JPH0681918A - Magnetic ball planetary deceleration device - Google Patents

Abstract

PURPOSE:To provide a ball planetary deceleration device which can easily keep and control frictional force of steel balls, has a simple structure, and can be miniaturized. CONSTITUTION:An iron driving disc 2 is fixed to a driving shaft. First and second circular magnets 3, 4 are fixed on both sides of the driving disc 2, with their same electrodes being opposed to each other in an axial direction. First and second steel balls are circularly arranged on both sides of the driving disc 2, and held by means of retainers 7 so as to simultaneously revolute. The driving shaft 1 is supported to a fixation member 9, and a driven shaft 13 is rotatably supported on the same axial line as the driving shaft 1. An iron driven disc 14 is fixed to the driven shaft 13 in a rolling contact manner with the line of the second steel balls 8, oppositely to the driving shaft 2. Circular recessions 12 are formed on the rolling surfaces of the steel balls on the fixation member 9, in which recessions the first steels balls 6 drop for rolling on the peripheries.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball planetary speed reducer utilizing the frictional force between a steel ball and an iron disk due to a magnetic force.

[0002]

2. Description of the Related Art Gear type planetary speed reducers that have been used for a long time have many problems in terms of performance in addition to the necessity of refueling and the generation of noise, and various improvements have been studied so far. There is. As one of them, a method utilizing friction of a roller has been proposed, but it has not been put into practical use due to problems such as a pressure contact structure of the roller and abrasion.

[0003]

Therefore, according to the present invention, the frictional force of the steel ball can be easily maintained and controlled, and the structure is simple.
An object of the present invention is to provide a ball planetary speed reducer that can be downsized.

[0004]

In the present invention, in order to solve the above-mentioned problems, an iron drive disk 2 is fixed to a drive shaft 1 and annular steel balls are rolled on both side surfaces of the drive disk 2. A surface is provided, and the first and second annular magnets 3 and 4 located on both sides of the drive disk 2 are fixed to each other with their poles facing each other in the axial direction, and are rolled on both sides of the drive disk 2. A fixed member in which first and second rows of steel balls 6 and 8 are movably arranged in an annular shape, and these are held by a retainer 7 so as to revolve around each other at the same time, and the drive shaft 1 faces the drive disk 2. 9 is rotatably supported, and the fixed member 9 is provided with a steel ball rolling surface that comes into rolling contact with the first row of six steel balls, and the driven shaft 13 is rotatable relative to the drive shaft 1 and a common shaft center. The driven shaft 13
An iron driven disk 14 having a steel ball rolling surface that is in rolling contact with the second row of steel balls facing the drive disk 2 is fixed to the one side of the first magnet 3-. Fixed member 9-first steel ball 6-driving disk 2-forms a magnetic circuit of the first magnet 3, and on the other side a second magnet 4-driven disk 2-second steel ball 8-driving disk 2 A magnetic circuit of the second magnet 4 is formed so that the first or second row of steel balls 6, 8 falls on the steel ball rolling surface of either the drive disk 2, the fixing member 9 or the driven disk 14. The magnet type ball planetary reduction gear is constructed by forming annular recesses 12, 17 and 20 rolling on the edges.

Further, in the above-mentioned magnetic ball planetary speed reducer, the retainer 21 is constructed so as to allow the radial movement of the first steel ball 6 toward the axial center side, and the width of the annular recess 12 is changed. Therefore, the reduction ratio can be changed by configuring the annular steel ball rolling surface 24 of the fixing member 9 to be movable in the axial direction.

[0006]

In the magnetic ball planetary speed reducer of the present invention, when the drive shaft 1 rotates, the first steel ball 6 in contact with the drive disk 2 rolls on the annular rolling surface of the fixing member 9 while rotating on its own axis. It moves and revolves in the same direction as the drive shaft 1 along the annular rolling surface. Similarly, the second steel ball 8 is connected to the first steel ball 8 via the retainer 7.
While revolving at the same time as the steel ball 6 of FIG. 1, the driven disk 14 is rotated by rotating in the direction opposite to the direction of the first steel ball 6. Thus, for example, the first steel ball 6 has the drive disk 2 at the top on one end side.
Of the second steel ball 8 is in contact with the steel ball rolling surface of the fixing member 9 at a position deviated from the top and is in contact with the steel ball rolling surface of the fixing member 9 at both ends. The steel disk rolling surfaces of the driving disk 2 and the driven disk 14 are in contact with each other at the top. Due to this difference in rolling position, the driven shaft 14 decelerates and rotates with respect to the drive shaft 1.

