Speed Reducer Frequently Asked Questions

Q. Why use a worm gear reducer?
A. A worm gear reducer is a right angle gear solution that allows the maximum speed reduction in the smallest package.

Q. Why use a bevel gearbox?
A. A bevel gearbox is yet another right angle gear solution but its efficiency is much higher than the worm gear. If you need a right angle solution with a low ratio the bevel gear is the right choice.

Q. Why use helical gear reducer?
A. Helical gears are more efficient and capable of handling higher OHLs. In-Line reducers are less expensive than the more traditional parallel shaft but the parallel shaft has more flexibility with more options.

Q. When do you use a helical gear reducer versus a worm gear reducer?
A. Worm gear reducers are used in low to moderate horsepower applications. They offer low initial cost, high ratios, and high output torque in a small package. They have a much higher tolerance for shock loading then helical gear reducers. Helical reducers are used in higher horsepower applications where long-term operational efficiency is more important than initial cost.

Q. How is the ratio determined for a helical gear set? A bevel gear set? A worm gear set?
A.

The ratio of a helical or bevel gear set is simply the number of teeth in the larger gear divided by the number of teeth in the smaller gear. For example, a gear set with 36 teeth in the larger gear and 12 teeth in the smaller gear has 3:1 ratio.

The ratio of a worm gear set is the ratio of the number of teeth in the gear to the number of threads (starts or leads) on the worm. For example, a worm with two threads and a mating gear with 60 teeth has a ratio of 30:1.

Q. What is meant by the hand of drive?
A. The location of the output shaft of a reducer relative to it's input shaft is called the configuration's hand. It is generally referred to as right handed (J), left handed (G) or left and right handed (H) if the output shaft is double extended.

Q. What are some of the advantages of ground gears?
A. Some of the advantages of hardened and ground gears are:
1. less noise
2. maximized efficiency
3.  higher load capacity
4.  correction of profile … longer life

Q. What are two major reasons for premature gear reducer failure?
A. Some of the most common causes for premature failure of a reducer include improper selection for the application, changing the motor horsepower or speed, incorrect alignment of couplings, improper or insufficient lubrication, and lack of regular maintenance.

Q. How can you minimize the size of a major drive component such as a motor and its reducer while maximizing output torque capacity?
A. Introduce mechanical advantage or ratios where possible.

Example: An application requires 700 in-lbs of torque at 90 RPM utilizing a 1HP 1750 RPM motor (36 in-lbs. of torque generated from 1HP motor SCI)

Option 1 - 20:1 reducer with 720 in-lbs of output torque capacity. 36 in-lbs X 20:1 ratio = 720 in-lbs capacity less efficiency loss through reducer.

Option 2 - 10:1 gear reducer. 36 in-lbs X 10:1 ratio = 360 in-lbs capacity less efficiency loss through reducer plus a 2:1 chain drive from reducer to drive shaft

Option 2 would be most economical because we are reducing the gearbox size requirements (capacity needed) by half and still mainating the application torque requirements at the drive shaft with the use of the chain drive.

Note: The more HP or torque that the application needs to transmit, the more money that can be saved by multiplying torque through reducers and auxiliary drive components.

Q. In what gearbox application would it be advantageous to use a synthetic lubrication?
A. Most synthetic lubricants have lower pour points, high oscillation resistance, and accept additives better than their conventional petroleum equivalents. Therefore, a gearbox in one of the following conditions would benefit from the use of synthetic lubricants: hot or cold ambient temperatures; heavy loads; continuous duty; or limited PM.

Q. How to Balance Shock Load vs. Running Load?
A. It depends on the load demands and duty cycle of your application. Is your load primarily frictional, inertial, or a combination? Frictional loads tend to require a small torque spike to start motion and a smaller relatively constant torque to maintain it. Inertial loads typically require high starting torques but low running torques.

Q. What is backlash?
A. Backlash is the free-play between input and output and is typically caused by movement of gear teeth back and forth within tooth spaces, and results in lost motion or error.

Q. Are worm gear reducers "self-locking"?
A. A worm gear set is said to be self-locking, or irreversible when the gear cannot drive the worm. This condition is obtained, if the lead angle of the worm is less than the friction angle, and as a consequence the efficiency for reversed driving is zero. The friction angle for static conditions will vary with such factors as surface finish and lubrication. Based upon the generally accepted value of static coefficient of friction equal to 0.15, the friction angle would be approximately 8°. However, the friction angle decreases rapidly with the start of motion, also, vibrations from nearby sources quite often upset the static condition of a locked set of gearing a sufficient amount to reduce the friction angle to a point where motion occurs, this is sometime called "stiction". These unpredictable factors make it advisable to resort to a brake rather than relying on the self-locking characteristics of the worm gearing.

Q. How hot does a speed reducer operate?
A. Under SCI conditions it is common for the internal temperature to rise 100F above ambient.

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Brand:OEM

Place Of Origin:   Changzhou

Type: R Series

HS Code: 84834090

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