HK1208522B

HK1208522B - Planetary gear type speed increaser/reducer having two-stage reduction gears

Info

Publication number: HK1208522B
Application number: HK15108876.5A
Authority: HK
Inventors: 饭山俊男
Original assignee: 欧利生电气株式会社
Priority date: 2013-10-01
Filing date: 2015-09-11
Publication date: 2018-04-27

Description

Planetary type speed increaser/decreaser with 2-stage reduction gear

Technical Field

The present invention relates to a transmission device for changing a power transmission state between an input shaft and an output shaft, and more particularly to a transmission device which is a planetary type speed increasing/decreasing gear including a plurality of stages of 2-stage reduction gears, is small in size, has a large gear ratio, and can perform a smooth speed increasing operation.

Background

In a power transmission system for driving a machine member, a working machine, or the like to rotate, a speed reducer for changing a rotation speed or a torque is generally used so as to be adapted to characteristics of the driven machine. In addition, there are many cases where apparatuses having various functions are interposed, such as a torque limiter for protecting a drive source such as a motor from excessive load torque.

As the speed increaser, although there is a friction drive type speed increaser such as a belt drive mechanism using pulleys having different diameters, a gear type speed increaser is generally used, and among them, there is a planetary gear type speed increaser using a planetary gear mechanism. The planetary gear mechanism is a mechanism as follows: a sun gear (sun gear) is provided at the center of the planetary gear mechanism, a ring gear (ring gear) as an internal gear is provided around the sun gear, and a plurality of planetary gears (planet gears) that mesh with both gears are disposed between the sun gear and the ring gear. The plurality of planetary gears are mounted on a carrier (also referred to as a carrier) that carries the plurality of planetary gears, and are supported by the carrier. In general, the carrier is configured to be rotatable about a rotation axis concentric with the sun gear and the ring gear, and when the carrier rotates, the planetary gears perform a planetary operation of rotating while revolving inside the ring gear.

The planetary gear type speed increasing/decreasing gearbox can freely select gears, components and the like as input/output elements for power transmission, and has a large degree of freedom in setting a gear ratio. Further, since the input shaft and the output shaft are concentrically arranged, the arrangement of the power transmission device can be easily designed, and the transmission ratio can be easily increased by making the arrangement into multiple stages.

As a conventional multi-stage planetary gear type speed increasing/decreasing gearbox, a multi-stage planetary gear type speed increasing/decreasing gearbox having a structure shown in fig. 8 is known. The multi-stage planetary gear type speed variator is a relatively small mechanical component using the planetary gear type speed variator as a speed reducer.

The planetary gear type speed increasing/decreasing gear of fig. 8 includes an input shaft IS provided with a sun gear SG, and a fixed housing HG provided with a ring gear RG, and 3 planetary gears PG meshing with both gears are disposed between the sun gear SG and the ring gear RG as shown in the a-a sectional view. Each of the planetary gears PG is fitted into a support shaft SS integrally erected on the carrier CR and is rotatably supported. A sun gear having the same shape as the sun gear SG of the input shaft IS formed on the carrier CR on the side opposite to the support shaft SS, and the sun gear SG of the input shaft IS and the carrier CR constitute a1 st-stage reduction gear. The same structure is repeated in sequence toward the left of the sectional view B-B, and the carrier of the final stage (3 rd stage) speed reducer is provided with an output shaft OS. The ring gear RG is a common gear that meshes with the planetary gears of all stages, and is formed as an internal gear that extends continuously to almost the entire length in the axial direction of the housing HG.

When the sun gear SG of the input shaft IS rotates, the planetary gear PG revolves along the ring gear RG while rotating on its axis. The carrier CR that pivotally supports the planetary gear PG rotates together with the revolution of the planetary gear in a traction manner, and the rotational direction thereof is the same as the rotational direction of the input shaft, and the rotational speed thereof is greatly reduced from the rotational speed of the input shaft. Further, the speed ratio between the sun gear SG and the carrier CR is determined by the following mathematical expression:

the sun gear rotational speed/carrier rotational speed is 1+ (number of teeth of ring gear/number of teeth of sun gear). The carrier CR is provided with a sun gear of the next stage, and the same speed reduction is performed also in the next stage, and the final speed ratio (reduction ratio) of the output shaft OS is a result that the speed ratio of the single stage is set to the power of the stage.

