JP6610461B2 - Crank mechanism motor and vacuum pump - Google Patents

Description

  The present invention relates to a motor with a crank mechanism and a vacuum pump, and more particularly to a motor with a crank mechanism and a vacuum pump that perform sensorless control.

  Conventionally, a motor that performs sensorless control is known (see, for example, Patent Document 1).

  The motor described in Patent Document 1 is a brushless motor including a stator having a plurality of phase coils and a rotor (magnet rotor) provided on the stator. Further, the motor detects a position of the rotor based on an induced voltage generated in each phase coil when the rotor is rotated, and controls the energization to each phase coil based on the detected rotor position. It has. The control means performs control to set the rotor to the initial position in order to change the rotor from the stationary state to the driving state when the power supply to the motor is interrupted. When the rotor is set to the initial position, control is performed to gradually change the ratio of the energization time for the coils of each phase.

JP 2008-263665 A

  However, in the motor described in Patent Document 1, since the electric control is performed when the control for setting the rotor (magnet rotor) to the initial position is performed, the performance of the motor is reduced due to heat generation or the like. There is a problem of doing.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to set the rotor in the initial position without performing electrical control, thereby improving the performance of the motor. It is an object to provide a motor with a crank mechanism and a vacuum pump capable of suppressing a decrease.

  A motor with a crank mechanism according to a first aspect of the present invention includes a stator having a coil and a rotor provided so as to face the stator, a motor in which sensorless control is performed based on an induced voltage generated in the coil, and a motor A crank portion connected to the rotating shaft, and a crank mechanism connected to the crank portion and moving back and forth in the crankcase as the motor rotates. The rotor and the crank portion are configured to move to a predetermined position when stopped, so that the rotor is set to an initial position when the moving member moves to a predetermined position in the crankcase. And are assembled.

  In the motor with a crank mechanism according to the first aspect of the present invention, as described above, when the moving member moves to a predetermined position in the crankcase, the rotor and the crank portion are set so that the rotor is set to the initial position. And the rotor can be automatically set to the initial position without performing electrical control. Thereby, since the heat generation of the motor when the rotor is set at the initial position can be suppressed, a decrease in the performance of the motor due to the heat generation or the like can be suppressed. Further, since control for setting the rotor to the initial position is unnecessary, it is possible to shorten the motor start-up time and to simplify the configuration (control) of the motor.

  In the motor with a crank mechanism according to the first aspect, preferably, the crankcase is provided on one side with respect to the moving member, the first chamber being a space surrounded by the moving member and the crankcase, and the moving member. And a second chamber, which is a space provided on the other side and surrounded by the moving member and the crankcase, and the moving member has a space between the first chamber and the second chamber when the rotation of the motor is stopped. Based on the pressure difference, it is configured to move to a predetermined position. When the moving member moves to a predetermined position in the crankcase, the rotor and the crank portion are set so that the rotor is set to the initial position. And are assembled.

  With this configuration, the rotor and the crank portion are set so that the rotor is set to the initial position when the moving member is moved to a predetermined position based on the pressure difference between the first chamber and the second chamber. And the rotor can be easily set to the initial position without performing electrical control. Further, even when the rotor is displaced from the initial position due to vibration or the like, the rotor returns to the initial position due to the pressure difference between the first chamber and the second chamber, so that a reduction in motor performance can be effectively suppressed.

  In this case, preferably, the first chamber is provided in the upper part of the moving member, and the second chamber is provided in the lower part of the moving member, and the moving member that reciprocates in the crankcase is provided in the first chamber. The motor and the crank portion are assembled so that the rotor is set at the initial position when the top dead center in the crankcase, which is the highest point, is moved.

