Hollow single-planet speed reducer without sun gear

Abstract

The utility model relates to a hollow type single -planet speed reducer without sun wheel, including frame, fixed gear ring, output part, including outer ring and inner ring, outer ring and fixed gear ring fixed connection, frame and fixed gear ring and output part are connected in proper order and are enclosed and become the box body, movable gear ring, be located in the box body, movable gear ring and fixed gear ring adjacent and with inner ring fixed connection, hollow type planet carrier, rotate and install in the box body, double gear, rotate and install in hollow type planet carrier, double gear includes first gear and second gear who sets up in parallel along the axial direction, first gear and fixed gear ring corresponding internal mesh, second gear and movable gear ring corresponding internal mesh. Through with the fixed gear ring output part and the frame integration as the box body, omit the sun wheel, has reduced the overall size, has shortened the drive chain, has reduced the processing difficulty, and can realize bigger speed ratio while can increase gear modulus and promote overall life.

Description

Technical Field

[0001] This utility model relates to the field of speed reducer technology, and in particular to a hollow single planetary speed reducer without a sun gear. Background Technology

[0002] Hollow single planetary gear reducers without a sun gear are a widely used industrial product suitable for various mechanical equipment, including aerospace, wind power, and robotics, primarily used in humanoid robots, medical robots, and industrial robots. Hollow planetary gear reducers with a sun gear utilize a hollow reducer structure to achieve the highest speed ratio, output torque, and transmission accuracy with the fewest parts and shortest transmission chain. They are economical and convenient to manufacture, and their structural design is scientifically sound and rational.

[0003] However, the hollow planetary reducer currently available has a small internal space due to its hollow structure, resulting in a low speed ratio, a small torque increase, and a long transmission chain that is prone to accumulating errors.

[0004] Therefore, how to achieve large speed-changing torque and reduce transmission error within a limited space has become an urgent problem to be solved. Utility Model Content

[0005] The purpose of this invention is to provide a hollow planetary gear reducer, which aims to solve the problems of traditional reducers such as large size, low speed ratio, small torque increase, and large error.

[0006] To solve the above-mentioned technical problems, this utility model provides a hollow planetary gear reducer, comprising: a base, which is an annular structure; a fixed gear ring, which is fixedly connected to the base along the axial direction; an output part including a crossed roller bearing, the crossed roller bearing including an outer ring and an inner ring that rotate relative to each other, the outer ring being fixedly connected to the fixed gear ring along the axial direction; the base, the fixed gear ring and the output part being sequentially connected to form a housing; a movable gear ring, which is disposed in the housing, adjacent to the fixed gear ring and fixedly connected to the inner ring; a hollow planetary carrier, which is rotatably mounted in the housing; and a double gear, which is rotatably mounted on the hollow planetary carrier; the double gear includes a first gear and a second gear arranged in parallel along the axial direction, the first gear meshing internally with the fixed gear ring, and the second gear meshing internally with the movable gear ring.

[0007] Furthermore, a first mounting position is provided on the inner edge of the base, and a second mounting position is provided on the inner edge of the inner ring. The two ends of the hollow planetary carrier are respectively mounted on the first mounting position and the second mounting position.

[0008] Furthermore, the hollow single planetary reducer without a sun gear also includes: a bearing 1, located at the first mounting position, for rotatably connecting the base and the hollow planetary carrier; and a bearing 2, located at the second mounting position, for rotatably connecting the inner ring and the hollow planetary carrier.

[0009] Furthermore, a groove is provided between the first gear and the second gear, and the first gear and the second gear have different numbers of teeth.

[0010] Furthermore, the base, the fixed gear ring, and the output section are provided with multiple sets of corresponding and connected bolt holes, so as to connect the three together by long bolts.

[0011] Furthermore, the hollow single planetary reducer without a sun gear also includes: a cylindrical pin, fixedly installed on the hollow planetary carrier; a double gear set outside the cylindrical pin; and a needle roller, installed between the cylindrical pin and the double gear.

[0012] Furthermore, the inner edge of the fixed gear ring is provided with a clearance groove corresponding to the second gear, and one end of the movable gear ring is installed in the clearance groove to mesh with the second gear.