A planetary gear type speed reducer is used in various rotary machines, and when the planetary gear type speed reducer is interposed in a power transmission path, the rotational speed decreases and the torque increases in inverse proportion thereto. For example, japanese patent application laid-open No. 9-254046 discloses a tool in which a planetary gear type speed reducer is applied to an electric driver driven by a motor, and describes the following: the sun gear of the planetary gear type speed reducer is driven by a motor through a permanent magnet type torque limiter, and a carrier is connected to a driver, and a screw is tightened while increasing torque. Further, japanese patent No. 4806544 discloses the following: the permanent magnet is incorporated in a planetary gear type speed reducer, and the speed reducer is constituted as a torque limiter itself used in a paper feeding device such as a copying machine.

Patent document 1: japanese laid-open patent publication No. 9-254046

Patent document 2: japanese patent No. 4806544

Disclosure of Invention

Problems to be solved by the invention

As in the reduction gear described in patent document 1 or patent document 2, in a planetary gear type reduction gear, a sun gear is generally used as an input shaft, and a carrier is generally used as an output shaft. With this configuration, a reduction gear having a large gear ratio (reduction ratio) between the input shaft and the output shaft can be obtained with a small device.

However, in this configuration, the carrier carrying the planetary gears rotates as an output shaft. When the rotating carrier vibrates or tilts, resistance due to friction between the planetary gear and the support shaft into which the planetary gear is fitted and friction between gears meshing with the planetary gear increases, and power transmission loss between the input shaft and the output shaft increases.

Here, by reversing the relationship between the input and the output, the planetary gear mechanism can operate as both a speed reducer and a speed increaser. Although the power transmission loss as described above lowers the transmission efficiency, if the planetary gear mechanism is operated as a speed reducer, there is hardly any case where the gears and the like are locked and the power transmission between the input shaft and the output shaft is not possible. In contrast, since the planetary gear mechanism operates as a speed-increasing gear, when the carrier is used as the input shaft and the sun gear is used as the output shaft, the drag torque due to friction is increased in addition to the relationship in which the ratio of the torque of the carrier and the torque of the sun gear is inversely proportional to the gear ratio, and the drag torque becomes large and acts on the carrier of the input shaft. Therefore, as a result of friction increase accompanying the oscillation or the like of the carrier that rotates, the following also occurs: the power transmission of the planetary gear mechanism does not proceed smoothly, and the carrier is substantially locked. In order to prevent this, it is conceivable to provide a rolling bearing between the planetary gear and the support shaft, but in this case, the outer diameter of the planetary gear increases, which inevitably leads to an increase in the size of the device.

The present invention addresses the problem of increasing the speed ratio between an input shaft and an output shaft and reducing friction of the gears by preventing the rotation of a rotating shaft and the like in a small transmission device in which a multi-stage planetary gear mechanism is combined, and particularly, to facilitate operation as a speed-increasing gear.

Means for solving the problems

In view of the above problem, a multi-stage planetary gear type speed increaser according to the present invention is configured to: a 2-stage reduction gear, which is a gear having a large and small diameter, is used as a planetary gear in the planetary gear mechanism of each stage, and the gear ratio is increased, and the carrier of the planetary gear mechanism is fixed to the housing, so that a speed change operation is performed between the sun gear and the ring gear, and the planetary gear mechanism is rotated stably. That is, the present invention is "a speed increaser comprising a casing and, incorporated therein, a plurality of planetary gear mechanisms, wherein each planetary gear mechanism comprises a sun gear, a ring gear and a planetary gear, the sun gear is disposed at the center of the planetary gear mechanism, the ring gear comprises an internal gear provided around the sun gear, and the planetary gear is interposed between the sun gear and the ring gear, wherein the planetary gear is provided with a large-diameter gear meshing with the sun gear and a small-diameter gear meshing with the ring gear, the planetary gear mechanism is provided with a disc-shaped carrier and a disc-shaped rotary drive member disposed adjacent to each other, and the disc-shaped carrier is provided with a support shaft for pivotally supporting the planetary gear, and a disc-shaped carrier fixed to the case, the disc-shaped rotary drive member being provided with the ring gear and the sun gear, the ring gear being provided on a peripheral portion of one surface of the rotary drive member, the sun gear being provided on a drive member center shaft formed on the other surface, the other surface of the rotary drive member being supported in the axial direction in contact with a surface of the carrier on a side opposite to the support shaft, the drive member center shaft being fitted into a center hole formed in the carrier and supported in the radial direction, the sun gear of the planetary gear mechanism disposed at one end of the speed increaser/increaser being provided with a sun gear connecting shaft, and the ring gear of the planetary gear mechanism disposed at the other end of the speed increaser/increaser being provided with a ring gear connecting shaft ".

