Patent Application
20190047064
This disclosure claims all benefits to Chinese patent application No. 201610981636.8, filed with the State Intellectual Property Office of the People's Republic of China on Nov. 8, 2016, titled “Cutters for processing the modified gear of ROV propeller”, and hereby incorporated by reference herein in its entirety.
This disclosure generally relates to ROV propeller, and more specifically to cutters for processing modified gear of a ROV propeller.
ROV (Remote Operated Vehicle) is a robot used for underwater observation, inspection and construction. Miniature ROV is energy self-supported and can operate nimbly. It can carry miniature camera and sensor so as to extend the observation range for a manned submersible with its ability of accessing to small or dangerous places where it is inconvenient for the manned submersible or even unable to get into.
ROV is driven mainly by ROV propellers installed on both sides and the tail of the ROV respectively. A lot of gears are used in the ROV propeller, such as planetary wheel in planetary reducer, a solar wheel connected to the planet reducer in the ROV propulsion motor shaft, and gear rings provided on other connecting parts, etc. Gears used in a conventional ROV propeller are standard gears made according to industry standard. When gears are in engagement or disengagement, shock and noise will be caused due to gear tooth error and the angular velocity fluctuation change caused by loading deformation. It is difficult to avoid the generation of such phenomenon even for gears of high precision. In the past, people are strived to make the gear as much precise as possible to be close to the theoretical tooth shape. In practice, however, it has been proved that gears of high precision cannot meet the requirement of precise engagement during high speed overloading transmission, whereas a modification to the addendum, dedendum flange and the tooth orientation can improve the engaging performance effectively, reduce the engaging shock, reduce noise, and also render a uniform load distribution of gear width, thus increasing the bearing capacity of the gears.
In one aspect, the disclosure relates to cutters for ROV propeller gear modification, comprising a cut holder and a hob provided on the cut holder. The hob comprises a plurality of continuous linearly arranged gear hobbings, each of which has a tooth depth of 1.65 cm, a tooth dedendum of 0.975 cm, and a tooth addendum of 0.675 cm, a tooth thickness of 0.946 cm, an addendum circle radius of 0.324 cm, a dedendum circle radius of 0.163 cm, and a dextrorotatory tooth thread with an angle of 1° 7′18″, with two adjacent gear teeth having a tooth pitch of 1.885 cm.
The modulus of hob may be 0.6, slot number may be 12, and the pressure angle may be 20°. A spiral angle of a blade groove may be 0°, and spiral direction may be formed as a straight flute; base circle radius may be 0.823 cm, base rounded angle may be 20° 1′49″. The modified gear of ROV propeller may be obtained by the gear hobbing processing of the hob.
In some embodiments, the hob is made of hard alloy and the heat treatment hardness is HRC63-66. Chip pocket adjacent pitch difference may be 0.016 cm. Chip pocket pitch cumulative error may be 0.02 cm. Tooth profile error may be 0.003 cm. Helix error of adjacent cutting edge may be 0.004 cm. Helix error of one round cutting edge may be 0.006 cm. Helix error of three rounds cutting edge may be 0.01 cm.
In some embodiments, the ROV propeller modified gear obtained from the hob processing method has a modulus of 0.6, a pressure angle of 20°, a number of teeth of 12, each tooth has an addendum circle diameter of 8.16 mm, a dedendum circle diameter of 5.85 mm, and a dedendum of 1.130 mm. The product has an involute initial circle diameter of 6.767 mm. Each tooth has a left and a right surface of drum shape and its upper portion has a left end and a right end, both of which have an end edge which are inclined inwards by a preset angle.
In some embodiments, the ROV propeller modified gear obtained from the hob processing is fit for the solar and planetary wheels of the ROV propeller.
The cutter used for processing the ROV propeller gear modification provided by the present disclosure modifies edge of addendum and dedendum as well as tooth orientation of a traditional tooth. The modification changes gear meshing performance, makes gear running more smoothly, reduces noise and vibration of the gear, makes the load distribution along the tooth width more uniform, improves the carrying capacity and prolongs the working lifetime of the gear.
A further detailed description of the technical solutions in the disclosure will be provided through the following drawings and examples.
Referring to
The modulus of hob is 0.6, with 12 slots and a pressure angle of 20°. The spiral angle of blade groove is 0°, spiral orientation is formed as a straight flute. The base circle radius is 0.823 cm, and the base rounded angle is 20° 1′49″. The modified gear of ROV propeller is obtained through processing by the hob gear hobbing.
This cutter for the ROV propeller gear modification as provided by the disclosure modifies the edge of tooth top and tooth root as well as tooth orientation of a traditional gear. The modification improves gear engaging performance, makes gear running more smoothly, reduces the noise and vibration, makes distribution of load along the tooth width uniformly, improves load capacity and prolongs the working lifetime of the gear.
In some embodiments, the hob is made of hard alloy and the heat treatment hardness is HRC63-66. It's chip pocket adjacent pitch difference is 0.016 cm, chip pocket pitch cumulative error is 0.02 cm, tooth profile error is 0.003 cm, helix error of adjacent cutting edges is 0.004 cm, helix error in one round of the cutting edge is 0.006 cm, and helix error in three rounds of the cutting edge is 0.01 cm.
Referring to
It should be noted that reference sign 11 in
After applying the modified gear to the ROV propeller motors and planetary reducer, the vibration of planetary reducer is very small, the noise is reduced (from more than 85 decibels before modification to 66-70 decibels after modification) at a high speed rotation. In addition, the highest temperature of the planetary reducer reduces from 60 to 47° C. as increasing of temperature caused by mechanical friction becomes slow.
In some embodiments, a modified gear of ROV propeller obtained from the gear hob processing method can be applied in the solar and planetary wheels of the ROV propeller.
A solar wheel which is subject to gear hobbing by the cutter provided in this disclosure for ROV propeller gear modification has a gear precision up to precision grade 6 as required by GB2363-90. The planetary wheel processed by the cutter provided in the disclosure for ROV propeller gear modification has a gear precision up to precision grade 6 as required by GB2363-90. The tooth ring is cut using a high precision and slow speed wire cutting method and the gear precision thereof meets precision grade 5 as required by GB2363-90.
The disclosure is not limited to the embodiments illustrated above. Variations made by those ordinary skilled in the art under the enlightenment in the disclosure, which are identical or equivalent to the solutions in this disclosure whether any changes in its shape or structure are made, shall fall within the scope of protection as defined by claims of this application. The term “first”, “second”, and “third” are applied for descriptive purpose only and are not intended to be interpreted as indicating or implying relative importance. The term “a plurality of” means two or more, unless otherwise specified.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201610981636.8 | Nov 2016 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2017/106489 | 10/17/2017 | WO | 00 |