[0013] Furthermore, the output section includes a crossed roller bearing, wherein the crossed roller bearing includes an outer ring, an inner ring, and rollers, the outer ring is fixedly connected to the fixed gear ring, and the inner ring is fixedly connected to the moving gear ring.

[0014] Furthermore, oil seal mounting grooves are provided between the inner and outer rings and between the hollow planetary carrier and the inner ring; the output section also includes oil seals, which are respectively installed in the oil seal mounting grooves.

[0015] Furthermore, the fixed gear ring is provided with a first positioning interface corresponding to the machine base, and the machine base is adapted to and connected to the first positioning interface; the fixed gear ring is provided with a second positioning interface corresponding to the outer ring, and the outer ring is adapted to and connected to the second positioning interface.

[0016] Implementing the embodiments of this utility model will have the following beneficial effects:

[0017] 1. By integrating the base, fixed gear ring, and output section into a single housing, the overall size is reduced.

[0018] 2. The hollow structure facilitates cable routing and increases cable routing safety.

[0019] 3. By using a sunless structure, the transmission chain is reduced, the speed ratio range is increased, the machining difficulty is reduced, and the gears can be machined to a larger module, thereby increasing the overall structural lifespan. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1This is a cross-sectional structural schematic diagram of a hollow single planetary reducer without a sun gear provided in an embodiment of the present disclosure;

[0022] Figure 2 This is a schematic diagram of the overall structure of a hollow single planetary reducer without a sun gear according to an embodiment of the present disclosure;

[0023] Figure 3 This is a schematic diagram of the mounting structure of the fixed gear ring and the first gear according to an embodiment of the present disclosure;

[0024] Figure 4 This is a schematic diagram of the mounting structure of the moving gear ring and the second gear according to an embodiment of the present disclosure;

[0025] Figure 5 This is a schematic diagram of the end face structure of a hollow single planetary reducer without a sun gear provided in one embodiment of the present disclosure;

[0026] Figure 6 This is a schematic diagram of the end face structure of a hollow single planetary reducer without a sun gear provided in one embodiment of the present disclosure, from another direction.

[0027] Figure label:

[0028] 100. Hollow single planetary reducer without sun gear; 110. Base; 111. First mounting position; 120. Fixed gear ring; 121. Clearance groove; 122. First positioning interface; 123. Second positioning interface; 130. Output section; 131. Outer ring; 132. Inner ring; 1321. Second mounting position; 133. Crossed roller bearing; 134. Oil seal; 140. Moving gear ring; 150. Hollow planetary carrier; 160. Double gear; 161. First gear; 162. Second gear; 163. Groove; 170. Housing; 180. Bearing 1; 190. Bearing 2; 200. Bolt hole; 210. Cylindrical pin; 220. Needle roller; 230. Oil seal mounting groove. Detailed Implementation

[0029] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0030] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] Hollow planetary gear reducers without a sun gear are widely used industrial products suitable for various mechanical equipment, including aerospace, wind power, and robotics, primarily used in humanoid robots, medical robots, and industrial robots. Hollow planetary gear reducers with a sun gear utilize a hollow reducer structure to achieve the highest speed ratio, output torque, and transmission accuracy with the fewest parts and shortest transmission chain. They are economical and convenient to manufacture, and their structural design is scientifically sound. However, current hollow planetary reducers suffer from limited internal space due to their hollow structure, resulting in a lower speed ratio, smaller torque increase, and a longer transmission chain that is prone to error accumulation. Therefore, achieving high speed and torque increase while reducing transmission errors within a limited space is a pressing issue that needs to be addressed.

[0033] This embodiment integrates the base, fixed gear ring, and output section into a single housing, reducing the overall size. The hollow structure facilitates wiring and increases wiring safety. The absence of a sun gear reduces the transmission chain, increases the speed ratio range, lowers machining difficulty, and allows for the machining of gears with larger modules, thus increasing the overall structural lifespan.

