TWI675160B - Precision cycloid device - Google Patents

Abstract

A precision cycloidal speed reducer is based on a cycloidal device with a dual-body structure, which accurately corrects the internal oscillations and approximates the short outer planetary profile of the cycloids. It uses the characteristics of backlash-free transmission of steel balls to replace traditional wear. The body pin realizes a short-range epicycloid transmission trajectory as the standard, which makes the transmission stable, low impact, eliminates traditional defects such as noise, vibration, and temperature rise, improves transmission performance, and precise backlash level, forming a new and precise transmission method.

Description

Precision Cycloidal Reducer

The present invention relates to a cycloidal speed reducer, especially a precision cycloidal speed reducer, which is radially meshed and uses a short-range outer cycloid planetary tooth profile that is accurately optimized internally, which is axially coupled and uses rigid balls to transmit without backlash. Features, instead of wearing a body pin, accurately output the deceleration trajectory.

Republic of China invention patent 092927, roller wave transmission device, please refer to the fifth figure, it is a typical example of rolling transmission, the meshing teeth are independent cycloidal teeth, ordinary outer cycloidal tooth profile, using the body pin to engage the output mechanism, output Angular speed movement, gear tooth meshing is simple point contact, no buffering, guide rail auxiliary effect, slight impact noise, vibration, temperature rise and other phenomena, conveying large angular backlash, insufficient positioning accuracy, suitable for medium speed ratio transmission, incomplete Suitable for precision backlash transmission.

The Republic of China I322241 patent, two-tooth differential roller transmission and its manufacturing method, please refer to the sixth figure, it is a typical example of two-tooth differential rolling transmission. The meshing teeth are independent cycloidal teeth. Body pin meshing output mechanism, output angular velocity movement, meshing transmission is simple point contact, no buffering, guide rail auxiliary effect, there may be centrifugal impact noise, vibration, temperature rise and other phenomena, conveying angular backlash and swing amplitude are large, positioning accuracy Inaccurate, suitable for low speed ratio transmission, extremely unsuitable for precision backlash transmission.

Retrieval data TW200634253, rigid cycloid transmission device, please refer to the seventh figure. The meshing teeth are rigid teeth with ordinary epicycloid tooth profile. It is a typical example of friction transmission. The body pin is used to engage the output mechanism and output the angular velocity. Movement, conveying angle backlash is large, positioning accuracy is not Very precise, high transmission accuracy requirements, easy to produce interference phenomenon, may have smooth transmission phenomenon, suitable for high-speed ratio transmission, not completely suitable for precision backlash transmission.

Traditional conventional technology, cycloid pin gear reducer, please refer to Figure 8. This is a typical example of semi-rolling transmission. The sun gear is composed of a rigid planetary gear with an external pin and a sleeve, and the sun tooth profile is a cycloid tooth. The internal cycloidal tooth profile adopts a body pin to engage the output mechanism to output angular velocity movement. The traditional typical cycloidal structure conveys a large angular backlash, the positioning accuracy is not very accurate, it is not suitable for low speed ratio transmission, and it is not completely suitable for precision backlash transmission. To improve transmission performance, there is still much room for improvement.

Therefore, in order to improve the transmission performance and make it suitable for precise transmission, the present invention accurately optimizes the internal swing planetary gear transmission to make it approximate a short external cycloidal tooth profile. In order to overcome the defects of the above-mentioned body pin meshing output mechanism, Utilizing steel ball backlash-free transmission characteristics, instead of wearing body pins, oscillating to optimize the circular groove track on the side of the planetary gear, and accurately transmitting short driving trajectories. External cycloidal tooth profile, meshing with sun gear with common epicycloidal tooth profile, or rollers with independent cycloidal teeth, the meshing trajectories are also ordinary transmission trajectories, the transmission is not precise and stable enough, noise, vibration, temperature rise And backlash are not suitable for high-speed precision transmission grades. The internally meshing planetary gears are usually swinging parts. Based on the fixed sun teeth, the internally swinging planetary gear tooth profiles are accurately connected, so that the approximate short outer cycloidal tooth profile, transmission. It is extremely smooth and does not cause interference, and minimizes the sun's tooth diameter to the limit safety intensity range, enlarges the planetary tooth diameter, and accurately modifies the tooth profile interference part to eliminate the interference amount and compensate The unilateral meshing gap is insufficient to meet the principle of short-range epicycloid. The planetary profile of the short-range epicycloid meshes with the sun profile of the ordinary epicycloid to obtain an approximately short-range transmission trajectory, which can make the transmission stable and the impact small. Create precision transmission benefits In order to seek to accurately optimize the planetary tooth profile, it will be explained in detail below.