The first steel ball 6 is allowed to move in the radial direction to the axial center side, the width of the annular recess 12 is changeable, and the steel ball rolling surface 24 of the fixing member 9 is axially arranged. When it is configured to be movable, the rolling position of the steel ball 6 can be changed to change the reduction ratio by adjusting the depth of the steel ball 6 falling into the recess 12.

[0008]

Embodiments of the present invention will be described with reference to the drawings.
1 is a vertical sectional front view of a speed reducer according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is a vertical sectional front view of a part of a speed reducer according to a second embodiment of the present invention. FIG. 4, FIG. 4 is a longitudinal sectional front view of a part of the speed reducer of the third embodiment of the present invention, FIG. 5 is a vertical sectional front view of a part of the speed reducer of the fourth embodiment of the present invention, and FIG. 5 is a sectional view taken along line VI-VI in FIG. 5, FIG. 7 is a vertical sectional front view of a part of the speed reducer of the fourth embodiment of the present invention, and FIG. 8 is a vertical sectional front view of a part of the speed reducer of the fourth embodiment of the present invention. FIG. 9 is a conceptual diagram of the present invention.

In FIG. 1 and FIG. 2, a drive disk made of iron is fixed to the drive shaft 1, and first and second annular magnets 3 and 4 located on both sides of the drive disk 2 are mutually attached. The same poles are fixed so as to face each other in the axial direction. Reference numeral 5 denotes a magnetically insulating cylinder that magnetically insulates the drive shaft 1 from the drive disk 2 or the magnets 3 and 4. The first steel balls 6 are annularly arranged in a row on one side surface of the drive disk 2 so as to be rollable, and retainers 7 are arranged so as to simultaneously revolve around the respective axes.
Is held by. The second steel ball 8 is the first steel ball 6
A plurality of them having the same diameter as the above are arranged in a row in a ring shape on the other side surface of the drive disk 2 so as to be rollable, and are held by a retainer 6 so as to revolve with the first steel balls 6 at the same time.

The fixing member 9 is fixed to the place where the speed reducer is installed, and rotatably supports the drive shaft 1.
It opposes the drive disk 2 and is rotatably in contact with the first steel ball 6. The fixed member 9 is configured to be movable in the axial direction with respect to the drive shaft 1. Steel ball 6 of fixing member 9
The inner and outer double concentric ribs 10, 1
1 is projected, and an annular recess 1 is provided between these ribs 10 and 11.
2 is formed. Then, the steel ball 6 has fallen into the annular recess 12. The ribs 10 and 11 have different protrusion heights, and are in contact with the steel ball 6 at the contact points P1 and P2, respectively. The intersection point P0 of the straight line connecting the contact points P1 and P2 and the axis of the drive shaft 1 is driven from the center of the steel ball 6 so that the steel ball 6 rolls without slipping on any of the ribs 10 and 11. It is set so as to coincide with the intersection of the perpendiculars drawn to the axis of the axis 1.

The driven shaft 13 is on the same axis as the drive shaft 1,
It is supported so as to be relatively rotatable and movable in the axial direction. The driven shaft 13 is made of iron and has a rolling surface facing the drive disc 2 and in contact with the second steel ball 8 so as to freely roll.
Is stuck.

A magnetic circuit connecting the first magnet 3-fixing member 9-first steel ball 6-driving disk 2-first magnet 3 is formed on one side, and the second magnet is formed on the other side. 4-Driven disk 14-Second steel ball 8-Driving disk 2-Second magnet 4 A magnetic circuit connected to is formed. The magnetic force generated by the magnetic circuit formed in this way is strong, attracts the fixed member 9 and the driven disk 14, and reliably transmits the rotation by the combined frictional force due to the pressing force between them and the magnetic frictional force.

