Anhui Pandeng Group

Products

Products Transmission Equipment

NJD (DSN) Low-speed Backstop

1. Structural Features and Working Principle The NJD (DSN) low-speed backstop (hereinafter referred to as the backstop) is a new non-return device specially designed for high-inclination and high-capacity belt conveyors. This backstop is composed of multiple special-shaped wedges arranged in a regular pattern within the raceway formed by the inner and outer rings, positioned by bearings to ensure smooth operation. The outer ring is connected to two end covers, which are integrated with the anti-rotation arm via pins; the anti-rotation arm is restrained by a fixed anti-rotation base. During normal operation of the main machine, relying on the special geometric profile of the wedges and mechanical principles, the wedges deflect by a certain angle and make light contact with the inner and outer rings. This reduces the friction coefficient and extends the service life of the backstop. When the main machine shuts down, the gravity of lifted materials forces the inner ring of the backstop to reverse, which in turn deflects the wedges. The wedges tightly wedge the inner and outer rings together to effectively prevent reverse rotation of the main machine. Therefore, this backstop serves as an ideal anti-reversal protection device for large belt conveyors, bucket elevators and other conveying equipment. 2. Operating Environment The applicable ambient temperature of the backstop ranges from -20℃ to 50℃. The backstop generates heat during operation and requires well-ventilated surroundings. Its surface temperature may reach up to 80℃ when running at the maximum allowable speed. Under this condition, its impact on the main equipment shall be inspected, and proper cooling measures shall be taken if necessary. Effective protective measures (such as ventilation or cooling equipment) shall be adopted when the ambient temperature exceeds 38℃ or the backstop works in open-air conditions. Corrosive chemicals shall not be placed around the backstop to avoid damage to its seals. Professional Terminology 1. backstop / non-return device 逆止器 2. special-shaped wedge 异形楔块 3. inner ring 内圈；outer ring 外圈 4. anti-rotation arm 防转臂 5. anti-reversal protection device 防逆转保护装置

Main Features

Model	Rated Backstop Torque (N·m)	Maximum Bore Diameter (mm)	Maximum Inner Ring Speed (r/min)	No-Load Drag Torque (N·m)	Main Mounting Dimensions									Maximum Mass (kg)
					B	C	D	L	H	E	F	h	ΦA
NJD(DSN)11	11000	Φ110	150	15	100	60	270	110	425	/	/	/	/	77
NJD(DSN)16	16000	Φ130	150	20	126	74	320	130	506	/	/	/	/	145
NJD(DSN)25	25000	Φ160	150	32	140	80	360	140	612	/	/	/	/	198
NJD(DSN)40	40000	Φ200	150	40	160	88	430	160	623	/	/	/	/	230
NJD(DSN)50	50000	Φ220	100	70	200	100	500	230	820	110	50	70	35	385
NJD(DSN)100	100000	Φ250	100	95	250	116	600	290	1000	120	55	70	40	696
NJD(DSN)130	130000	Φ270	90	90	280	122	650	290	1100	120	60	80	40	812
NJD(DSN)200	200000	Φ300	90	100	320	130	780	290	1300	135	60	80	45	1130
NJD(DSN)280	280000	Φ320	90	130	360	140	850	320	1500	150	70	100	50	1480
NJD(DSN)330	330000	Φ350	80	145	400	142	930	360	1600	160	70	100	55	1997
NJD(DSN)530	530000	Φ420	80	200	450	146	1030	450	1800	180	80	120	60	3090
NJD(DSN)710	710000	Φ450	80	225	500	160	1090	480	2000	210	100	120	70	3580
NJD(DSN)1000	1000000	Φ510	70	260	560	170	1200	500	2200	230	110	150	80	4420
NJD(DSN)1350	1350000	Φ560	60	320	630	180	1350	520	2400	250	120	150	90	5250
NJD(DSN)1750	1750000	Φ620	50	400	710	190	1500	540	2600	270	130	160	100	7100

(1) The recommended fit between backstop bore and mounting shaft is F7/h6.

(2) The connection between backstop bore and mounting shaft adopts flat key fit. The dimensions of keys and keyways shall comply with GB/T1095-1979. The tolerance of keyway on backstop bore shall be machined to D10 per GB/T1095-1979.

(3) The length of mounting shaft extension shall be equal to inner ring length L of the backstop as far as possible. Its minimum length shall not be less than 5/6 of the inner ring length to guarantee the strength of mounting shaft extension and key.