Operating mechanism of four-connecting-rod type reclosing circuit breaker
Technical Field
The invention belongs to an opening and closing electric operating mechanism for a small-sized reclosing circuit breaker, and particularly relates to an operating mechanism of a four-connecting-rod type reclosing circuit breaker.
Background
The electric operating mechanism of the reclosing circuit breaker is an accessory used for a remote electric opening and closing circuit breaker, is matched with a special miniature circuit breaker for a prepayment ammeter, can realize reclosing after owing and opening and paying, and can realize manual opening and closing of the circuit breaker by separating the electric operating mechanism from the circuit breaker mechanism after automatic closing and paying.
Reclosing circuit breaker operating device on the market at present generally all is the gear reduction mechanism of constant drive ratio, can divide into two types according to the drive mode of motor: one type is an electric operating mechanism driven by a motor in a one-way mode, the outer edges of the circumferences of a driving gear and a handle wheel of the operating mechanism are respectively provided with a section of gear teeth, the driving gear is driven by the motor to rotate during switching-on operation, a gear section arranged on the circumference of the driving gear is meshed with a gear section on the circumference of a handle rotating wheel to drive the handle wheel to rotate to a switching-on position, the driving gear continues to rotate after the handle wheel is switched on, so that the gear section on the circumference of the driving gear is separated from the gear section on the circumference of the handle wheel, and the handle can be manually; the other type is an electric operating mechanism with a motor needing forward and reverse rotation driving, and unidirectional transmission is realized between a driving gear and a handle wheel of the electric operating mechanism through a boss structure. When the switch is closed, the motor rotates positively to drive the driving gear to rotate, and the driving gear drives the handle to rotate the handle wheel to the switch-on position. After the switch is switched on, the motor reversely rotates to drive the driving gear to rotate to the initial position, the driving gear is separated from the handle wheel, and the handle wheel can be manually and freely switched on and off.
The two mechanisms have obvious defects, the first mechanism has the defects that the meshing amount of the driving gear and the handle rotating block is small at the moment of separation, and the driving mechanism is easy to wear and lose efficacy due to more operation times; the second mechanism has high requirement on the control precision of the rotating position of the driving gear, namely, the control precision of the motor, because when the driving gear drives the handle rotating block to the switching-on position, if the motor is completely stopped, the motor can be blocked and the mechanism can be locked.
The invention content is as follows:
technical problem to be solved
The invention discloses a four-connecting-rod type reclosing circuit breaker operating mechanism, which structurally solves the problems of gear abrasion and motor locked rotation and jamming of the existing electric operating mechanism, and improves the closing speed of the circuit breaker by utilizing the variable ratio transmission characteristic of the four-connecting-rod mechanism.
Technical scheme adopted for solving technical problem
An operating mechanism of a four-connecting-rod type reclosing circuit breaker comprises a handle, a motor, a fixed-ratio transmission mechanism and a variable-ratio transmission mechanism; the rotor output shaft of the motor is connected with and drives the fixed ratio transmission structure, and the fixed ratio transmission structure synchronously rotate;
the handle is connected with a rotating shaft; the variable ratio transmission mechanism comprises a connecting rod, a first connecting mechanism of the connecting rod and a second connecting mechanism of the connecting rod; the first connecting mechanism of the connecting rod is connected with the handle, and the second connecting mechanism of the connecting rod is connected with the ratio-changing transmission mechanism; the head end and the tail end of the connecting rod are respectively connected with a first connecting point and a second connecting point of the connecting rod;
when the first connecting point action path passes through the virtual position, the connecting rod is pulled by the first connecting point;
when the second connecting point action path passes through the virtual position, the connecting rod is pulled by the second connecting point; the fixed ratio transmission mechanism is connected with a tripping rod traction mechanism.
One implementation is as follows: waist-shaped holes are formed in the head end and the tail end of the connecting rod;
the first connecting mechanism of the connecting rod is a rotating block connected to a rotating shaft of the handle, and the rotating block synchronously rotates along with the handle; the rotating block is provided with a convex column which is connected in a waist-shaped hole at the head end of the connecting rod; the convex column is parallel to the rotating shaft of the handle;
the fixed ratio transmission mechanism comprises a driving gear, and the driving gear and a rotor output shaft of the motor synchronously act; the circular surface of the driving gear is provided with a convex column which is connected in a kidney-shaped hole at the tail end of the connecting rod; the convex column is parallel to the rotating shaft of the driving gear;
and a tripping rod traction mechanism is also arranged on the circular surface of the driving gear.
