Second-stage three-cycloidal-pin-wheel RV speed reducer

Abstract

The utility model provides a second-stage RV speed reducer with three cycloidal pin wheels. The second-stage RV speed reducer with the three cycloidal pin wheels comprises a pin wheel housing, an output side flange, an input side flange, an eccentric high-speed shaft, planet wheels, the cycloidal pin wheels and an input shaft. The eccentric high-speed shaft is provided with three sets of eccentric protrusions, the phase difference of the three sets of eccentric protrusions is 120 degrees, the number of the cycloidal pin wheels is three, the outer diameter faces of the eccentric protrusions are sleeved with sliding bearings, and circular through holes c of the three cycloidal pin wheels are formed in the corresponding sliding bearings respectively. According to the RV speed reducer, the three sets of cycloidal pin wheels distributed at 120 degrees are arranged, so that in the second-stage speed reduction process of the RV speed reducer, meshing between teeth is increased, rotation is stable, torque is evenly transmitted, and the technical problems that a traditional two-cycloidal pin wheel RV speed reducer is unstable in stress in the transmission process and low in transmission precision are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of RV reducers, in particular to a second-stage three-piece cycloid pinwheel RV reducer. Background Art

[0002] The application areas of RV reducers are mostly precision transmission devices with high transmission accuracy requirements, such as robots, radars, and the elbow joints of precision machine tools. Therefore, RV reducers must have high transmission accuracy.

[0003] Chinese patent CN201710568994.0 discloses an RV reducer. The RV reducer provided by the present invention includes an input gear shaft, a crankshaft, planetary gears, two epicycloidal wheels, an internal meshing mechanism and two output members, and the RV reducer also includes an output transmission unit, the output transmission unit includes three transmission blocks and three pairs of matching holes, wherein: two matching holes in a pair of matching holes are respectively arranged on the adjacent end faces of the two epicycloidal wheels, and two matching holes in each pair of matching holes in the other two pairs of matching holes are respectively arranged on the adjacent end faces of an epicycloidal disk and an output member, and the three transmission blocks are respectively arranged in the three pairs of matching holes, and the difference between the inner diameter of each matching hole and the outer diameter of the transmission block is equal to 2-2.5 times the eccentricity of the epicycloidal wheel. The RV reducer of the present invention only needs to be provided with one crankshaft to achieve uniform distribution of output force, has a simple structure, low installation difficulty and high assembly efficiency.

[0004] However, this technical solution adopts a double-piece cycloidal pinwheel transmission. During the cycloidal pinwheel transmission process, there is instability, resulting in low transmission accuracy. At the same time, the axial positioning of the rotating bearing of the crank shaft adopts a limit spring. Under the condition that the bearing is subjected to large force, the limit spring is easy to deform, resulting in a change in the limit clearance of the tapered roller bearing, which further leads to a decrease in its transmission accuracy. Utility Model Content

[0005] The purpose of the utility model is to provide a second-stage three-piece cycloidal pinwheel RV reducer in view of the deficiencies in the prior art. By setting three groups of cycloidal pinwheels distributed at 120°, the RV reducer has increased tooth meshing, stable rotation, and uniform torque transmission during the second-stage deceleration process, thereby solving the technical problems of the traditional two-piece cycloidal pinwheel RV reducer, the unstable force during the transmission process, and the low transmission accuracy.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] The second stage three-piece cycloidal pinwheel RV reducer includes:

[0008] A needle gear housing, wherein a plurality of first needle gear grooves are provided in the needle gear housing, roller needles are correspondingly provided in the first needle gear grooves, and first bearing mounting positions for mounting bearings are provided on both sides of the first needle gear grooves;

[0009] An output side flange, wherein three circular through holes a are evenly distributed on the circumference of the output side flange;

[0010] An input side flange, wherein three circular through holes b are evenly distributed on the circumference of the input side flange;

