Small trailers are vehicles for small tractors. The correct selection and use of small trailers is of great importance for ensuring the safety of operations and reducing the operating costs. 1, the purchase of trailers (1) try to buy brand-name quality products. For those trailers that have no trademark, no site, no certification, or “three no†trailers or repair shops, they should be carefully selected. The quality of such products is not guaranteed, so try not to purchase them. (2) The quality of the trailer should be small to improve the loading capacity. The general quality must not exceed 40%-50% of the trailer load. (3) It is necessary to correct itself, and the four-corner hooks should be complete; there must be traffic signs and lighting facilities; and the tractor's pneumatic brake joints, hydraulic brake joints, power plugs and other connections are reliable and convenient for hanging and picking. (4) The trailer shall have a leaf spring damper device, the spring stiffness shall be appropriate, the travel shall be smooth, the brake shall be reliable, and the no-load test may be conducted when selected. (5) The traction tripod of the trailer should be equal waist symmetry, that is, the hanging wheel axle should be perpendicular to the traction centerline, the distance between the two tires to the traction centerline should be equal, and the trailer traction hole (traction point) should be located on the traction centerline. (6) When the traction tripod is full, it should be able to keep parallel with the ground and allow the front end to lift slightly; when rotating 90 degrees, the tripod should not interfere with the rear wheel of the tractor. (7) The tightness of the wheel bearing should be appropriate, the radial and end surfaces of the wheel should not be significantly beaten, and the main parts such as bearings, brakes, and wheels should be highly generalized, and the main parameters should meet the requirements of the standard. (8) The welding of various parts of the trailer should be smooth, and there should be no phenomenon of imaginary welding or desoldering; the paint should be beautiful; the quality of the tire should meet the requirements, and bulging, cracking, etc. should not occur. 2. Correct use (1) The new trailer should run in. At the time of running-in, the load must not exceed 80% of the rated load; after driving at a speed of about 150km at medium speed, attention should be paid to observing the temperature of the bearing and the hub, and whether the fasteners of the leaf spring and wheels are tightened. Tighten the parts once and fasten them after 3 times. (2) A comprehensive inspection shall be conducted before leaving the vehicle. The connection with the main engine is required to be correct and reliable, the braking system is normal, and the tire pressure is in compliance with the regulations. No loosening, cracking or deformation may occur at all parts. (3) Load by limited load, do not overload. The load distribution inside the compartment should be uniform so as to avoid the risk of car tilting. (4) When loading hard and heavy objects such as stones and ironwork, they should be gently moved and gently placed to avoid damage to the carriage. When loading firewood and other objects, ropes should be used to secure and fasten the buckles. (5) The unit should start steadily. Do not place your foot on the brake pedal while driving. Minimize emergency braking. (6) During driving, check whether the brake is hot, whether there is abnormal odor, or whether the trailer's traveling device is deflected. If there is any abnormality, stop the vehicle immediately and check it out. (7) After the daily operation is completed, the carriages should be cleaned or cleaned to check the looseness of the fasteners and lubricate the relevant parts. (8) After every 500-600 hours of operation, check the bearing clearance of the tire. When inspecting, lift up the carriage and pull the wheels. There should be no obvious shaking. If there is obvious shaking, it should be adjusted. The method is to remove the bearing cap, screw the shaft head groove nut to the end, and then return 1/6 turn, at this time the bearing clearance is about 0.25mm. (9) Regularly check and adjust the brakes and perform tests to ensure good braking performance. The braking distance must not exceed 5m. There should be no partial braking, and the trailer braking time should be slightly earlier than the main vehicle. The adjustment of the brake is mainly based on adjusting the clearance. The method is to rotate the brake camshaft or mandrel or turn the reversed cone roller so that the left and right brake clearances (generally 0.30.05 mm) are consistent. (10) The brake linings shall be inspected on a regular basis and they shall continue to be used with little wear; if the wear exceeds 1/2 of the new thickness, they shall be replaced. (11) Check regularly whether the trolley girder and traction tripod have been detached, broken and bent; regularly check the lubrication condition of the wheel bearing; if the oil is short of oil, it should be replenished promptly. The lubricating oil is generally calcium-based grease and can not be replaced with oil or other oil. It is advisable to fill 2/3 of the hub cavity of the bearing. Regularly clean the leaf spring and apply graphite grease to check the wear of the leaf spring and the bushing. If any problem arises, it should be repaired or replaced. (12) When the trailer is parked and stored, it should be placed in the storage shed to avoid the sun and rain, and to support the wheel oil to reduce the load of the tire, while the exposed parts of the exposed oil rust.