In the speed reducer configured as described above, when the drive shaft 1 rotates together with the drive disc 2, the first steel ball 6 in contact with the drive disc 2 revolves along with the retainer 7 while rotating. Paying attention to the revolution speed in this case, when the rolling surface of the fixing member 9 is smooth, the revolution speed becomes 1/2 of the rotation speed of the drive disk 2, but in this embodiment, the fixing member 9 is used. There is a recess 12 on the rolling surface of the steel ball 6
Fall into this, and the parts P1 and P2 that are not the top of the steel ball
Is in contact with the fixing member 9. Therefore, the traveling speed of the steel ball 6 with respect to the fixed member 9 becomes slower than that in the case where the steel ball 6 is in contact with the top portion, and the revolution speed is eventually 1 / the rotation speed of the drive disk 2.
The speed is slower than 2. On the other hand, the second steel ball 8
While revolving at the same time as the first steel ball 6 through the retainer 7 and rotating in the opposite direction to the first steel ball 6 at the same speed, the steel ball 8 contacts the driven disk at the top. Therefore, the driven disk 14 tries to revolve at a speed half the rotation speed of the drive disk 2. Therefore, the driven disk 14 is rotated in the direction opposite to the drive shaft 1 at the rotation speed corresponding to the difference between the two revolution speeds.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, the same components as those in the first embodiment shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. Thus, in this embodiment, inner and outer double concentric circular ribs 15 and 16 are provided on the surface of the drive disk 2 on which the steel balls 8 roll, and an annular recess is formed between the ribs 15 and 16. 17 are formed. Then, the steel ball 8 has fallen into the annular recess 17. The ribs 15 and 16 have different protrusion heights, and are in contact with the steel ball 8 at the contact points P1 and P2, respectively.
The drive shaft 1 and the straight line connecting the contact points P1 and P2 so that the steel ball 8 rolls without slipping on any of the ribs 15 and 16.
The intersection point P0 with the axis center of is set to coincide with the intersection point of the perpendiculars drawn from the center of the steel ball 8 to the axis of the drive shaft 1.

In the speed reducer configured as described above, when the drive shaft 1 rotates with the drive disc 2, the first steel ball 6 contacting the drive disc 2 rotates together with the retainer 7 while rotating the drive disc 2. It revolves at half the speed. The steel ball 8 held by the tenor 7 is forced to revolve at the same speed as the steel ball 6, but there is a recess 17 on the rolling surface of the drive disc 2, and the steel ball 8 falls into this, causing the steel ball 8 to fall. Since the portions P1 and P2 that are not the tops of the steel balls are in contact with the drive disk 2, the rotation speed of the steel balls 8 is faster than the rotation speed of the steel balls 6. Therefore, the steel ball 8 tries to revolve with respect to the driven disk 14 at a speed faster than half the rotational speed of the drive disk 2. Therefore, the driven disk 14 is rotated in the direction opposite to the drive shaft 1 at the rotation speed corresponding to the difference between the two revolution speeds.

FIG. 4 shows a third embodiment of the present invention. In this embodiment, the same components as those in the first embodiment shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. Therefore, in this embodiment, inner and outer double concentric circular ribs 18 and 19 are projected on the surface of the driven disk 14 on which the steel balls 8 roll, and an annular recess is formed between these ribs 18 and 19. 20 are formed. Then, the steel ball 8 has fallen into the annular recess 20. The ribs 18 and 19 have different projecting heights, and are in contact with the steel ball 8 at the contact points P1 and P2, respectively. The intersection point P0 between the straight line connecting the contact points P1 and P2 and the shaft center of the drive shaft 1 is driven from the center of the steel ball 8 so that the steel ball 8 rolls without slipping on any of the ribs 18 and 19. Axis 1
It is set so as to coincide with the intersection of the perpendiculars drawn down to the axis center of.

