AA2FM28/61W-VBD527

Manufacturer: Bosch Rexroth

Material #: R902232703

Model : AA2FM28/61W-VBD527

***Disclaimer: The following summary contains information gathered from various sources such as product descriptions, technical specifications and catalogs. While efforts have been made to provide accurate details, inaccuracies may occur. It is advised to verify all information by contacting Bosch Rexroth directly.***
The Bosch Rexroth AA2FM28/61W-VBD527 (R902232703) is a high-performance hydraulic motor characterized by its robust bent-axis design, making it suitable for a wide range of demanding applications. This all-purpose high-pressure motor is engineered to deliver exceptional power density and boasts an impressive size variety, enabling precise adaptation to specific application requirements. The AA2FM28/61W-VBD527 is designed to operate effectively with both open and closed circuits, ensuring versatility in its use. With a nominal pressure of up to 280 bar and the capability to handle maximum pressures of up to 350 bar, this motor ensures reliable performance under challenging conditions. The high total efficiency and superior starting efficiency highlight the motor's quality engineering and contribute to its overall performance and longevity. This model comes equipped with working ports that feature either SAE flange or thread options, catering specifically to the US market's requirements. Additionally, it offers optional features such as an integrated pressure relief valve for enhanced operational safety. For further customization, there is the possibility of mounting additional valves like counterbalance valve BVDBVE or flushing and boost pressure valve, which can significantly expand the motor's functionality in various hydraulic systems. The Bosch Rexroth AA2FM28/61W-VBD527 stands out for its adaptability and efficiency in high-pressure environments, making it an ideal choice for professionals seeking a reliable hydraulic motor solution.

$4,253.00 USD

More are expected on March 21, 2025

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Status: This product is temporarily out of stock.

Qty: Delivered as early as March 21, 2025 when ordered in

This product is eligible for factory repair.

Repairs from $855.00

Large variety of available nominal sizes allows exact adjustment to the application High power density Very high total efficiency High starting efficiency Working ports SAE flange or thread Optional with integrated pressure relief valve Optional with mounted addifitonal valve: counterbalance valve (BVD/BVE), flushing and boost-pressure valve Bent-axis design

1)	Threaded ports at the sides plugged with threaded plugs.
2)	Please contact us.
3)	Threaded ports and fastening threads are metric
4)	Specify ordering code of counterbalance valve according to data sheet 95522 (BVD) respectively data sheet 95525 (BVE) separately.
5)	Specify ordering code of sensor according to data sheet 95133 (DSA) respectively data sheet 95135 (HDD) separately.

Table of values

Size				10	12	16	23	28	32	107	125	160	180	250
Displacement geometric, per revolution		Vg	cm³	10.3	12	16	22.9	28.1	32	106.7	125	160.4	180	250
Nominal pressure		pnom	bar	400	400	400	400	400	400	400	400	400	400	350
Maximum pressure		pmax	bar	450	450	450	450	450	450	450	450	450	450	400
Maximum speed		nnom 1)	rpm	8000	8000	8000	6300	6300	6300	4000	4000	3600	3600	2700
Maximum speed		nmax 2)	rpm	8800	8800	8800	6900	6900	6900	4400	4400	4000	4000
Inlet flow 3)	at nnom	qV	l/min	82	96	128	144	177	202	427	500	577	648	675
Torque 4)	at pnom	M	Nm	66	76	102	146	179	204	679	796	1021	1146	1393
Rotary stiffness		c	kNm/rad	0.92	1.25	1.59	2.56	2.93	3.12	11.2	11.9	17.4	18.2	73.1
Moment of inertia for rotary group		JTW	kg·m²	0.0004	0.0004	0.0004	0.0012	0.0012	0.0012	0.0116	0.0116	0.022	0.022	0.061
Maximum angular acceleration		ɑ	rad/s²	5000	5000	5000	6500	6500	6500	4500	4500	3500	3500	10000
Case volume		V	l	0.17	0.17	0.17	0.2	0.2	0.2	0.8	0.8	1.1	1.1	2.5
Weight (approx.)		m	kg	5.4	5.4	5.4	9.5	9.5	9.5	32	32	45	45	73