The present invention accurately optimizes the planetary gear 1515 to form a short outer cycloidal tooth profile. The sun tooth diameter + 2 times the eccentricity is set as a standard arc, and the gear tooth meshing state is examined. If the sun tooth 1626 and the symmetrical planet tooth 1525 intersect The top cut amount gb of the planet tooth 1525 should be deleted. The standard arc is unchanged. See figure 12. If the sun tooth 1626 and the symmetric planet tooth 1525 are not tangent, the unilateral distance is g, see eleven. In the figure, the standard arc should be enlarged to be tangent to the planet tooth 1525. Because it is a single-sided mesh, the standard arc should be +2 times the diameter of the sun tooth + eccentricity + g.

The rigid bead coupling output mechanism of the present invention, please refer to the tenth figure, including a plate of semicircular circular groove track 1555, an equidistant ring is arranged on the side of the internal swinging planet gear 1515, and a plate corresponding to the wearing bodies 1212 and 1313 on both sides is provided. The steel balls 2222 in equidistant rings are shown in the left half of the second picture. The steel balls can only rotate and cannot move. The depth of the circular groove rail 1555 and steel ball 2222 is slightly smaller than the diameter of the steel ball. When the circular groove rail 1555 is combined with the steel ball After 2222, the distance between the two transmission surfaces should be at least about 0.5mm. If the eccentricity is smaller than the diameter of the steel ball, the semicircular arc of the inner circumferential surface of the circular groove rail 1555 may not exist. See the fourth figure. If the eccentricity is large enough, the The circular groove track 1555 is as shown in the third figure, as long as the outer diameter of the inner circumferential surface is kept in a semi-arc shape. The circular groove track 1555 has a standard pitch diameter of 2 times the eccentricity + steel ball diameter and swings. The circular groove rail 1555 fits correspondingly to the steel ball 2222. Please refer to the right half of the second picture, which can push the wearing body on both sides to rotate radially. Please refer to the first picture. Backlash-free transmission characteristics.

Generally, the transmission device of the present invention, as shown in the first figure, includes a housing 1010. The inner circumferential surface of the housing is formed with equidistant sun teeth 1626 to form a fixed sun gear 1011. The precise and optimized planetary tooth profile is connected therein. The two planetary gears 1515 formed are supported by a double eccentric crankshaft 1636. The outer crankshafts 1638 are arranged 180 degrees symmetrically on the outer circumference, and the rotatable planetary gears 1515 are respectively placed. By means of the two crankshafts 1638, the external unilaterally meshing sun gear 1011 of the two planetary gears 1515 generates reverse deceleration and self-rotating eccentric swinging. A circular groove track 1555 on the side of the swing fits at least one rigid ball 2222 corresponding to the wearing body 1212, 1313. Pushing the wearing bodies 1212 and 1313 on both sides in a radial direction, a short revolution trajectory, between the two rows of planetary gears 1515, a steel ball spacer ring 1717 is placed. Please refer to the ninth figure, between the wearing bodies 1212, 1313 on both sides and the housing 1010 It is supported by an oblique ball bearing 1818. Between the bodies on both sides, a group of bolts 2225 is passed through the bolt holes 2226 of the two rows of planetary gears 1515 to form a single body. An oil seal 1919 is attached to the bearing.

