TWI694217B - A power transmission apparatus with an inscribed cam and cylinderical pinions - Google Patents

Abstract

The invention provides a power transmission device with high transmission capacity and having High rigidity, no backlash, high-precision positioning, low friction, and the best reduction ratio.

The power transmission device of the present invention is equipped with a horse with a motor shaft Up to, connected to the turret of the motor shaft, a plurality of cylindrical gears arranged on the turret, an internal cam with a plurality of internal teeth along the inner surface, and a power transmission device connected to the output shaft of the internal cam, The plurality of cylindrical gears are arranged at equal intervals along the circumferential direction on the end surface of the turret, and the cylindrical side surface of at least one of the plurality of cylindrical gears and the plurality of internal teeth The cam surface of at least one internal tooth is in contact, whereby the output shaft connected to the internal cam rotates.

Description

Power transmission device using internal cam and cylindrical gear Field of invention

The invention relates to a power transmission device capable of efficiently transmitting the rotation of a motor, positioning with high precision, and making the service life longer.

Background of the invention

The power transmission device, especially the speed reducer, is a type that can reduce the rotational speed of the power obtained from a power source such as a motor through a gear, etc., and then output torque to obtain a torque proportional to the reduction ratio. Device. The power transmission device is provided between the device operable by the power transmission device and the power source, and can obtain the required torque and rotation speed. Power transmission devices are used in industrial machinery such as robots, factory transportation lines, propellers of ships, and propellers of aircraft.

Patent Document 1 discloses a speed reduction device as a power transmission device including: an internally toothed gear having a plurality of internal teeth formed radially inward on the inner peripheral side; and an externally toothed gear , Which is arranged on the inner peripheral side of the internally toothed gear, and is formed with a plurality of external teeth directed radially outward to mesh with the internal teeth, and along with the rotation of the rotating shaft Shake to spin.

In addition, Patent Document 2 discloses a reducer as a power transmission device including: an internally toothed gear having a plurality of external pins (pins) or rollers embedded in the external pins; and external The toothed gear, which is arranged on the inner peripheral side of the internally toothed gear, has a plurality of external teeth facing radially outward, and the externally toothed gear is connected to the input shaft, and the external pin or the circle of the roller embedded in the external pin The side of the cylinder and the plurality of external teeth of the external tooth gear can be engaged inwardly.

Prior technical literature Patent Literature

[Patent Document 1] Japanese Patent Publication No. 2014-185744

[Patent Document 2] Japanese Patent Publication No. 2009-47214

Summary of the invention

Generally speaking, an internally toothed gear having a plurality of internal teeth, and an externally toothed gear arranged on the inner peripheral side of the internally toothed gear and having a plurality of external teeth that mesh with the internal teeth, are provided with the internally toothed gear and external teeth as above The gear reducer will transmit the power obtained from the power source from the external gear to the internal gear to reduce the rotation speed and output. Furthermore, in order to make the transmission capacity between the internal gear and the external gear of the reducer high efficiency, the tooth thickness of the internal gear and the external gear must be large, that is, the modulus must be large. The relationship between tooth thickness (s) and modulus (m) is expressed by s=π/2×m, and the modulus (m) is determined by The diameter (d) and number of teeth (z) of the gear are represented by m=d/z. On the other hand, the reduction ratio represents the input rotation number of the reducer relative to the output rotation number. The reduction ratio is determined by the ratio of the number of teeth of the internal gear to the number of teeth of the external gear. The tooth thickness of the gear becomes larger to make the reduction ratio as small as possible, and the diameter of the internal gear must be made as small as possible.