[0034] Combination Figures 1 to 6As shown, this embodiment of the present disclosure provides a hollow single planetary reducer 100 without a sun gear, including a base 110, a fixed gear ring 120, an output section 130, a movable gear ring 140, a hollow planetary carrier 150, and a double gear 160. The base 110 has an annular structure, and the fixed gear ring 120 is adapted and fixedly connected to the base 110 along the axial direction. The output section 130 includes an outer ring 131 and an inner ring 132 that rotate relative to each other, and the outer ring 131 is adapted and fixedly connected to the fixed gear ring 120 along the axial direction. The base 110, the fixed gear ring 120, and the output section 130 are sequentially connected to form a housing 170. The movable gear ring 140 is disposed inside the housing 170, adjacent to the fixed gear ring 120 and fixedly connected to the inner ring 132. The movable gear ring 140 is adjacent to the fixed gear ring 120 and the output section 130 on both sides along the axial direction, respectively. One end of the movable gear ring 140 is provided with an internal gear, which is adjacent to the internal gear of the fixed gear ring 120. The other end of the movable gear ring 140 is connected to the inner ring 132 of the output part 130 by a fastener. The hollow planetary carrier 150 is axially rotatably inserted into the housing 170 via bearing one and bearing two. The double gear 160 is rotatably mounted on the hollow planetary carrier 150. The double gear 160 meshes with the fixed gear ring 120 and the movable gear ring 140 respectively. The double gear 160 includes a first gear 161 and a second gear 162 arranged side by side along the axial direction. The first gear 161 meshes internally with the fixed gear ring 120, and the second gear 162 meshes internally with the movable gear ring 140 respectively. Power is input from the motor through the hollow planetary carrier 150. The rotation of the planetary carrier drives the double gear 160 to rotate around the central axis of the planetary carrier. The first gear 161 meshes with the fixed gear ring 120, which remains stationary. The first gear 161 is driven to rotate, which in turn drives the second gear 162 to rotate. The second gear 162 meshes with the moving gear ring 140, driving the moving gear ring 140 to rotate. The moving gear ring 140 is fixedly connected to the inner ring 132, driving the inner ring 132 to rotate and output power.

[0035] Combination Figure 1 As shown, a first mounting position 111 is provided on the inner edge of the base 110, and a second mounting position 1321 is provided on the inner edge of the inner ring 132. The hollow planetary carrier 150 is mounted at both ends of the first mounting position 111 and the second mounting position 1321 respectively. The first mounting position 111 is located at the input port, and the second mounting position 1321 is located at the output port. The hollow planetary carrier 150 is horizontally inserted from the input port to the output port along the axial direction, so that the double gear 160 meshes with the fixed gear ring 120 and the moving gear ring 140 respectively.

[0036] Combination Figure 1As shown, the hollow single planetary reducer 100 without a sun gear also includes a first bearing 180 and a second bearing 190. The first bearing 180 is located at a first mounting position 111, used to rotatably connect the base 110 and the hollow planetary carrier 150; the second bearing 190 is located at a second mounting position 1321, used to rotatably connect the inner ring 132 and the hollow planetary carrier 150. The first mounting position 111 includes a bearing mounting position. The base 110 has a shoulder at the end corresponding to the input port at the first mounting position 111. The first bearing 180 is installed into the first mounting position 111, and abuts against the shoulder of the base 110 at the first mounting position 111 to prevent the first bearing 180 from moving axially toward the input port side. The hollow planetary carrier 150 has a shoulder at the end that mates with the first bearing 180, abutting against the end face of the bearing corresponding to the output port side to restrict the hollow planetary carrier 150 from moving axially toward the input port direction. Similarly, corresponding to both ends of bearing 190 along the axial direction, the inner ring 132 is provided with a shoulder to restrict the movement of bearing 190 along the axial direction towards the output port, and the hollow planetary carrier 150 is provided with a shoulder to restrict the movement of bearing 190 along the axial direction towards the input port, thereby restricting the movement of the hollow planetary carrier 150 along the axial direction towards the output port. The relative positions between the hollow planetary carrier 150, the base 110, and the output section 130 are determined by the cooperation of bearing 180 and bearing 190 with each shoulder.