The second implementation mode comprises the following steps: folding legs are arranged at the head end and the tail end of the connecting rod to form a U-shaped connecting rod;
the first connecting mechanism of the connecting rod is a rotating block connected to a rotating shaft of the handle, and the rotating block synchronously rotates along with the handle; the rotating block is provided with an arc waist-shaped through hole, and a folding leg at the head end of the connecting rod is arranged in the waist-shaped through hole; the folding legs are parallel to the rotating shaft of the handle;
the fixed ratio transmission mechanism comprises a driving gear, and the driving gear and a rotor output shaft of the motor synchronously act; the driving gear is connected with a second rocker arm; one end of the second rocker arm is rotatably connected to the rotating shaft of the driving gear, and the other end of the second rocker arm is rotatably connected with the folding leg at the tail end of the connecting rod; a limiting mechanism is arranged between the second rocker arm and the driving gear, and the relative rotation range of the second rocker arm and the driving gear is within the range limited by the limiting mechanism; and a tripping rod traction mechanism is also arranged on the circular surface of the driving gear.
The limiting mechanism between the second rocker arm and the driving gear is as follows: the circular surface of the driving gear is provided with a guide groove, and the radial section of the guide groove is in a fan-shaped ring shape; the rotating connecting end of the connecting rod and the second rocker arm extends into the guide groove;
the tripping rod traction mechanism on the circular surface of the driving gear is an annular stop wall positioned on the opposite side of the second rocker arm; the annular stopping wall and the driving gear rotate coaxially, the radial section of the annular stopping wall is fan-shaped, and the side surface of the radial diameter of the annular stopping wall corresponding to one side of the fan-shaped and the circular arc is a surface for abutting against the trip rod.
The third implementation mode comprises the following steps:
the first connecting mechanism of the connecting rod comprises a handle rotating block and a first rocker arm; the handle is connected to the handle rotating block;
the fixed ratio transmission mechanism comprises a worm, a worm gear set, a relay gear and a driving gear; the rotating shafts of the driving gear, the relay gear and the worm gear set are parallel; the worm wheel and the worm of the worm wheel set form a worm wheel and worm structure; the worm is connected with a rotor output shaft of the motor; the power output gear of the worm gear set drives the driving gear to rotate through the relay gear;
the driving gear is connected with a second rocker arm; one end of the second rocker arm is rotatably connected to the rotating shaft of the driving gear, and the other end of the second rocker arm is rotatably connected with the tail end of the connecting rod; a limiting mechanism is arranged between the second rocker arm and the driving gear, and the relative rotation range of the second rocker arm and the driving gear is within the range limited by the limiting mechanism; a tripping rod traction mechanism is also arranged on the circular surface of the driving gear;
one end of the first rocker arm is rotatably connected to a rotating shaft of the handle rotating block, and the other end of the first rocker arm is rotatably connected with the head end of the connecting rod; a limiting mechanism is arranged between the first rocker arm and the handle rotating block, and the relative rotation range of the first rocker arm and the handle rotating block is within the range limited by the limiting mechanism.
Further, the limiting mechanism between the second rocker arm and the driving gear is as follows: the circular surface of the driving gear is provided with a guide groove, and the radial section of the guide groove is in a fan-shaped ring shape; the rotating connecting end of the connecting rod and the second rocker arm extends into the guide groove;
the tripping rod traction mechanism on the circular surface of the driving gear is an annular stop wall positioned on the opposite side of the second rocker arm; the annular stopping wall and the driving gear rotate coaxially, the radial section of the annular stopping wall is fan-shaped, and the side surface of the radial diameter of the annular stopping wall corresponding to one side of the fan-shaped and the circular arc is a surface for abutting against the trip rod.
Further, be equipped with stop gear between first rocking arm and the rotatory piece of handle and be: the outer edge surface of the handle rotating block is provided with a boss; the action track of the rotating connecting end of the connecting rod and the first straight rocker arm on the outer edge surface of the handle rotating block is an arc line, and the boss is in an arc shape.