In the deceleration device of Patent Document 1, the diameter of the external gear and the tooth thickness of the internal gear and the external gear may not be changed. If the diameter of the internal gear is reduced, the deceleration can be relatively small, but the internal gear The tooth front end of the toothed gear and the external toothed gear becomes thinner, or the tooth height of the internal toothed gear and the external toothed gear needs to be made smaller. However, if the tip of the teeth is thinned, the rigidity of the teeth will be weakened, and if the tooth height of the internal gear and the external gear is made small, the transmission capacity between the internal gear and the external gear will become small, so , To make the diameter of the internal toothed gear smaller is problematic. For example, in reducers used in industrial machinery such as robot arms and belt conveyors, the problem will be greater if the reduction ratio is 3 or less. In addition, if the number of teeth of the internal gear and the external gear is small, the friction when the internal gear and the external gear are engaged tends to increase, and there is also a problem that backlash easily occurs.

In addition, the speed reducer of Patent Document 2 has an external roller in the internal gear, so compared to the speed reducer of Patent Document 1, the friction when the internal gear and the external gear are engaged can be reduced. Like the speed reduction device of 1, the external gear with a plurality of external teeth facing radially outward is arranged on the inner peripheral side of the internal gear, so the reduction gear of Patent Document 2 will also produce the same as that of Patent Document 1. The same problem with the reduction gear.

Therefore, the object of the present invention is to solve the above problems and provide A power transmission device has high transmission capacity, high rigidity, no backlash for rotation input to the power transmission device, can be positioned with high precision, has low friction, and can be the optimal reduction ratio.

According to the present invention, the above object can be achieved by a power transmission device which is a power transmission device provided with the following components: a motor with a rotatable motor shaft; a rotatable substantially cylindrical rotation The tower is connected to the motor shaft and has a first end surface and a second end surface; a plurality of cylindrical gears are arranged on the turret; the internal cam is a substantially circular internal cam, and the internal surface of the internal cam A plurality of internal teeth at equal intervals along the circumferential direction; and a rotatable output shaft connected to the internal cam, and the plurality of cylindrical gears are arranged at equal intervals along the circumferential direction at the first end surface of the turret , And the cylindrical side surface of at least one cylindrical gear among the plurality of cylindrical gears will contact the cam surface of at least one internal tooth among the plurality of internal teeth, thereby connecting to the output shaft of the internal cam Will rotate.

Also, it is preferably a power transmission device as follows: the cylindrical side surface of two cylindrical gears among the plural cylindrical gears will contact the cam surface of any internal tooth among the plural internal teeth, thereby connecting to The output shaft of the internal cam will rotate.

The power transmission device is preferably as follows: the two cylindrical gears are in contact with the cam surface of the one internal tooth as sandwiching one internal tooth arranged between the two cylindrical gears.

It should be the following power transmission device: one cylindrical gear is arranged between the two cylindrical gears, one of the two cylindrical gears The side surface of the cylinder will be in contact with the cam surface of the internal tooth in the direction in which one cylindrical gear is arranged, and the side surface of the cylinder gear in the other of the two cylindrical gears will be in contact with one The cam surfaces of the internal teeth in the direction of the cylindrical gear are in contact.

It should be the following power transmission device: 1 cylindrical gear will not contact any internal teeth of the plurality of internal teeth.

It should be the following power transmission device: the contact between the plurality of cylindrical gears and the plurality of internal teeth is a sliding contact.

It should be the following power transmission device: the contact between the plurality of cylindrical gears and the plurality of internal teeth is rolling contact.

It is preferably a power transmission device as follows: each of the plurality of cylindrical gears is a roller follower or a cam follower.

A plurality of cylindrical gears are arranged on the end surface of the turret at equal intervals along the circumferential direction, so that the cylindrical side surface of the cylindrical gear is in contact with the cam surface of the internal teeth, whereby the dimensions of the cylindrical gears and internal teeth can be made Larger, so the cylindrical gear and internal teeth can have high rigidity, and can achieve the effect of high transmission capacity. Furthermore, by bringing the cylindrical side surfaces of at least two cylindrical gears into contact with the side surfaces of any one of the plurality of internal teeth, the effect of having a high transmission capacity can be further achieved.