  Here, when the pressure difference between the first chamber and the second chamber is used, the moving member automatically moves to the top dead center, so that the moving member is moved to the top dead center, which is the uppermost point of the first chamber. Is relatively easy compared to moving the moving member to other than the uppermost point of the first chamber. Therefore, when the moving member moves to the top dead center in the crankcase which is the uppermost point of the first chamber, the motor and the crank portion are assembled so that the rotor is set to the initial position. The rotor can be automatically set to the initial position more easily.

  In the motor with a crank mechanism in which the motor is set to the initial position when the moving member moves to the top dead center, preferably, the crank mechanism is configured to evacuate the inside of the object. The air in the object is sucked into the first chamber when descending the crankcase, and the air in the first chamber is exhausted to the outside when the moving member rises in the crankcase. In the intake or exhaust process, when the rotation of the motor is stopped, the moving chamber is moved to the top dead center by the atmospheric pressure in the second chamber and the negative pressure in the first chamber. It is configured as follows.

  Here, in the crank mechanism that evacuates the inside of the object, the first chamber in which the air in the object is sucked or the air is discharged to the outside is in a lower pressure than the atmospheric pressure. Therefore, a state in which the pressure in the first chamber is lower than the pressure in the second chamber, which is atmospheric pressure, can be easily created, so that the moving member can be easily moved to the top dead center.

  In the motor rotating electric machine with a crank mechanism according to the first aspect, preferably, the rotor is driven from a stationary state after the moving member has moved to a predetermined position in the crankcase and the rotor is set to the initial position. It is configured to be controlled to be in a state.

  Here, when the rotor is not set at the initial position and the rotor is changed from the stationary state to the driving state, an inappropriate voltage is applied to the rotor, and the motor does not operate normally. Therefore, after the rotor is set to the initial position, the rotor can be appropriately switched from the stationary state to the driving state by being controlled so as to be driven from the stationary state, and the motor can be operated normally. Can do.

  A vacuum pump according to a second aspect of the present invention includes a stator having a coil and a rotor provided to face the stator, a motor in which sensorless control is performed based on an induced voltage generated in the coil, and rotation of the motor A crank mechanism that includes a crank portion connected to the shaft and a moving member that is connected to the crank portion and reciprocates in the crankcase as the motor rotates, and is configured to evacuate the object. The moving member is configured to move to a predetermined position when rotation of the motor is stopped, and when the moving member moves to a predetermined position in the crankcase, the rotor is The rotor and the crank portion are assembled so as to be set at the initial position.

  In the vacuum pump according to the second aspect of the present invention, as described above, when the moving member moves to a predetermined position in the crankcase, the rotor and the crank portion are arranged so that the rotor is set to the initial position. By being assembled, the rotor can be automatically set to the initial position without electrical control. Thereby, the heat generation when the rotor is set at the initial position can be suppressed. As a result, it is possible to suppress a decrease in performance of the motor and to suppress a decrease in pump capacity.

  The following configuration is also conceivable in the vacuum pump according to the second aspect.

(Additional item 1)
In the vacuum pump according to the second aspect, preferably, the crank mechanism is configured to evacuate the object, and when the moving member descends in the crankcase, the air in the object is The air is sucked into one chamber and the air in the first chamber is exhausted to the outside when the moving member moves up in the crankcase, and the rotation of the motor stops in the intake or exhaust process. When this is done, the moving member is moved to the top dead center by the atmospheric pressure in the second chamber and the negative pressure in the first chamber.

  Here, in the vacuum pump that evacuates the inside of the object, the first chamber in which the air in the object is sucked or the air is discharged to the outside is in a lower pressure state than the atmospheric pressure. Therefore, a state in which the pressure in the first chamber is lower than the pressure in the second chamber, which is atmospheric pressure, can be easily created, so that the moving member can be easily moved to the top dead center.

It is a perspective view of the whole structure of the motor with a crank mechanism by one Embodiment of this invention. It is a side view of the motor with a crank mechanism by one Embodiment of this invention. It is a top view for demonstrating the initial position of the rotor by one Embodiment of this invention. It is a side view of the motor with a crank mechanism when the moving member by one Embodiment of this invention arrives at a top dead center.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  With reference to FIGS. 1-4, the structure of the vacuum pump 100 (an example of a motor with a crank mechanism) by this embodiment is demonstrated.

