摘要:
An actuator with switchable releasing speed includes an actuation rod, a screw, and a motor. The motor drives the screw rotating so that the actuation rod axially moves relative to the screw. The motor includes a stator, a rotor, a plurality of commutators, and at least three brushes. The at least three brushes have a positive brush, a negative brush, and at least one auxiliary brush. The positive brush is connected to a positive DC voltage. One of the negative brush and the least one auxiliary brush is adjusted to connect to a negative DC voltage so as to change a rotational speed of the rotor, thereby controlling a movement speed of the actuation rod. Accordingly, the releasing speed of the actuator is switchable.
摘要:
In an electric motor, magnets (4) have two pairs of poles, the number of teeth (9) is 18, and the number of segments (14) of a commutator is 18. Winding wires (12, 25) for forming an armature coil (7) are formed by a first conductive wire (110) or a second conductive wire (120). The winding wire (25) has a first coil winding wire (7A) and a second coil winding wire (7B). The coil winding wires are each wound around four teeth (9) adjacent to each other. An end (31) of the second coil winding wire is connected to a segment (14) adjacent to a segment arranged at a position which is point symmetric with respect to a segment to which an end (30) of the first coil winding wire is connected. According to the invention, in the electric motor capable of changing the rotational speed of the armature by switching application of an electric current among three brushes, vibration and operating noise can be reduced, and mounting of the connecting wires and the winding wires can be facilitated.
摘要:
A slide surface of each segment defines a plane orthogonal to an axial direction of a direct current motor. A power supply brush is pressed against and contacted with the slide surface. The power supply brush includes a main brush and a sub-brush. The sub- brush has electrical resistance that is higher than that of the main brush. At least the main brush supplies an armature with power. The sub-brush is arranged more inward in the radial direction of the commutator than the main brush.
摘要:
The invention describes an electrical machine having an armature with armature slots for accommodating armature coils. At least one armature coil is formed from two coil elements which are arranged symmetrically with respect to one another in relation to an axis of symmetry, which runs through the center-point of the armature shaft. The coil elements are connected to two adjacent commutator laminates of a commutator. A first brush, a second brush and a third brush bear against the commutator in a manner such that they can slide. The second brush interacts with the first brush or the third brush. The third brush is arranged in relation to the two coil elements in such a way that, when the two adjacent commutator laminates come into contact with one another, the third brush and the center-point of the armature shaft form an axis which has an angle of 90 DEG−(180 DEG/number of laminates)−(180 DEG/3×number of laminates) up to 90 DEG +(180 DEG/number of laminates)+(180 DEG/3×number of laminates) in relation to the axis of symmetry of the two coil elements.
摘要:
A brush structure for a motor is provided for realizing an equalization of wear of brushes without causing an early wear of a specific brush while not necessitating a complicated conduction controlling device. A first brush, which is one of four brushes, conducted at both Lo mode and Me mode is formed to have a larger sliding contact area for contacting a commutator slidably compared with a sliding contact area of a second brush which is conducted at Hi mode only. Current density in the first brush at Lo mode and Me mode becomes smaller than current density at Hi mode.
摘要:
A multi-speed, direct current motor (120) incorporates a high speed (24) brush disposed between the low speed (22) and the common ground (26) brushes and having a non-arcuate end face (25) which, unlike the conventional arcuate brush end face (23,27), is not subject to speed-drift erosion. The non-arcuate end face (25) is configured of two offset surfaces (55,65 & 57,67) which intersect to provide a line of contact (43) between the end face (25) of the high speed brush (24) and the commutator (40) which is displaced from the center line of the high speed brush (24) in a direction counter to the direction of rotation of the motor, that is toward the leading edge (21) of the brush (24). The intersecting surfaces (55,65 & 57,67) may comprise either flat planar surfaces or contoured surfaces.
摘要:
A multi-speed, direct current motor (120) incorporates a high speed (24) brush disposed between the low speed (22) and the common ground (26) brushes and having a non-arcuate end face (25) which, unlike the conventional arcuate brush end face (23,27), is not subject to speed-drift erosion. The non-arcuate end face (25) is configured of two offset surfaces (55,65 & 57,67) which intersect to provide a line of contact (43) between the end face (25) of the high speed brush (24) and the commutator (40) which is displaced from the center line of the high speed brush (24) in a direction counter to the direction of rotation of the motor, that is toward the leading edge (21) of the brush (24). The intersecting surfaces (55,65 & 57,67) may comprise either flat planar surfaces or contoured surfaces.
摘要:
The invention provides a method of commutation control, for changing the speed of a direct current electric motor of the constant flux type, having an encapsulated inductive winding with n poles, each of which is supplied by a separate brush. In this method, a speed at a level i, where i is in the range 1 to n-1 inclusive, is obtained by connecting a group of i+1 brushes to the terminal of the direct current supply source. The state of connection of the brushes is modified in accordance with a control characteristic which comprises modifying the composition of the group of i+1 brushes to be connected in order to obtain a motor speed at a predetermined level i, and/or by interrupting the connection of one of two consecutive brushes to the brush previously connected during a speed changing operation.