1)	These values are valid at: - for the optimum viscosity range from vopt = 36 to 16 mm2/s - with hydraulic fluid based on mineral oils
2)	Intermittent maximum speed: overspeed for unload and overhauling processest, t < 5 s and Δp < 150 bar
3)	Restriction of input flow with counterbalance valve
4)	Torque without radial force, with radial force see table "Permissible radial and axial forces of the drive shafts"

Note

The values in the table are theoretical values, without consideration of efficiencies and tolerances. The values are rounded. Exceeding the maximum or falling below the minimum permissible values can lead to a loss of function, a reduction in operational service life or total destruction of the axial piston unit. Other permissible limit values, such as speed variation, reduced angular acceleration as a function of the frequency and the permissible angular acceleration at start (lower than the maximum angular acceleration) can be found in data sheet 90261.

Speed range

No limit to minimum speed nmin. If uniformity of motion is required, speed nmin must not be less than 50 rpm.

Determining the operating characteristics
Inlet flow		[l/min]
Rotational speed		[rpm]
Torque		[Nm]
Power		[kW]

Key
Vg	Displacement per revolution [cm3]
Δp	Differential pressure [bar]
n	Rotational speed [rpm]
ηv	Volumetric efficiency
ηhm	Hydraulic-mechanical efficiency
ηt	Total efficiency (ηt = ηv • ηhm)

Hydraulic fluids

The axial piston unit is designed for operation with mineral oil HLP according to DIN 51524.

Application instructions and requirements for hydraulic fluids should be taken from the following data sheets before the start of project planning:

90220: Hydraulic fluids based on mineral oils and related hydrocarbons 90221: Environmentally acceptable hydraulic fluids 90222: Fire-resistant, water-free hydraulic fluids (HFDR, HFDU) 90223: Fire-resistan, water-containing hydraulic fluids (HFAE, HFAS, HFB, HFC) 90225: Restricted technical data for operation with fire-resistant hydraulic fluids

Viscosity and temperature of hydraulic fluids

	Viscosity	Shaft seal	Temperature1)	Comment
Cold start	νmax ≤ 1600 mm²/s	NBR2)	ϑSt ≥ -40 °C	t ≤ 3 min, without load (p ≤ 50 bar), n ≤ 1000 rpm, permissible temperature difference between axial piston unit and hydraulic fluid max. 25 K
Cold start	νmax ≤ 1600 mm²/s	FKM	ϑSt ≥ -25 °C
Warm-up phase	ν = 400 … 1600 mm²/s			t ≤ 15 min, p ≤ 0.7 • pnom and n ≤ 0.5 • nnom
Continuous operation	ν = 10 … 400 mm²/s3)	NBR2)	ϑ ≤ +78 °C	measured at port T
	ν = 10 … 400 mm²/s3)	FKM	ϑ ≤ +103 °C	measured at port T
	νopt = 16 … 36 mm²/s			range of optimum operating viscosity and efficiency
Short-term operation	νmin = 7 … 10 mm²/s	NBR2)	ϑ ≤ +78 °C	t ≤ 3 min, p ≤ 0.3 • pnom measured at port T
Short-term operation	νmin = 7 … 10 mm²/s	FKM	ϑ ≤ +103 °C	t ≤ 3 min, p ≤ 0.3 • pnom measured at port T

1)	If the specified temperatures cannot be maintained due to extreme operating parameters, please contact us.
2)	Special version, please contact us.
3)	Equates e.g. with the VG 46 a temperature range of +5 °C to +85 °C (see selection diagram)

Note

To reduce high temperature of the hydraulic fluid in the axial piston unit we recommend the use of a flushing and boost pressure valve (see chapter Extended functions and versions).

Selection of hydraulic fluid

Bosch Rexroth evaluates hydraulic fluids on the basis of the Fluid Rating according to the technical data sheet 90235.

Hydraulic fluids with positive evaluation in the Fluid Rating are provided in the following technical data sheet:

90245: Bosch Rexroth Fluid Rating List for Rexroth hydraulic components (pumps and motors)

The hydraulic fluid should be selected so that the operating viscosity in the operating temperature range is within the optimum range (νopt; see selection diagram).

