RV speed reducer with planet carrier integrated four-point contact bearing structure

Abstract

The utility model relates to the technical field of RV speed reducers, and discloses an RV speed reducer with a planet carrier integrated four-point contact bearing structure, which is characterized in that a pin gear meshing mechanism is fixed on an upper-stage joint shell of a robot; the bearing assemblies are mounted on the front and rear sides of the inner ring of the pin tooth meshing mechanism; wherein the bearing assembly comprises a four-point contact ball bearing and a spacer ring; two ends of the bearing bracket are respectively connected with the four-point contact ball bearing and the spacer ring; the four-point contact ball bearing and the spacer ring are in contact installation with the front side and the rear side of the pin tooth meshing mechanism; a four-point contact bearing raceway is integrated on the side, connected with the pin gear meshing mechanism through the four-point contact ball bearing, of the bearing support, and the four-point contact bearing raceway wraps the four-point contact ball bearing to form four contact points to keep the precision of the RV speed reducer. The cycloid driving mechanism is meshed with the inner ring of the pin tooth meshing mechanism to realize circumferential rotation motion; and one side of the transmission chain mechanism is connected with the cycloid driving mechanism.

Description

Technical Field

[0001] The utility model relates to the technical field of RV reducers, and in particular to an RV reducer with a planetary carrier integrated four-point contact bearing structure. Background Art

[0002] RV reducer is a high-precision, high-rigidity and high-efficiency reduction device, widely used in robots, CNC machine tools, automation equipment and other fields; RV reducer has become an important component in industrial robots and other high-demand applications due to its unique design and performance advantages.

[0003] Chinese patent publication number CN114444224512A discloses an RV reducer with an integrated tapered roller outer ring bearing on a planetary carrier. In the patent, two sets of single-row angular contact ball bearings are used. The two sets of angular contact bearings are placed on both sides of the pinion housing respectively. The two sets of angular contact bearings provide radial loads and axial loads; the planetary carrier and the outer ring bearing are respectively ground with a set of curvatures and form a set of contact angles with the steel balls. Therefore, the bearings at the junction of the conventional structure need to be paired with two sets of bearings to jointly bear the radial load and axial load.

[0004] In view of the above, the present application proposes an RV reducer with a planetary carrier integrated four-point contact bearing structure, which replaces the two sets of single-row angular contact ball bearings conventionally used with a set of four-point contact ball bearings, so that a single bearing can bear all loads, simplifies the structure, reduces the number of components, and also relatively reduces the cost of parts. Utility Model Content

[0005] In view of the deficiencies in the prior art, the utility model provides an RV reducer with a planetary carrier integrated with a four-point contact bearing structure, which solves the problems raised in the above-mentioned background technology.

[0006] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] An RV reducer with a planetary carrier integrated four-point contact bearing structure is used in a robot joint system, including:

[0008] The pin-tooth meshing mechanism is fixed on the upper joint housing of the robot;

[0009] The bearing assembly is installed on the front and rear sides of the inner ring of the pin-tooth meshing mechanism; wherein the bearing assembly includes a four-point contact ball bearing and a spacer ring;

[0010] The bearing bracket has two ends connected with a four-point contact ball bearing and a spacer ring respectively; and is installed in contact with the front and rear sides of the pin-tooth meshing mechanism through the four-point contact ball bearing and the spacer ring; wherein a four-point contact bearing raceway is integrated on one side where the bearing bracket is connected with the pin-tooth meshing mechanism through the four-point contact ball bearing, and the four-point contact bearing raceway wraps the four-point contact ball bearing to form four contact points to maintain the accuracy of the RV reducer;

[0011] The cycloid drive mechanism meshes with the inner ring of the pin-tooth meshing mechanism to realize circumferential rotational motion;

[0012] The transmission chain mechanism is connected to the cycloid drive mechanism on one side and to the external motor shaft on the other side. The transmission chain mechanism is driven by the torque transmitted by the motor to cause the cycloid drive mechanism to perform eccentric reciprocating motion.

[0013] Optionally, the pin-tooth engagement mechanism comprises a pin-tooth housing and a pin-tooth pin;

[0014] The pin gear housing is the housing of the RV reducer;

[0015] The needle gear housing is provided with a plurality of mounting grooves;

[0016] The needle tooth pin is arranged in the mounting groove and contacts the needle tooth housing.

[0017] Optionally, an oil seal is provided between the pin gear housing and the bearing bracket.