[Overall configuration of vacuum pump]
As shown in FIG. 1, the vacuum pump 100 includes a motor 1. The motor 1 is accommodated in the housing 101. Further, the vacuum pump 100 includes a crank mechanism 2 configured to evacuate the inside of an object 6 (see FIG. 2) described later. The motor 1 is disposed on the Y2 direction side with respect to the crank mechanism 2. Specifically, the housing 101 is disposed on the Y2 direction side of the housing 102 described later. The rotating shaft 1a of the motor 1 extends from the motor 1 in the Y1 direction. FIG. 1 is a schematic diagram showing the configuration of the vacuum pump 100.

  As shown in FIG. 2, the crank mechanism 2 includes a crank portion 3. The crank part 3 has a rod 3a. The crank portion 3 includes a connecting portion 3b and a balancer 3c housed in the housing 102.

  When the motor 1 (see FIG. 1) rotates, the crank portion 3 rotates integrally with the connecting portion 3b and the balancer 3c (rotates on the XZ plane), and the rod 3a moves vertically (Z direction). ) To reciprocate.

  The crank mechanism 2 includes a piston 4 (an example of a moving member). The piston 4 is accommodated in a crankcase 5 disposed at the upper part of the housing 102. The crankcase 5 has a cylinder shape in which a columnar cavity is provided. The piston 4 is connected to the rod 3a of the crank portion 3 and reciprocates in the crankcase 5 in the vertical direction (Z direction) in conjunction with the reciprocating motion of the rod 3a. The crankcase 5 and the housing 102 are configured to communicate with each other, and the rod 3 a is provided across the crankcase 5 and the housing 102.

  The crankcase 5 is provided on the Z1 direction side with respect to the piston 4 and includes a first crank chamber 5a (an example of a first chamber) that is a space surrounded by the piston 4 and the crankcase 5. The crankcase 5 includes a second crank chamber 5 b (an example of a second chamber) that is provided on the Z2 direction side with respect to the piston 4 and is a space surrounded by the piston 4 and the crankcase 5. Further, the crankcase 5 is connected to the object 6 via the connection portion 103. The object 6 is, for example, a brake booster. In addition, the crankcase 5 is connected to the outside via the connecting portion 104.

  When the piston 4 descends in the crankcase 5 (moves in the Z2 direction side), air in the object 6 is sucked into the first crank chamber 5a and the piston 4 rises in the crankcase 5 (Z1 direction). When moving to the side), the air in the first crank chamber 5a is exhausted to the outside. Specifically, the air in the object 6 is configured to flow into the first crank chamber 5a when the piston 4 descends and the volume of the first crank chamber 5a increases.

  Specifically, when the piston 4 is lowered (moved in the Z2 direction side), the volume of the first crank chamber 5a is increased, whereby the pressure in the first crank chamber 5a is reduced, and the check provided in the crankcase 5 is performed. Valve 105 opens. In this case, the air in the object 6 flows into the first crank chamber 5a through the check portion 105 via the connection portion 103. Further, when the piston 4 is raised (moved in the Z1 direction side), the volume of the first crank chamber 5a is reduced, so that the pressure in the first crank chamber 5a is increased and the check valve 106 provided in the crankcase 5 is increased. Opens. In this case, the air in the first crank chamber 5 a passes through the check valve 106 and flows out to the outside through the connection portion 104.

[Motor configuration]
As shown in FIG. 3, the motor 1 (see FIG. 1) is configured as a three-phase brushless motor, for example. The motor 1 includes a stator 11 having a coil 10. The motor 1 includes a rotor 12 provided to face the stator 11. The motor 1 is configured so that sensorless control is performed based on the induced voltage generated in the coil 10. That is, the motor 1 is configured to perform control for estimating the position (rotation angle) of the rotor 12 based on the induced voltage generated in the coil 10 as the rotor 12 rotates.

