GN 3975-BWorm Gear Reducers

Continuous drive

Housing Aluminum

Technical datasheet

GN 3975-B

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Catalogue	m₁	d₁ j6	Gear ratio i	b₁	b₂	b₃ JS9	d₂ H7	d₃	d₄	d₅	d₆*	d₇

GN 3975-20-B-12-5-AN	20	12	5	35	4	4	12	30	20	27.4	M 4	4.2
GN 3975-20-B-12-13-AN	20	12	13	35	4	4	12	30	20	27.4	M 4	4.2
GN 3975-20-B-12-15-AN	20	12	15	35	4	4	12	30	20	27.4	M 4	4.2
GN 3975-20-B-12-18-AN	20	12	18	35	4	4	12	30	20	27.4	M 4	4.2
GN 3975-20-B-12-23-AN	20	12	23	35	4	4	12	30	20	27.4	M 4	4.2
GN 3975-20-B-12-30-AN	20	12	30	35	4	4	12	30	20	27.4	M 4	4.2
GN 3975-20-B-12-40-AN	20	12	40	35	4	4	12	30	20	27.4	M 4	4.2
GN 3975-20-B-12-65-AN	20	12	65	35	4	4	12	30	20	27.4	M 4	4.2
GN 3975-30-B-12-5-AN	30	12	5	40	4	5	14	30	25	27.4	M 5	5.5
GN 3975-30-B-12-10-AN	30	12	10	40	4	5	14	30	25	27.4	M 5	5.5
GN 3975-30-B-12-17-AN	30	12	17	40	4	5	14	30	25	27.4	M 5	5.5
GN 3975-30-B-12-20-AN	30	12	20	40	4	5	14	30	25	27.4	M 5	5.5
GN 3975-30-B-12-25-AN	30	12	25	40	4	5	14	30	25	27.4	M 5	5.5
GN 3975-30-B-12-34-AN	30	12	34	40	4	5	14	30	25	27.4	M 5	5.5
GN 3975-30-B-12-45-AN	30	12	45	40	4	5	14	30	25	27.4	M 5	5.5
GN 3975-30-B-12-64-AN	30	12	64	40	4	5	14	30	25	27.4	M 5	5.5

* Usable thread depth: min. 1.6 x d₆ / d₈

Types

Type A: One-side drive
Type B: Continuous drive

Housing

Aluminum

Sealed to prevent dust entry

Anodized, natural color AN

Worm screw

Steel

Worm wheel

Brass
Steel for m₁=20 and i=5

Ball bearing

Steel

Sealed (sealing disks 2RS)

Operating temperature -20 °C to +60 °C

Worm gear reducers GN 3975 can transmit high torque despite their very compact dimensions. They can readily be used for a multitude of applications, such as incline adjustments or to change the direction of shaft rotation.

The numerous fastening holes allow for simple mounting in any orientation or position. The parallel keys can take any angular positions.

Depending on the gear ratio, there may be no static self-braking between the worm screw and worm wheel, meaning that the worm wheel can be turned out of a resting state by a torque coming from the output end.

Circumferential backlash at the drive shaft	1° ± 0.5°
Shaft direction of rotation	Any
Worm screw direction	Left
Life expectancy	1.000 hours under full load at a rotational speed of 500 rpm,
	assuming the gear box is operating for 20% of every 5 minutes (guide value)
	(1 minute of operation + 4 minutes break) at an ambient temperature of 20 °C
Maintenance	Permanent lubrication with grease, maintenance-free

m₁	Gear ratio	Max. input torque in Nm*			Max. output torque in Nm*			Input side		Output side		Efficiency in %	Selfbraking
m₁	Gear ratio	at 100 min^-1	at 500 min^-1	at 1000 min^-1	at 100 min^-1	at 500 min^-1	at 1000 min^-1	Max. radial force in N**	Max. axial force in N***	Max. radial force in N**	Max. axial force in N***	Efficiency in %	Selfbraking
20	5	2.9	2.3	1.7	10	8	6	200	200	500	500	70	-
20	13	2.1	1.8	1.5	15	13	11	200	200	500	500	56	-
20	15	1.5	1.3	1	12	10	8	250	250	500	500	52	-
20	18	1.1	0.9	0.7	11	9	7	250	250	500	500	55	-
20	23	0.9	0.7	0.5	10	8	6	250	250	500	500	50	-
20	30	0.6	0.5	0.4	8.5	7	5.5	350	350	500	500	45	-
20	40	0.35	0.31	0.31	5.5	4.8	4	400	400	500	500	39	x
20	65	0.24	0.2	0.2	4.5	3.8	3	500	500	500	500	29	x
30	5	5.4	4.9	4.3	19	17	15	400	300	800	800	70	-
30	10	3.4	3.1	2.8	20	18	16	400	300	800	800	58	-
30	17	2.2	1.9	1.8	17	15	14	400	400	800	800	46	-
30	20	1.7	1.6	1.4	15	13.5	12	800	400	800	800	43	-
30	25	1.3	1.2	1.1	13.5	12	11	800	800	800	800	41	-
30	34	1.2	1.1	1	12	11	10	600	800	800	800	29	-
30	45	0.9	0.8	0.8	10.5	9.5	9	700	600	800	800	25	-
30	64	0.5	0.4	0.3	8.5	7.5	6	700	600	800	800	27	x

* Input side speed

** at axial force = 0

*** at radial force = 0

Do not exert any forces onto the housing or into the bearings during assembly. Use of the threaded holes d₈ in the shaft is recommended. The use of a corresponding coupling is recommended to compensate for manufacturing-related shaft offsets and runout tolerances as well as for damping vibrations and shocks.