[0011] The eccentric high-speed shaft is provided with three eccentric high-speed shafts, and both ends of the eccentric high-speed shafts are rotatably mounted on the output side flange and the input side flange through tapered bearings; that is, the outer ring of the tapered bearing is mounted in the through hole a and the through hole b, and the shaft diameter of the eccentric high-speed shaft is mounted on the inner ring of the tapered bearing;

[0012] Planetary gears, three of which are arranged on one side of the output side flange and connected to the eccentric high-speed shaft;

[0013] A cycloidal pin wheel, wherein the outer diameter surface of the cycloidal pin wheel is provided with second needle tooth grooves, and the number of the second needle tooth grooves is the same as that of the first needle tooth grooves; the cycloidal pin wheel is provided with three circular through holes c and three trapezoidal through holes alternately arranged with the circular through holes c; and

[0014] An input shaft, which is a gear shaft, passes through the output side flange and the input side flange, and one end of which is meshed with the three planetary gears at the same time;

[0015] It is characterized in that three groups of eccentric protrusions are provided on the eccentric high-speed shaft, the phase difference between the three groups of eccentric protrusions is 120°, three cycloid pin wheels are provided, the outer diameter surface of the eccentric protrusion is provided with a sliding bearing, and the circular through holes c of the three cycloid pin wheels are respectively arranged on the corresponding sliding bearings.

[0016] As an improvement, a positioning step for positioning the tapered bearing is provided on the input side flange; the outer ring end face of the tapered bearing abuts against the positioning step, and the inner ring end face thereof abuts against the side face of the eccentric protrusion via a limiting ring.

[0017] As an improvement, a step hole for installing a tapered bearing is provided on the output side flange, and the inner ring of the tapered bearing on this side abuts against the side surface of the eccentric protrusion through a limiting ring, and the other side of the inner ring of the tapered bearing abuts against the end face of the planetary gear through a limiting ring.

[0018] As an improvement, an angular contact bearing is installed in the first bearing mounting position; the outer ring of the angular contact bearing is arranged in the first bearing mounting position, and its inner ring is contacted and positioned with the outer diameter surface of the output side flange or the input side flange, that is, the outer diameter surface of the output side flange or the input side flange is provided with a positioning step for positioning the inner ring of the angular contact bearing, so that the inner ring of the angular contact bearing is against the side of the cycloidal pin wheel.

[0019] As an improvement, the planetary gear is drivingly connected to the end of the eccentric high-speed shaft via a spline.

[0020] As an improvement, three trapezoidal protrusions are provided on the output side flange and are alternately arranged with the three circular through holes a.

[0021] As an improvement, the input side flange is provided with three trapezoidal grooves alternately arranged with the three circular through holes b; the trapezoidal protrusion is arranged to match the size of the trapezoidal groove, so that the trapezoidal protrusion is inserted into the trapezoidal groove.

[0022] As an improvement, the output side flange is connected to the input side flange via fasteners.

[0023] As an improvement, a stabilizing pin is further provided between the output side flange and the input side flange.

[0024] Preferably, the trapezoidal protrusion cooperates with the trapezoidal groove, and the output side flange and the input side flange are connected into an integral structure by fasteners. At the same time, a stabilizing pin is used to improve the stability of the overall structure of the output side flange and the input side flange after they are connected as one during the rotation process.

[0025] As an improvement, the sliding bearing is made of super strong nylon.

[0026] The beneficial effects of the utility model are:

[0027] (1) The utility model provides three groups of cycloidal pinwheels distributed at 120 degrees, so that in the second stage deceleration process of the RV reducer, the inter-tooth meshing is increased, the rotation is smooth, and the torque is transmitted evenly. Compared with the traditional two-piece cycloidal pinwheel RV reducer, the transmission accuracy is higher and the force imbalance phenomenon in the transmission process of the two groups of cycloidal pinwheels is reduced.

[0028] (2) The utility model improves the stability of the RV reducer transmission process by replacing the traditional tapered bearing or ball bearing used to support the rotation of the pin gear housing with an angular contact bearing, thereby improving the rotation accuracy.