Furthermore, folding legs are arranged at the head end and the tail end of the connecting rod to form a U shape; the two folding legs respectively form a rotating connecting end of the connecting rod and the second rocker arm and a rotating connecting end of the connecting rod and the first straight rocker arm.
The worm gear set is formed by connecting a worm gear and a power output gear which are coaxial and have the same angular speed;
the driving gear is composed of a large gear and a small gear which are coaxial and have the same angular velocity, the large gear is meshed with a power output gear of the worm gear set, and the small gear is meshed with the driving gear;
referring to fig. 6-10, the principle of the operating mechanism is as follows: the electric wrench consists of a handle, a handle rotating block, a first rocker arm, a connecting rod, a second rocker arm, a driving gear, a relay gear, a worm gear set, a worm and a motor.
The first rocker arm, the handle rotating block and the handle are coaxially arranged, and the folding leg at one end of the connecting rod is inserted into a hole at the end part of the rocker arm and forms unidirectional driving with the step stop of the handle rotating block.
The driving gear and the second rocker arm are coaxially arranged, and the folding leg at the other end of the connecting rod is inserted into the hole at the end part of the second rocker arm and extends into the annular connecting rod guide groove of the driving gear. The driving gear, the relay gear, the worm gear set and the worm form a transmission gear set.
When the operating mechanism is at an initial position, the motor is electrified to drive the driving gear to rotate anticlockwise, the driving end of the annular connecting rod guide groove arranged on the driving gear touches the connecting rod folding leg and drives the four-bar mechanism to swing, and the folding leg at the other end of the connecting rod touches the handle rotating block stepped stop to drive the handle to rotate and rotate towards the handle closing direction.
When the connecting rod and the second rocker arm are in the same straight line (namely the critical point position of the four-bar mechanism), the handle reaches the switching-on position, at the moment, if the motor is not stopped in time, the driving gear continues to drive the second rocker arm to rotate anticlockwise, the first rocker arm rotates reversely (clockwise) under the driving of the connecting rod after the motor passes the critical point, and the connecting rod and the handle rotating block are driven in a single direction, so that the handle rotating block cannot be driven to rotate when the first rocker arm rotates reversely, and the problems of separation abrasion of the first type of operating mechanism and high positioning accuracy requirement of the second type of operating mechanism in the market at present are solved.
After the driving handle is switched on, the driving gear rotates clockwise to an initial position, and at the moment, the connecting rod is separated from the handle rotating block and has a certain gap, so that the handle can be switched on and off manually. The driving gear rotates clockwise by a certain angle at the initial position, and the annular stop wall arranged on the driving gear pushes the tripping rod led out from the circuit breaker mechanism to trip the circuit breaker, so that the circuit breaker is switched off. Because the connecting rod folding foot can freely slide in the annular connecting rod guide groove on the driving gear and the design angle of the annular connecting rod guide groove is far larger than the angle required by the driving gear to drive the tripping rod to trip, the requirement on the precision of the movement position of the driving rod by tripping operation is also very low.
After the operating mechanism finishes tripping operation, the operating mechanism rotates anticlockwise to an initial position to prepare for next operation.
The principle that the four-bar linkage mechanism improves the closing speed of the circuit breaker is as follows:
the first half section of the closing stroke of the operating resistance of the contact mechanism of the circuit breaker comes from a spring of the circuit breaker mechanism, and after a moving contact of the second half section of the closing stroke contacts with a static contact, the operating force overcomes the resistance of the mechanism spring and the contact spring at the same time, namely, the operating resistance is suddenly increased.
The transmission ratio of the existing electric operating mechanism is designed according to the maximum operating resistance moment of the circuit breaker mechanism because the transmission ratio is fixed, and the driving moment and the driving speed of the electric operating mechanism are constant no matter in the first half or the second half of the closing stroke of the circuit breaker contact mechanism.
The transmission ratio of the four-bar linkage mechanism is changed, and the driving torque curve and the transmission speed curve of the four-bar linkage mechanism are increased progressively and decreased progressively in the switching-on process of a driving circuit breaker by designing the initial angles of the driving rod and the driven rod in the four-bar linkage mechanism. The four-link transmission mechanism meets the requirement of large torque required at the later stage of the closing stroke of the contact mechanism of the circuit breaker, and simultaneously improves the closing speed at the early stage of the closing stroke, so that the total closing speed of the contact mechanism of the circuit breaker is higher than that of the existing constant transmission ratio electric operating mechanism.
