Please select the most similar patent number from A, B, C and D. Which number is?
A stepping double-sided shot blasting apparatus, comprising a cleaning chamber (1), a guide rail (2), shaft racks (3), hanging racks (4), a speed reducer (5), a motor (6), a frame (7), and inner supports (8). The cleaning chamber is located below the frame and above the speed reducer. A gap is formed between the cleaning chamber and the frame by means of the inner supports, and the guide rail is horizontally disposed at the gap. The outer wall of the cleaning chamber is provided with impeller heads (1.1), and two sections are provided with gates (1.2). The upper ends of the shaft racks extend into the guide rail, and the lower ends are inserted into gear holes provided inside the speed reducer to move along therewith. Each shaft rack hangs two hanging racks, and the shaft racks and the hanging racks are used for hanging gear blanks. The speed reducer is a planetary speed reducing mechanism, the shaft racks are inserted in shaft holes of four second star wheel (5.6), and when the speed reducer operates, the second star wheels rotate and revolve in linkage with the shaft racks. Under this structural condition, the gear blanks enter the cleaning chamber to be subjected to uniform shot blasting on both sides, and the shaft racks and the hanging racks temporarily located outside the cleaning chamber can be used for loading and unloading the gear blanks to be processed. In the apparatus, the shot blasting procedure and the loading and unloading procedure do not interfere with each other, and therefore, the production efficiency and equipment utilization rate are greatly improved.
A: An endless belt shot blasting device comprises a shot blasting cabinet. A shot blaster is disposed above the shot blasting cabinet. A shot inlet of the shot blaster is connected to a shot outlet (51) of a shot-sand separator. A laterally inclined steel belt (9) is disposed inside the shot blasting cabinet. A feed roller (8) and a discharge roller (8&#39;) are arranged at two sides of the shot blasting cabinet to cooperate with the steel belt to convey shot. The shot blasting device further comprises a shot blasting cabinet angle adjustment mechanism comprising a support (23). A worm gear mechanism (24) is disposed above the support. An inner thread is arranged in a central hole of a worm wheel of the worm gear mechanism. A connecting and supporting block (26) is disposed on a screw mating with the thread of the worm wheel. The shot blasting cabinet is disposed on the connecting and supporting block. The invention uses the angle adjustment mechanism to change a duration a workpiece passes through the shot blasting cabinet, and the use of the steel belt for conveyance enables thorough shot blasting of the workpiece without missing any area of the workpiece.
B: Disclosed is a speed reducer for driving a window curtain or a door curtain, comprising at least one involute planetary gear reducing mechanism (2), a cycloid gear reducing mechanism (1) in transmission connection to the involute planetary gear reducing mechanism (2), an output shaft (3) connected to the cycloid gear reducing mechanism (1), and a housing assembly (5), wherein the involute planetary gear reducing mechanism (2) comprises a sun gear (21) and at least one planetary gear (22), and the middle of the planetary gear (22) is provided with a mandrel (23) passing therethrough; the cycloid gear reducing mechanism (1) comprises a camshaft (11), the output shaft (3) sheathed at the upper end of the camshaft (11), at least one cycloid gear (13) sheathed on a cam of the camshaft (11), a plurality of pinwheels (14) meshed with a side face of the cycloid gear (13), and at least one pin shaft (15) in parallel to the axial direction for the cycloid gear (13) to pass through, and the upper end of the pin shaft (15) is fixedly connected to the output shaft (3); and the lower end of the camshaft (11) is fixedly connected to a first planet carrier (12), the mandrel (23) penetrates the first planet carrier (12) and is fixedly connected to the first planet carrier (12), the lower end of the sun gear (21) is sheathed with a first bearing (41), and the lower part of the camshaft (11) is further sheathed with a second bearing (42). The size of the speed reducer is small, the transmission efficiency is high, the noise is low, and the self-locking performance is good.
C: A pellet former for sawdust, comprising: a machine base (1) on which a first electric motor (2) is placed; a reducer (3) connected to one end of an output shaft of the first electric motor (2); a forming mould (4) disposed at a side of the reducer (3), the forming mould (4) comprising a first fixed frame (5), a second fixed frame (6) and a transmission shaft (7), wherein the transmission shaft (7) is connected to the reducer (3), and the transmission shaft (7) is mounted between the first fixed frame (5) and the second fixed frame (6); extrusion gears (8) disposed on the transmission shaft (7); a baffle (9) disposed at the end of the extrusion gears (8) connected to the reducer (3); and an extrusion gear reinforcement lid (10) provided with an outlet orifice, which is disposed at the other end of the extrusion gears (8). The number of the extrusion gears (8) is greater than or equal to two, and two adjacent extrusion gears (8) rotate in opposite directions. An inlet orifice (11) is disposed above two extrusion gears (8), and a casing (12) is disposed surrounding the extrusion gears (8). The pellet former for sawdust can improve efficiency, allow pellets with high density to be formed, and is more labor-saving by means of two extrusion gears pressing inwardly toward each other. The whole former is simple in structure and small in volume, thus requiring smaller space for production and being convenient to repair.
D: A three-stage two-gear speed reducer and an electric vehicle, relating to the technical field of mechanical transmission. The three-stage two-gear speed reducer comprises a shell (5), and an I-stage speed reducing mechanism, an II-stage speed reducing mechanism, an III-stage speed reducing mechanism and a meshing sleeve (9) which are arranged in the shell (5). The III-stage speed reducing mechanism is a driving and driven cylindrical gear speed reducing mechanism and comprises a driving cylindrical gear (7), and the I-stage speed reducing mechanism and the II-stage speed reducing mechanism are planetary speed reducing mechanisms correspondingly arranged on two axial sides of the driving cylindrical gear (7); and the meshing sleeve (9) is arranged between the II-stage speed reducing mechanism and the III-stage speed reducing mechanism, and is used for connecting the driving cylindrical gear (7) to a planetary gear (3) of the I-stage speed reducing mechanism or a planetary gear (10) of the II-stage speed reducing mechanism, such that two-gear shifting of the speed reducer is achieved. Compared with the three-stage speed reducer in the prior art, according to the three-stage two-gear speed reducer, a multi-parallel-shaft structure is avoided, the I-stage speed reducing mechanism and the II-stage speed reducing mechanism are correspondingly arranged on two sides of the driving cylindrical gear, the layout is more compact, and the power density is high; and furthermore, the stress deformation of parts is reduced, the rigidity of the parts is improved, unbalance loading is reduced, and the service life is prolonged.
Answer: A