[0029] (3) The utility model eliminates the limit springs of the tapered roller bearings at both ends of the eccentric high-speed shaft and uses a limit ring in combination with a positioning step to limit and fix the tapered roller bearings, thereby reducing the difficulty of processing the output side flange and the input side flange. In addition, the utility model solves the technical problem that the limit springs are easily deformed under force due to the traditional fixing method, which causes the installation clearance of the tapered roller bearing to change, thereby affecting the transmission accuracy.

[0030] (4) The utility model connects the output side flange and the input side flange as a whole by means of the trapezoidal protrusion on the output side flange cooperating with the trapezoidal groove on the input side flange and the connection of the fasteners, thereby achieving efficient transmission. At the same time, by means of the setting of the stabilizing pin, high-precision transmission is achieved and the clearance of the fastener connection is reduced.

[0031] In summary, the utility model has the advantages of stable transmission and high transmission accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0033] Figure 2 It is a schematic diagram of the overall front view of the utility model;

[0034] Figure 3 For this utility model Figure 2 Middle BB cutaway diagram;

[0035] Figure 4 This is a schematic diagram of the output side flange of the utility model;

[0036] Figure 5 This is a schematic diagram of the input side flange of the utility model;

[0037] Figure 6 This is a schematic diagram of the needle gear housing of the utility model;

[0038] Figure 7 This is a schematic diagram of the cycloid pinwheel of the utility model;

[0039] Figure 8 This is a schematic diagram of the input shaft of the utility model;

[0040] Fig. 9 This is a schematic diagram of the eccentric high-speed shaft of the utility model;

[0041] Fig.10 This is a schematic diagram of the working state of the eccentric high-speed shaft of the utility model. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0043] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the equipment or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0044] Embodiment 1

[0045] like Figure 1-10 As shown, this embodiment provides a second-stage three-piece cycloid pinwheel RV reducer, including:

[0046] A needle gear housing 1, wherein a plurality of first needle gear grooves 11 are provided in the needle gear housing 1, and roller needles 12 are correspondingly provided in the first needle gear grooves 11, and first bearing mounting positions 13 for mounting bearings are provided on both sides of the first needle gear grooves 11;

[0047] An output side flange 2, wherein three circular through holes a21 are evenly distributed on the circumference of the output side flange 2;

[0048] An input side flange 3, wherein three circular through holes b31 are evenly distributed on the circumference of the input side flange 3;

[0049] The eccentric high-speed shaft 4 is provided with three eccentric high-speed shafts 4, and both ends thereof are rotatably mounted on the output side flange 2 and the input side flange 3 through tapered bearings; that is, the outer ring of the tapered bearing is mounted in the circular through hole a21 and the circular through hole b31, and the shaft diameter of the eccentric high-speed shaft 4 is mounted on the inner ring of the tapered bearing;

[0050] Planetary gears 5, three of which are arranged on one side of the output side flange 2 and connected to the eccentric high-speed shaft 4;

[0051] A cycloid pinwheel 6, wherein the outer diameter surface of the cycloid pinwheel 6 is provided with second needle tooth grooves 61, and the number of the second needle tooth grooves 61 is the same as the number of the first needle tooth grooves 11; the cycloid pinwheel 6 is provided with three circular through holes c62 and three trapezoidal through holes 63 alternately arranged with the circular through holes c62; and

[0052] An input shaft 7, which is a gear shaft, passes through the output side flange 2 and the input side flange 3, and one end of which is meshed with the three planetary gears 5 at the same time;

[0053] The eccentric high-speed shaft 4 is provided with three groups of eccentric protrusions 41, and the phase difference between the three groups of eccentric protrusions 41 is 120°. Three cycloid pinwheels 6 are provided, and the outer diameter surface of the eccentric protrusions 41 is provided with a sliding bearing 42. The circular through holes c62 of the three cycloid pinwheels 6 are respectively arranged on the corresponding sliding bearings 42.