As described in claim 2, it is preferable that a protrusion be formed on an outer periphery of the disc-shaped carrier, and a groove into which the protrusion is fitted be formed on an inner surface of the casing so as to extend in the axial direction. In this case, as described in claim 3, a plurality of grooves may be formed as grooves into which the protrusions are fitted, the grooves being set to have lengths in the axial direction corresponding to the disc-shaped carrier in the multistage planetary gear mechanism.

As described in claim 4, it is preferable that the following structure is made: the sun gear coupling shaft is supported in a radial direction by a wall portion formed at one end of the housing in an axial direction, and the ring gear coupling shaft is supported in the axial direction and in the radial direction by a cover body fitted into the other end of the housing in the axial direction.

Further, as defined in claim 5, it is preferable that a small-diameter center shaft be provided at a front end of the sun gear coupling shaft and a front end of a driver center shaft of the rotary driver, and a center hole into which the center shaft is fitted be provided at a rear end of the ring gear coupling shaft and a rear end of the rotary driver.

ADVANTAGEOUS EFFECTS OF INVENTION

The speed variator of the present invention is basically a transmission device in which a multistage planetary gear mechanism (planetary gear train) is combined and accommodated in a case. The planetary gear mechanism of each stage includes a sun gear provided at the center of the planetary gear mechanism, a ring gear composed of an internal gear provided around the sun gear, and a plurality of planetary gears interposed between the sun gear and the ring gear. The planetary gear is formed by arranging a large-diameter gear meshing with the sun gear and a small-diameter gear meshing with the ring gear in parallel, and constitutes a so-called 2-stage reduction gear. The carrier that supports the planetary gears is a disk-shaped member fixed to the housing, and each planetary gear is rotatably fitted into a support shaft provided upright on one surface of the carrier. A disk-shaped rotary drive member provided with a ring gear and a sun gear of the next stage is disposed adjacent to the carrier.

In the planetary gear mechanism having this configuration, when the sun gear of the 1 st stage rotates, the rotary drive member provided with the ring gear rotates in the opposite direction via the fixed planetary gear. A sun gear of a planetary gear mechanism of a next stage is integrally provided on a drive central axis formed on a surface of the rotary drive opposite to the ring gear, and the same speed change is performed also in the next stage.

That is, the speed change of the planetary gear mechanism of each stage is performed by a so-called simple gear train in which a sun gear and a ring gear of a planetary gear having a fixed rotation shaft are interposed, and the planetary gear serves as an intermediate gear of the gear train. When two gears having different numbers of teeth are arranged in parallel in the planetary gear, and the gear ratio of these gears is γ (however, γ >1), the transmission ratio of the single-stage planetary gear mechanism is as follows (since the rotation directions are opposite, the symbol-b):

sun gear speed/ring gear speed- γ (number of ring gears/number of sun gears).

As described above, in the present invention, since the 2-stage reduction gear is used for the planetary gear, the speed ratio γ times that of the planetary gear using a single gear can be obtained without increasing the axial length of the planetary gear so much. The speed variator of the present invention has a sun gear connecting shaft disposed at one end and a ring gear connecting shaft disposed at the other end as an input shaft and an output shaft, and the speed ratio between the input shaft and the output shaft is the single-stage speed ratio described above, which is the order of the number of stages, and the ratio of the torque between the input shaft and the output shaft is the reciprocal of the speed ratio.

Since the planetary gear mechanism of the present invention is supported by the carrier fixed to the housing, unlike a planetary gear mechanism in which a normal carrier rotates, the support shaft does not vibrate or rock even if the planetary gear is formed by arranging 2 gears in parallel. Further, a disk-shaped surface of the rotary drive provided with the ring gear and the next-stage sun gear on the side opposite to the ring gear abuts against a disk-shaped surface of the carrier and is axially supported, and a drive center shaft provided with the sun gear is fitted into a center hole formed in the carrier and is radially supported. Since the carriage is provided with the slide bearing surface of the rotary drive element, the rotary drive element can be rotated stably without causing the drive element to vibrate.

As described above, the rotating members such as the gears of the planetary gear mechanism of the present invention rotate stably and have very small frictional resistance. Therefore, while the power transmission loss of the speed increaser is reduced, smooth speed increase is achieved when the ring gear connecting shaft is used as the input shaft, the sun gear connecting shaft is used as the output shaft, and the speed increaser is operated as the speed increaser.

The invention of the technical scheme 2 is as follows: a projection is formed on the outer periphery of the disc-shaped carrier, and a groove into which the projection is fitted is formed on the inner surface of the casing so as to extend in the axial direction. Since the speed increaser according to the present invention is configured by axially overlapping single-stage planetary gear mechanisms, it is possible to manufacture the speed increaser by sequentially assembling carriers having the same shape to the housing, and it is possible to efficiently manufacture and assemble the speed increaser, by employing the configuration of the invention according to claim 2.