In addition, the two cylindrical gears are brought into contact with the cam surfaces of the internal teeth as if the internal teeth arranged between the cylindrical gears are sandwiched, thereby achieving the effect of highly accurate positioning without backlash. Even if one cylindrical gear is arranged between the two cylindrical gears, one of the two cylindrical gears The cylindrical side surface of the square cylindrical gear is in contact with the cam surface of the internal tooth in the direction where one cylindrical gear is arranged, so that the cylindrical side surface of the other cylindrical gear is in the direction where one cylindrical gear is arranged The cam surfaces of the internal teeth of the gears are in contact, thereby achieving the effect of high-precision positioning without backlash. At this time, by preventing the one cylindrical gear from contacting any one of the plurality of internal teeth, the accuracy error of the power transmission device during processing can be absorbed, and the cylindrical gear and the internal teeth can be slipped The effect of smooth contact and action.

In addition, by making the contact between the cylindrical gear and the internal teeth into sliding contact, the cylindrical gear can be constituted by one part, so the rigidity of the cylindrical gear can be increased, and the effect of reducing the manufacturing cost can be achieved.

In addition, the contact between the cylindrical gear and the internal teeth is rolling contact, and a roller follower or a cam follower is used as the cylindrical gear, whereby the friction between the cylindrical gear and the internal teeth can be reduced, and Achieving the effect of efficiently transmitting rotation from the cylindrical gear to the internal teeth.

In addition, other objects, features, and advantages of the present invention should be clearly clarified from the following description of the embodiments of the present invention with reference to the drawings.

101‧‧‧Power transmission device

102‧‧‧Motor

103‧‧‧Motor shaft

104‧‧‧Outer cover

105‧‧‧Outer cover

106‧‧‧ Output shaft

107‧‧‧Turret

108‧‧‧The first end of the turret

109‧‧‧Internal cam

110‧‧‧1st internal tooth

111‧‧‧ 2nd internal tooth

112‧‧‧The first cam surface

113‧‧‧ 2nd cam surface

114‧‧‧Cylinder gear

115‧‧‧The first cylindrical gear

116‧‧‧Second cylindrical gear

117‧‧‧3rd cylindrical gear

118‧‧‧Cylinder side of cylindrical gear

119‧‧‧Link requirements

120‧‧‧Sealing device

121‧‧‧Bearing

122‧‧‧bearing

123‧‧‧bearing

124‧‧‧Sealing device

III‧‧‧Cut line

[Fig. 1] A perspective view from the front of the power transmission device of the present invention.

[FIG. 2] A cross-sectional view seen from the side of the power transmission device of the present invention.

[Fig. 3] A cross-sectional view showing a state in which the turret and the inscribed cam are rotated when viewed from the front of the power transmission device of the present invention.

[Figure 4] shows the rotation from the front of the power transmission device of the present invention A cross-sectional view of the state of the tower and the inscribed cam during rotation.

Forms for carrying out the invention

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

1-4, the embodiment of the power transmission device of the present invention will be described. In FIG. 1, a schematic view of the power transmission device 101 is shown. The power transmission device 101 includes a motor 102, covers 104, 105, and a rotatable output shaft 106. In FIG. 2, a cross-sectional view of the power transmission device 101 viewed from the side is shown. The power transmission device 101 includes a motor 102 having a rotatable motor shaft 103, a rotatable substantially cylindrical turret 107, and a substantially cylindrical turret having a first end face 108 and a second end face 107, and is connected to the motor shaft 103 on the second end face side by a connecting element 119; a plurality of cylindrical gears 114 arranged on the turret 107; an internal cam 109, which is generally circular in shape and substantially circular in its shape The annular inner surface has a plurality of internal teeth at equal intervals along the circumferential direction; and a rotatable output shaft 106 connected to the internal cam 109. In addition, the power transmission device 101 includes bearings 121, 122, and 123. The bearing 121 is disposed between the housing 104 and the rotatable turret 107, and the bearings 122 and 123 are disposed between the housing 105 and the output shaft 106. The power transmission device 101 further includes sealing devices 120 and 124 useful for holding and sealing oil, grease, and the like. Examples of sealing devices include oil seals, gaskets, and mechanical seals.

FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 2 and showing the state of the turret and the internal cam at a certain point in time when the power transmission 101 rotates. As shown in Fig. 3, on the first end face of the turret 107 108. A plurality of cylindrical gears 114 (115, 116, 117) are arranged at regular intervals along the circumferential direction of the substantially cylindrical turret 107. Furthermore, the cylindrical side surface 118 of at least one cylindrical gear (for example, the second cylindrical gear 116) among the plurality of cylindrical gears will be in contact with the cam surface of at least one internal tooth among the plurality of internal teeth (for example , The second cam surface 113) of the first internal tooth 110 contacts, whereby the rotation of the turret 107 connected to the motor shaft 103 is transmitted to the internal cam 109, and the output connected to the internal cam 109 can be made The shaft 106 rotates.

A plurality of cylindrical gears 114 (115, 116, 117) are arranged on the first end surface 108 of the turret 107, and the cam surfaces 112, 113 of each internal tooth 110, 111 and each circumferential side surface of the plurality of cylindrical gears 114 118 contacts, thereby reducing the size of the entire power transmission device without increasing the size of the entire power transmission device as compared with a reduction gear equipped with external gears formed with a plurality of external teeth facing radially outward as in Patent Documents 1 and 2 Make the size of the cylindrical gear and internal teeth larger. Therefore, the cylindrical gear and internal teeth of the power transmission device of the present invention can have high rigidity, and can have high transmission capacity.

In FIG. 3, the number of cylindrical gears arranged on the first end surface 108 of the turret 107 is 6, and the number of internal teeth of the inscribed cam 109 is 12, therefore, by using the turret 107 of FIG. The output shaft 106 of the cam 109 and the power transmission device 101 can output the number of rotations (half reduction ratio 2) relative to the number of rotations of the motor shaft 103 of the motor 102. In addition, the number of cylindrical gears and the number of internal teeth of the internal cam 109 are not limited to the numbers shown in FIG. 3, but may be a combination of all numbers, thereby obtaining a desired reduction ratio.

In addition, in FIG. 3, each cylinder of at least two cylindrical gears (for example, the first cylindrical gear 115 and the second cylindrical gear 116) among the plural cylindrical gears The side surface 118 is in contact with the cam surface of at least one internal tooth (for example, the first cam surface 112 and the second cam surface 113 of the first internal tooth 110).

In addition, in FIG. 3, the two cylindrical gears (the first cylindrical gear 115 and the second cylindrical gear 116) will be disposed in the first between the first cylindrical gear 115 and the second cylindrical gear 116 The teeth 110 are sandwiched, and each cylindrical side surface 118 of the first cylindrical gear 115 and the second cylindrical gear 116 comes into contact with the first cam surface 112 and the second cam surface 113 of the first internal tooth 110. In this way, the two cylindrical gears are arranged so as to sandwich the internal teeth between them, thereby bringing the two cylindrical gears into contact with the internal teeth to eliminate backlash. Moreover, since there is no backlash, the power transmission device 101 can accurately position the output shaft 106 to the motor shaft 103.

FIG. 4 is a cross-sectional view taken along the line III-III of FIG. 2 and showing the state of the turret and the inscribed cam when the power transmission 101 rotates at a different point from FIG. 3 from the front. Between the two cylindrical gears (for example, the first cylindrical gear 115 and the third cylindrical gear 117), one cylindrical gear (for example, the second cylindrical gear 116) is arranged, and the two cylindrical gears The cylindrical side surface 118 of one of the cylindrical gears (for example, the first cylindrical gear 115) is in contact with the first internal teeth 110 located in the direction in which one cylindrical gear (second cylindrical gear 116) is arranged The first cam surface 112 contacts, and the cylindrical side surface 118 of the other cylindrical gear (the third cylindrical gear 117) among the two cylindrical gears is in contact with the one cylindrical gear The second cam surface 113 of the second internal tooth 111 in the direction of (second cylindrical gear 116) contacts. In this way, even when other cylindrical gears are arranged between the two cylindrical gears, the two cylindrical gears can be arranged so as to clamp the two internal gears located between the two cylindrical gears In this way, two cylindrical gears are brought into contact with two internal teeth to eliminate backlash. Moreover, by Since there is no backlash, the power transmission device 101 can correctly position the output shaft 106 to the motor shaft 103.