[0018] Optionally, the cycloid drive mechanism includes a cycloid wheel, a needle bearing, a tapered roller bearing and a crank shaft;

[0019] The outer side of the cycloid wheel is meshed with the pin-tooth pin;

[0020] The needle roller bearing is connected to the cycloid wheel;

[0021] The tapered roller bearings are connected to both sides of the bearing bracket;

[0022] The crank shaft is mounted on the cycloid wheel.

[0023] Optionally, the transmission chain mechanism includes a planetary gear and a motor gear shaft;

[0024] The planetary gear is connected to the rear end of the crankshaft and meshes with the motor gear shaft;

[0025] The motor gear shaft is connected to the external motor shaft, receives the torque transmitted by the external motor, and drives the crank shaft to rotate through the planetary gear.

[0026] Optionally, the bearing support includes a long planet carrier and a short planet carrier;

[0027] One side of the long planetary frame is mounted on the front side of the pin gear housing through a bearing assembly, and the other side of the long planetary frame is fixed to the next level joint of the robot;

[0028] The short planet carrier is installed on the rear side of the pin gear housing through a bearing assembly.

[0029] Optionally, the long planet carrier comprises an inner frame, a retainer and an outer ring bearing;

[0030] The outer ring of the inner frame and the inner ring of the outer ring bearing are both processed into arc shapes, and the two arc shapes form a four-point contact bearing raceway;

[0031] The retainer is arranged at the middle part of the connection between the inner frame and the outer ring bearing.

[0032] Optionally, a ball filling hole is provided on the outer ring bearing, and an adaptable plunger is inserted into the ball filling hole; and a cylindrical pin for fixing the plunger is provided on the outer ring bearing.

[0033] The utility model provides an RV reducer with a planetary carrier integrated four-point contact bearing structure, which has the following beneficial effects:

[0034] 1. Through the matching setting of the four-point contact ball bearing and the bearing bracket, one set of four-point contact ball bearings is equivalent to two sets of single-row angular contact ball bearings (single-row angular contact bearings are actually in two-point contact during operation), so the four-point contact bearings can provide the same load-bearing capacity.

[0035] 2. Through the matching arrangement of four-point contact ball bearings and spacer rings, the conventional two sets of angular contact bearing parts are simplified into one set of four-point contact bearings, reducing the number of parts, weight and part costs;

[0036] 3. Through the matching setting of the bearing bracket and the bearing assembly, compared with the conventional method of installing two sets of angular contact bearings, the assembly process saves one assembly link and improves the assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the structure of the utility model;

[0038] Figure 2 This is a schematic diagram of the bearing bracket structure of the utility model;

[0039] Figure 3 It is a schematic diagram of the structure of a four-point contact ball bearing of the utility model.

[0040] In the figure: 1. needle gear meshing mechanism; 11. needle gear housing; 12. needle gear pin; 2. bearing assembly; 21. four-point contact ball bearing; 22. spacer ring; 3. bearing bracket; 31. long planet carrier; 311. inner frame; 312. retainer; 313. outer ring bearing; 32. short planet carrier; 4. cycloid drive mechanism; 41. cycloid wheel; 42. needle bearing; 43. tapered roller bearing; 44. crankshaft; 5. transmission chain mechanism; 51. planetary gear; 52. motor gear shaft; 6. oil seal; 10. ball filling hole; 101. plunger; 102. cylindrical pin. DETAILED DESCRIPTION

[0041] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments.

[0042] In the description of the present invention, it should be understood that the terms "lateral", "longitudinal", "end", "edge", "sidewall", "up", "down", "upper part", "lower part", "directly above", "surface", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "end", "head" and "tail" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the technical solution of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0043] This application proposes an RV reducer with a planetary carrier integrated four-point contact bearing structure, which is optimized without reducing the precision of the reducer under the condition of reducing the cost. The details are as follows;

[0044] For reference Figure 1 , the present application is mainly composed of a pin-tooth meshing mechanism 1, a bearing assembly 2, a bearing bracket 3, a cycloid drive mechanism 4 and a transmission chain mechanism 5, thereby constituting an RV reducer that is superior in terms of manufacturing cost and assembly compared to existing conventional reducers;

[0045] For reference Figure 1 The pin-tooth meshing mechanism 1 is used for relative movement with the cycloid driving mechanism 4 to realize the eccentric movement of the reducer; the pin-tooth meshing mechanism 1 includes a pin-tooth housing 11 and a pin-tooth pin 12, the pin-tooth housing 11 is used as the outer shell and basic structure of the entire reducer, and is used to fix and support other components; the inner ring of the pin-tooth housing 11 is provided with a plurality of mounting grooves, and the pin-tooth pin 12 is arranged in the mounting groove and contacts with the pin-tooth housing 11 to participate in the motion transmission during the deceleration process; an oil seal is arranged between the pin-tooth housing 11 and the bearing bracket 3 to prevent the leakage of lubricating oil.

