JPH0733575Y2 - Brushless motor for speed control with reduction gear - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is based on the assumption that the thrust load generated by the bevel gear of the speed control brushless motor with reduction gear is FG magnet and FG
The present invention relates to a structure that prevents adverse effects on variations in the facing gap of a substrate.

[Conventional technology]

Although there are various fixing methods for bearing devices such as conventional rotary motors as shown in Japanese Patent Application No. 1-35558, a brushless motor for speed control with a reduction gear has an FG magnet for speed detection and an FG substrate. Is common. In this case, it is necessary to keep the small clearance between the FG magnet and FG board facing each other constantly regardless of the load fluctuation motor rotation direction, while increasing the number of parts and fixing them as in the conventional method. It is not advantageous in terms of cost to increase the number of parts, and it is necessary to suppress the movement of the ball bearing in the thrust direction without increasing the number of parts.

[Problems to be solved by the invention]

Generally, the reduction gear of the speed control brushless motor with a reduction gear generally uses a bevel gear to secure performance such as gear noise and uneven rotation.In this case, the helix angle, direction of the bevel gear, In addition, the direction of thrust load generated by the bevel gear changes depending on the motor rotation direction, and the effect of this affects the deceleration detection FG magnet for deceleration control and the minute gap between the FG board. Depending on the size, this minute gap may become zero and the FG magnet may rotate in contact with the FG board, resulting in impairing the function as a brushless motor for speed control. Conventionally, it can be used for both rotations. I could not do it.

Another object of the present invention is to provide a structure in which the FG gap always maintains a constant gap regardless of the thrust load acting on the motor rotary shaft gear.

[Means for Solving the Problems]

The present invention relates to a brushless motor for speed control and a brushless motor for speed control with a reduction gear that is formed by dividing a reduction gear unit. In the motor frame of the brushless motor, a disc-shaped base is provided and extends so as to stand up at the center of the base. Provide a cylindrical ball bearing mounting part, insert the ball bearing inside this ball bearing mounting part, press fit the motor rotating shaft of the bevel gear part inside this ball bearing, and fix it to the motor rotating shaft. The motor yoke of the rotor is fixedly supported on the side opposite to the bevel gear part, the main magnet is fixed to the inner circumference of the motor yoke, and the FG board is provided on the side opposite to the main magnet on the base part. Opposing FG magnets are provided on the rotor, the gear frame that constitutes the reduction gear unit is provided with a beveled output gear, and the gear shaft that supports the beveled output gear is provided on the gear frame. A projection part that meshes the output gear of the bevel gear with the bevel gear part of the motor rotation shaft, and abuts the ball bearing on the gear frame to prevent the ball bearing from moving in the ball bearing mounting portion in the axial direction. Is provided.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

Reference numeral 1 is a stator winding as a brushless motor, 2 is a main magnet for driving the stator winding, and 3 is a speed detection for deceleration control.
An FG magnet 4 holds the main magnet 2 and the FG magnet 3, and a rotor yoke made of a steel plate for transmitting the rotational force. A motor fixed shaft gear 5 for press-fitting and fixing the rotor yoke and transmitting the rotational force to the outside. A ball bearing is used, and the ball bearing 7 is press-fitted and fixed to the motor rotary shaft gear 5. 6 is a brushless motor,
A motor frame for holding the rotary shaft gear 5, the rotor yoke 4 and the like through the stator winding 1 and the ball bearing 7. This motor frame is a clearance fit state with the outer periphery of the ball bearing 7 keeping. Reference numeral 8 is a thrust spring for giving an appropriate preload to the ball bearing 7, and the ball bearing 7 and the motor frame 6
The ball bearing 7 and the motor frame 6 are located between the ball bearing mounting portions of No. 2 and are capable of giving a preload to the ball bearing 7 because of the clearance spring, and are larger than the previous preload in the P direction of the motor rotary shaft gear 5. When the thrust load is applied, the rotary shaft gear 5 moves in the P direction together with the ball bearing 7.
Reference numeral 9 is an FG board having an FG coil for deceleration detection, which is located opposite to the FG magnet 3 and is set so that a generated voltage can be obtained by the rotating action of the FG magnet 3. In order to obtain this generated power in a proper, effective and stable state, FG
FG gap Q between magnet 3 and FG board 9 is approximately 1mm
It is desirable that the FG gap Q is set to the following minute gap and that the FG gap Q does not change during rotation of the FG magnet 3, that is, the rotary shaft gear 5.

