High stiffness reducer

This is a page of frequently asked questions (FAQ) about high stiffness reducers. We answer questions about our products in a Q&A format.


How do you install a high stiffness reducer?
The installation method of the high stiffness reducer is described in the instruction manual.
Refer to "Installation".

Product specifications

What type of grease is used?

Lithium grease containing extreme pressure additive with consistency equivalent to NLGI-0 is used.

"Consistency" is a basic physical property value that indicates the hardness of grease.
* "NLGI" is an abbreviation for National Lubricating Grease Institute.

In order to prevent leakage of grease inside the reducer ,is it necessary to seal up or take any other measures?

There is no need to seal it up because the large hollow shaft type (DGH) is a reducer has sealing structure.
A flat, lightweight type (DGF) does not have sealing structure.
Please prevent grease leakage by yourself according to following two steps:
[1] An oil seal is not attached to input side. Thus, you need to attach oil Seal to the equipment.
*Fill 70 to 80 % of the spatial volume of the device with our dedicated grease (sold separately).
[2] Attach the O-rings (two types) supplied with the product to the mounting area of the reducer.

Can I use commercially available grease as lubricant?
Using grease in over or under designated amount or different grease may result in performance deterioration or early damage.
How can I get grease for refill?
When purchasing grease, please contact any of our sales offices.
A dedicated grease (35 g) for lightweight and compact types is available.
Can items with reduction ratios not listed in the catalog be manufactured?
For reduction ratios not listed in the catalog, please contact our sales offices.
How long is the life of a high stiffness reducer?
It is designed for 10,000 hours (10% damage probability) as a guide under specific rated torque and rated rotation speed.
However, the life depends on the usage environment and conditions, so please contact our sales office for details.
What is the angle transmission error?
The angle transmission error is the difference between the theoretical rotation angle and the actual rotation angle of the output shaft when an arbitrary rotation angle is given to the input.
(Unit: arc min)
What is the torsional rigidity?
When the input shaft is fixed and torque is applied to the output shaft, a torsion occurs in the output shaft in proportion to the torque.
The torsional stiffness (spring constant) represents the helix angle for torque between 50 and 100% of the rated torque. (Unit: Nm/arc min)
Please tell me about hysteresis loss.
When you fix the input shaft and apply torque to the output shaft, the output shaft causes torsion proportional to the torque.
When you apply torque up to the rating and then returned to “zero,” torsion will not be eliminated thoroughly to “zero” and will slightly remain due to the impact of internal friction, etc.
(Helix angle at a torque of zero on a hysteresis curve (arc min))
This return error amount is called hysteresis loss.

CAD data

Can I download the CAD data?
2D CAD data (PDF / DXF format) and 3D CAD data (STEP format) are available. Click here to download.
For a format other than the above, please contact our sales office.

Failure / maintenance / inspection

Does the grease need to be replenished or replaced?
All models use grease lubrication, so there is no need to replace or replenish the grease.

Product warranty

What is the warranty period and coverage of your products?

The warranty period and coverage of our products are as follows.

1. Warranty period: 18 months from the factory shipping date or 12 months after the start of use, whichever that's shorter.

2. Warranty coverage:
(1) The warranty coverage is limited to our production range.
(2) During the warranty period, if there is a problem that the function of the delivered product cannot be exhibited under the operating conditions under the normal installation / connection and handling
(inspection / maintenance) described in this instruction manual. , We will repair it free of charge. However, we will not be liable for any costs for removing or installing our products in your device for replacement or repair, costs of transportation for repairs, or indirect damages.

3. Warranty disclaimer:
(1) For repair, parts replacement or replacement delivery due to wear caused by the customer dismantling or modifying the product.
(2) When the product is operated under conditions outside of the rated data described in our catalog / instruction manual or the mutually agreed specifications.
(3) When there is a problem (centering of the coupling, etc.) in the power transmission of the customer's device.
(4) When a force majeure such as a natural disaster (earthquake, lightning strike, fire, flood, etc.) or human error causes a failure.
(5) When a secondary failure occurs due to a failure caused by a malfunction of the customer's device.
(6) When a failure occurs due to a part or drive unit supplied or specified by the customer (motor, servo motor, flood control unit, etc.).
(7) When the delivered product is not properly stored, maintained or handled.
(Refer to "Storage" for the explanation of storage.)
(8) Failures due to other reasons that cannot be attributed to our manufacturing responsibility.
(9) We are not liable for any loss of opportunity due to operational failure , damage to products
other than ours as a result of using our products.


Nissei Corporation Sales Planning department.
Oversea sales sect.
TEL: 0566-92-5312
FAX: 0566-92-7002