As shown in the invention of claim 3, when the structure of the invention of claim 2 is adopted and the projection of the carrier is fitted into the groove of the inner surface of the housing, a plurality of grooves can be formed as grooves into which the projection is fitted, the plurality of grooves being set to have lengths in the axial direction corresponding to the disc-shaped carrier in the multistage planetary gear mechanism, respectively, on the inner surface of the housing. Thus, each of the plurality of carriers is fitted into a so-called dedicated groove, and the carrier is pressed in the axial direction, so that the projection abuts against an end of the groove, thereby automatically positioning the carrier with respect to the casing. In this way, the groove into which the carrier is fitted functions as a so-called spacer, and the carriers of the adjacent stages are held at the set positions. Since the interval between the planetary gear and the rotary drive of the planetary gear mechanism is also maintained at an appropriate value, smooth rotation of the speed increaser can be ensured.

It is to be noted that the configuration of the groove of the housing and the projection of the carrier is not limited to the speed-increasing/reducing gear using the 2-stage reduction gear as the planetary gear, and can be applied to a speed-increasing/reducing gear using a single gear.

In the invention according to claim 4, the sun gear connecting shaft and the ring gear connecting shaft, which serve as the input shaft and the output shaft of the transmission, are supported by the case to prevent rotational vibration and the like. In the present invention, the sun gear coupling shaft is supported in the axial direction by a wall portion formed at one end in the axial direction of the housing, and the ring gear coupling shaft is formed with a disc-shaped surface, and is also supported in the radial direction and the axial direction by a lid body fitted into the open end of the housing. Therefore, when the speed increaser is used as the speed increaser, the rotation of the input shaft is stabilized, and smooth power transmission is performed.

In addition, the invention of claim 5 is: a small-diameter center shaft is provided at the front end of the sun gear connecting shaft and the front end of the driver center shaft of the rotary driver, and center holes are provided at the rear end of the ring gear connecting shaft and the rear end of the rotary driver, so that the center shaft and the center holes are fitted to each other. This supports the center portions of the adjacent rotating bodies with each other, and thus can more reliably prevent the vibration of the rotating shaft.

Drawings

Fig. 1 is a diagram showing an overall configuration of a speed increaser according to the present invention.

Fig. 2 is a diagram showing a single-piece case and a carrier of the speed increaser according to the present invention.

Fig. 3 is a view showing a rotary drive element and a planetary gear of the speed increaser according to the present invention in a single piece.

Fig. 4 is a diagram showing the sun gear connecting shaft and the ring gear connecting shaft of the transmission according to the present invention as a single member.

Fig. 5 is a diagram in which the speed increaser of the present invention is applied to a torque limiter device.

Fig. 6 is a diagram in which the speed increaser of the present invention is applied to an operating speed reduction device.

Fig. 7 is a view of a centrifugal clutch constructed by using the speed increaser of the present invention.

Fig. 8 is a diagram showing a structure of a conventional planetary gear type speed increaser.

Description of the reference numerals

1 casing

12 groove

2 sun gear connecting shaft

3 Gear rack

31 supporting axle (of planetary gear)

32 protrusions

33 center hole

4 Rotary drive element

41 driving element central shaft

SG sun gear

PG planetary gear

PG1 big diameter gear (planetary gear)

PG2 minor diameter gear (planetary gear)

RG ring gear

Detailed Description

The speed increasing/decreasing device of the present invention will be described below with reference to the accompanying drawings. First, fig. 1 shows an overall configuration of the speed variator of the present invention, in which fig. 2 shows a casing and a carrier as fixed members in a single-piece view, fig. 3 shows a planetary gear and a rotary drive as rotating members in a single-piece view, and fig. 4 shows a sun gear coupling shaft and a ring gear coupling shaft as input and output shafts in a single-piece view.