On the other hand, FIG. 3 shows a reduction gear structure, 10 is a gear frame, and positioning with the motor in FIG.
Φd ₁ part of the device part of the ball bearing 7 and φd _{2 of the} gear frame 10
The parts are fitted with a clearance fit. 11 is a gear cover, 12 is a gear shaft, and 13 is an output gear, which are set so as to mesh with the rotary shaft gear 5. 14 is a metal bearing A, 15 is a metal bearing B, and 16 is a thrust washer. In this case, generally, as the reduction gear for a brushless motor, a bevel gear having better performance than a spur gear is generally used in order to suppress noise and uneven rotation. In consideration of these points, the output gear 13 and the motor rotary shaft gear 5 meshing with the output gear 13 are bevel gears. In this helical gear, a load in the thrust direction is generated according to the helix angle and the load. The direction of this thrust load is determined by the direction of the helix angle of the helical gear and the direction of motor rotation. On the other hand, in the state of the brushless motor shown in FIG.
Corresponding to the torsional angle of the helical gear and the applied load. When the thrust load in the P direction is applied more than the preload of the thrust spring 8, the clearance between the FG magnet 3 and the FG board 9 via the rotor yoke 4 integrated with the motor rotation shaft 5, that is, the FG gap Q is small. When the FG magnet 3 is displaced in a certain direction and a larger thrust load is applied, the FG magnet 3 comes into contact with the FG board 9, and the FG magnet 3 rotates while making contact with the FG magnet 9, which damages the FG board. As a result, the function of controlling the rotation speed of the brushless motor is lost.

In order to prevent this drawback, the present invention, when the brushless motor shown in FIG. 2 and the reduction gear shown in FIG. 3 are fixed with the gear fixing screws 17 in FIG. 1, the φd ₂ end surface of the gear frame 10 is fixed. But,
The structure is such that it contacts the end surface 7a of the ball bearing 7, and as a result, even when a thrust load acts in the P direction in FIG. 1, the end surface 7a of the ball bearing 7 is press-fitted and fixed to the motor rotary shaft gear 5. Is in contact with the φd ₂ end surface of the gear frame 10, it is possible to prevent the motor rotation shaft gear from further changing in the P direction. As a result, the movement of the FG magnet, which is the main object of the present invention, can be restricted, and the FG gearup Q can always have a constant gearup regardless of load fluctuation and rotation direction.

[Effect of device]

As described above, the present invention is a brushless motor for speed control and a brushless motor for speed control with a reduction gear that is formed by dividing the reduction gear unit. Provide a cylindrical ball bearing mounting portion that extends so as to stand up, insert a ball bearing inside this ball bearing mounting portion, press fit and fix the motor rotation shaft of the bevel gear section inside this ball bearing, On the motor rotation shaft, the rotor motor yoke is fixedly supported on the side opposite to the bevel gear, the main magnet is fixed on the inner circumference of the motor yoke, and the base has an FG board on the side facing the main magnet. An FG magnet facing the FG board is provided on the rotor, a gear frame that constitutes the reduction gear unit is provided with an output gear having beveled teeth, and a gear shaft that supports the output gear having beveled teeth Attached to the gear frame, engagement with the output gear of the helical teeth of the helical gear portion of the motor rotary shaft,
In the brushless motor for speed control with a reduction gear, the gear frame is provided with a protrusion that comes into contact with the ball bearing to prevent the ball bearing from moving axially in the ball bearing mounting portion.

According to this configuration, the rotor does not move in the axial direction, so that a stable deceleration detection voltage can be obtained.

[Brief description of drawings]

FIG. 1 is a structural view of an assembly of a brushless motor and a reduction gear according to an embodiment of the present invention, FIG. 2 is a structural view of the brushless motor, and FIG. 3 is a structural view of the reduction gear. 1 ... Stator winding, 2 ... Main magnet, 3 ... FG
Magnet, 4 ... Rotor yoke, 5 ... Motor rotating shaft gear, 6 ... Motor frame, 7 ... Ball bearing, 8 ... Thrust spring, 9 ... FG substrate, 10 ... Gear frame, 11 ...
… Gear cover, 12 …… Gear shaft, 13 …… Output gear, 14 ……
Metal bearing A, 15 …… Metal bearing B, 16 …… Thrust washer, 17 …… Gear fixing screw, P …… Thrust load,
φd ₁ …… Motor frame inner diameter, φd ₂ …… Gear frame outer diameter, 7a …… Ball bearing end face, 10a …… Gear frame outer diameter φd ₂
End face, Q ... Motor FG gap.

Claims (1)

[Scope of utility model registration request] 1. A brushless motor for speed control, and a brushless motor for speed control with a reduction gear having a reduction gear portion divided into a disc-shaped base portion on a motor frame of the brushless motor and extending so as to stand up at the center of the base portion. Provide the existing cylindrical ball bearing mounting part, insert the ball bearing inside this ball bearing mounting part, press-fit the motor rotating shaft of the bevel gear part inside this ball bearing, and fix it to the motor rotating shaft. Fixedly supports the motor yoke of the rotor on the side opposite to the helical gear,
A main magnet is fixed to the inner circumference of the motor yoke, an FG board is provided on the side surface facing the main magnet at the base, and an FG magnet facing the FG board is provided on the rotor to form the reduction gear section. The gear frame is provided with a beveled output gear, and a gear shaft that supports this beveled output gear is attached to the gear frame, and the beveled output gear and the beveled gear portion of the motor rotating shaft are meshed with each other to form a gear frame. A brushless motor for speed control with a gear, characterized in that a protrusion portion is provided on the gear bearing to prevent the ball bearing from moving axially in the ball bearing mounting portion.