Greetings all, its been long since I last posted question here. May I know what is the function of a swivel? Also, if I am trying to dismantle it and replace the hoses, what should I do? I also read something about marking the hoses, what is that about? =S I am still a newbie in this. Please kindly advise
center swivel The center swivel turns 360 degrees in either direction. It has a inner section and a outer section, one part is connected to the upper section, where you sit. The other part is connected to the lower center frame, with it mounted in the center of the machine as you swing it turns just like the swing bearing would. Hyd oil travels through the inner section by machined ports to the outer sections machined ports. Between each port inside their are O-rings and backup rings, with some having dirt/grease seals also at the top and bottom. Some swivels have ball bearings, wear rings, built into them to turn with less friction to help keep the ports inline. Most have 5-9 ports at the top where the hyd hoses hook to and 5-9 ports on the outer section up under the machine that connect the drive motors, case drain, brakes, two speed travel, and blade functions. I tag my lines, put center punch dots, number stamp hoses to aid in removal and install. You can cross lines up and have issues if you don't plus, loss of fluid trying to unhook and change ports over and over until you get it correct. Some machine have a swing bearing that is a internal open gear, or outside open gear. Others have a internal swing bearing gear that has a grease chamber that your swivel will go through with grease boots that keep water and dirt from getting in. Clean the machine area to be worked on, upper side and under. If it's a mini you may want to put it up on blocks to give more clearance to work on it. Lower all attachments to the ground (the blade will drop if it has one when the hoses are unhooked). I do not know the machine you are working on so really can't go much more. So when you move the pedal to make the right track go forward, hyd oil goes from the control valve to tubes/hoses to the top inlet port on the swivel, through the swivel and out the outer swivel section port to the drive motor. The other hose for the drive motor returns oil on a different port through the swivel back to the control valve. At the same time a line to the brake release is going through a different swivel port to release the brake on that side. Also a case drain line coming from the drive motor is bleeding oil that is leaking back through the system by ways of the center swivel on another port. So if you were walking forward with both tracks you would be using (6) ports through the center swivel at this time. IF you are just replacing hoses you do not need to take the swivel apart, if the swivel is leaking then it has to come apart. This is just some basic info, hope it helps some.
sheepfoot, thanks for explaining that in detail I have always wandered how they functioned. Very well spoken.
Question Sheepfoot, first of all, thanks for your kindest concern in replying me =D. I appreciate your effort so much. I am not really understanding the quoted sentence above. Can you please clarify for me? What is the function of swing bearing? And what to do with an internal open gear and an outside open gear? What's the function of it? Sorry if I am causing troubles.
Swing bearing We got off subject some, the turn table bearing (slew ring bearing) on trackhoes connect the upper half to the lower half of the machine, most machines the drive box that makes the machine swing is mounted to the upper half. The drive box has a shaft with a gear that drops below the upper deck and is engaged into the drive ring on the turn table bearing. This ring gear can be made with the gear to the outside or inside of the bearing. Most machines you lube the bearing with a grease gun, but the ring gear is lubed with a brush or spray on lube if it is exposed to the outside or up in the lower half exposed. The newer type machines have the gear to the inside and is contained. There is a grease cavity that holds several pounds of grease, as the machine swings the gear from the swing drive box runs in around 1/4" of this grease lubing the ring gear on it's own. Now back to the swivel, if it has a old style bearing the swivel is a self contained unit. Most have a top mounting bracket bolted down to the top deck and holds the inner section of the swivel in the center of the machine, the outer section of the swivel is retained by a end plate on the inner swivel. The outer swivel is connected to the lower structure by a bracket to keep it from turning. Now if it's a newer style machine with a grease cavity the swivel mounts much the same but it is sealed on the lower end along with a boot seal at the top threw this cavity to keep dirt and water from mixing with the grease that lubes the swing gear and drive box gear. Once again if it is not leaking external, and has no issues that would make you think the internal o-rings are bad then just replace your hoses that are leaking. You never said what size or make machine you are working on. If you have more questions ask, some have swivels inside of swivels along with elect swivels that run inside of the center of the swivels, wow!