Selection diagram

Filtration of the hydraulic fluid

Finer filtration improves the cleanliness level of the hydraulic fluid, which increases the service life of the axial piston unit.

A cleanliness level of at least 20/18/15 is to be maintained according to ISO 4406.

At a hydraulic fluid viscosity of less than 10 mm²/s (e.g. due to high temperatures in short-term operation) at the drain port, a cleanliness level of at least 19/17/14 according to ISO 4406 is required.

For example, the viscosity is 10 mm²/s at:

HLP 32 a temperature of 73°C HLP 46 a temperature of 85°C

Operating pressure range

Pressure at working port A or B (high-pressure side)			Definition
Nominal pressure	pnom	see table of values	The nominal pressure corresponds to the maximum design pressure.
Maximum pressure	pmax	see table of values	The maximum pressure corresponds to the maximum operating pressure within the single operating period. The sum of the single operating periods must not exceed the total operating period.
Single operating period		10 s
Total operating period		300 h
Minimum pressure	pHP min	25 bar	Minimum pressure on high-pressure side (port A or B) required to prevent damage to the axial piston unit.
Minimum pressure at inlet (pump operating mode)	pE min	see diagram	To prevent damage to the axial piston motor in pump mode (change of high-pressure side with unchanged direction of rotation, e.g. when braking),a minimum pressure must be guaranteed at the working port (inlet). The minimum pressure depends on the rotational speed and displacement of the axial piston unit.
Total pressure	pSu	700 bar	The summation pressure is the sum of the pressures at both work ports (A and B).
Rate of pressure change			Definition
with integrated pressure relief valve	RA max	9000 bar/s	Maximum permissible rate of pressure build-up and reduction during a pressure change over the entire pressure range.
without pressure relief valve	RA max	16000 bar/s
Case pressure at port T			Definition
Continuous differential pressure	ΔpT cont	2 bar	Maximum averaged differential pressure at the shaft seal (case to ambient)
Pressure peaks	pT peak	10 bar	t < 0.1 s

Note

Working pressure range valid when using hydraulic fluids based on mineral oils. Values for other hydraulic fluids, please contact us.

Minimum pressure at inlet (pump operating mode)

This diagram is only valid for the optimum viscosity range of vopt = 16 to 36 mm2/sec..

If the above mentioned conditions cannot be ensured, please contact us.

Pressure definition

1)	Total operating period = t1 + t2 + ... + tn

Rate of pressure change

Maximum differential pressure at the shaft seal

Note

The service life of the shaft seal is influenced by the speed of the axial piston unit and the case pressure. The service life decreases with an increase of the mean differential pressure between the case and the ambient pressure and with a higher frequency of pressure spikes. The case pressure must be equal to or higher than the ambient pressure.

Direction of flow

Direction of rotation, viewed on drive shaft
clockwise	counter-clockwise
A to B	B to A

Permissible radial and axial forces of the drive shaft

Size
Drive shaft		Code
Maximum radial force at distance a (from shaft collar)		Fq max
Maximum radial force at distance a (from shaft collar)		a
Permitted torque at Fq max		Tq max
Permitted differential pressure at Fq max		Δpq max
Maximum axial force, when standstill or in non-pressurized conditions		+ Fax max
		- Fax max
Maximum axial force, per bar operating pressure		+ Fax max

General instructions

The values given are maximum values and do not apply to continuous operation. The axial force in direction −Fax is to be avoided as the service life of the bearing is reduced. Special requirements apply in the case of belt drives. Please contact us.

Notes for size 250:

In case of radial forces limited performance data is valid. Please contact us. In case of axial forces during operation of the unit please contact us.

Effect of radial force Fq on the service life of bearings

By selecting a suitable direction of radial force Fq the load on the bearings caused by the internal rotary group forces can be reduced, thus optimizing the service life of the bearings. Recommended position of mating gear is dependent on direction of rotation. Examples:

Toothed gear drive, size 10 … 180

Toothed gear drive, size 250

1	Direction of rotation "counter-clockwise", pressure at port B
2	Direction of rotation "clockwise", pressure at port A
3	Direction of rotation "bidirectional"

Long-Life bearing

Size 250

For long service life and use with HF hydraulic fluids. Identical external dimensions as version with standard bearings. Subsequent conversion to long-life bearings is possible. Bearing and case flushing via port U is recommended.

