented from rotating and fixed axially relative to the stator. Shaft 2, on the other hand, is fixed against rotation and axially movable relative to the rotor 5. Thus, the rotation of the rotor 5 causes the shaft 2 to rotate and the shaft to move axially through the interaction of the shaft's threads with the threads of the nut forming element 71. When the rotor rotates clockwise, shaft 2 moves axially in a first direction to at most one of its end positions. When the rotor rotates counterclockwise, shaft 2 moves axially in a second, opposite direction to at most the other of its end positions.Between these two end-of-stroke positions, as soon as the rotor stops rotating, the shaft ceases to move axially and occupies a stable position relative to the stator.

[0072] In [Fig. 12], the operation is similar to Figures 6 to 11 except This is because it is not the shaft 2 that moves axially relative to the rotor / stator assembly and element 71, but rather the rotor / stator assembly and element 71 that move axially, that is, along an axis parallel to the longitudinal axis of the shaft relative to the shaft. In this embodiment, an additional housing is provided to accommodate the shaft 2, the electric motor 3, and the other components of device 1. The shaft is mounted axially fixed relative to this housing, and the rest of the device moves axially along the shaft 2 when driven by the rotor's rotation. Note that a portion of the rotor protrudes from the housing; this protruding portion of the rotor is equipped with the working tool 21.

Claims

Demands

1. A device (1) for rotating at least one shaft (2), said drive device (1) comprising, in addition to said shaft (2), an electric motor (3) comprising a stator (4) and a rotor (5) with two directions of rotation, the rotor (5) for rotating said shaft (2) being traversed by said shaft (2), the device (1) comprising: - a first configuration in which the shaft (2) and the stator (4) are, independently of any rotational movement of the rotor (5), arranged axially fixed relative to each other, and - a second configuration in which, depending on the rotational movement of the rotor (5), the shaft (2) and the stator (4) are mounted, relative to each other, axially movable in a direction parallel to the longitudinal axis of the shaft (2) to move from one axial relative position between the stator (4) and the shaft (2) to another axial relative position between the stator (4) and the shaft (2). (4) and tree (2),each relative axial position between the stator (4) and the shaft (2) being a stable position, characterized in that the device (1) comprises at least one element (71, 72) threaded onto the shaft (2), this rotating element (71, 72) being mounted rotationally fixed to the shaft (2) at least in the first configuration and mounted rotationally fixed in the second configuration, in that the shaft (2) and the element (71, 72) are mounted axially movable relative to each other in the second configuration, in that said device comprises an activatable / deactivatable system (9) for immobilizing the rotation of said element (71, 72) relative to the stator (4), in that the first configuration of the device (1) corresponds to the configuration in which the activatable / deactivatable system (9) for immobilizing the rotation of the element (71, 72) is in the deactivated state,and in that the second configuration of the device (1) corresponds to the configuration in which the switchable / switchable rotational immobilization system (9) of the element (71, 72) is in the activated state.

2. A device (1) for rotating at least one shaft (2) according to claim 1, characterized in that the activatable / deactivatable system (9) for rotating immobilization of the element (71, 72) comprises at least one part (10) rotationally fixed to the element (71, 72) and a part (11) independent of the element (71, 72), said parts (10, 11) being mounted movable in the direction of approaching or moving apart from each other and being, in the activated state of the system (9) activatable / deactivatable of the rotation immobilization of the element (71, 72), in a position close to each other.

3. A device (1) for rotating at least one shaft (2) according to claim 2, characterized in that the activatable / deactivatable system (9) for rotating immobilization of the element (71, 72) is an electromagnetic system comprising at least one coil (91) and an armature (92) or a core.

4. A device (1) for rotating at least one shaft (2) according to any one of claims 1 to 3, characterized in that the shaft (2) is a shaft threaded over at least part of its length and in that the element (71) and / or the rotor (5) comprise a tapping (81, 83) in permanent contact with the thread (6) of the shaft (2).

5. A device (1) for rotating at least one shaft (2) according to claim 4, of the type in which the rotor (5) comprises a tapped hole (83) permanently engaged with the thread (6) of the shaft (2), characterized in that the element (72) is mounted rotationally fixed with the rotor (5) in the first configuration and in that the element (72) is, with the shaft (2), mounted fixed in rotation relative to the rotor (5) in the second configuration.

6. A device (1) for rotating at least one shaft (2) according to claim 5, characterized in that the element (72) has the shape of a ring with one of its faces (721) facing the rotor (5), this face (721) having protruding or recessed parts (122) adapted to cooperate with parts (51) of complementary shape to the rotor (5) for a rotationally fixed mounting of the element (72) and the rotor (5) in the first configuration, this element (72) being mounted axially movable in the direction of a separation of the rotor (5) when the activatable / deactivatable system (9) for locking the rotation of the element (72) from the deactivated state to the activated state.

7. A device (1) for rotating at least one shaft (2) according to claim 4, of the type in which the element (71) comprises a tapped hole (81) permanently engaged with the thread (6) of the shaft (2), characterized in that the rotor (5) and the shaft (2) are, directly or indirectly, permanently engaged for a fixed mounting in rotation and free in axial movement, and in that the element (71) is mounted fixed axially in a direction parallel to the longitudinal axis of the shaft (2) relative to the stator (4).

8. Device (1) for rotating at least one shaft (2) according to claim 7, characterized in that the element (71) is a so-called braked nut equipped with a brake (121) with permanent action on the nut.

9. A device (1) for rotating at least one shaft (2) according to any one of claims 1 to 8, characterized in that it comprises one or more stops (14, 15) for the end of the axial relative displacement of the shaft (2) and the stator (4).

10. A device (1) for rotating at least one shaft (2) according to claim 9, characterized in that the device (1) comprises several, namely at least two stops (14, 15) for the end of the axial relative displacement of the shaft (2) and the stator (4), said stops (14, 15) are selectively activatable depending on the direction of rotation of the rotor (5).

11. A device (1) for rotating at least one shaft (2) according to any one of claims 1 to 10, characterized in that it comprises at least one sensor (16) for detecting the angular position of the rotor (5), and a rotor (5) control unit (18), in that the control unit (18) is configured to acquire the data provided by the sensor(s) (16) for detecting the angular position of the rotor (5) and to control the rotor (5) with a view to a predetermined axial relative positioning of the shaft (2) and the stator (4) as a function of at least the data provided by the sensor(s) (16) for detecting the angular position of the rotor (5).

12. A device (1) for rotating at least one shaft according to any one of claims 1 to 11, characterized in that said device (1) comprises a working tool (21) and in that the working tool (21) is coupled to the rotor (5) or to the shaft (2) of said device (1).

13. Machine tool (20) comprising a device (1) for rotating a shaft (2), characterized in that the device (1) for rotating a shaft (2), which comprises a working tool (21) coupled to the rotor (5) or to the shaft (2) of said device (1), conforms to any one of claims 1 to 11.

14. Rolling machine (22) comprising a device (1) for rotating a shaft (2), characterized in that the device (1) for rotating a shaft (2), which comprises a tool (21) working coupled to the rotor (5) or to the shaft (2) of said device (1) conforms to one of claims 1 to 11.

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