In the speed reducer configured as described above, when the drive shaft 1 rotates together with the drive disk 2, the first steel balls 6 contacting the drive disk 2 rotate together with the retainer 7 while rotating the drive disk 2. It revolves at half the speed. The steel ball 8 held by the retainer 7 is forced to rotate and revolve at the same speed as the steel ball 6, but there is a recess 20 on the rolling surface of the driven disk 14, and the steel ball 8 falls into this, Since the non-top portions P1 and P2 of the ball 8 are in contact with the driven disk 14, the traveling speed of the steel ball 8 with respect to the driven disk 14 is
It becomes slower than the case of contacting at the top, and eventually, the driven disk 14 tries to revolve at a speed slower than half the rotation speed of the drive disk 2. Therefore, the driven disk 14 is rotated in the same direction as the drive shaft 1 at a rotation speed corresponding to the difference between the two revolution speeds.

5 to 8 show a fourth embodiment of the present invention. In this embodiment, the same components as those in the first embodiment shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. Therefore, in this embodiment, an adjusting ring 22 is provided instead of the rib 10 in the embodiment of FIG. The adjustment ring 22 is supported by the fixing member 9 by the bolts 23, and its position can be changed in the axial direction. Therefore, the first steel ball 6 is in rolling contact with the rib 11 and the adjusting ring 22 and has fallen into the recess 12 formed between them. The adjusting ring 22 is a steel ball 6.
Is provided with a sloping rolling surface 24 for contacting with each other, and the rolling surface 24 irrespective of the position of the adjusting ring 22 in the axial direction, the straight line connecting the contact points P1 and P2 with the steel ball 6 and the drive shaft. 1
The intersection point P0 with the axis center of is set to coincide with the intersection point of the perpendiculars drawn from the center of the steel ball 6 to the axis of the drive shaft 1.

The fixing member 9 is constructed so that its axial position can be adjusted with respect to the drive shaft 1 so that the axial position of the adjusting ring 22 can be changed in response to the change of the axial position of the adjusting ring 22. ing.

Further, the retainer 21 is provided with a U-shaped holding recess 25 directed toward the shaft center so that the holding position of the first steel ball 6 can be changed to the shaft center side in the radial direction. .

However, the mechanism of deceleration of this embodiment is the same as that of the first embodiment. However, in this embodiment, the reduction ratio can be changed by changing the width of the recess 12 and changing the amount of depression of the steel ball 6 by moving the adjusting ring 22 in the axial direction.

FIG. 9 shows a conceptual diagram common to any of the above embodiments. The speed reduction ratio η of the speed reducer according to the present invention can be represented by an equation with reference to FIG. 9 as follows.

[Equation 1]

Each of the above embodiments has the following features. (1) Since steel balls for bearings that are extremely hard, highly accurate, and inexpensive can be used as steel balls, a structure having a simple structure and high performance can be manufactured. (2) It does not require refueling and has low noise. (3) When the load exceeds the design allowable transmission force, slippage occurs between the disk and the steel ball, so there is no risk of failure due to overload. (4) Since the reduction ratio can be determined only by the width of the recess where the steel ball falls, standardization is easy. (5) Since the rotation transmitting force of the steel ball is secured only by the strong magnetic force of the small magnet, it is easy to reduce the size and weight.

The present invention is not limited to the illustrated embodiment, and for example, the first steel balls 6 and the second steel balls 8 do not have to have the same diameter, their number, and their The arrangement radius of can also be freely selected. Further, the adjusting ring 22 can be applied to any of the second and third embodiments.

[0025]

As described above, according to the present invention, the iron drive disk 2 is fixed to the drive shaft 1, and the annular steel ball rolling surfaces are provided on both side surfaces of the drive disk 2 to drive the drive disk 2. First and second annular magnets 3, 4 located on both sides of the disk 2
Are fixed to each other with their poles facing each other in the axial direction, and are rotatably mounted on both sides of the drive disc 2.
Eight rows are arranged in an annular shape, and they are held by retainers 7 so as to revolve around each other at the same time, and the drive shaft 1 is rotatably supported by a fixed member 9 facing the drive disk 2. Is provided with a steel ball rolling surface that rotatably contacts the first six rows of steel balls, and the driven shaft 13 is arranged so as to be relatively rotatable on the common shaft center with the drive shaft 1. An iron driven disk 14 having a steel ball rolling surface, which is in contact with the second row of steel balls 8 so as to be freely rollable, is fixed to the disk 2, and the first magnet 3-fixing member 9- The first steel ball 6-drive disk 2-forms the magnetic circuit of the first magnet 3, and the other has the second magnet 4-driven disk 2-second steel ball 8-drive disk 2-second. The magnetic circuit of the magnet 4 is formed, and the first or second row of steel balls 6, 8 falls on the steel ball rolling surface of any of the drive disk 2, the fixing member 9 or the driven disk 14. Recess 1 of the annular rolling the edge
Since the magnet type ball planetary speed reducer is formed by forming 2, 17 and 20, it is not necessary to refuel, the frictional force of the steel ball can be easily maintained and managed, the structure is simple, and the ball can be downsized. A planetary speed reducer can be provided.