Bearing flushing

Flushing flow (recommended)

Size		250
Flushing flow qv	l/min	10

Size 10 … 16

1)	Flange SAE J744

Drive shafts S, P and B

1)	Toothing data valid for basic number of teeth 48
2)	Thread according to ASME B1.1
3)	Center bore according to DIN 332 (thread according to DIN 13)

Ports

Size			10	12	16
A, B	Working port	Size	1 1/16 in 12UN-2B; 20 mm deep
		Standard 1)	ISO 11926
		State on delivery	With protective cover (must be connected)
T1	Drain port	Size	9/16 in 18UNF-2B; 13 mm deep
		Standard 1)	ISO 11926
		State on delivery 2)	Plugged (observe installation instructions)
T2	Drain port	Size	9/16 in 18UNF-2B; 13 mm deep
		Standard 1)	ISO 11926
		State on delivery 2)	With protective cover (observe installation instructions)

1)	The spot face can be deeper than specified in the appropriate standard.
2)	Unless otherwise specified. Other layouts on request.

Size 23 … 180

1)	Flange SAE J744

Size	D1		D8	D11	D17	D18	D19	D20	D25	D28	D29	D32
Size	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm
23	127	0 - 0.05	20	12.7	25	123	56	59	146	162	14.3	106
28	127	0 - 0.05	20	12.7	25	123	56	59	146	162	14.3	106
32	127	0 - 0.05	20	12.7	25	123	56	59	146	162	14.3	106
107	152.4	0 - 0.05	25	12.7	40	172	86	97	200	228.6	20.6	150
125	152.4	0 - 0.05	25	12.7	40	172	86	97	200	228.6	20.6	150
160	152.4	0 - 0.05	25	12.7	47	190	96	104	200	228.6	20.6	180
180	152.4	0 - 0.05	25	12.7	47	190	96	104	200	228.6	20.6	180

Drive shafts S and U

1)	Thread according to ASME B1.1

Splined shaft SAE J744

NG	Code	Designation 1)	Thread G	N2	N3	N4	N5	ØN6	N9	⌀N10
NG	Code	Designation 1)	Thread G	mm	mm	mm	mm	mm	mm	mm
23	S	1 1/4 in 14T 12/24 DP	7/16-14UNC-2B	9.5	28	40	48	35	55.9	80
28	S	1 1/4 in 14T 12/24 DP	7/16-14UNC-2B	9.5	28	40	48	35	55.9	80
32	S	1 1/4 in 14T 12/24 DP	7/16-14UNC-2B	9.5	28	40	35	35	55.9	80
107	U	1 1/2 in 23T 16/32 DP	5/8-11UNC-2B	12	36	56	62	50	69.9	125
107	S	1 3/4 in 13T 8/16 DP	5/8-11UNC-2B	12	36	55	67	50	74.9	125
125	U	1 1/2 in 23T 16/32 DP	5/8-11UNC-2B	12	36	56	62	50	69.9	125
125	S	1 3/4 in 13T 8/16 DP	5/8-11UNC-2B	12	36	55	67	50	74.9	125
160	S	1 3/4 in 13T 8/16 DP	5/8-11UNC-2B	12	36	55	67	60	74.9	140
180	S	1 3/4 in 13T 8/16 DP	5/8-11UNC-2B	12	36	55	67	60	74.9	140

1)	Toothing data valid for basic number of teeth 48

Drive shafts P and B

1)	Center bore according to DIN 332 (thread according to DIN 13)