[0046] For reference Figure 1 , the bearing assembly 2 is installed on both sides of the front and rear of the bearing assembly 2; wherein the bearing assembly 2 includes a four-point contact ball bearing 21 and a spacer ring 22; compared with the conventional use of a single-row angular contact ball bearing, the present application can provide radial load and axial load through a single bearing structure;

[0047] Further explanation, in a conventional reducer, two sets of angular contact bearings are placed on both sides of the pinion housing, and the two sets of angular contact bearings provide radial loads and axial loads. The planetary carrier and the outer ring bearing are each ground with a curvature to form a set of contact angles with the steel ball. Since each bearing can only withstand axial loads in a single direction, two sets of bearings are required to be used in pairs to jointly withstand radial loads and axial loads. Through the optimization of this application, the traditional design of using two sets of single-row angular contact ball bearings is optimized to a combination of four-point contact ball bearings 21 and low-cost spacer rings 22, which reduces the number of independent components and reduces the complexity of assembly and maintenance. By eliminating a high-cost main bearing and replacing it with a main bearing spacer ring 22, not only the structure is simplified, but also the production and maintenance costs are reduced. The main bearing spacer ring 22 is simpler and cheaper than a complete bearing assembly, but it can still provide the necessary support and positioning functions.

[0048] For reference Figure 1-2 The bearing bracket 3 includes a long planetary carrier 31 and a short planetary carrier 32. One side of the long planetary carrier 31 is installed on the front side of the pin gear housing through the bearing assembly 2, which is responsible for transmitting motion and load, and at the same time realizes relative motion with the pin gear housing through the bearing assembly 2 to ensure the normal operation of the reducer; the other side of the long planetary carrier 31 is fixed to the next-level joint of the robot to ensure that the power and motion output by the reducer can be accurately transmitted to the robot joint to achieve precise motion control; the short planetary carrier 32 is installed on the rear side of the pin gear housing through the bearing assembly 2 to bear and distribute the force from the motion and load to ensure the stable operation of the reducer; secondly, the short planetary carrier 32, together with the long planetary carrier 31, provides support and positioning for the internal components of the reducer to ensure that each component maintains the correct position and clearance during movement.

[0049] In order to ensure the stable operation of the four-point contact ball bearing 21, a four-point contact bearing raceway is integrated on one side of the bearing bracket 3 connected to the pin-tooth meshing mechanism 1 through the four-point contact ball bearing 21, and the four-point contact bearing raceway wraps the four-point contact ball bearing 21 to form four contact points to maintain the accuracy of the RV reducer; when the long planetary carrier 31 is selected to set the four-point contact ball bearing 21, the structure is optimized into three parts: the inner frame 311, the retainer 312 and the outer ring bearing 313 to cooperate with the movement of the four-point contact ball bearing 21; the outer ring bearing 313 is sleeved on the outside of the inner frame 311, and the outer ring bearing 313 is coaxially arranged with the inner frame 311; the outer ring of the inner frame 311 and the inner ring of the outer ring bearing 313 are both processed into arc shapes, and the two arc shapes form a four-point contact bearing raceway; the retainer is arranged in the middle of the connection between the inner frame 311 and the outer ring bearing 313 to maintain the stability of the four-point contact ball bearing 21 during movement;

[0050] To further explain, the four-point contact ball bearing 21 can be set on the short planetary carrier 32 or the long planetary carrier 31, and there is no restriction between the two. When the four-point contact ball bearing 21 is set on one side, the spacer ring 22 can be set on the other side, depending on the specific assembly situation; when the four-point contact ball bearing 21 is set on one side of the short planetary carrier 32, the structure of the short planetary carrier 32 can be consistent with the structure of the long planetary carrier 31.