As shown in FIGS. 3 and 4, when the motor shaft 103 of the power transmission 101 rotates, regardless of the state in which the turret 107 connected to the motor shaft 103 and the internal cam 109 are engaged, the cylinder There is no backlash between the gear and the internal teeth, so the power transmission device 101 can accurately position the output shaft 106 to the motor shaft 103 in various states of the motor shaft 103.

In addition, in FIG. 4, one cylindrical gear (second cylindrical gear 116) disposed between the first cylindrical gear 115 and the third cylindrical gear 117 does not intersect with the plurality of internal cams 109 Any internal tooth contact. In this way, as shown in FIGS. 3 to 4, the turret 107 rotates clockwise, and the cam surface contacting the second cylindrical gear 116 changes from the second cam surface 113 of the first internal tooth 110 to the second internal tooth 111. Between the first cam surface 112, the second cylindrical gear 116 does not temporarily contact with any internal teeth of the plurality of internal teeth of the internal cam 109, that is, by setting the clearance, the cylindrical gear and the internal gear can be absorbed The precision of the teeth in machining is error, and the cylindrical gear and the internal teeth can be smoothly contacted to rotate the turret and the internal cam.

In addition, a plurality of cylindrical gears 114 (115, 116, 117) may be fixed to the turret 107 so that the contact between the plurality of cylindrical gears 114 and the plurality of internal teeth 110, 111 is a sliding contact. By fixing a plurality of cylindrical gears to the turret, the manufacturing steps of the power transmission device can be simplified, and the power transmission device can be manufactured at a lower cost.

In addition, the contact between the plurality of cylindrical gears 114 (115, 116, 117) and the plurality of internal teeth 110, 111 may be rolling contact. By making it roll Dynamic contact, the friction between the cylindrical gear and the internal teeth will be reduced, the power transmission device 101 can efficiently rotate the output shaft 106 relative to the rotation of the motor shaft 103, and also can make the service life of the power transmission device 101 Longer. As shown in FIGS. 3 and 4, by rotating the turret 107 connected to the motor shaft 103 clockwise, the plurality of cylindrical gears 115, 116, and 117 arranged on the first end face 108 of the turret 107 will be The internal teeth 110 and 111 of the cam 109 are in contact, and the internal cam 109 can be rotated clockwise. In FIG. 3, when the cylindrical side surface 118 of the second cylindrical gear 116 contacts the second cam surface 113 of the first internal tooth 110, the second cylindrical gear 116 also rotates clockwise, and the second circle The friction between the cylindrical gear 116 and the first internal teeth 110 is reduced. When the cylindrical side surface 118 of the first cylindrical gear 115 contacts the first cam surface 112 of the first internal tooth 110, the first cylindrical gear 115 also rotates clockwise, and the first cylindrical gear 115 and the first 1 The friction between the internal teeth 110 becomes smaller. In addition, in FIG. 4, when the cylindrical side surface 118 of the third cylindrical gear 117 comes into contact with the second cam surface 113 of the second internal tooth 111, the third cylindrical gear 117 also rotates clockwise. 3. The friction between the cylindrical gear 117 and the second internal teeth 111 decreases. When the cylindrical side surface 118 of the first cylindrical gear 115 contacts the first cam surface 112 of the first internal tooth 110, the first cylindrical gear 115 also rotates clockwise, and the first cylindrical gear 115 and the first 1 The friction between the internal teeth 110 becomes smaller.