[0054] As an improvement, an angular contact bearing 8 is installed in the first bearing mounting position 13; it should be noted that the outer ring of the angular contact bearing 8 is arranged in the first bearing mounting position 13, and its inner ring is in contact with the outer diameter surface of the output side flange 2 or the input side flange 3 for positioning, that is, the outer diameter surface of the output side flange 2 or the input side flange 3 is provided with an outer positioning step for positioning the inner ring of the angular contact bearing 8, so that the inner ring of the angular contact bearing 8 rests against the side of the cycloidal pin wheel 6.

[0055] It should be noted that the present application adopts an angular contact bearing as the rotation support bearing of the pin gear housing 1, so as to realize the bearing of the main radial force of the RV reducer with a smaller axial force, thereby improving the transmission accuracy.

[0056] Embodiment 2

[0057] like Figure 1-10 As shown, the components identical or corresponding to those in the first embodiment are marked with the corresponding reference numerals in the first embodiment. For the sake of simplicity, only the differences from the first embodiment are described below. The second embodiment differs from the first embodiment in that:

[0058] In this embodiment, a positioning step 32 for positioning the tapered bearing is provided on the input side flange 3; the outer ring end face of the tapered bearing abuts against the positioning step 32, and the inner ring end face thereof abuts against the side face of the eccentric protrusion 41 through a limiting ring 33.

[0059] Furthermore, a step hole 23 for installing a tapered bearing is provided on the output side flange 2, and the inner ring of the tapered bearing on this side abuts against the side surface of the eccentric protrusion 41 through a limiting ring 33, and the other side of the inner ring of the tapered bearing abuts against the end face of the planetary gear 5 through a limiting ring 33.

[0060] It should be noted that by eliminating the traditional bearing fixing method using a limit spring, and coordinating the setting of the positioning step 32 and the setting of the limit ring 33, rapid installation during the assembly process is achieved. At the same time, the efficiency of component production is improved, and the manufacturing process is simpler and easier to produce.

[0061] Furthermore, when the bearing is subjected to large forces, the traditional process uses a limit spring to fix the bearing, which can easily cause the spring to deform, so that the installation clearance and preload force of the bearing cannot meet the process values ​​for normal operation, resulting in a significant impact on the transmission accuracy of the reducer.

[0062] In addition, the present application adopts a positioning step 32 in conjunction with a limiting ring 33 to achieve the adjustment of the bearing installation preload, and enables the bearing to always maintain normal working preload and installation clearance during normal operation, so that the reducer transmission process maintains stable transmission accuracy.

[0063] Embodiment 3

[0064] like Figure 1-10 As shown, the components identical or corresponding to those in the first embodiment are marked with the corresponding reference numerals in the first embodiment. For the sake of simplicity, only the differences from the first embodiment are described below. The differences between the third embodiment and the first embodiment are as follows:

[0065] In this embodiment, the planetary gear 5 is transmission-connected to the end of the eccentric high-speed shaft 4 via a spline, thereby improving the transmission accuracy and stability of the planetary gear.

[0066] As an improvement, the output side flange 2 is provided with three trapezoidal protrusions 22 which are alternately arranged with the three circular through holes a21 .

[0067] Furthermore, the input side flange 3 is provided with three trapezoidal grooves 34 alternately arranged with the three circular through holes b31 ; the trapezoidal protrusion 22 is arranged to match the size of the trapezoidal groove 34 , so that the trapezoidal protrusion 22 is inserted into the trapezoidal groove 34 .

[0068] As an improvement, the output side flange 2 is connected to the input side flange 3 via a fastener 9 .

[0069] Furthermore, a stabilizing pin 10 is provided between the output side flange 2 and the input side flange 3 .

[0070] It should be noted that the trapezoidal protrusion 22 cooperates with the trapezoidal groove 34, and the output side flange 2 and the input side flange 3 are connected as an integral structure by the fastener 9. At the same time, the stabilizing pin 10 is used to improve the stability of the overall structure of the output side flange 2 and the input side flange 3 after being connected as one during the rotation process.