The greatest effect of the present invention is to provide a cycloidal speed reducer which is accurate and can improve transmission performance, eliminate traditional transmission defects, and has a precise backlash level.

1010‧‧‧shell

1011‧‧‧Sun Gear

1212‧‧‧ right body

1313‧‧‧Left body

1515‧‧‧ planetary gear

1525‧‧‧Planetary teeth

1535‧‧‧Body pins

1536‧‧‧Body Cover

1545‧‧‧Ball bearings

1555‧‧‧Circular groove track

1616‧‧‧Pin sets

1626‧‧‧Sun Tooth

1636‧‧‧Double Eccentric Crankshaft

1637‧‧‧Keyway

1638‧‧‧Crankshaft

1717‧‧‧Steel ball spacer ring

1818‧‧‧Angle Ball Bearing

1919‧‧‧oil seal

2222‧‧‧ Gangzhu

2225‧‧‧Bolt

2226‧‧‧bolt hole

Do‧‧‧Solar tooth pitch

DP‧‧‧ planetary tooth pitch diameter

df‧‧‧standard arc

dr‧‧‧planet tooth diameter

g‧‧‧Unilateral clearance

gb‧‧‧Top cutting amount

e‧‧‧eccentricity

The first figure is a schematic plan view of the structural cross section of the present invention.

The second figure is a schematic view of a steel ball (right half) and a steel ball (left half) engaged with a circular groove rail of the present invention.

The third figure is one of the schematic cross-sectional views of the circular groove track of the present invention.

The fourth figure is the second schematic sectional view of the circular groove track of the present invention.

The fifth figure is a schematic plan view of the roller wave transmission device of the pre-patent case.

The sixth figure is a schematic plan view of the two-tooth differential transmission in the pre-patent case.

The seventh diagram is a schematic plan view of a conventional rigid round-tooth cycloid drive.

The eighth figure is a schematic plan view of a conventional cycloidal pin gear transmission.

The ninth figure is a perspective view of the shape of the steel ball spacer ring of the present invention

The tenth figure is a schematic cross-sectional view of a circular grooved rail engaging steel ball of the present invention.

The eleventh figure is a line chart of the planetary tooth profile correction non-tangent condition of the present invention.

The twelfth figure is a line diagram of the planet tooth profile correction of the present invention having an intersection condition.

The preferred embodiment of the present invention is a cycloid reducer with a dual-body structure. Please refer to the first figure, which includes a housing 1010, and an inner circumferential surface with n + 1 sun teeth 1626, forming a sun gear 1011. Two planetary gears 1515 are connected inside, n planetary teeth 1525 are arranged on the outer circumferential surface, and they are connected by an optimized standard arc to form an epicycloidal tooth profile, which is supported by a double eccentric crankshaft 1636. The two crankshafts 1638 is symmetrically arranged at 180 degrees, and a rotatable planetary gear 1515 is installed. Between the two axial planetary gears 1515, a steel ball spacer ring 1717 is placed through a ring of steel balls 2222. The diameter of the steel balls is slightly larger than the thickness of the spacer ring. Separate the two planetary gears 1515, and eliminate eccentric swings to avoid preloading. The planetary teeth 1525 unilaterally engage the sun teeth 1626, so that the two planetary gears 1515 produce reverse deceleration and eccentric swings. A circular groove track 1555 on the side follows the swings. , Just fit a pair of steel balls corresponding to the wearing bodies 1212 and 1313 on both sides, and eccentrically rotate the center of the steel ball, push at least one steel ball in the radial direction, orbit a short drive trajectory at the same speed, the steel ball can only rotate and cannot move, The two transmission surfaces should be kept at least 0.5 mm to avoid contact friction. A preloaded angled ball bearing 1818 is set between the body 1212, 1313 on both sides and the housing 1010. A pair of bolts 2225 are worn between the bodies on both sides. Through the bolt holes 2226 of the planet gear 1515, they are connected to form a whole. The group of bolts 2225 can also be used as preload for oblique ball bearings 1818. Oil seals 1919 are placed outside the bearings to prevent leakage, and the bodies are worn at oblique angles Ball bearing inward rotation, or case rotating out of beveled ball bearing, can be regarded as output shaft respectively.