Parallel keyed shaft DIN 6885

NG	Code	Designation	Thread G	⌀N1		N2	N3	N5	⌀N6	N7	N8	N9	⌀N10
NG	Code	Designation	Thread G	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm
23	P	⌀25, AS8x7x40	M8 × 1.25	25	+ 0.015 + 0.002	6	19	50	35	28	8	57.9	80
23	B	⌀30, AS8x7x50	M10 × 1.5	30	+ 0.015 + 0.002	7.5	22	50	35	33	8	57.9	80
28	P	⌀25, AS8x7x40	M8 × 1.25	25	+ 0.015 + 0.002	6	19	50	35	28	8	57.9	80
28	B	⌀30, AS8x7x50	M10 × 1.5	30	+ 0.015 + 0.002	7.5	22	50	35	33	8	57.9	80
32	B	⌀30, AS8x7x50	M10 × 1.5	30	+ 0.015 + 0.002	7.5	22	50	35	33	8	57.9	80
107	P	⌀40, AS12x8x63	M12 × 1.75	40	+ 0.018 + 0.002	9.5	28	80	50	43	12	87.9	125
107	B	⌀45, AS14x9x63	M16 × 2	45	+ 0.018 + 0.002	12	36	80	50	48.5	14	87.9	125
125	B	⌀45, AS14x9x63	M16 × 2	45	+ 0.018 + 0.002	12	36	80	50	48.5	14	87.9	125
160	P	⌀45, AS14x9x70	M16 × 2	45	+ 0.018 + 0.002	12	36	90	60	48.5	14	97.9	140
160	B	⌀50, AS14x9x70	M16 × 2	50	+ 0.018 + 0.002	12	36	90	60	53.5	14	97.9	140
180	B	⌀50, AS14x9x70	M16 × 2	50	+ 0.018 + 0.002	12	36	90	60	53.5	14	97.9	140

Port plate 51

SAE working ports at rear

Size	D3	D4	D14	D15	D34	D40	D41	D42	D46
Size	mm	mm	mm	mm	mm	mm	mm	mm	mm
23 … 32	190	106	78	170	115	18.2	40.5	13	59
107 … 125	284	156	120	258	194	31.8	66.7	32	99
160 … 180	326	188	134	284	194	31.8	66.7	32	99

Port plate 52

SAE working ports at side, opposite

Size	D3	D4	D7	D12	D13	D40	D41	D42
Size	mm	mm	mm	mm	mm	mm	mm	mm
23 … 32	207	117	120	70	161	18.2	40.5	13
107 … 125	317	181	178	110	245	31.8	66.7	32
160 … 180	326	187	202	121	269	31.8	66.7	32

Port plate 53

Threaded ports at side, opposite

Size	D3	D4	D7	D12	D13
Size	mm	mm	mm	mm	mm
23 … 32	207	117	120	70	161

Port plate 54

Threaded ports at side and rear

Size	D3	D4	D7	D12	D13	D14	D15	D34	D46
Size	mm	mm	mm	mm	mm	mm	mm	mm	mm
23 … 32	207	118	130	70	161	89	183	120	58

Port plate 60

SAE working ports at bottom

Size	D3	D4	D14	D15	D33	D34	D40	D41	D42	D46
Size	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm
107 … 125	293	158	136	258	194	70	31.8	66.7	32	99

Note

The dimensional drawings of the port plates with valves can be found in the chapter "Extended functions and versions".

Ports

Size			23	28	32	107	125	160	180
A, B (plate 51, 52, 60)	Working port	Size	1/2 in			1 1/4 in
		Standard	Dimensions according to SAE J518
		Fastening thread	5/16 18UNC-2B; 18 mm deep			1/2 13UNC-2B; 19 mm deep
		State on delivery	With protective cover (must be connected)
A, B (plate 53, 54)	Working port	Size	1 5/16 12UN-2B; 20 mm deep
		Standard 1)	ISO 11926
		State on delivery 2)	With protective cover (must be connected)
T1	Drain port	Size	3/4 16UNF-2B; 15 mm deep			7/8 14UNF-2B; 17 mm deep
		Standard 1)	ISO 11926
		State on delivery 3)	With protective cover (observe installation instructions)
T2	Drain port	Size	3/4 16UNF-2B; 15 mm deep			7/8 14UNF-2B; 17 mm deep
		Standard 1)	ISO 11926
		State on delivery 3)	Plugged (observe installation instructions)

1)	The spot face can be deeper than specified in the appropriate standard.
2)	Unless otherwise specified: In case of connection plate 54 ports at the sides plugged. Other layouts on request.
3)	Unless otherwise specified. Other layouts on request.

