Eight questions to ask your hydraulic motor supplier
and how THOTH answers them.
Unit price and catalog torque are where the comparison starts, not where the risk shows up. Field failures, late shipments and requalification cost come later. Here are the questions worth asking up front, with THOTH’s answers and the documents behind them.
When an OEM adds a hydraulic motor supplier, the purchase order is the easy part. The real cost of a supplier shows up over years: in how consistently parts perform, how fast they arrive, and how well problems are traced and closed.
Whether you are qualifying a first source or adding a second one, these eight questions separate a parts vendor from a partner you can build a machine around.
What performance data do you publish?
A torque number on a brochure tells you little about how a motor behaves at your operating point, or after thousands of hours.
The THOTH orbital catalog publishes a performance grid for every model: measured output torque and speed at each combination of pressure and flow, so you can calculate efficiency at your own duty point (see how in our orbital vs. radial piston selection guide). Ratings are listed separately as continuous, intermittent (10% of each minute) and peak (1% of each minute).ZI-2
Beyond the catalog, THOTH provides shaft seal curves, and additional test reports, such as durability tests, are available on request.
The THOTH data pack: what you can see before you order.
How do you machine and inspect?
Every motor passes three inspection gates. The last one is a 100% final performance test, with test data and a final test report kept for each unit.ZI-1
Purchased and outsourced parts inspected on arrival
Checks during machining and assembly
Performance test, test data and final report
| Instrument | What it checks |
|---|---|
| CMM (ZEISS) | 3D dimensions, flatness and cylindricity, hole positions, contours |
| Gear measuring machine | Tooth profile, pitch error, helix angle, runout |
| Particle counter | Fluid contamination, filter performance |
| Vickers hardness tester | Hardness and heat-treatment effect |
| Spectrometer (SPECTRO) | Material composition |
| Roughness, cylindricity, image measuring | Surface finish, ovality and taper, non-contact 2D dimensions |
| Source: THOTH company profile.ZI-1 | |
Machining runs on JUNKER grinding and Mazak machining centers with robot cells, automatic tool detection, vision identification, contact probing, online detection and an automated warehouse.ZI-1
Can you trace every unit?
Yes. From design to shipment, THOTH runs one connected data chain. Orders are tracked through picking, assembly, inspection and storage, and tool life is managed in the system. Quality issues are logged on a management board with cause, action, owner and due date, and overseas quality issues follow a dedicated closed-loop log.ZI-1
What is your track record?
THOTH has built hydraulic motors since 1971. Sales are split evenly between China and export, with shipments to more than 80 countries including Germany, the UK, Italy, the USA, Canada and Brazil.ZI-1 The company is recognized as a national “Little Giant” specialized enterprise in China.ZI-3
Supplier awards from major Chinese equipment makers include Zoomlion (2005), SANY (2009), Wantong Heavy Industry (2009) and Sinotruk.ZI-1
What does the warranty cover?
from the production date, or 12 months from the start of service, whichever comes first.ZI-1
Lead time and minimum order?
Standard specifications ship in 3 to 4 weeks, special specifications in 6 weeks, and minimum order quantity is flexible. Capacity comes from two plants: Ningbo, with 1,000,000 units a year, and Wuhu in Anhui, in production since 2012.ZI-1
Which certifications do you hold?
THOTH’s quality system is certified to ISO 9001:2015 for the design, production and service of hydraulic motors, alongside ISO 14001:2015 and ISO 45001:2018. A wide range of orbital motors, including BMM, BMP, BMR, BMH, BS, BH and the BM3, BM4, BM5 and BM6 families, carries CE marking under the Machinery Directive 2006/42/EC.ZI-4
A parts vendor or a system partner?
THOTH makes orbital motors, radial piston motors, transmissions, slew drives, steering units, winches, brakes and valve blocks. That means one supplier can review several drives on the same machine.ZI-1
| Machine | THOTH products used together |
|---|---|
| Truck-mounted concrete pump | BMH, BM3Y, ZCM3, QJM / BM4 |
| Motor grader | TMS, BM3, BDAS5 steering unit |
| Combine harvester | BM4, ZBMR brake motor, BPBS steering unit |
| Boom lift | TMS, ZCM |
| Road roller | TMS, TMK |
| Injection molding machine | JMDG, BMR |
| Tunnel drilling jumbo | ZXG3 slew drive |
| Source: THOTH company profile.ZI-1 | |
THOTH designs for form and function compatibility with widely used mounting and performance standards. Tell us the model you run today, and we will send a compatibility reference with the matching THOTH model on request.
A good supplier answers before you ask. Ours is in the data pack.
| Question | THOTH answer |
|---|---|
| Performance data | Grid for every model, separate ratings, shaft seal curves, durability reports on request |
| Machining and inspection | Three gates, 100% final performance test with report |
| Traceability | PLM to BI data chain, overseas closed-loop quality log |
| Track record | Since 1971, 80+ countries, national Little Giant |
| Warranty | 18 months from production or 12 from service start |
| Lead time and MOQ | 3–4 weeks standard, 6 weeks special, flexible MOQ |
| Certifications | ISO 9001, 14001, 45001; CE on a wide orbital range |
| System capability | Motors, transmissions, slew drives, steering, winches |
Frequently asked questions
- What warranty does THOTH offer on its motors?
- 18 months from the production date or 12 months from the start of service, whichever comes first.
- What is the standard lead time?
- 3 to 4 weeks for standard specifications and 6 weeks for special specifications. Minimum order quantity is flexible.
- Can I get test reports and a shaft seal curve?
- Yes. Every motor gets a 100% final performance test with test data and a final test report. Shaft seal curves are provided, and additional test reports such as durability tests are available on request.
- Can THOTH match the motor I use today?
- Send us the model you currently use. THOTH provides a compatibility reference on request and proposes the matching model.
Ask us all eight questions,
we’ll send the documents.
Tell us the model you use today, the machine and your annual volume. THOTH will reply with the performance grid, shaft seal curve, certificates, drawings and a recommended model.
- ZI-1THOTH / ZiHYD company profile (2025). Company overview, plants, supply terms, quality system, digital system, supplier awards, multi-product system examples.
- ZI-2ZIHYD Orbital Motor Catalog (2026.03). Performance grids by model; continuous, intermittent and peak rating definitions.
- ZI-3ZIHYD Piston Motor Catalog (2026.03). Company recognition on cover; plant photos p.3.
- ZI-4THOTH / ZiHYD certificates: ISO 9001:2015, ISO 14001:2015, ISO 45001:2018, CE (Machinery Directive 2006/42/EC).