Claims (7)

A precision cycloidal speed reducer includes a casing, a sun gear formed by n + 1 sun teeth formed on an inner circumferential surface, an inner gear connected to the sun gear, and n planetary teeth formed on an outer circumferential surface, and a side ring A pair of circular groove rails are arranged, and the planetary tooth profile is optimized. The two planetary gears formed are supported by a double eccentric crankshaft supported on both sides of the body. Each crankshaft is connected with a ball bearing. Rotating planetary gear, the two crankshafts are symmetrically formed at 180 degrees, a steel ball spacer ring is arranged between the two rows of planetary gears, and the housing and the body on both sides are supported by preloaded angular ball bearings, and the same group of bolts are worn The two planetary gears pass through the two planetary gear bolt holes and are connected to the wearers on both sides to form an integrated body. The group of bolts can also be used for preloading of angular ball bearings. It is characterized in that the aforementioned planetary gears have precisely optimized planetary tooth profiles and are made by the crankshaft. The planetary gear that meshes with the sun gear unilaterally oscillates. A circular grooved track on the side follows the oscillating movement. A pair of steel balls corresponding to the wearing bodies on both sides are combined. The center of the steel balls is eccentrically rotated and pushed at least one radially. It can be used as an output shaft if the steel balls are rotated inside the beveled ball bearing with the body worn on both sides, or the case is rotated out of the beveled ball bearing. For example, the precision cycloid reducer of item 1 of the patent application scope, wherein the formation of the planetary tooth profile is precisely optimized by setting the sun tooth diameter + 2 times the eccentricity as the standard arc. If the sun teeth and the planets are arranged symmetrically The teeth intersect, and the planetary tooth top cut amount gb should be deleted, and the standard arc is unchanged. For example, the precision cycloid reducer of item 1 of the scope of patent application, wherein the formation of the optimized planetary tooth profile is based on the sun tooth diameter + 2 times the eccentricity as the standard arc. If the sun teeth and the planetary teeth are arranged symmetrically It does not intersect, the unilateral distance is g, the standard arc should be enlarged to be tangent to the planet teeth, and the standard arc should be, the diameter of the sun teeth + 2 times the eccentricity + g. For example, the precision cycloid reducer of item 1 of the patent scope, wherein the side of the planetary gear The circular groove track is a semi-circular circular groove with a depth slightly smaller than the diameter of the steel ball. The standard pitch diameter of the circular groove track is 2 times the eccentricity + the diameter of the steel ball. If the eccentricity is less than the diameter of the steel ball, The semicircular arc shape of the inner circumferential surface of the circular groove rail may not exist, as long as the semicircular arc shape of the outer circumferential surface is maintained, and the transmission accuracy is not affected. For example, the precision cycloid reducer of item 1 of the scope of patent application, in which one steel ball of the wearing body ring line is stored on the wearing body plane corresponding to the circular groove rail. The steel ball can only rotate, cannot move, and the depth is slightly smaller than the steel ball. Diameter, when the swinging planet gear circular groove track meets the steel ball of the wearing body, the two transmission interfaces should be kept at least 0.5 mm to avoid contact. For example, the precision cycloid reducer of item 1 of the patent application scope, wherein the steel ball spacer ring runs through a group of steel balls, and the steel ball group can rotate freely, and the diameter of the steel ball is slightly larger than the thickness of the steel ball spacer ring to separate the two rows. Star gear, and eliminate eccentric swing, to avoid pre-press jam. For example, the precision cycloid reducer of item 1 of the scope of patent application, in which the external diameter of the external sun teeth should be reduced to the limit of the maximum safety strength range, and the planetary tooth diameter should be enlarged to comply with the principle of short external cycloid.