As shown in the upper left view of fig. 1, which is a longitudinal sectional view of the entire speed increasing/decreasing gearbox in the axial direction, the speed increasing/decreasing gearbox of the present invention is a transmission device in which a multi-stage (3-stage in this embodiment) planetary gear mechanism is combined and accommodated in a casing 1 from the front to the rear (for convenience, the right side of the drawing is the front, and the left side is the rear). As shown in the section A1-A1 and the section B-B, each stage of planetary gear mechanism includes: a sun gear SG that is disposed at the center; a ring gear RG formed of an internal gear provided around the sun gear SG; and 3 planetary gears PG interposed between these gears. A sun gear coupling shaft 2 forming a sun gear SG of the 1 st-stage planetary gear mechanism is provided at the tip of the speed increasing/decreasing gear unit, and is fitted into a center hole 11 (see fig. 2) of the tip wall portion of the housing 1 to be radially supported, and a flange portion provided on the outer periphery of the sun gear coupling shaft 2 abuts on the tip wall portion of the housing 1 to be axially supported. As shown in fig. 3 and 4, a small-diameter center shaft 21 is formed at the tip end of the sun gear coupling shaft 2, the center shaft 21 is fitted into the center hole 43 of the rotary driver 4, and the sun gear coupling shaft 2 and the rotary driver 4 are supported by each other in the radial direction (see the vertical cross-sectional view of fig. 1).

In the present invention, planetary gear PG is a gear formed by axially arranging large diameter gear PG1 and small diameter gear PG2 (see fig. 3), and in the 1 st-stage planetary gear mechanism, large diameter gear PG1 meshes with sun gear SG of sun gear coupling shaft 2 (cross section a1-a1), and small diameter gear PG2 meshes with ring gear RG (cross section B-B). The 3 planetary gears PG are rotatably supported by being fitted into a support shaft 31 provided upright on the carrier 3. Since the carrier 3 is fixed to the casing 1 so as not to be rotatable, the planetary gear PG functions as a 2-stage reduction gear of a gear train that transmits power from the sun gear SG to the ring gear RG.

As shown in fig. 2, which is a single-piece view, the carrier 3 is a disk-shaped member having a support shaft 31 standing on a rear surface thereof, and 3 protrusions 32 fitted into grooves of the housing 1 are formed on an outer periphery thereof at angular intervals of 120 °. As shown in the housing diagram of fig. 2, in the present embodiment, a total of 9 grooves 12 are formed in the housing 1 as grooves into which the projections 32 are fitted so as to correspond to the 3-gear carrier 3 provided in the speed increasing/decreasing gear.

The grooves 12 of the housing 1 are formed by 3 sets of grooves 12A, 12B, 12C, each having an angular interval of 120 °, and the length of the grooves in the axial direction is set to a length corresponding to the position where the housing 3 is provided. That is, the groove 12A into which the projection 32 of the carrier 3 of the 1 st stage is fitted extends from the opening end of the casing 1 to the front end wall portion. The groove 12B into which the projection 32 of the carrier 3 of the 2 nd stage is fitted is formed at an angular position 60 ° out of phase with the groove 12A with an axial length of about 2/3 of the axial length of the groove 12A, and the groove 12C into which the projection 32 of the carrier 3 of the 3 rd stage is fitted is formed at an angular position 30 ° out of phase with the groove 12A with an axial length of about 1/3 of the axial length of the groove 12A.

When the groove 12 is configured as described above, each of the plurality of carriers is fitted into a so-called dedicated groove, and when the transmission is manufactured and assembled, the carrier 3 is pressed in the axial direction, and the projection 32 comes into contact with an end portion of the groove 12 to automatically position each carrier 3 with respect to the casing 1, whereby the carrier 3 is fixed at the position of the casing 1. The planetary gear PG supported by the carrier 3 and the rotary drive 4 rotate stably with their intervals maintained at predetermined values, and the power transmission loss of the speed increasing/decreasing gear is not increased. Since the carriers 3 are attached to the casing 1 in this manner, the 2 nd-stage planetary gear PG is disposed at a position having a phase difference of 60 ° with respect to the 1 st-stage planetary gear (section a2-a2 in fig. 1), and the 3 rd-stage planetary gear PG is disposed at a position having a phase difference of 30 ° with respect to the 1 st-stage planetary gear (section A3-A3 in fig. 1).

A ring gear RG as an internal gear meshing with the small-diameter gear PG2 of the planetary gear PG is formed in the rotary drive 4 shown in fig. 3. The rotary drive 4 is a disk-shaped member having a ring gear RG formed on the peripheral edge portion on the front surface side, and a drive center shaft 41 having a sun gear SG of the next stage provided therein is provided upright at the center on the rear surface side. The driver center shaft 41 has the same shape as the front portion of the sun gear coupling shaft 2, and a small-diameter center shaft 42 is formed at the tip end thereof, and the center shaft 42 is fitted into a center hole 43 of the next-stage rotary driver 4. As shown in the vertical sectional view of fig. 1, the rotary driver 4 has a disk-shaped front surface that abuts against the distal end of the support shaft 31 of the carrier 3 and is axially supported, and the driver central shaft 41 is inserted into the central hole 33 (see fig. 2) of the carrier 3 and is also radially supported. At the same time, a flange portion provided on the outer periphery of the sun gear connecting shaft 2 is also fitted into the center hole of the carrier and radially supported.