  The stator 11 is provided with a plurality of (for example, nine) teeth 11b that protrude radially inward from the back yoke 11a at equal angular intervals. In FIG. 3, the nine teeth 11b are numbered (numbered 1 to 9) for ease of explanation. Slots 13 are formed between adjacent teeth 11b.

  The rotor 12 is disposed inside the annular stator 11 so as to face the stator 11. The rotor 12 has a plurality of (for example, six) permanent magnets 14 having a rectangular cross section (rectangular shape) as viewed in the axial direction (Y direction) embedded in the circumferential direction at equal angular intervals. That is, the motor 1 (see FIG. 1) is configured as a 6-pole 9-slot rotating electric machine. The permanent magnet 14 is embedded in the circumferential direction so that the N-pole permanent magnet 14a and the S-pole permanent magnet 14b are alternately arranged.

  The coil 10 is wound around each of the first to ninth teeth 11b. The stator 11 is provided with a U-phase terminal, a V-phase terminal, and a W-phase terminal, which are not shown. Further, by applying a voltage to the U-phase terminal and grounding the V-phase terminal (hereinafter referred to as U-V energization), the S poles are located near the teeth 11b of Nos. 1, 4, and 7. The coil 10 is wound so that a magnetic field is generated. In this case, an N-pole magnetic field is generated in the vicinity of the teeth 11b other than No. 1, No. 4, and No. 7. Further, the arrangement of FIG. 3 in which each of the first, fourth, and seventh teeth 11b that generate the S-pole magnetic field and the N-pole permanent magnet 14a are opposed to each other when the U-V current is supplied. The initial position of the rotor 12. Note that the initial position of the rotor 12 is a position where the rotor 12 stops when the UV is energized.

[Configuration of crank mechanism]
Here, in the present embodiment, as shown in FIG. 4, the piston 4 is configured to move to a predetermined position when the rotation of the motor 1 (see FIG. 1) is stopped. Further, the rotor 12 and the crank portion 3 are assembled so that the rotor 12 is set to the initial position (see FIG. 3) when the piston 4 moves to a predetermined position in the crankcase 5. Specifically, when the piston 4 moves to the top dead center 7 (an example of a predetermined position) in the crankcase 5 that is the uppermost point of the first crank chamber 5a, the rotor 12 is set to the initial position. Thus, the motor 1 and the crank part 3 are assembled | attached. That is, when the piston 4 moves to the top dead center 7, the motor 1 and the crank portion 3 are assembled so that the coil 10 that generates the south pole magnetic field and the north pole permanent magnet 14a are opposed to each other. .

  In the present embodiment, the piston 4 has a top dead center 7 based on the pressure difference between the first crank chamber 5a and the second crank chamber 5b when the rotation of the motor 1 (see FIG. 1) is stopped. Configured to move to. Specifically, when the rotation of the motor 1 is stopped in the intake or exhaust process, the inside of the second crank chamber 5b is at atmospheric pressure and the inside of the first crank chamber 5a is at negative pressure (pressure lower than atmospheric pressure). ), The piston 4 is configured to be moved to the top dead center 7. Specifically, when the first crank chamber 5a has a negative pressure and the second crank chamber 5b has an atmospheric pressure, the air in the second crank chamber 5b tends to flow into the first crank chamber 5a, thereby Since 4 is pushed toward the Z1 direction, the piston 4 moves toward the Z1 direction.

  More specifically, when the air in the object 6 is sucked into the first crank chamber 5a, the object 6 and the first crank chamber 5a are in a substantially vacuum state. In this case, the atmospheric pressure (substantially vacuum) in the first crank chamber 5a is lower than the atmospheric pressure (substantially atmospheric pressure) in the second crank chamber 5b. Thereby, when the air in the second crank chamber 5b tries to flow into the first crank chamber 5a, the piston 4 is pushed toward the Z1 direction, so that the piston 4 moves toward the Z1 direction.

