Two-stage planetary gearbox with involute sprockets

Abstract

This utility model pertains to mechanical engineering. A two-stage planetary gearbox with involute sprockets comprises an input shaft and a coaxial output shaft, an involute gear, a three-beam planet carrier, involute satellite sprockets, and a closed single-row roller chain. The gearbox also comprises an intermediate shaft, mounted coaxially with the input and output shafts and capable of rotation on an intermediate shaft support. A three-beam planet carrier is secured to one end of the intermediate shaft, and a secondary involute gear is secured to the other end. A secondary three-beam planet carrier is rigidly secured to the output shaft, and secondary involute satellite sprockets are rotatably mounted at each end of the planet carrier, meshing with a closed secondary single-row roller chain and a secondary involute gear.The secondary closed single-row roller chain is secured against rotation by a secondary pin, rigidly attached to one of the secondary closed single-row roller chain links, allowing for vertical longitudinal movement along a groove formed in the intermediate shaft support. This ensures an increase in the gearbox transmission ratio. 4 fig.

Description

[0001] The utility model relates to mechanical engineering, in particular to mechanical transmissions containing gears that perform planetary motion, as well as a roller chain transmission.

[0002] A planetary gearbox with involute sprockets is known (RU Patent No. 2850016 - prototype), comprising an input and output shaft, a pinion, and a carrier, at the ends of which satellite sprockets are mounted for rotation and engaged with a closed chain. The pinion has involute external teeth and is rigidly attached to the input shaft, which is mounted for rotation on the input shaft support, while the carrier is three-beam and rigidly attached to the output shaft, which is mounted for rotation on the output shaft support coaxially with the input shaft. Moreover, the satellite sprockets are sprockets with involute teeth, engaged with both the chain and the pinion. In this case, the chain is a single-row roller chain and is fixed from rotation by means of a pin rigidly fixed on one of the chain links with the possibility of vertical longitudinal movement along a groove made in the support of the input shaft.

[0003] The disadvantage of this gearbox is its low gear ratio, due to the single-stage arrangement of the involute gear and chain drive. For example, the gear ratio of a planetary gearbox with an involute gear tooth count of z1 = 17 and a single-row roller chain link count of W3 = 102 is:

[0004]

[0005] Most mechanisms that use planetary gearboxes require gear ratios between 20 and 50. Therefore, the small gear ratio of the planetary gearbox with involute sprockets limits its scope of application.

[0006] The objective of the utility model is to improve the planetary gearbox with involute sprockets to expand the scope of its application.

[0007] The technical result of the utility model is an increase in the gear ratio of a planetary gearbox with involute sprockets by using two stages of involute gear and chain transmissions.

[0008] The technical result is achieved by a two-stage planetary gearbox with involute sprockets (hereinafter referred to as the gearbox), comprising an input shaft and an output shaft coaxial with it, an involute gear, a three-beam carrier, at the ends of which involute satellite sprockets are mounted for rotation, which are in mesh with a closed single-row roller chain and with an involute gear. Moreover, the involute gear is rigidly fixed to the input shaft, which is mounted for rotation on the input shaft support. Moreover, the closed single-row roller chain is fixed from rotation by means of a pin rigidly fixed to one of the links of the closed single-row roller chain with the possibility of vertical longitudinal movement along a groove formed in the input shaft support, and the output shaft is mounted for rotation on the output shaft support.The gearbox also includes an intermediate shaft mounted coaxially with the input and output shafts and capable of rotation on an intermediate shaft support. A three-beam carrier is secured to one end of the intermediate shaft, while a secondary involute gear is secured to the other end. A secondary three-beam carrier is rigidly secured to the output shaft, and secondary involute satellite sprockets are mounted at each end of the carrier and capable of rotation. These sprockets mesh with a closed secondary single-row roller chain and a secondary involute gear. The secondary closed single-row roller chain is secured against rotation by a secondary pin, which is rigidly secured to one of the links of the secondary closed single-row roller chain and allows vertical longitudinal movement along a groove formed in the intermediate shaft support.

[0009] Fig. 1 shows a two-stage planetary gearbox with involute sprockets with the pin in the groove in the extreme upper position. Fig. 2 shows a two-stage planetary gearbox with involute sprockets with the pin in the groove in the extreme upper position (side view). Fig. 3 shows a two-stage planetary gearbox with involute sprockets with the pin in the groove in the extreme upper position (rear view). Fig. 4 shows a two-stage planetary gearbox with involute sprockets with the pin in the groove in the extreme lower position.