A ring gear RG of the last planetary gear mechanism is disposed at the rear end of the speed increasing/decreasing gearbox, and the ring gear RG is formed on the periphery of a disk-shaped portion of a ring gear coupling shaft 5 (see fig. 1 and 4) disposed at the rear end. The back surface of the disk-shaped portion of the ring gear coupling shaft 5 abuts on a lid 6 fitted into the rear end of the housing 1 and closing the opening end, and the central shaft portion is inserted into the center hole of the lid 6 and supported in the axial direction and the radial direction.

The operation of the speed increaser according to the present invention will be described below with reference to the overall diagram of fig. 1 and the like.

When the sun gear SG of the 1 st-stage planetary gear mechanism is rotated by the rotation of the sun gear coupling shaft 2 at the tip of the speed increasing/decreasing gearbox, the large-diameter gear PG1 of the planetary gear PG meshing with the sun gear SG rotates in the opposite direction, and the ring gear RG meshing with the small-diameter gear PG21 of the planetary gear PG is driven to rotate. The number of teeth of each gear in the present embodiment is set as follows: the number of teeth of the sun gear SG is 9, the number of teeth of the large-diameter gear PG1 of the planetary gear PG is 12, the number of teeth of the small-diameter gear PG2 is 9, and the number of teeth of the ring gear RG is 30; according to the above mathematical expression, the speed ratio (sun gear SG rotation speed/ring gear RG rotation speed) of the single-stage planetary gear mechanism is-40/9.

That is, the planetary gear PG fitted to the support shaft 31 of the fixed carrier 3 functions as a 2-stage reduction gear, and the ring gear RG rotates in the opposite direction from the speed 9/40 of the speed of the sun gear SG. Since the speed increaser is combined with a 3-stage planetary gear mechanism, the rotational speed of the ring gear connecting shaft 5 at the rear end is reduced to the rotational speed of the sun gear connecting shaft 2 (9/40)³Approximately 1/88, when used as a speed-increasing gear, a high speed-increasing gear ratio of approximately 88 times can be obtained. Meanwhile, each gear in the embodiment is a cycloid gear with higher tooth strength based on a cycloid gear curve.

In the speed increaser of the present invention, even if the planetary gear PG is a gear in which 2 gears are arranged, the planetary gear PG is supported by the carrier 3 fixed to the case 1, and therefore the planetary gear PG does not vibrate or rock during operation. The rotary drive member 4 provided with the ring gear RG and the next-stage sun gear SG is supported by the fixed carrier 3 in the axial direction and the radial direction, and is supported by the central hole provided at the tip end and the central hole provided at the rear end. Therefore, since the rotating members such as the gears of the speed governor rotate stably without rocking, the frictional resistance is very small, and the power transmission loss of the speed governor is reduced.

In particular, when the ring gear coupling shaft 5 is operated as an input shaft, the sun gear coupling shaft 2 is operated as an output shaft, and the speed increasing/decreasing gear is operated as a speed increasing gear, the torque of the output shaft is increased and acts on the input shaft.

However, it is needless to say that the speed increaser of the present invention can be incorporated in a power transmission system to decelerate or accelerate rotation, that is, it can be applied to a functional member that controls a power transmission state according to torque or rotation speed. Hereinafter, an example of a functional component used in various machines as a speed-increasing gear according to the present invention will be described.

Fig. 5 shows an example in which the speed increaser according to the present invention is applied to a torque limiter disposed in a power transmission system in order to protect a motor or the like of a drive source.

In the torque limiter of fig. 5, a flange portion 1F is provided in a case 1 of the speed increasing/decreasing gear according to the present invention, and the flange portion 1F is fastened to a transmission gear TG by a bolt. The transmission gear TG engages with a driven gear DG that transmits power to a load side, and the ring gear coupling shaft 5 is coupled to a motor (not shown) that drives the load. A magnet type torque limiting member TL is provided between the case 1 and the sun gear coupling shaft 2, and the magnet type torque limiting member TL is formed by opposing a permanent magnet fixed to the sun gear coupling shaft 2 to a magnetic material fixed to the case 1.