[0037] Combination Figure 1As shown, a groove 163 is provided between the first gear 161 and the second gear 162, and the first gear 161 and the second gear 162 have different numbers of teeth. The first gear 161 and the second gear 162 respectively mesh with the fixed gear ring 120 and the moving gear ring 140. The fixed gear ring 120 is sandwiched between the outer ring 131 of the base 110 and the output part 130, and the moving gear ring 140 is fixedly connected to the inner ring 132 of the output part 130 by fasteners. The fixed gear ring 120 is fixed and the moving gear ring 140 rotates relative to the fixed gear ring 120. In order to avoid interference between the fixed gear ring 120 and the moving gear ring 140, a gap is provided between the fixed gear ring 120 and the moving gear ring 140 in the axial direction. The first gear 161 meshes with the fixed gear ring 120, and the second gear 162 meshes with the movable gear ring 140. To avoid interference between the first gear 161 and the movable gear ring 140, and between the second gear 162 and the fixed gear ring 120, a groove 163 is provided between the first gear 161 and the second gear 162. The width of the groove 163 is greater than the gap between the fixed gear ring 120 and the movable gear ring 140, so that when the first gear 161 meshes with the fixed gear ring 120 and the second gear 162 meshes with the movable gear ring 140, the first gear 161 and the movable gear ring 140 will not interfere, and the second gear 162 and the fixed gear ring 120 will not interfere. By setting the first gear 161 and the second gear 162 to have the same module but different numbers of teeth, the transmission ratio can be set. The transmission ratio can be changed by changing the number of teeth of the first gear, the second gear, the fixed gear ring, and the movable gear ring, and the meshing condition can be adjusted by adjusting the center distance of the two meshing gears.

[0038] Combination Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, the base 110, the fixed gear ring 120, and the output section 130 are provided with multiple sets of corresponding and interconnected bolt holes 200 to connect the three together using long bolts. Each set of bolt holes 200 passes through the outer ring 131 of the base 110, the fixed gear ring 120, and the output section 130, and the long bolts pass through the bolt holes 200 to connect the base 110, the fixed gear ring 120, and the outer ring 131 of the output section 130 together. The multiple sets of bolt holes 200 are evenly distributed circumferentially.

[0039] Combination Figure 1As shown, the hollow single planetary reducer 100 without a sun gear also includes a cylindrical pin 210 and a needle roller 220. The cylindrical pin 210 is fixedly installed on the hollow planetary carrier 150. The axis of the cylindrical pin 210 is parallel to the rotation axis of the hollow planetary carrier 150. The hollow planetary carrier 150 has a pin hole, and the cylindrical pin 210 is fixedly installed on the hollow planetary carrier 150 by inserting it into the pin hole. The cylindrical pin 210 and the pin hole are interference-fitted to fix the relative position between the cylindrical pin 210 and the hollow planetary carrier 150 and prevent the cylindrical pin 210 from moving axially relative to the hollow planetary carrier 150. A double gear 160 is fitted around the cylindrical pin 210, and the needle roller 220 is installed between the cylindrical pin 210 and the double gear 160. The hollow planetary carrier is provided with a mounting groove for the double gear 160. The width of the mounting groove is adapted to the width of the double gear 160 so that the axial movement space of the double gear 160 is less than the width of the groove 163, so as to prevent the first gear 161 from interfering with the moving gear ring 140 and the second gear 162 from interfering with the fixed gear ring 120.

[0040] Combination Figure 1 As shown, the inner edge of the fixed gear ring 120 has a clearance groove 121 corresponding to the second gear 162. One end of the movable gear ring 140 is installed in the clearance groove 121 to mesh with the second gear 162. The first gear 161 and the second gear 162 have the same module but different number of teeth, resulting in different pitch circle diameters. To ensure that the first gear 161 meshes with the fixed gear ring 120 and the second gear 162 meshes with the movable gear ring 140 simultaneously, a clearance groove 121 is provided on the inner edge of the fixed gear ring 120 corresponding to the second gear 162. The portion of the movable gear ring 140 with internal teeth is installed in the clearance groove 121. By changing the depth of the clearance groove 121 and the structural dimensions of the movable gear ring 140, the portion of the movable gear ring 140 that drives the internal teeth is always adapted to the clearance groove 121, thereby controlling the center distance between the double gear 160 and the movable gear ring 140 to adapt to different speed ratios.

[0041] Combination Figure 1 As shown, the output section 130 includes a crossed roller bearing 133, which includes an outer ring 131, an inner ring 132, and rollers. The outer ring 131 is fixedly connected to a fixed gear ring 120, and the inner ring 132 is fixedly connected to a movable gear ring 140. The outer ring 131 has bolt holes 200 for fixed connection with the fixed gear ring 120 and the base 110. The inner ring 132 has screw holes, and the movable gear ring 140 has through holes corresponding to the screw holes of the inner ring 132. The movable gear ring 140 and the inner ring 132 are fixedly connected by screws.