Advantageous effects
The invention improves the reliability and mechanical life of the electric operating mechanism, and simultaneously improves the closing speed of the circuit breaker and the electrical life of the circuit breaker under the condition that the volume of the whole transmission mechanism is not changed.
Drawings
FIG. 1 is a schematic view of the structure of an operating mechanism of example 1
FIG. 2 is a schematic view (front view) of the structure of the drive gear of example 1;
FIG. 3 is a schematic view (rear surface) of the structure of the drive gear of example 1;
FIG. 4 is a partial schematic view of the handle rotation block of example 1;
FIG. 5 is a schematic view of a structure of a portion of the drive gear of example 1;
FIG. 6 is a schematic view of the operating mechanism of example 1 in a circuit breaker configuration;
FIG. 7 is a schematic view showing the state of the operating mechanism of example 1 in the open state of the circuit breaker;
FIG. 8 is a schematic view of the operating mechanism of example 1 in a closed state of the circuit breaker;
FIG. 9 is a schematic view showing the state of the operating mechanism of example 1 in the case where the circuit breaker has passed the critical point;
FIG. 10 is a schematic view of the operating mechanism of example 1 in a further operating condition of the circuit breaker of FIG. 9; (the driving gear is at the initial position, and the handle wheel can be switched on and off at the moment)
Fig. 11 is a schematic view showing the state of the operating mechanism of example 1 in a trip state of the circuit breaker;
FIG. 12 is a schematic structural view of example 2;
FIG. 13 is a schematic structural view of example 3;
in the figure: the handle comprises a handle 1, a motor 2, a handle rotating block 3, a first rocker arm 4, a connecting rod 5, a second rocker arm 6, a driving gear 7, a relay gear 8, a worm gear set 9, a worm 10, a guide groove 11, an annular stop wall 12, a trip rod 13, a boss (stepped stop) 14, a limiting action end 15 of the guide groove, a driving action end 16 of the guide groove, a kidney-shaped hole 17 on the connecting rod, a rotating block 18 connected to a handle rotating shaft, a convex column 19, and a kidney-shaped hole 20 (connected to the rotating block on the handle rotating shaft).
Detailed Description
The operating mechanism is further described below with reference to the accompanying drawings:
an operating mechanism of a four-connecting-rod type reclosing circuit breaker comprises a handle, a motor, a fixed-ratio transmission mechanism and a variable-ratio transmission mechanism, wherein the fixed-ratio transmission mechanism is connected with the motor; the rotor output shaft of the motor is connected with and drives the fixed ratio transmission structure, and the fixed ratio transmission structure synchronously rotate;
the handle is connected with a rotating shaft; the variable ratio transmission mechanism comprises a connecting rod, a first connecting mechanism of the connecting rod and a second connecting mechanism of the connecting rod; the first connecting mechanism of the connecting rod is connected with the handle, and the second connecting mechanism of the connecting rod is connected with the ratio-changing transmission mechanism; the head end and the tail end of the connecting rod are respectively connected with a first connecting point and a second connecting point of the connecting rod;
when the first connecting point action path passes through the virtual position, the connecting rod is pulled by the first connecting point;
when the second connecting point action path passes through the virtual position, the connecting rod is pulled by the second connecting point; the fixed ratio transmission mechanism is connected with a tripping rod traction mechanism.
Example 1: referring to fig. 1 to 5, an operating mechanism of a four-link reclosing circuit breaker includes a handle and a motor. The handle rotating block, the first rocker arm, the connecting rod, the second rocker arm, the driving gear, the relay gear, the worm gear set and the worm are further included; the handle is connected to the handle rotating block;
the rotating shafts of the driving gear, the relay gear and the worm gear set are parallel; the worm wheel and the worm of the worm wheel set form a worm wheel and worm structure; the worm is connected with a rotor output shaft of the motor; the power output gear of the worm gear set drives the driving gear to rotate through the relay gear;
one end of the second rocker arm is rotatably connected to the rotating shaft of the driving gear, and the other end of the second rocker arm is rotatably connected with the tail end of the connecting rod; a limiting mechanism is arranged between the second rocker arm and the driving gear, and the relative rotation range of the second rocker arm and the driving gear is within the range limited by the limiting mechanism; a tripping rod traction mechanism is also arranged on the circular surface of the driving gear;
one end of the first rocker arm is rotatably connected to a rotating shaft of the handle rotating block, and the other end of the first rocker arm is rotatably connected with the head end of the connecting rod; a limiting mechanism is arranged between the first rocker arm and the handle rotating block, and the relative rotation range of the first rocker arm and the handle rotating block is within the range limited by the limiting mechanism.