[0010] A two-stage planetary gear reducer with involute sprockets comprises an input shaft 1 and an output shaft 2 coaxial with it, an involute gear 3, a three-beam carrier 4, at the ends of which involute satellite sprockets 5 are mounted with the possibility of rotation, which are in engagement with a closed single-row roller chain 6 and with an involute gear 3. In this case, the involute gear 3 is rigidly fixed on the input shaft 1, which is mounted with the possibility of rotation on the support of the input shaft 7. Moreover, the closed single-row roller chain 6 is fixed from rotation by means of a pin 8, rigidly fixed on one of the links of the closed single-row roller chain 6 with the possibility of vertical longitudinal movement along a groove 9 made in the support of the input shaft 7, and the output shaft 2 is mounted with the possibility of rotation on the support of the output shaft 10.In addition, the gearbox comprises an intermediate shaft 11 mounted coaxially with the input 1 and output 2 shafts with the possibility of rotation on the support of the intermediate shaft 12. Moreover, a three-beam carrier 4 is fixed to one end of the intermediate shaft 11, and a secondary involute gear 13 is fixed to the other end. In this case, a secondary three-beam carrier 14 is rigidly fixed to the output shaft 2, at the ends of which secondary involute satellite sprockets 15 are mounted with the possibility of rotation, which are in engagement with a closed secondary single-row roller chain 16 and with a secondary involute gear 13. Moreover, the closed secondary single-row roller chain 16 is fixed from rotation by means of a secondary pin 17, rigidly fixed to one of the links of the closed secondary single-row roller chain 16 with the possibility of vertical longitudinal movement along a groove 18 made in the support of the intermediate shaft 12.

[0011] The gear reducer works as follows.

[0012] Input shaft 1 rotates together with involute gear 3 (Fig. 1, 2). By means of involute gearing, rotation is transmitted from involute gear 3 to involute satellite sprockets 5, which, while rotating, roll along closed single-row roller chain 6, causing three-beam carrier 4 to rotate together with intermediate shaft 11. Moreover, closed single-row roller chain 6 does not rotate, since it is fixed relative to input shaft support 7 by means of pin 8, which moves in a vertical plane along groove 9 (Fig. 1, 4) when the radius of the location of the link of closed single-row roller chain 6 relative to the shaft axes changes. The intermediate shaft 11 rotates together with the secondary involute gear 13, which, by means of gear engagement, causes the secondary involute satellite sprockets 15 to rotate.The rotating secondary involute satellite sprockets 15 roll along the closed secondary single-row roller chain 16, causing the secondary three-beam carrier 14 to rotate together with the output shaft 2 (Fig. 3). Moreover, the secondary closed single-row roller chain 16 does not rotate, since it is fixed relative to the support of the intermediate shaft 12 by means of the secondary pin 17, which moves in the vertical plane along the groove 18 (Fig. 1, 4) when the radius of the location of the link of the closed secondary single-row roller chain 16 relative to the axes of the shafts changes.

[0013] In this case, the gear ratio is determined by the formula:

[0014]

[0015] where z1 is the number of teeth of the involute gear 3, W3 is the number of links of the single-row roller chain 6, z4 is the number of teeth of the secondary involute gear 13, W6 is the number of links of the secondary single-row roller chain 16.

[0016] As an example, using formula (1), we will calculate the gear ratio of a two-stage planetary gearbox with involute sprockets with the following parameters z1=17, W3=102, z=18, W6=108:

[0017]

[0018] Thus, the implementation of two stages of involute gear and chain transmissions in the design of a planetary gearbox makes it possible to obtain a two-stage planetary gearbox with involute sprockets, which has an increased gear ratio.

Claims

A two-stage planetary gearbox with involute sprockets, comprising an input shaft and an output shaft coaxial with it, an involute gear, a three-beam carrier, at the ends of which involute sprockets-satellites are mounted with the possibility of rotation, which are in engagement with a closed single-row roller chain and with an involute gear, wherein the involute gear is rigidly fixed on the input shaft, which is mounted with the possibility of rotation on the input shaft support, and the closed single-row roller chain is fixed from rotation by means of a pin rigidly fixed on one of the links of the closed single-row roller chain with the possibility of vertical longitudinal movement along a groove made in the input shaft support, and the output shaft is mounted with the possibility of rotation on the output shaft support, characterized in that it contains an intermediate shaft mounted coaxially with the input and output shaft with the possibility of rotation on the intermediate shaft support,wherein a three-beam carrier is secured to one end of the intermediate shaft, and a secondary involute gear is secured to the other end, wherein a secondary three-beam carrier is rigidly secured to the output shaft, at the ends of which secondary involute satellite sprockets are mounted with the possibility of rotation, which are engaged with a closed secondary single-row roller chain and with a secondary involute gear, wherein the secondary closed single-row roller chain is fixed from rotation by means of a secondary pin, rigidly secured to one of the links of the secondary closed single-row roller chain with the possibility of vertical longitudinal movement along a groove made in the support of the intermediate shaft.

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