Magnetic Coupling

A magnetic coupling is a non-contact coupling that usually consists of two magnetic hubs (usually a pair of discs with magnets – Disc Type, or two magnetic inner rotors and outer rotors – Coaxial Type). One of the magnetic hubs is connected to the driving part and the other is connected to the driven part. The magnetic field transfers the torque from the driving part of the coupling to the driven part. Without any physical contact, the torque is transmitted via the gap air or non-magnetic sealing barrier (such as stainless steel or fiberglass). The two magnetic hubs are completely isolated. This is the greatest advantage of magnetic couplings over other mechanical couplings: contactless transmission of torque, thus transforming a dynamic seal into a static seal and achieving zero leakage.

Due to non-contact and leak-free torque transmission in magnetic drive pumps and magnetic stirrers, magnetic coupling is widely used in applications with highly toxic or corrosive mediums where sealing drives are essential to prevent harmful mediums from leaking. As an experienced leading supplier, EPI Magnets provides a wide range of custom magnetic couplings from single products to whole solutions.

Product Details

Two Types of Magnetic Coupling

The Disc Type Magnetic Coupling has two face-to-face discs with a series of Neodymium magnets (or SmCo magnets) and the torque is transmitted from one disc to the other through an air gap. The design is so simple that even with angular misalignment up to 3° or parallel misalignment up to 1/4”, it can still transmit rotational torque almost without loss. A plain non-magnetic barrier can isolate the atmosphere or liquid medium around the two discs. This is the simplest magnetic coupling to design and manufacture.

Disc Type Magnetic Coupling Structure

A Coaxial Type Magnetic Coupling generally consists of an inner hub, an outer hub, and an optional sealing barrier. The inner and outer hubs are the rotors attached with Neodymium magnets (or SmCo magnets). The driven shaft of the inner rotor is connected to the driven devices such as impellers, and the driving shaft of the outer rotor is connected to the motors. Through Coaxial Type magnetic couplings, the force of the motor is transferred to the impeller without direct contact: The inner rotor revolves in synchrony with the outer rotor thanks to the magnetic force that transfers the torque from the motor to the inner rotor. Lastly, the impeller is made to rotate by the inner rotor.

The sealing barrier seals the inner rotor and the medium inside the pump to prevent the toxic or corrosive medium from flowing out of the pump. Depending on the type of the medium, the inner rotor needs to be sealed inside a sealing barrier of different materials to protect the inner rotor from damage. Carbon steel, stainless steel, or plastic(PTFE, PFA, TFM, PVDF) are frequently used for inner rotor construction. Materials used as common sealing barriers include titanium, plastic(PTFE, PFA, TFM, PVDF), stainless steel, and Hastelloy. Since the outer rotor typically operates in a typical working environment without any particular chemical requirements, carbon steel and other less expensive materials are frequently used. The material to be used depends on the environment and medium to which the magnetic coupling will be subjected determine, hence it is important for our customers to provide specific usage conditions or requirements.

Coaxial Type Magnetic Coupling Structure and the Data Sheet for our regular Coaxial Type Magnetic Couplings

Type	Nom. Torque	Over Load	Inner Rotor (mm)						Outer Rotor (mm)					Sealing can/Flange (mm)
Type	Nom. Torque	Over Load	A	B	C	D	E	F	I	J	K	L	M	G	H	N	O	P
EPICC03	3	4.5	42	20	10	5	15	25	49	52	M5	68	50	44	46	6.6	80	57
EPICC08	8	12	58	26	12	10	18	35	66	70	M5	90	65	60	62	6.6	96	67
EPICC16	16	26	58	26	14	30	20	62	66	70	M6	90	95	60	62	6.6	96	94
EPICC22	22	35	88	50	20	10	30	50	97	100	M6	120	85	90	92	8.6	132	82
EPICC30	30	48	88	50	24	20	30	62	97	100	M6	120	100	90	92	8.6	132	94
EPICC50	50	80	122	80	30	10	30	60	132	136	M8	164	85	126	128	8.6	176	88
EPICC65	65	100	122	80	30	20	30	65	132	136	M8	164	100	126	128	8.6	176	104
EPICC80	80	130	142	90	35	20	30	65	152	156	M8	184	100	146	148	10.8	208	106
EPICC110	110	165	142	90	35	30	30	80	152	156	M8	184	115	146	148	10.8	208	122
EPICC140	140	210	142	90	40	40	40	110	152	156	M10	190	145	146	148	10.8	208	152
EPICC180	180	290	142	90	40	60	50	140	152	156	M10	190	180	146	148	10.8	208	182
EPICC220	220	330	142	90	48	70	60	160	152	156	M10	190	200	146	148	10.8	208	204
EPICC280	280	380	142	90	48	90	60	180	152	156	M10	190	230	146	148	10.8	208	224
EPICC320	320	430	164	110	50	90	60	190	174	178	M12	214	230	168	170	10.8	230	240
EPICC380	380	500	164	110	50	100	80	240	174	178	M12	214	280	168	170	10.8	230	290
EPICC500	500	650	186	130	60	115	90	300	196	190	M12	240	300	190	192	10.8	250	310