[0042] Combination Figure 1As shown, oil seal mounting grooves 230 are provided between the inner ring 132 and the outer ring 131, and between the hollow planetary carrier 150 and the inner ring 132; the output section 130 also includes an oil seal 134. The oil seals 134 are respectively installed in the oil seal mounting grooves 230.

[0043] Combination Figure 1 As shown, the fixed gear ring 120 has a first positioning interface 122 corresponding to the base 110, and the base 110 is adapted to and connected to the first positioning interface 122; the fixed gear ring 120 has a second positioning interface 123 corresponding to the outer ring 131, and the outer ring 131 is adapted to and connected to the second positioning interface 123. The first positioning interface 122 includes mutually perpendicular positioning surfaces, and one end of the base 110 is respectively attached to two surfaces of the first positioning interface 122. The second positioning interface 123 has mutually perpendicular positioning surfaces, and one end of the outer ring 131 is attached to two surfaces of the second positioning interface 123.

[0044] For example, the hollow single planetary reducer 100 without a sun gear provided in this embodiment of the present disclosure can be installed according to the following steps:

[0045] Step 1: Install bearing 2 190 into cross roller bearing 133, and fix moving gear ring 140 to inner ring 132 with screws to form output assembly.

[0046] Step 2: Insert the needle roller 220 into the double gear 160, and install the double gear 160 with the needle roller 220 into the hollow planetary carrier 150 through the cylindrical pin 210 to form the planetary carrier assembly.

[0047] Step 3: Install the output component and the planetary carrier component.

[0048] Step 4: Install bearing 180 onto the planetary carrier assembly.

[0049] Step 5: Install the bearing 180 corresponding to the base 110.

[0050] Step 6: Secure the machine base 110, fixed gear ring 120 and outer ring 131 with bolts.

[0051] Step 7: Install oil seal 134.

[0052] For example, the working principle of the hollow single planetary reducer 100 without a sun gear provided in this embodiment of the present disclosure is as follows:

[0053] The hollow single planetary reducer 100 without a sun gear provided in this embodiment has a double gear 160 installed in a hollow planetary carrier 150 via a cylindrical pin 210 and a needle roller 220. The double gear 160 has a groove 163 in the middle. The speed ratio is changed by setting the two gears with different numbers of teeth. The double gear 160 meshes with the fixed gear ring 120 and the moving gear ring 140 respectively, and is divided into a driving gear and a driven gear. The first gear 161 meshes with the fixed gear ring 120 as the driving gear, and the second gear 162 meshes with the moving gear ring 140 as the driven gear. The motor is connected to and driven by the hollow planetary carrier 150. The rotation of the hollow planetary carrier 150 drives the double gear 160 to rotate. The first gear 161 meshes with the fixed gear ring 120, which remains stationary. The rotation of the first gear 161 drives the second gear 162 to rotate, which in turn drives the movable gear ring 140 to rotate. The movable gear ring 140 is connected to the inner ring 132 of the crossed roller bearing 133 by screws, causing the inner ring 132 to rotate for output. The driving gear part generates force through the rotation of the meshing fixed gear ring 120, and the driven gear part rotates along with it, meshing with the movable gear ring 140. The fixed gear ring 120 is fixed to the crossed roller bearing 133, and the movable gear ring 140 drives the inner ring 132 of the crossed roller bearing 133 to rotate together for output. The single hollow planetary carrier 150 and the single double gear 160 are divided into two sections, with different numbers of teeth at each end, which are matched and meshed with the moving gear ring 140 and the fixed gear ring 120 respectively. The entire gear engages and disengages simultaneously.

[0054] The formula for calculating the speed ratio is:

[0055] i = Z 动 / (Z 动 -Z 定 / Z 主 ×Z 从 )

[0056] Among them, Z 定 For a fixed gear ring with 120 teeth or a pitch circle diameter, Z 动 For the moving gear ring with 140 teeth or pitch circle diameter, Z 从 Z represents the number of teeth or pitch circle diameter of the second gear 162 on the double gear 160. 主 The number of teeth or pitch circle diameter of the first gear 161 on the double gear 160.