Size 250

1)	Flange SAE J744

Drive shafts S and K

1)	Toothing data valid for basic number of teeth 48
2)	Thread according to ASME B1.1

Port plate 51

SAE working ports at rear

Port plate 52

SAE working ports at side, opposite

Ports

Size			250
A, B	Working port	Size	1 1/4 in
		Standard	Dimensions according to SAE J518
		Fastening thread	1/2 13UNC-2B; 19 mm deep
		State on delivery	With protective cover (must be connected)
T1	Drain port	Size	7/8 14UNF-2B; 17 mm deep
		Standard 1)	ISO 11926
		State on delivery 2)	With protective cover (observe installation instructions)
T2	Drain port	Size	7/8 14UNF-2B; 17 mm deep
		Standard 1)	ISO 11926
		State on delivery 2)	Plugged (observe installation instructions)
U	Bearing flushing	Size	9/16 18UNF-2B; 13 mm deep
		Standard 1)	ISO 11926
		State on delivery	Plugged

1)	The spot face can be deeper than specified in the appropriate standard.
2)	Unless otherwise specified. Other layouts on request.

Flushing and boost pressure valve

The flushing and boost pressure valve is used in closed circuits for the removal of heat and to ensure a minimum boost pressure level.

Hydraulic fluid is directed from the respective low pressure side into the motor housing. This is then fed into the reservoir, together with the leakage. The removed hydraulic fluid must be replaced by cooled hydraulic fluid from the boost pump.

With port plate 527, the valve is mounted directly on the fixed motor (sizes 23 to 250).

Cracking pressure of pressure retaining valve

(observe when setting the primary valve)

Sizes 23 to 250, fixed setting: 16 bar

Switching pressure of flushing piston Δp

Sizes 23 to 250: 8±1 bar

Flushing and boost pressure valve

The flushing and boost pressure valve is used in closed circuits for the removal of heat and to ensure a minimum boost pressure level.

With port plate 527, the valve is mounted directly on the fixed motor (sizes 23 to 250).

Cracking pressure of pressure retaining valve

(observe when setting the primary valve)

Sizes 23 to 250, fixed setting: 16 bar

Switching pressure of flushing piston Δp

Sizes 23 to 250: 8±1 bar

Circuit diagram

Flushing flow qv

Orifices can be used to adjust the flushing flows as required. The following information is based on:
ΔpND = pND – pG = 25 bar und ν = 10 mm2/s

(pND = low pressure, pG = case pressure)

Flushing flow qv

Orifices can be used to adjust the flushing flows as required. The following information is based on:
ΔpND = pND – pG = 25 bar und ν = 10 mm2/s

(pND = low pressure, pG = case pressure)

Size 23 … 180

Material number of orifice	Flushing flow qv	Orifice-⌀
Material number of orifice	l/min	mm
R909651766	3.5	1.2
R909419695	5	1.4
R902030345	6.5	1.6
R909419696	8	1.8
R909419697	10	2
R902107424	13	2.3
R909444361	14	2.4

Size 23 … 180

Material number of orifice	Flushing flow qv	Orifice-⌀
Material number of orifice	l/min	mm
R909651766	3.5	1.2
R909419695	5	1.4
R902030345	6.5	1.6
R909419696	8	1.8
R909419697	10	2
R902107424	13	2.3
R909444361	14	2.4

For flushing flows deviating from the values in the table, please state the required flushing flow when ordering.

The flushing flow without orifice is approx. 12 to 14 l/min at low pressure ΔpND = 25 bar.

For flushing flows deviating from the values in the table, please state the required flushing flow when ordering.

The flushing flow without orifice is approx. 12 to 14 l/min at low pressure ΔpND = 25 bar.

Size 250

Standard flushing flow: 10 l/min

For other flushing flows please contact us.

Size 250

Standard flushing flow: 10 l/min

For other flushing flows please contact us.

Dimensions

Port plate 527

SAE working ports at side, opposite

Port plate 527

SAE working ports at side, opposite

Pressure relief valve

The MHDB pressure relief valves protect the hydraulic motor from overload. As soon as the set cracking pressure is reached, the hydraulic fluid flows from the high-pressure side to the low-pressure side.

The pressure relief valves are only available in conjunction with connection plates 181, 191 or 192. (Connection plate 181: see section “BVD and BVE counterbalance valve”

Setting range of cracking pressure: 50 up to 420 bar

For versions “with pressure sequencing stage” (code 192), a higher pressure setting can be implemented by connecting an external pilot pressure of 25 up to 30 bar at port pSt.