[0071] Furthermore, the sliding bearing 42 is made of super-strong nylon, which improves the stability of the transmission process and reduces the wear of the cycloid pinwheel 6 and the eccentric high-speed shaft 4, thereby increasing its practical life.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. The second stage three-piece cycloidal pinwheel RV reducer includes: A needle gear housing, wherein a plurality of first needle gear grooves are provided in the needle gear housing, roller needles are correspondingly provided in the first needle gear grooves, and first bearing mounting positions for mounting bearings are provided on both sides of the first needle gear grooves; An output side flange, wherein three circular through holes a are evenly distributed on the circumference of the output side flange; An input side flange, wherein three circular through holes b are evenly distributed on the circumference of the input side flange; An eccentric high-speed shaft, wherein three eccentric high-speed shafts are provided, and both ends of the eccentric high-speed shafts are rotatably mounted on the output side flange and the input side flange through tapered bearings; Planetary gears, three of which are arranged on one side of the output side flange and connected to the eccentric high-speed shaft; A cycloidal pin wheel, wherein the outer diameter surface of the cycloidal pin wheel is provided with second needle tooth grooves, and the number of the second needle tooth grooves is the same as that of the first needle tooth grooves; the cycloidal pin wheel is provided with three circular through holes c and three trapezoidal through holes alternately arranged with the circular through holes c; and An input shaft, which is a gear shaft, passes through the output side flange and the input side flange, and one end of which is meshed with the three planetary gears at the same time; It is characterized in that three groups of eccentric protrusions are provided on the eccentric high-speed shaft, the phase difference between the three groups of eccentric protrusions is 120°, three cycloid pin wheels are provided, the outer diameter surface of the eccentric protrusion is provided with a sliding bearing, and the circular through holes c of the three cycloid pin wheels are respectively arranged on the corresponding sliding bearings.

2. The second-stage three-piece cycloid pinwheel RV reducer according to claim 1 is characterized in that: The input side flange is provided with a positioning step for positioning the tapered bearing; the outer ring end face of the tapered bearing abuts against the positioning step, and the inner ring end face thereof abuts against the side face of the eccentric protrusion via a limiting ring.

3. The second-stage three-piece cycloid pinwheel RV reducer according to claim 2 is characterized in that: The output side flange is provided with a stepped hole for installing a tapered bearing. The inner ring of the tapered bearing on this side abuts against the side surface of the eccentric protrusion through a limiting ring, and the other side of the inner ring of the tapered bearing abuts against the end surface of the planetary gear through a limiting ring.

4. The second-stage three-piece cycloid pinwheel RV reducer according to claim 1 is characterized in that: An angular contact bearing is installed in the first bearing installation position.

5. The second-stage three-piece cycloid pinwheel RV reducer according to claim 1 is characterized in that: The planetary gear is drivingly connected to the end of the eccentric high-speed shaft through a spline.

6. The second-stage three-piece cycloid pinwheel RV reducer according to claim 1, characterized in that: The output side flange is provided with three trapezoidal protrusions alternately arranged with the three circular through holes a.

7. The second-stage three-piece cycloid pinwheel RV reducer according to claim 6, characterized in that: The input side flange is provided with three trapezoidal grooves alternately arranged with the three circular through holes b; the trapezoidal protrusion is arranged to match the size of the trapezoidal groove so that the trapezoidal protrusion is inserted into the trapezoidal groove.

8. The second-stage three-piece cycloid pinwheel RV reducer according to claim 7, characterized in that: The output side flange is connected to the input side flange via fasteners.

9. The second-stage three-piece cycloid pinwheel RV reducer according to claim 8, characterized in that: A stabilizing pin is further provided between the output side flange and the input side flange.

10. The second-stage three-piece cycloid pinwheel RV reducer according to claim 8, characterized in that: The sliding bearing is made of nylon.

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