[0057] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations, and individual components and functions are optional unless explicitly required, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the terms “comprise” and its variations “comprises” and / or “comprising” refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Unless otherwise specified, an element defined by the phrase "comprising a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on its differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, then the relevant parts can be referred to the description of the method section.

[0058] The above-described embodiments merely illustrate several implementation methods of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combinations of these technical features do not contradict each other, they should be considered within the scope of this specification. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A hollow single planetary gear reducer without a sun gear, characterized in that, include: The base (110) is a ring structure; A fixed gear ring (120) is fixedly connected to the machine base (110) along the axial direction; The output section (130) includes an outer ring (131) and an inner ring (132) that rotate relative to each other, and the outer ring (131) is fixedly connected to the fixed gear ring (120) along the axial direction; The base (110), the fixed gear ring (120), and the output section (130) are connected in sequence to form a housing (170); The movable gear ring (140) is located inside the housing (170). The movable gear ring (140) is adjacent to the fixed gear ring (120) and is fixedly connected to the inner ring (132). A hollow planetary carrier (150) is rotatably mounted inside a housing (170); A double gear (160) is rotatably mounted on a hollow planetary carrier (150). The double gear (160) includes a first gear (161) and a second gear (162) arranged in parallel along the axial direction. The first gear (161) meshes internally with the fixed gear ring (120), and the second gear (162) meshes internally with the moving gear ring (140).

2. The hollow single planetary reducer without a sun gear according to claim 1, characterized in that, The inner edge of the base (110) is provided with a first mounting position (111), and the inner edge of the inner ring (132) is provided with a second mounting position (1321). The two ends of the hollow planetary carrier (150) are respectively installed at the first mounting position (111) and the second mounting position (1321).

3. The hollow single planetary reducer without a sun gear according to claim 2, characterized in that, Also includes: Bearing 1 (180) is located at the first mounting position (111) and is used to rotatably connect the base (110) and the hollow planetary carrier (150); Bearing 2 (190), located in the second mounting position (1321), is used to rotatably connect the inner ring (132) and the hollow planetary carrier (150).

4. The hollow single planetary reducer without a sun gear according to claim 1, characterized in that, The first gear (161) and the second gear (162) have different numbers of teeth.

5. The hollow single planetary reducer without a sun gear according to claim 1, characterized in that, The base (110), the fixed gear ring (120), and the output section (130) are provided with multiple sets of corresponding and connected bolt holes (200) so as to connect the three together by long bolts.

6. The hollow single planetary reducer without a sun gear according to claim 1, characterized in that, Also includes: A cylindrical pin (210) is fixedly installed on a hollow planetary carrier (150); The double gear (160) is mounted on the hollow planetary carrier (150) by means of a sleeve on the cylindrical pin (210); Needle roller (220) is installed between cylindrical pin (210) and double gear (160).

7. The hollow single planetary reducer without a sun gear according to any one of claims 1 to 6, characterized in that, The inner edge of the fixed gear ring (120) is provided with a clearance groove (121) corresponding to the second gear (162), and one end of the movable gear ring (140) is installed in the clearance groove (121) to mesh with the second gear (162).

8. The hollow single planetary reducer without a sun gear according to any one of claims 1 to 6, characterized in that, The output section (130) includes a crossed roller bearing (133), wherein the crossed roller bearing (133) includes an outer ring (131), an inner ring (132) and rollers, the outer ring (131) is fixedly connected to the fixed gear ring (120), and the inner ring (132) is fixedly connected to the moving gear ring (140).

9. The hollow single planetary reducer without a sun gear according to any one of claims 1 to 6, characterized in that, Oil seal mounting grooves (230) are provided between the inner ring (132) and the outer ring (131) and between the hollow planetary carrier (150) and the inner ring (132); The output section (130) also includes an oil seal (134), which is installed in the oil seal mounting groove (230).

10. The hollow single planetary reducer without a sun gear according to any one of claims 1 to 6, characterized in that, The fixed gear ring (120) is provided with a first positioning interface (122) corresponding to the machine base (110), and the machine base (110) is adapted to the first positioning interface (122); The fixed gear ring (120) is provided with a second positioning interface (123) corresponding to the outer ring (131), and the outer ring (131) is adapted to the second positioning interface (123).

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