[0051] For reference Figure 3 , further illustrating that the arcs of the outer ring bearing 313 and the inner frame 311 form four contact points with the four-point contact ball bearing 21, namely P1, P2, P3, and P4; the arc processed on the inner frame 311 is semicircular, divided into upper and lower ends, and the two ends form two contact areas of P1 and P4; the arc processed on the outer ring bearing 313 is semicircular, divided into upper and lower ends, and the two ends of the arc are P2 and P3.

[0052] In order to facilitate internal installation, a ball filling hole 10 is opened on the outer ring bearing 313 for installing the four-point contact ball bearing 21 into the retainer 312; an adaptive plunger 101 is inserted in the ball filling hole 10, and both ends of the plunger 101 are processed into a specific curvature so that it can accurately match the curved surfaces of the outer ring bearing 313 and the retainer 312; a cylindrical pin 102 for fixing the plunger 101 is provided on the outer ring bearing 313, and the plunger 101 and the cylindrical pin 102 play the effect of blocking the ball filling hole 10; by closing the ball filling hole 10, the four-point contact ball bearing 21 is prevented from escaping from the retainer 312.

[0053] To further illustrate, during the assembly process, the inner frame 311 and the outer ring bearing 313 are aligned and placed together to prepare for the next assembly step, and the retainer 312 is inserted into the bearing through the retaining edge gap between the inner frame 311 and the outer ring bearing 313; the four-point contact ball bearings 21 are loaded into the retainer 312 one by one through the ball filling holes 10 on the outer ring bearing 313, and after each steel ball is loaded, the outer ring bearing 313 is rotated an angle to load the next four-point contact ball bearing 21; the four-point contact ball bearings 21 are evenly distributed in the retainer 312 one by one by rotating the outer ring bearing 313 until all the steel balls are filled. After all the four-point contact ball bearings 21 are loaded, the ball filling holes 10 are no longer needed, and a plunger 101 with a groove curvature at both ends is inserted into the ball filling holes 10 to seal the orifice; and the plunger 101 is fixed with a cylindrical pin 102 to prevent it from falling off, so as to ensure the integrity of the bearing structure and that the steel balls will not fall out of the retainer 312.

[0054] For reference Figure 1 The cycloid drive mechanism 4 meshes with the inner ring of the pin-tooth meshing mechanism 1 to realize circumferential rotational motion; wherein the cycloid drive mechanism 4 includes a cycloid wheel 41, a needle roller bearing 42, a tapered roller bearing 43 and a crank shaft 44; the outer side of the cycloid wheel 41 meshes with the pin-tooth pin 12 to realize eccentric reciprocating motion, transmit and convert power, and realize deceleration; the needle roller bearing 42 is connected to the cycloid wheel 41; the tapered roller bearing 43 is connected to both sides of the bearing bracket 3; the needle roller bearing 42 and the tapered roller bearing 43 play a role in the stability of the connection between the cycloid wheel 41 and the transmission chain mechanism 5; the crank shaft 44 is connected to the cycloid wheel 41 through the needle roller bearing 42 to reduce friction,

[0055] The transmission chain mechanism 5 is used to transmit the torque of the external motor, wherein the transmission chain mechanism 5 includes a planetary gear 51 and a motor gear shaft 52; the front and rear ends of the crank shaft 44 are connected to the long planetary carrier 31 and the short planetary carrier 32 through tapered roller bearings 43, and the rear end of the crank shaft 44 is connected to the planetary gear 51, which meshes with the motor gear shaft 52 to transmit the torque of the motor to the crank shaft 44 and participate in the deceleration process; the motor gear shaft 52 is used to connect the motor and transmit the torque of the motor to the planetary gear 51, thereby serving as a power input shaft to transmit the power of the external motor to the reducer.

[0056] In the utility model, the working steps of the device are as follows:

[0057] 1. First, the external motor transmits torque to the planetary gear 51 through the motor gear shaft 52. The planetary gear 51 meshes with the motor gear shaft 52 to transmit power to the crank shaft 44.

[0058] 2. Secondly, the crankshaft 44 rotates, driving the cycloid wheel 41 to perform eccentric reciprocating motion through the needle bearing 42, and the cycloid wheel 41 is meshed through the outer needle pin 12 to achieve circumferential rotation motion;

[0059] 3. Then, through the meshing of the pin gear pin 12 and the pin gear housing 11, and the movement of the planetary gear 51 and the cycloid wheel 41, a two-stage reduction is achieved, and finally a low-speed and high-torque movement is output;

[0060] 4. Finally, during operation, the four-point contact ball bearing 21 provides four-point contact support inside to ensure the stability and accurate positioning of the planet carrier.