  Further, when the piston 4 descends (moves in the Z2 direction side), the volume of the first crank chamber 5a increases, whereby the pressure in the first crank chamber 5a decreases, and the atmospheric pressure (negative pressure) in the first crank chamber 5a decreases. Pressure) is lower than the atmospheric pressure (substantially atmospheric pressure) in the second crank chamber 5b. Thereby, since the piston 4 is pushed to the Z1 direction side, the piston 4 moves to the Z1 direction side.

  Further, in the present embodiment, the rotor 12 is controlled so as to change from the stationary state to the driven state after the rotor 12 is set to the initial position due to the piston 4 moving to the top dead center 7 in the crankcase 5. It is configured to be. Specifically, the rotor 12 is changed from a stationary state to a driving state by energizing the U-V with the rotor 12 in the initial position. And after the rotor 12 will be in a drive state, the rotor 12 rotates by changing an electricity supply state for every predetermined time.

[Effect of this embodiment]
In the present embodiment, the following effects can be obtained.

  In this embodiment, when the piston 4 moves to a predetermined position in the crankcase 5, the rotor 12 and the crank portion 3 are assembled so that the rotor 12 is set to the initial position. The rotor 12 can be automatically set to the initial position without performing any control. Thereby, since the heat_generation | fever etc. of the motor 1 at the time of setting the rotor 12 to an initial position can be suppressed, the fall of the performance of the motor 1 resulting from heat_generation | fever etc. can be suppressed. Further, since the control for setting the rotor 12 to the initial position is not required, the startup time of the motor 1 can be shortened and the configuration (control) of the motor 1 can be simplified.

  In the present embodiment, the rotor 12 is set to the initial position when the piston 4 is moved to a predetermined position based on the pressure difference between the first crank chamber 5a and the second crank chamber 5b. Since the rotor 12 and the crank portion 3 are assembled, the rotor 12 can be easily set to the initial position without performing electrical control. Further, even when the rotor 12 is deviated from the initial position due to vibration or the like, the rotor 12 returns to the initial position due to the pressure difference between the first crank chamber 5a and the second crank chamber 5b, which effectively reduces the performance of the motor 1. Can be suppressed.

  Here, when the pressure difference between the first crank chamber 5a and the second crank chamber 5b is used, the piston 4 automatically moves to the top dead center 7, so that the piston 4 is the uppermost point of the first crank chamber 5a. Moving to the top dead center 7 is relatively easier than moving the piston 4 to a position other than the uppermost point of the first crank chamber 5a. Therefore, in this embodiment, when the piston 4 moves to the top dead center 7 in the crankcase 5 that is the uppermost point of the first crank chamber 5a, the motor 1 is set so that the rotor 12 is set to the initial position. As a result, the rotor 12 can be automatically set to the initial position more easily.

  Here, in the crank mechanism 2 that evacuates the inside of the object 6, the first crank chamber 5a in which the air in the object 6 is sucked or the air is discharged to the outside has a lower pressure than the atmospheric pressure. It becomes the state of. Accordingly, in the present embodiment, a state in which the pressure in the first crank chamber 5a is lower than the pressure in the second crank chamber 5b, which is atmospheric pressure, can be easily created. Can be moved to.

  Here, when the rotor 12 is not set to the initial position and the rotor 12 is changed from the stationary state to the driving state, an inappropriate voltage is applied to the rotor 12, and the motor 1 operates normally. do not do. Therefore, in this embodiment, after the rotor 12 is set to the initial position, the rotor 12 can be appropriately switched from the stationary state to the driving state by being controlled so as to change from the stationary state to the driving state. The motor 1 can be operated normally.