In this example, the limiting mechanism between the second rocker arm and the driving gear is: the circular surface of the driving gear is provided with a guide groove, and the radial section of the guide groove is in a fan-shaped ring shape; the rotating connecting end of the connecting rod and the second rocker arm extends into the guide groove;
the tripping rod traction mechanism on the circular surface of the driving gear is an annular stop wall positioned on the opposite side of the second rocker arm; the annular stopping wall and the driving gear rotate coaxially, the radial section of the annular stopping wall is fan-shaped, and the side surface of the radial diameter of the annular stopping wall corresponding to one side of the fan-shaped and the circular arc is a surface for abutting against the trip rod.
Be equipped with stop gear between first rocking arm and the rotatory piece of handle and do: the outer edge surface of the handle rotating block is provided with a boss; the action track of the rotating connecting end of the connecting rod and the first straight rocker arm on the outer edge surface of the handle rotating block is an arc line, and the boss is in an arc shape.
Folding legs are arranged at the head end and the tail end of the connecting rod to form a U shape; the two folding legs respectively form a rotating connecting end of the connecting rod and the second rocker arm and a rotating connecting end of the connecting rod and the first straight rocker arm.
In the existing transmission mechanism, the transmission of the driving wheel to the handle wheel is gear transmission, and the scheme is changed into connecting rod transmission. While the specific structure of the connecting rod transmission can have various designs, the above example is only based on part of the realization way in the idea.
The transmission mechanism consists of two parts, one part is a gear transmission mechanism with a constant transmission ratio, and the other part is a four-bar variable-ratio transmission mechanism.
The gear reduction mechanism (such as a worm gear structure) with a constant reduction ratio drives the ratio-changing connecting rod mechanism to realize the ratio-changing transmission of the handle wheel. The specific implementation of the ratio-change linkage mechanism is various.
In example 2, as shown in fig. 12, the two ends of the connecting rod are provided with waist-shaped holes;
the first connecting mechanism of the connecting rod is a rotating block connected to a rotating shaft of the handle, and the rotating block synchronously rotates along with the handle; the rotating block is provided with a convex column which is connected in a waist-shaped hole at the head end of the connecting rod; the convex column is parallel to the rotating shaft of the handle;
the fixed ratio transmission mechanism comprises a driving gear, and the driving gear and a rotor output shaft of the motor synchronously act; the circular surface of the driving gear is provided with a convex column which is connected in a kidney-shaped hole at the tail end of the connecting rod; the convex column is parallel to the rotating shaft of the driving gear;
and a tripping rod traction mechanism is also arranged on the circular surface of the driving gear.
In example 3, as shown in fig. 13, the variable ratio transmission mechanism portion has the same principle as that of example 1, and the fixed ratio transmission mechanism portion has the same principle as that of example 2.
Folding legs are arranged at the head end and the tail end of the connecting rod to form a U-shaped connecting rod;
the first connecting mechanism of the connecting rod is a rotating block connected to a rotating shaft of the handle, and the rotating block synchronously rotates along with the handle; the rotating block is provided with an arc waist-shaped through hole, and a folding leg at the head end of the connecting rod is arranged in the waist-shaped through hole; the folding legs are parallel to the rotating shaft of the handle;
the fixed ratio transmission mechanism comprises a driving gear, and the driving gear and a rotor output shaft of the motor synchronously act; the driving gear is connected with a second rocker arm; one end of the second rocker arm is rotatably connected to the rotating shaft of the driving gear, and the other end of the second rocker arm is rotatably connected with the folding leg at the tail end of the connecting rod; a limiting mechanism is arranged between the second rocker arm and the driving gear, and the relative rotation range of the second rocker arm and the driving gear is within the range limited by the limiting mechanism; and a tripping rod traction mechanism is also arranged on the circular surface of the driving gear.