In order to make it into rolling contact, for example, a plurality of cylindrical gears 114 may be used, such as a roller follower or a cam follower. The cam follower is provided with a screw nut (shaft) and an outer wheel, and the roller follower is provided with an inner wheel and an outer wheel. The screw nut or inner wheel is fixed to the turret 107 so that the outer wheel can rotate around the screw nut or inner wheel. Use the cam follower or roller follower as the cylindrical gear 115, 116, 117而 allocation on the turret 107. In this way, by arranging the cam follower or roller follower on the turret, the outer wheel of the cam follower or roller follower will come into contact with the internal teeth of the internal cam, and the cam follower or roller follower The outer wheel will rotate, so that the friction between the outer wheel and the internal teeth of the cam follower or roller follower is small. In addition, in the cam follower or roller follower, the screw nut or the inner wheel and the outer wheel may be sliding bearings, or rollers such as needle rollers may be used between the screw nut or the inner wheel and the outer wheel. The rotation of the roller bearings to make the rollers rotate.

The above description is made about specific embodiments, but the present invention is not limited to this. Those familiar with this art should understand that various changes and modifications can be made within the scope of the principles of the present invention and the scope of patent application .

101‧‧‧Power transmission device

102‧‧‧Motor

103‧‧‧Motor shaft

104‧‧‧Outer cover

105‧‧‧Outer cover

106‧‧‧ Output shaft

107‧‧‧Turret

108‧‧‧The first end of the turret

109‧‧‧Internal cam

114‧‧‧Cylinder gear

119‧‧‧Link requirements

120‧‧‧Sealing device

121‧‧‧Bearing

122‧‧‧bearing

123‧‧‧bearing

124‧‧‧Sealing device

III‧‧‧Cut line

Claims (6)

A power transmission device is a power transmission device provided with a motor having a rotatable motor shaft; a rotatable generally cylindrical turret connected to the motor shaft and having a first end surface and a second End face; a plurality of cylindrical gears, which are arranged in the turret; the inscribed cam is a substantially circular inscribed cam, and the inner surface of the inscribed cam has a plurality of internal teeth at equal intervals along the circumferential direction; And a rotatable output shaft connected to the internal cam, wherein the plurality of cylindrical gears are arranged at equal intervals along the circumferential direction on the first end surface of the turret, and the plurality of cylindrical gears The cylindrical side surfaces of the two cylindrical gears in will come into contact with the cam surface of any one of the plurality of internal teeth, whereby the output shaft connected to the internal cam will rotate at a certain point of rotation , A cylindrical gear is arranged between the two cylindrical gears, and the cylindrical side surface of one of the two cylindrical gears is in contact with the cam surface of the internal tooth in the following direction , The direction is the direction in which the above one cylindrical gear is arranged, and the cylindrical side surface of the other cylindrical gear among the two cylindrical gears comes into contact with the cam surface of the internal tooth in the following direction , This direction is the direction in which the one cylindrical gear is arranged, and the one cylindrical gear does not Any cam surfaces of several internal teeth are in contact. The power transmission device according to claim 1, wherein the two cylindrical gears sandwich one internal tooth disposed between the two cylindrical gears at a rotation timing different from the aforementioned one Contact with the cam surface of the aforementioned one internal tooth. The power transmission device as claimed in claim 1, wherein each of the two cylindrical teeth contacts the cam surface of the inscribed cam without backlash. The power transmission device according to any one of claims 1 to 3, wherein the contact between the plurality of cylindrical gears and the plurality of internal teeth is a sliding contact. The power transmission device according to any one of claims 1 to 3, wherein the contact between the plurality of cylindrical gears and the plurality of internal teeth is rolling contact. The power transmission device according to claim 5, wherein each cylindrical gear of the aforementioned plurality of cylindrical gears is a roller follower or a cam follower.

Images