When the torque transmitted from the drive motor to the driven gear DG via the ring gear coupling shaft 5 and the transmission gear TG is small, the sun gear coupling shaft 2 and the housing 1 are in a pulled-together state by an attractive force between the permanent magnet of the torque limiter TL and the magnetic material when the ring gear coupling shaft 5 rotates. Therefore, the housing 1 is substantially integrated with the ring gear coupling shaft 5, and transmits power to the driven gear DG. On the other hand, when the transmission torque between the housing 1 and the sun gear coupling shaft 2 exceeds a predetermined value due to a reason such as the rotation of the driven gear DG being stopped by an abnormality on the load side, the drag due to the attraction force of the permanent magnet cannot be performed, the sun gear coupling shaft 2 idles with respect to the housing 1, and the transmission of the power is interrupted.

In this torque limiting device, the speed increasing/reducing mechanism of the present invention is used as a speed increasing mechanism, and the torque of the sun gear connecting shaft 2 provided with the torque limiting member TL is greatly reduced as compared with the torque of the ring gear connecting shaft 5. Therefore, even if the torque limiter TL is a small component, it can be used in a power transmission system that transmits a large torque. In the present embodiment, a magnet type member is used as the torque restricting member, but another torque restricting member such as a spring interposed between the housing and the sun gear coupling shaft may be used.

Fig. 6 shows an example in which the speed increaser according to the present invention is applied to an operation speed reducer for preventing an impact or the like accompanying an abrupt operation in a revolving door of a building opened and closed by a hinge, an opening and closing cover of a copying machine, a winding device of a rolling screen of a stage, or the like.

In the operating speed reduction device of fig. 6, a target member to be operated such as a hinge-type rotary door is coupled to the ring gear coupling shaft 5, the housing 1 is fixed, and a centrifugal resistance applying member CL that applies resistance to rotation of the shaft when the rotational speed reaches a predetermined value is provided on the sun gear coupling shaft 2. As shown in the cross-sectional view a-a, the centrifugal resistance applying member CL is as follows: a rubber body RB having a circular cross section is fixed to the tip of the arm AM, the root of the arm AM is fitted into a boss fixed to the sun gear coupling shaft 2, and a tension spring SP is provided between the arm AM and the boss.

When a member such as a revolving door is manually operated, the ring gear connecting shaft 5 rotates, and the rotation is increased in speed to rotate the sun gear connecting shaft 2 at a high speed. The rubber body RB is expanded outward against the tension spring SP by the centrifugal force with the root of the arm AM as a fulcrum, and contacts the surrounding casing 1 when reaching a predetermined rotation speed. Therefore, the resisting torque acts on the sun gear connecting shaft 2, and when the resisting torque increases to become the resisting torque when the work target member such as the revolving door is operated, the opening and closing speed of the manual operation is reduced. When the operating speed of the swing door or the like increases, the friction between the rubber body RB and the housing 1 increases and the resisting moment increases, so that the operating speed is substantially constant.

Although the operating speed reducing device of fig. 6 operates by frictional resistance to reduce the speed when the rotational speed exceeds a predetermined rotational speed, another resistance applying member (which may be the same as the torque limiting member of fig. 5) may be provided to always apply a resistance torque. Further, by using the speed increaser of the present invention in the operating speed reduction device, a large resistive torque can be applied to the member to be operated even if the resistance applying member is small.

The embodiment shown in fig. 7 is a centrifugal clutch in which power transmission is connected and disconnected at a predetermined rotational speed by using two speed reducers having the same configuration in combination.

As shown in fig. 7, in this centrifugal clutch, one speed increasing/decreasing gear which operates as a speed increasing gear with the ring gear connecting shaft 5 on the left side of the drawing as an input shaft and the other speed increasing/decreasing gear which operates as a speed reducing gear with the ring gear connecting shaft 5 'on the right side of the drawing are disposed in a so-called back-to-back manner, and flange portions formed in the cases 1, 1' of the two speed increasing/decreasing gears are butt-joined. A centrifugal clutch member CC for connecting or disconnecting the sun gear coupling shaft 2 of the speed-increasing gear and the sun gear coupling shaft 2' of the speed-reducing gear is provided in the center portion.

As shown in the sectional view of a-a, the centrifugal clutch component CC has a structure similar to the centrifugal resistance applying component of fig. 6 in which an arm-shaped weight W fitted to the sun gear coupling shaft 2 of the speed-increasing machine is disposed so as to face an annular peripheral wall portion formed on the sun gear coupling shaft 2' of the speed-reducing machine, and a tension spring is provided between the weight W and the sun gear coupling shaft 2. When the ring gear connecting shaft 5 as an input shaft rotates, the sun gear connecting shaft 2 rotates at a high speed, and when the rotation speed exceeds a predetermined value, the arm-shaped weight W expands outward and comes into contact with the peripheral wall portion of the sun gear connecting shaft 2'. At this time, the sun gear coupling shaft 2 'rotates due to friction between the weight W and the surrounding wall portion, the rotation thereof is decelerated, and the ring gear coupling shaft 5' as an output shaft rotates at the same rotational speed as the input shaft. When the rotation speed of the input shaft is lower than a predetermined value, the weight W is pulled by the tension spring to be separated from the annular peripheral wall portion, and the power transmission from the input shaft to the output shaft is interrupted.