When ordering, state in plain text:

Cracking pressure of pressure relief valve Cracking pressure with pilot pressure applied to pSt (only with version 192)

Pressure relief valve

The pressure relief valves are only available in conjunction with connection plates 181, 191 or 192. (Connection plate 181: see section “BVD and BVE counterbalance valve”

Setting range of cracking pressure: 50 up to 420 bar

For versions “with pressure sequencing stage” (code 192), a higher pressure setting can be implemented by connecting an external pilot pressure of 25 up to 30 bar at port pSt.

When ordering, state in plain text:

Cracking pressure of pressure relief valve Cracking pressure with pilot pressure applied to pSt (only with version 192)

Version without pressure boost facility (code 191)

Version with pressure boost facility (code 192)

Dimensions

Counterbalance valve BVD and BVE

Function

Travel drive/winch counterbalance valves are designed to reduce the danger of overspeeding and cavitation of axial piston motors in open circuits. Cavitation occurs if the motor speed is greater than it should be for the given input flow while braking, travelling downhill, or lowering a load.

If the inlet pressure drops, the counterbalance spool throttles the return flow and brakes the motor until the inlet pressure returns to approx. 20 bar.

Note

BVD available for sizes 28 to 180 and BVE available for sizes 107 to 180. The counterbalance valve must be ordered additionally. We recommend ordering the counterbalance valve and the motor as a set. Ordering example: A2FM(E)90/61W–VAB188 + BVD20F27S/41B–V03K16D0400S12 The counterbalance valve does not replace the mechanical service brake and park brake. Observe the detailed notes on the BVD counterbalance valve in data sheet 95522 and BVE counterbalance valve in data sheet 95525! For the design of the brake release valve, we must know for the mechanical park brake: the pressure at the start of opening the volume of the counterbalance spool between minimum stroke (brake closed) and maximum stroke (brake released with 21 bar) the required closing time for a warm device (oil viscosity approx. 16 mm2/s)

Travel drive counterbalance valve BVD...F

Application option:

Travel drive on wheeled excavators

Counterbalance valve BVD and BVE

Function

If the inlet pressure drops, the counterbalance spool throttles the return flow and brakes the motor until the inlet pressure returns to approx. 20 bar.

Note

Travel drive counterbalance valve BVD...F

Application option:

Travel drive on wheeled excavators

Example schematic for travel drive on wheeled excavators

A2FM(E)090/61W-VAB188 + BVD20F27S/41B–V03K16D0400S12

Example schematic for travel drive on wheeled excavators

A2FM(E)090/61W-VAB188 + BVD20F27S/41B–V03K16D0400S12

Winch counterbalance valve BVD...W and BVE

Application options:

Winch drive in cranes (BVD and BVE) Track drive in excavator crawlers (BVD)

Winch counterbalance valve BVD...W and BVE

Application options:

Winch drive in cranes (BVD and BVE) Track drive in excavator crawlers (BVD)

Example schematic for winch drive in cranes
A2FM(E)090/61W-VAB188 + BVE25W385/51ND-V100K00D4599T30S00-0

Dimensions

Speed sensors

The versions AA2FM...U and AA2FM...F ("prepared for speed sensor", i.e. without sensor) are equipped with a toothed ring on the rotary group.

On deliveries "prepared for speed sensor", the port is plugged with a pressure-resistant cover.

With the DSA or HDD speed sensor mounted a signal proportional to motor speed can be generated. The sensors measures the speed and direction of rotation.

Ordering code, technical data, dimensions and details on the connector, plus safety information about the sensor can be found in the relevant data sheet.

DSA: data sheet 95133

HDD: data sheet 95135

The sensor is mounted at the specially provided port as follows:

DSA: with one mounting bolt

HDD: with two mounting bolts

We recommend ordering the AA2FM fixed motor complete with sensor mounted.

Speed sensors

The versions AA2FM...U and AA2FM...F ("prepared for speed sensor", i.e. without sensor) are equipped with a toothed ring on the rotary group.

On deliveries "prepared for speed sensor", the port is plugged with a pressure-resistant cover.