[0061] The above shows and describes the basic principles, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited to the above embodiments. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of protection claimed by the utility model. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. An RV reducer with a planetary carrier integrated four-point contact bearing structure, used in a robot joint system, characterized by: include, The pin-tooth meshing mechanism (1) is fixed on the upper joint housing of the robot; A bearing assembly (2) is mounted on both sides of the inner ring of the pin-tooth meshing mechanism (1); wherein the bearing assembly (2) comprises a four-point contact ball bearing (21) and a spacer ring (22); The bearing bracket (3) has two ends respectively connected to a four-point contact ball bearing (21) and a spacer ring (22); and is installed in contact with the front and rear sides of the pin-tooth meshing mechanism (1) through the four-point contact ball bearing (21) and the spacer ring (22); wherein a four-point contact bearing raceway is integrated on one side of the bearing bracket (3) connected to the pin-tooth meshing mechanism (1) through the four-point contact ball bearing (21), and the four-point contact bearing raceway wraps the four-point contact ball bearing (21) to form four contact points to maintain the accuracy of the RV reducer; The cycloid drive mechanism (4) meshes with the inner ring of the pin-tooth meshing mechanism (1) to achieve circumferential rotational motion; The transmission chain mechanism (5) is connected to the cycloid drive mechanism (4) on one side and to an external motor shaft on the other side. The transmission chain mechanism (5) is driven by the torque transmitted by the motor to cause the cycloid drive mechanism (4) to perform eccentric reciprocating motion.

2. The RV reducer with a planetary carrier integrated four-point contact bearing structure according to claim 1, characterized in that: The pin-tooth meshing mechanism (1) comprises a pin-tooth housing (11) and a pin-tooth pin (12); The pin gear housing (11) is an RV reducer housing; The needle tooth housing (11) is provided with a plurality of mounting grooves; The needle tooth pin (12) is arranged in the installation groove and contacts the needle tooth housing (11).

3. The RV reducer with a planetary carrier integrated four-point contact bearing structure according to claim 2, characterized in that: An oil seal (6) is provided between the pin gear housing (11) and the bearing support (3).

4. The RV reducer with a planetary carrier integrated four-point contact bearing structure according to claim 2, characterized in that: The cycloid drive mechanism (4) comprises a cycloid wheel (41), a needle roller bearing (42), a tapered roller bearing (43) and a crank shaft (44); The outer side of the cycloid wheel (41) is meshed with the needle tooth pin (12); The needle roller bearing (42) is connected to the cycloid wheel (41); The tapered roller bearing (43) is connected to both sides of the bearing bracket (3); The crankshaft (44) is mounted on the cycloid wheel (41).

5. The RV reducer with a planetary carrier integrated four-point contact bearing structure according to claim 4, characterized in that: The transmission chain mechanism (5) comprises a planetary gear (51) and a motor gear shaft (52); The planetary gear (51) is connected to the rear end of the crankshaft (44) and meshes with the motor gear shaft (52); The motor gear shaft (52) is connected to an external motor shaft, receives torque transmitted by the external motor, and drives the crank shaft to rotate through the planetary gear (51).

6. The RV reducer with a planetary carrier integrated four-point contact bearing structure according to claim 1, characterized in that: The bearing support (3) comprises a long planet carrier (31) and a short planet carrier (32); The long planet carrier (31) is mounted on the front side of the pin gear housing (11) via a bearing assembly (2); The short planet carrier (32) is mounted on the rear side of the pin gear housing (11) via a bearing assembly (2).

7. The RV reducer with a planetary carrier integrated four-point contact bearing structure according to claim 6, characterized in that: The long planet carrier (31) comprises an inner frame (311), a retainer (312) and an outer ring bearing (313); The outer ring of the inner frame (311) and the inner ring of the outer ring bearing (313) are both processed into arc shapes, and the two arc shapes form a four-point contact bearing raceway; The retainer is arranged at the middle of the connection between the inner frame (311) and the outer ring bearing (313).

8. The RV reducer with a planetary carrier integrated four-point contact bearing structure according to claim 7, characterized in that: The outer ring bearing (313) is provided with a ball filling hole (10), and an adapted plunger (101) is inserted into the ball filling hole (10); the outer ring bearing (313) is provided with a cylindrical pin (102) for fixing the plunger (101).

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