In this centrifugal clutch, even if the centrifugal clutch member CC is small, it can be used in a power transmission system for transmitting a large torque, and since the clutch is disconnected and connected by the sun gear connecting shaft 2 in which the rotational speed of the ring gear connecting shaft 5 as an input shaft is increased, the accuracy of the rotational speed at which the power transmission is disconnected and connected is improved.

As shown in the above detailed description, the present invention is the following apparatus: in a small-sized transmission device in which a multistage planetary gear mechanism is combined, the planetary gear can be operated smoothly as an increase/decrease gear by increasing the speed ratio using a 2-stage reduction gear, fixing a carrier to a housing to perform a speed change operation between a sun gear and a ring gear, and supporting a rotating member such as a gear by the carrier to prevent rocking or the like. In the above-described embodiment, the gears in the planetary gear mechanism are integrally formed with the respective members, but the gears may be assembled to the respective members using other materials, or the two gears of the planetary gear may be separately manufactured and combined. It is to be noted that, as the tooth profile curve of each gear, a tooth profile having a special shape such as an involute tooth profile, a rolling bearing, a material having excellent lubricity, or the like may be used, and various modifications may be made to the above-described embodiment.

Claims

1. A speed variator in which a plurality of planetary gear mechanisms are combined in a casing, wherein the planetary gear mechanism includes a sun gear, a ring gear, and a planetary gear, the sun gear is disposed at the center of the planetary gear mechanism, the ring gear includes an internal gear provided around the sun gear, and the planetary gear is interposed between the sun gear and the ring gear,

the planetary gear is provided with a large-diameter gear engaged with the sun gear and a small-diameter gear engaged with the ring gear in parallel,

in the planetary gear mechanism, a disk-shaped carrier and a disk-shaped rotary drive are disposed adjacent to each other, a support shaft for pivotally supporting the planetary gear is provided on the disk-shaped carrier, the disk-shaped carrier is fixed to the case, the disk-shaped rotary drive is provided with the ring gear and the sun gear, and,

the ring gear is provided on a peripheral portion of one surface of the rotary driving member, and the sun gear is provided on a driving member center axis formed on the other surface,

the other surface of the rotary drive member is supported in the axial direction while abutting against the surface of the carrier on the side opposite to the support shaft, and the drive member center shaft is fitted into the center hole formed in the carrier and supported in the radial direction,

a sun gear connecting shaft is provided on the sun gear of the planetary gear mechanism disposed at one end of the speed increaser, a ring gear connecting shaft is provided on the ring gear of the planetary gear mechanism disposed at the other end of the speed increaser,

a projection is formed on the outer periphery of the disc-shaped carrier, and a groove into which the projection is fitted is formed on the inner surface of the housing so as to extend in the axial direction.

2. The speed increaser according to claim 1, wherein,

the grooves into which the protrusions are fitted are formed in the inner surface of the housing, and the grooves are set to have lengths in the axial direction corresponding to the disc-shaped carriers in the multistage planetary gear mechanism.

3. A speed variator in which a plurality of planetary gear mechanisms are combined in a casing, wherein the planetary gear mechanism includes a sun gear, a ring gear, and a planetary gear, the sun gear is disposed at the center of the planetary gear mechanism, the ring gear includes an internal gear provided around the sun gear, and the planetary gear is interposed between the sun gear and the ring gear,

the sun gear coupling shaft is supported in a radial direction by a wall portion formed at one end of the housing in an axial direction, and the ring gear coupling shaft is supported in the axial direction and in the radial direction by a cover body fitted into the other end of the housing in the axial direction.

4. A speed variator in which a plurality of planetary gear mechanisms are combined in a casing, wherein the planetary gear mechanism includes a sun gear, a ring gear, and a planetary gear, the sun gear is disposed at the center of the planetary gear mechanism, the ring gear includes an internal gear provided around the sun gear, and the planetary gear is interposed between the sun gear and the ring gear,

a small-diameter center shaft is provided at a front end of the sun gear connecting shaft and a front end of a driver center shaft of the rotary driver, and a center hole into which the center shaft is fitted is provided at a rear end of the ring gear connecting shaft and a rear end of the rotary driver.