[Modification]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, an example in which the crank mechanism-equipped motor is a vacuum pump is shown, but the present invention is not limited to this. In the present invention, the motor with a crank mechanism may be other than a vacuum pump.

  In the above-described embodiment, an example has been described in which the rotor 12 is driven by energizing the UV from the state where the rotor 12 is stationary at the initial position. However, the present invention is not limited to this. In the present invention, the rotor 12 that is stationary at the initial position may be put into a driving state by performing other than the U-V energization (for example, U-W energization).

  Moreover, in the said embodiment, although the motor 1 showed the example of the structure which is a rotary electric machine of 6 pole 9 slots, this invention is not limited to this. In the present invention, a rotating electrical machine other than 6 poles and 9 slots may be used.

  Moreover, although the initial position of the rotor 12 showed the example which is a position where the rotor 12 stops by UV energization in the said embodiment, this invention is not limited to this. In the present invention, the position at which the rotor 12 stops other than the U-V energization (for example, the U-W energization) may be set as the initial position.

DESCRIPTION OF SYMBOLS 1 Motor 2 Crank mechanism 3 Crank part 4 Piston (moving member)
5 Crankcase 5a First crank chamber (first chamber)
5b Second crank chamber (second chamber)
6 Object 7 Top dead center (predetermined position)
10 Coil 11 Stator 12 Rotor 100 Vacuum pump (motor with crank mechanism)

Claims (6)

A motor including a stator having a coil and a rotor provided so as to face the stator, and performing sensorless control based on an induced voltage generated in the coil;
A crank mechanism including a crank portion connected to a rotation shaft of the motor, and a moving member connected to the crank portion and reciprocatingly moved in the crankcase as the motor rotates.
The moving member is configured to move to a predetermined position when rotation of the motor is stopped,
A motor with a crank mechanism in which the rotor and the crank portion are assembled so that the rotor is set to an initial position when the moving member moves to a predetermined position in the crankcase. The crankcase is provided on one side with respect to the moving member, and is provided on the other side with respect to the moving member, the first chamber being a space surrounded by the moving member and the crankcase, and the movement A second chamber that is a space surrounded by the member and the crankcase,
The moving member is configured to move to a predetermined position based on a pressure difference between the first chamber and the second chamber when rotation of the motor is stopped.
The crank according to claim 1, wherein the rotor and the crank portion are assembled so that the rotor is set at an initial position when the moving member moves to a predetermined position in the crankcase. Motor with mechanism.   The first chamber is provided at an upper part of the moving member, the second chamber is provided at a lower part of the moving member, and the moving member that reciprocates in the crankcase is provided in the first chamber. The said motor and the said crank part are assembled | attached so that the said rotor may be set to the initial position when it moves to the top dead center in the said crankcase which is the highest point of the Motor with crank mechanism. The crank mechanism is configured to evacuate the object,
When the moving member descends in the crankcase, air in the object is sucked into the first chamber, and when the moving member rises in the crankcase, The air is exhausted to the outside,
In the intake or exhaust process, when the rotation of the motor is stopped, the second chamber is at atmospheric pressure and the first chamber becomes negative pressure, whereby the moving member is moved to the top dead center. The motor with a crank mechanism according to claim 3, wherein the motor is configured as described above.   The rotor is configured to be controlled from a stationary state to a driving state after the rotor is set to an initial position by moving the moving member to a predetermined position in the crankcase. The motor with a crank mechanism according to any one of claims 1 to 4. A motor including a stator having a coil and a rotor provided so as to face the stator, and performing sensorless control based on an induced voltage generated in the coil;
A crank portion connected to the rotating shaft of the motor; and a moving member connected to the crank portion and reciprocatingly moved in the crankcase as the motor rotates. A crank mechanism configured,
The moving member is configured to move to a predetermined position when rotation of the motor is stopped,
A vacuum pump in which the rotor and the crank portion are assembled so that the rotor is set to an initial position when the moving member moves to a predetermined position in the crankcase.

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