With the DSA or HDD speed sensor mounted a signal proportional to motor speed can be generated. The sensors measures the speed and direction of rotation.

Ordering code, technical data, dimensions and details on the connector, plus safety information about the sensor can be found in the relevant data sheet.

DSA: data sheet 95133

HDD: data sheet 95135

The sensor is mounted at the specially provided port as follows:

DSA: with one mounting bolt

HDD: with two mounting bolts

We recommend ordering the AA2FM fixed motor complete with sensor mounted.

DSA speed sensor mounted (code V)

HDD speed sensor mounted (code H)

Installation information

General information

During commissioning and during operation, the axial piston unit must be filled with hydraulic fluid and bled. This must also be observed during longer standstill as the axial piston unit might drain itself via the hydraulic lines. Complete filling and bleeding must especially be ensured with the “Drive shaft upwards” installation position as there is, for example, the risk of running dry. The leakage in the housing area must be discharged to the tank via the highest-located drain port (T1, T2). If one joint drain line is used for several units, it is to be ensured that the relevant housing pressure is not exceeded. The joint drain line must be dimensioned so that the maximum admissible housing pressure of all connected units is not exceeded in any operating state, particularly during cold start. If this is not possible, separate drain lines have to be laid, if necessary. In order to achieve favorable noise values, all connection lines are to be decoupled using elastic elements and over-tank installation is to be avoided. The tank line must lead into the tank below the minimum liquid level in every operating state.

Installation position

See the following examples 1 to 8.

Further installation positions are possible upon request. Recommended installation position: 1 and 2.

Note

For installation position 4 and 8 "shaft upwards" an air bleed port R is required (specify in plain text when ordering, special version).

With size 250, port U is provided as standard in the area near the bearings for air bleeding.

Below-tank installation (standard)

Below-tank installation is at hand if the axial piston unit is installed below the minimum liquid level outside the tank.

Installation position	Air bleeding	Filling
1	‒	T1
2	‒	T2
3	‒	T1
4	R (U)	T2

Above-reservoir installation

Above-reservoir installation means that the axial piston unit is installed above the minimum fluid level of the reservoir.

Recommendation for installation position 8 (drive shaft upward): A check valve in the drain line (cracking pressure 0,5 bar) can prevent draining of the pump housing.

Installation position	Air bleeding	Filling
5	F	T1 (F)
6	F	T2 (F)
7	F	T1 (F)
8	R (U)	T2 (F)

Key
F	Filling / Air bleeding
R	Air bleed port
U	Bearing flushing / air bleed port
T1, T2	Tank port
ht min	Minimum required immersion depth (200 mm)
hmin	Minimum required spacing to reservoir bottom (100 mm)

	Note: Connection F is part of the external piping and must be provided on the customer side to simplify the filling and bleeding.

General project planning notes

The axial piston unit is designed to be used in open and closed circuits. The project planning, installation and commissioning of the axial piston unit require the involvement of qualified skilled personnel. Before using the axial piston unit, please read the corresponding instruction manual completely and thoroughly. If necessary, request it from Bosch Rexroth. Before finalizing your design, request a binding installation drawing. The specified datas and notes must be observed. Preservation: Our axial piston units are supplied as standard with preservative protection for a maximum of 12 months. If longer preservative protection is required (maximum 24 months), please specify this in plain text when placing your order. The preservation times are valid under optimal storage conditions. Details of these conditions can be found in the data sheet 90312 or the instruction manual. Not all versions of the product are approved for use in a safety function according to ISO 13849. Please consult the responsible contact person at Bosch Rexroth if you require reliability parameters (e.g. MTTFD) for functional safety. A pressure relief valve is to be provided in the hydraulic system. Observe the instructions in the instruction manual regarding tightening torques of connection threads and other threaded joints used. The notes in the instruction manual on tightening torques of the port threads and other screw joints must be observed. The ports and fastening threads are designed for the permissible maximum pressure pmax (see instruction manual). The machine or system manufacturer must ensure that the connecting elements and lines correspond to the specified operating conditions (pressure, flow, hydraulic fluid, temperature) with the necessary safety factors. The working ports and function ports are designated only to accommodate hydraulic lines.