In the magnetic ball planetary speed reducer, the retainer 21 is constructed so as to allow the first steel ball 6 to move in the radial direction toward the axis, and the width of the annular recess 12 is changed. Therefore, if the annular steel ball rolling surface 24 of the fixing member 9 is configured to be movable in the axial direction, the reduction ratio can be changed steplessly.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a speed reducer according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a vertical sectional front view of a part of the speed reducer according to the second embodiment of the present invention.

FIG. 4 is a vertical sectional front view of a part of a speed reducer according to a third embodiment of the present invention.

FIG. 5 is a vertical sectional front view of a part of the speed reducer according to the fourth embodiment of the present invention.

6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is a vertical sectional front view of a part of the speed reducer according to the fourth embodiment of the present invention.

FIG. 8 is a vertical sectional front view of a part of the speed reducer according to the fourth embodiment of the present invention.

FIG. 9 is a conceptual diagram of the present invention.

[Explanation of symbols]

 1 Drive shaft 2 Drive disk 3 1st magnet 4 2nd magnet 6 1st steel ball 7 Retainer 8 2nd steel ball 9 Fixing member 12 Annular recess 13 Driven shaft 14 Driven disk 17 Annular recess 20 Annular recess 21 Retainer 22 Adjustment ring 24 Annular steel ball rolling surface

Claims (4)

[Claims] 1. An iron drive disk having annular steel ball rolling surfaces on both sides is fixed, and first and second annular magnets having the same poles on both sides of the drive disk. Drive shafts fixedly opposed to each other in the axial direction, and first and second steels that are annularly arranged on both sides of the drive disk and are retained by a retainer so as to simultaneously revolve around the shafts. A ball row, a fixing member that rotatably supports the drive shaft, and a steel ball rolling surface that faces the drive disk and is in rolling contact with the first steel ball row; An iron driven disk having steel ball rolling surfaces facing each other and rotatably contacting the second steel ball row is fixed,
A drive shaft and a driven shaft arranged so as to be rotatable relative to each other on a common axis, the first magnet-fixing member-first steel ball-driving disk-magnetic circuit of the first magnet; A magnetic circuit of the second magnet-the driven disk-the second steel ball-the driving disk-the second magnet is formed, and the steel ball rolling surface of any one of the driving disk, the fixing member or the driven disk, A magnetic ball planetary speed reducer characterized in that an annular recess is formed in which the first or second row of steel balls falls and rolls along the edge thereof. 2. An intersection of a straight line connecting two contact points of the first or second steel ball and the annular recess, which are separated from each other in the radial direction, and the common axis is fitted in the annular recess. Alternatively, the magnetic ball planetary speed reducer according to claim 1, wherein the magnet type ball planetary speed reducer is set so as to coincide with an intersection of a perpendicular line drawn from the center of the second steel ball to the common axis. 3. The retainer is configured to hold the first steel ball while allowing the radial movement of the first steel ball toward the axial center side, and the annular recess has a width thereof. And a reduction ratio can be changed by the annular steel ball rolling surface of the fixing member being movable in the axial direction. 1
Alternatively, the magnetic ball planetary speed reducer according to 2 is provided. 4. An edge of the fixing member on the axial center side of the annular recess is provided on a rolling surface of an axially movable adjusting ring, and the rolling surface is the same as the first steel ball. Is set so as to always be placed in a position that satisfies the condition described in claim 2, and the width of the annular recess can be changed by moving the adjustment ring in the axial direction. The magnetic ball planetary speed reducer according to claim 3.